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OpenDX User Guide - Oregon State University

1. 0 2 200000002 eee 236 TV Line Resolution lle 236 TV Color Resolution len 237 Animation and Frame Rates lll 237 A 5 Presentation Issues and Techniques 238 O Copyright IBM Corp 1991 1997 211 A 1 Using Data Explorer Effectively Following are some hints for using Data Explorer more effectively debugging visual programs and using memory efficiently Common Problems Debugging One of the most useful tools for debugging visual programs is the Print module For example if you are getting an error from a module that a particular field is inappropriate for processing you can print out the object to see if it is what you expect it to be Print can be used to see the structure of and data values in any object The options parameter is used to set the level of detail printed the default o prints just the top level object for example Field with 4 four components If options is set to r more information about each component is printed for example how many items in each component and the data type You can also print out some or all of the values in the components The output of Print appears in the Message window Stopping Execution There are two ways to stop execution of a visual program e End Execution in the Execute menu stops execution after the currently executing module has finished e Disconnect from Server in the Connection menu kil
2. llle 110 Using the Compute Module Configuration Dialog Box 111 Locating Tools The Find Tool Dialog Box 111 Customizing the VPE Window 113 Adding Comments to a Visual Program llis 114 Adding Annotation to a Visual Program lll 115 Creating pages in the VPE o 115 Saving and Restoring a Visual Program 0 115 6 3 Using the Colormap Editor ss 119 Entering Values in a Colormap Editor 121 Using Data Driven Colormap Editors 125 Copyright IBM Corp 1991 1997 73 This chapter discusses how to use e The Image window e The Visual Program Editor e The Colormap Editor 6 1 Using the Image Window Once an image appears in the Image window it can be altered and manipulated in many ways This section describes how to manipulate the image directly using the interactor features accessed through the Options menu in the Image window Notes 1 These features are enabled only if you used the Image tool in your visual program to render the image If you used another tool such as Display you will not be able to use many of the Image window options The Image tool is found in the Rendering category See Image on page 160 in BM Visualization Data Explorer User s Reference for more information 2 It is also possible to control many chara
3. 015 6 126 7 237 8 Figure 14 Mesh Array of Two Path Arrays with Regular Connections Constant Array Encodes a set of numbers all with the same value This can be useful for example for specifying the colors associated with an object if the object has a single color An example of a Constant Array is shown in Figure 15 type float real vector 3 items n origin x Yo Zo Figure 15 Example of a Constant Array Chapter 3 Understanding the Data Model 33 U y cr y o O D mal Groups Fields can be combined into Groups A Group is a collection of members that themselves may be Fields or other Groups A member can be referred to either by name or by index An example of a Group is given in Figure 16 Group o pressure 1 ratepiane Figure 16 Example of a Group This example shows a Group describing a visualization scene composed of two parts The member named pressure is a Field of volumetric data to be volume rendered representing pressure in an airflow around an airplane The member named airplane is a geometric model describing the surface of the airplane It in turn can be a Group where each member is one of the constituent parts of the airplane such as wing fuselage and so on The top level Group could then be passed into the renderer to produce an image of the airplane combined with a volume rendering of the pressure Field Named Group members can
4. 00000000 ee eee 33 Example ora Group rers Aaa Sooo Pe db EEG SRL ES 34 Example of a Series Group esci e o an ku Eee ep x aw QuE 35 cus 39 EXQNIDIO 2 arg ce gender QoS d qp e ur A ieu 41 Example 3 2444444805 x X Gee A Ra dh e dent ob oes oed es 43 Example d uas 26 ee AOR a de wee RO EERE Re 44 cunei 2eosacos pena ars e e A h E AA 46 Example 6 sa A Red qe EPOR Re Bh a ee Be o e 48 EXAME mais ee onm it Be dede eee A o ie d 49 EXAMI A cL 51 EXANImDIG B wat 2 2 RANA SR Bb ee ee eS og erf e 52 mium aie hated a SAE Pd SRS ES a Se BO Re RS OR ee eS 53 EXAMDIO WU wwe we dh tue oce me de ug Bt Ae E eS wr s 54 EXIMPISTZ as maga e utes Go dente hop deg Be hb gd a reps 55 Visual Program Editor Window 61 Example of an Option Box lll 64 Sample Help Window cre 66 Sequence Control Panel 68 Sequencer Frame Control Dialog Box 69 View Control Dialog Box o 75 View Control Modes with Accelerator Keys 75 Set View Option Box 20000000 2 76 Navigate Portion of the View Control Dialog Box 81 Camera Settings Portion of the View Control Dialog Box 83 3 D Cursor with a Selected Point 86 AutoAxes Configuration dialog box 89 Expanded AutoAxes Configuration Dialog Box 90 Rendering Options Dialog Box lll
5. 3098039 6000000 7490196 0000000 0000000 1960784 Appendix G Accelerator Keys The following table is a summary of the accelerator keys available in Data Explorer To learn how to use these keys and their functions see Selecting Pull Down Menus and Pull Down Menu Options on page 62 Table 12 Summary of Data Explorer Accelerator Keys Active Primary Window Image Control Colormap Message Window Panel Editor Window Accelerator VPE Window Key Add Input Tab Camera mode Configuration Dee omose Y Delete Select Conv Pals meet Ena Execution Ovens v Execute on Orange onc v Execute Once foo v hoones fom v avaro mode fonn T oaeo OMN LOpmAlCoomapEdos OME O PaniZoom mode Jone J emos OY PemsEm Joe me oe S Re Ow ron Ow Porte mode Jon o Seles Al Cono Polis oma Ue SC OY enc fow o zoom made omz L lt lt lt gt 9 2 D ES D o ct o tn al O Copyright IBM Corp 1991 1997 31 316 IBM Visualization Data Explorer User s Guide Glossary Some of the definitions in this glossary are taken from the BM Dictionary of Computing SC20 1699 A accelerator A shortcut that minimizes the number of keystrokes or mouse clicks required to complete a task anchor window The window in which a Data Explorer session starts either the Visual Program Editor or the Image window The window
6. Control Panel Access Allows you to specify which control panels and control panel groups are accessible from the Control Panels Open All Control Panels option under the Windows menu See Restricting Control Panel Access on page 140 Grid Allows you to select the grid type you want to use on the layout area A dialog box displays the choices See Customizing the VPE Window on page 113 for more information about the Grid option See Changing the Alignment of Interactors in the Control Panel on page 134 IBM Visualization Data Explorer User s Guide Dialog Style Changes a control panel to dialog style see Control Panels as Dialog Boxes on page 138 Startup Control Panel Allows you to specify whether the Control Panel is opened automatically when Data Explorer is started with the Image window or menu bar as the anchor window See Specifying a Startup Control Panel on page 141 Help Menu The options in this menu are discussed in 5 3 Using Online Help on page 65 Image Window Menu Bar The Image window menu bar displays the names of six menus e File e Execute e Windows e Connection e Options e Help Image Window File Menu The File menu displays the options you use to open save and close visual programs and load macros The File menu lists the following options Open Displays a dialog box for specifying a file path name to load a visual program or if the path name ends in a director
7. Page Dimensions opecifies the size of the page By default this is specified in inches Output PPI Specifies the pixels per inch of the output image Note Unless you specifically care to set the precise pixels per inch you do not typically need to set this Margin Width Specifies a margin width of white space on the page For PostScript formats the printed image will by default fill the page to within Margin Width of the edge of the page If Allow Rerendering is off the pixels in the image will be sized appropriately to scale the image to fill the page but the same number of pixels as in the currently displayed image will be used If this results in a grainy image set Allow Rerendering on and enter a different Input image size For example if the displayed image is 640x480 and you want to double the resolution just enter 1280 in the Input image size field and Data Explorer will recalculate the new value of y 960 and the new higher value for Output PPI Print command Contains a text field where you can enter a command to print the image for example lpr P myPrinter Pushbuttons Apply Causes the command specified by Print Command to be executed Restore Restores settings in the dialog to what they were the last time that Apply was depressed Close Causes the dialog to be closed without printing an image 6 2 Using the VPE A visual program is a collection of interconnected tools that acts upon one or more inp
8. connections temperature data and wind data For this example assume that wind is a 3 D vector Using the Structuring category tools Mark and Unmark you can convert any Field component into the data component When you Mark wind for example the old data component if any is moved into a safe place called saved data and the wind values are copied into the data component Since wind is a 3 D vector the new current data component becomes a 3 D vector also The Compute module is used to make changes in the data component of a Field So by multiplying the first x component of our 3 D data we are in effect scaling in X For example the Compute expression in this case would be a x 2 0 a y a z to double the size of each x component of each data point while leaving the y and z IBM Visualization Data Explorer User s Guide Vector Fields components the same Any module connected to the output of Compute will see the scaled wind values as the data component of the Field However the old unscaled wind values are still kept in memory also By connecting other modules to the originally imported wind values you still have access to those original values at the same time To operate on the temperature data first use Unmark to return the data to the wind component The result will be to place the scaled wind values into the wind component for all modules connect
9. e o cr mall o e E Removes the Open Save and Save As menu commands from the Image window s File menu DX noImageSaving Removes the Save Image menu command from the Image window s File menu DX noInteractorAttribute Removes the Set Attributes menu command from the Control Panel s Edit menu DX noInteractorEdits Removes the Set Style Set Layout Set Dimensionality and Set Interactor Label menu commands from the Control Panel s Edit menu DX noInteractorMovement Restricts the ability to move interactor instances within a Control Panel DX noMessageInfoOption Removes the Information Messages toggle button from the Message window s Options menu DX noMessageWarningOption Removes the Warning Messages toggle button from the Message window s Options menu DX noOpenAl 1 Panels Removes the Open All Panels menu command from the Panels menu of the Control Panel and the Windows menu of the Image window DX noPGroupAssignment Removes the Execution Group Assignment menu command from the Image windows Connection menu DX noPanelAccess Removes 1 the Control Panel s Panels menu and all its menu commands 2 the Open All Control Panels and Open Control Panel by Name menu commands from the Image window s Windows menu DX noPanel Edit IBM Visualization Data Explorer User s Guide Hemoves the Control Panel s Edit menu and all its menu commands This is equivalent to the
10. opecify the macro s outputs with the Output tool from the Special category Place the Output tool icon on the canvas and connect it to the appropriate output tab from another tool icon The Output also inherits its type from the output tab to which it is connected The Configuration dialog box for the Output tool is similar to the one for Input but the Options toggle buttons and the Default Value field are grayed out Before you can use the macro you must first name it save it and then load it making it available in the tool palette To name the macro select the Macro Name option from the Edit pull down menu The Name dialog box opens The Name dialog box for the example macro is illustrated in Figure 77 on page 152 Type a name for the macro in the Name field The name must consist only of letters and numbers no spaces or underscores and must begin with a letter By default the macro is assigned to the Macros category You can assign the macro to a different category by typing a new name in the Category field The category you choose can be a new or existing category Chapter 7 Graphical User Interface Control Panels Interactors and Macros 151 e c El A o E cr m o m ma o E D md tn Name Category Macros Deseripion Set Cancel Figure 77 Macro Name Dialog Box Name To save the macro after it has been named use the Save As option of the File pull down menu Because m
11. 20 You could use the statement grid marker xdim 0 2 8 2 This specifies that one should start reading after xdim read the first dimension from 2 characters skip 8 characters then read the second dimension from 2 characters Example 3 suppose that the data file contains the following lines xsize 20 ysize 30 You could use the statements grid marker xsize X marker ysize Or grid marker xsize 0 3 X lines 1 8 2 The first specifies that the first dimension should be read following the marker xsize and the second dimension should be read following the marker ysize The second statement specifies that the first dimension should be read from 3 characters after skipping O characters following xsize and that the second dimension should be read from 2 characters after skipping 1 line and 8 characters The syntax for the points keyword is in addition to the syntax given in 5 3 Header File Syntax Keyword Statements on page 85 in BM Visualization Data Explorer QuickStart Guide Appendix B Importing Data File Formats 243 ms mall o D ms o ms 3 y cr tn bytes n points format type lines n skip width marker string where format is the format in which the grid values will be found and must be one of the following binary ieee text or ascii The first two parameters are synonymous as are the second two For type and the other p
12. Show Memory Use Displays the current memory usage see Usage on page 362 in IBM Visualization Data Explorer User s Reference Message Window Options Menu The Message window Options menu displays the options used to edit the current Message window The Message Window Options menu lists the following options See also 8 2 Using the Message Window on page 174 Information Messages Allows you to either display or not display Information messages Warning Messages Allows you to either display or not display Warning messages Error Messages Allows you to either display or not display Error messages Chapter 8 Graphical User Interface Menus Options and the Message Window 173 8 2 Using the Message Window 174 The Message window allows you to monitor the progress of a visual program as it executes It displays information warning and error messages from the executive and output from the Print and Echo modules if you include them in your visual program You can use the Print module for example to print the contents of an object See Print in IBM Visualization Data Explorer Users Reference for more information You can use the Echo module to print values or strings See Echo in BM Visualization Data Explorer User s Reference To open the Message window select the Open Message Window option from the Windows pull down menu of either the Image window or the VPE window The Message window consists of a text window and va
13. component data value 3 end ms mall o D ms o ms 3 y ct un Figure 87 Regular Skewed Grid Example The argument off front has been substituted for off diagonal in the script used to generate this figure see Examples on page 246 Example 3 A Warped Regular Grid Appendix B Importing Data File Formats 249 Figure 88 Warped Regular Grid Example The example file in usr lpp dx samples data deformedregular dx defines a warped regular grid and shows how to imbed data as text in a header section The values of the positions component are irregular and must be enumerated Figure 88 shows the resulting structure The irregular 3 dimensional positions object 1 class array type float rank 1 shape 3 items 24 data follows 0 0 0 0 0 1 0 0 2 0 2 0 0 2 1 0 2 2 1 0 841471 0 1 0 841471 1 1 0 841471 2 1 2 841471 0 1 2 841471 1 1 2 841471 2 2 0 9092974 0 2 0 9092974 1 2 0 9092974 2 2 2 909297 0 2 2 909297 1 2 2 909297 2 3 0 14112 0 3 0 14112 1 3 0 14112 2 3 2 14112 0 3 2 14112 1 3 2 14112 2 250 IBM Visualization Data Explorer User s Guide The regular connections object 2 class gridconnections counts 4 2 3 The data in a one to one correspondence with the positions object 3 class array type float rank 0 items 24 data follows 1 3 4 5 2 3 4 Dd 0 3 4 5 1 2 3 4 1 2 1 6 8 9 1 Zed 4 5 5 3 4 3 1 2 1 2 3 3 2 attribute dep string positions The field with
14. dialog box displaying To by default and in Figure 39 allows you to select the vector values to be displayed To change the value of one of the vectors do the following 1 Select the vector to change using the option box The choices in the option menu are To From and Up The current values for the vector you choose are displayed in the X Y and Z fields to the right of the options Chapter 6 Graphical User Interface Important Windows 83 84 2 Change each field to the new value Do this by clicking on the field typing in the new number and pressing the enter key 3 Repeat these steps for each vector you want to change Remember to see the results of your changes you must specify Execute or Execute on Change Changing the Size of the Image Window Data Explorer lets you specify the exact height and width of the image display area in the Image window in pixels When you change the size of the image display area the image is resized accordingly To change the width and height of the image display 1 Click on the Window Width field of the View Control dialog box illustrated in Figure 39 on page 83 2 Type a new value specified in pixels for the width Press the enter key 3 Repeat steps 1 and 2 for the Window Height field To see effect of the changes specify Execute or Execute on Change Setting the Camera Width If you select Orthographic projection then you can also specify the width of the field of
15. 1 00000e 06 Minimum 1 00000e 06 Global Increment 1 00000 Decimal Places 5 gt Global Update Continuously OK Cancel Figure 61 Set Attributes Dialog Box In this box you can e Set maximum and minimum values e Change the step increment e Change the number of decimal places displayed In the case of an integer interactor the decimal place field is disabled e Choose whether to update the image continuously as you change the interactor values or to update only when the mouse button is released This applies only when Execute on Change is enabled Note Many interactor types can also be data driven meaning that their attributes are derived at run time from data in the visual program See Using Data Driven Interactors on page 147 The increment and update options can be applied to the either just the current instance or to all instances of the interactor To affect all instances click on the option box for the attribute you want to set increment or update and select the Global option from option menu To affect only the current instance select the Local option Having multiple instances of an interactor with different increments allows coarse and fine controls For example you may want one instance of a scalar interactor to change by increments of 1 0 another instance by 0 10 and a third instance by 0 01 Note that the global option will not override interactors which have been exp
16. 2 Select the Edit menu Show Selected Interactor s option in the Control Panel The interactor corresponding to the stand in will become selected If no interactors in the Control Panel are associated with the selected stand in the Show Selected Interactor s option will be grayed out If you have more than one Control Panel and you are unsure which of them contains the interactor corresponding to the stand in Step 2 above can be applied to each Control Panel Alternatively you can double click on the stand in This will highlight the corresponding interactor To locate a stand in corresponding to an interactor 1 Select the interactor in a Control Panel by clicking on it 2 Select the Edit menu Show Selected Tool option in the Control Panel The stand in corresponding to the interactor will be selected If the stand in is not in the currently displayed portion of the visual program the display will be updated so the selected stand in is visible Deleting Control Panels To delete a Control Panel 1 Delete the interactors in the Control Panel 2 Click on the Close option of the File menu Saving and Restoring Control Panels The Program Settings option of the anchor window allows you to save your own configuration of the Control Panel s independently of the rest of the network You can save the values of the Control Panels as well as the configuration of all of the stored Control Panels for the current visual program Se
17. BM Visualization Data Explorer Programmer s Reference for information If the function is a macro a missing argument or an argument explicitly specified as NULL causes the default value to be used If no default is specified the parameter is set to NULL Example The module Camera takes the following arguments to The position in space to which the camera is pointed The default is 0 O 0 from The position in space where the camera is located The default is O 0 1 width The width in user units of the camera s view The default is 100 resolution The horizontal resolution in pixels of the image generated by the camera The default is 640 aspect The aspect ratio of the image generated by the camera i e its height divided by its width The default is 0 75 Chapter 10 Data Explorer Scripting Language 201 10 n m mall o O cr mall o E Q r o E Q e y e D up The direction in the world coordinate system that the camera considers up The default is O 1 0 perspective The projection method The default is 0 indicating orthographic view angle projection The viewing angle This applies only in perspective projection and the default is 30 background The image background color The default is black The following function calls are all equivalent and construct the default Camera Object cl Camera 0 0 0 0 0 1 100 640 0 75 0 1 0 0 black
18. Changing the Interactor Dimensionality When vector and vector list interactors are created by default their dimensionality to set to 3 Dimensionality can be changed using the Edit menu Set Dimensionality option Changing the Interactor Layout When an interactor is created its layout is vertical that is the interactor label is placed at the top of the interactor Data Explorer allows you to choose between this vertical layout and a horizontal layout The horizontal layout places the label on the left side of interactor To change the layout of the interactor 1 Select the interactor 2 Click on the Edit menu Set Layout option A cascade menu appears for you to choose the layout you desire Setting Interactor Attributes You can have several instances of the same interactor Each instance can be a different style stepper dial or slider and can have a different increment value However all instances of an interactor have the same value and the same minimum and maximum limits As you change the value or range of one instance the other instances of that interactor are automatically updated To change the range of values of an interactor select the interactor and select the Set Attributes option in the Edit menu or double click on the interactor in the Control Panel The Set Attributes dialog box Figure 61 on page 135 appears IBM Visualization Data Explorer User s Guide EF ER Set Attributes Maximum
19. Colormap on page 84 and Sequencer on page 297 in BM Visualization Data Explorer User s Reference You can execute the visual program from the Execute menu of a VPE window a Control Panel an Image window or a Message window The options are the same in all four windows When a visual program is executed an Image window is created if one is not already open You can also control execution using the Execute module See BM Visualization Data Explorer User s Reference Note If the Execute options are grayed out your workstation may not be connected to the server For information about connecting to the server see 9 3 Connecting to the Server on page 183 Although you can initiate execution from the Control Panel VPE Image and Message windows you may find it more efficient to execute your visual program through the Control Panel menu if you are using a Control Panel This efficiency Chapter 5 Graphical User Interface Basics 67 is due to the ease with which you can change inputs with interactors and initiate execution You can choose one of four options from the Execute menu when executing a visual program Select the first option Execute Once to execute the program once using the values currently set in the interactors If you change any interactor values after execution the visual program does not automatically execute you must again choose an option from the Execute menu to execute the altered program Choosing
20. Hierarchies on page 138 Control Panel Groups Displays a dialog box that allows you to create modify and delete control panel groups See Control Panel Access Groups and Hierarchies on page 138 Grid Allows you to select the grid type you want to use on the canvas A dialog box displays the choices See Customizing the VPE Window on page 113 for more information about the Grid option Help Menu The options in this menu are discussed in 5 3 Using Online Help on page 65 Control Panel Menu Bar 162 The Control Panel menu bar Figure 60 on page 129 displays the names of six menus you can use within the Control Panel window e File e Edit e Execute e Panels IBM Visualization Data Explorer User s Guide e Options e Help The following sections describe the options available on these menus Control Panel File Menu The File menu lists the following options Close Closes the current Control Panel Close All Control Panels Closes all control panels Control Panel Edit Menu The Edit menu lists the options you can use to edit and delete interactors in the Control Panel Set Style Allows you to change the type of selected interactors on the layout area See Changing the Interactor Style on page 134 Set Dimensionality Allows you to set the dimensionality of the selected interactors in the layout area See Changing the Interactor Dimensionality on page 134 Set Layout Allow
21. Readimage on page 250 and Render on page 264 in IBM Visualization Data Explorer User s Reference Cache Control Executive n general it is not necessary to change how the executive caches intermediate results However in a few cases it may be advantageous to do so For example if you are reading a live data feed into your program it is probably not necessary to cache the downstream outputs You can change how and if the executive caches intermediate output values by opening the Configuration dialog box of a module and changing the option menu to the right of each output You can also choose Output Cacheability from the Edit menu of the VPE and set the cacheability of a group of modules show the cacheability of a group of modules or ask Data Explorer to use a heuristic to automatically optimize the caching for the current visual program In general it is most efficient to cache only the results of the last module in a single file line of modules for example to cache the output of Isosurface but not Import Note that if you do this however if you need to change the isosurface value the data file will need to be reimported slowing execution Appendix A Using Data Explorer Some Useful Hints 215 c tn D m mi mall o gt cr tn 216 If you want to turn off caching altogether you can use the cache off command line option to Data Explorer Cache Control Display Some modules use the caching system to
22. Regular Array Objects to obtain a grid of equally spaced points in n space in such a case it is generally more convenient to use the gridpositions keyword described earlier IBM Visualization Data Explorer User s Guide A Regular Array Object is a linear sequence of points in n space starting at some origin specified by the origin clause and separated by some constant delta specified by the delta clause The delta clause has the same number of elements as origin The dimensionality of the space that the linear sequence is embedded in is determined by the number of coordinates specified in the origin clause Regular Array Objects are always of rank 1 object number class regulararray items number name type unsigned byte signed byte unsigned short signed short unsigned int signed int hyper float double string origin number delta number Product Array Objects A Product Array is a compact encoding of a generalized notion of a regular grid lt is frequently used to describe a rectilinear grid as a product of Regular Arrays in such a case it is generally more convenient to use the gridpositions keyword described earlier ms mall o D ms o ms 3 y cr tn A Product Array is the set of all possible sums of the poinis of the terms forming the product For example the product of a set of Arrays each of which is a Regular Array as described above is a lattice of points with basis vectors equal
23. Saturation Value or Opacity is currently selected in the Colormap Editor For example if Saturation is the selected area the dialog will display steppers for Data value and Saturation value The value for Hue Saturation Value or Opacity can be a value between 0 and 1 Use the Add button to add the control points to the selected area in the Colormap Editor IBM Visualization Data Explorer User s Guide Add Control Points Data value 0 to 2 5 000000 gt Hue value 0 0 to 1 0 0 0000 gt Add Close Figure 58 Colormap s Add Control Points Dialog Box Selecting Control Points Control points can be selected by doing one of the following e Select a single control point by simply clicking on it once e Select a group of control points by clicking on a point in the selected area and dragging the cursor around the desired points e Select all of the control points in an area by using the Select All Control Points option under the Edit menu Note A control point is selected automatically when it is created When one control point is created all other previously selected points in that area are automatically deselected Deleting Selected Control Points To delete selected control points you can do one of the following e Double click on each of them one at a time e Choose the Edit menu then click on the Delete Selected Control Points option Moving Control Points To move
24. SuperviseWindow on page 336 in BM Visualization Data Explorer User s Reference C2 Command Line Options 1 1 Table 5 lists the command line options available with Data Explorer Those most commonly used are identified by a bullet e Table 6 on page 297 lists command line options of particular interest to developers lt o m mall o o o al D tn e cr mall o o E tn Command line options always override corresponding environment variables As such they offer a quick way to temporarily override environment settings If parameters conflict the last one entered takes precedence Table 5 Page 1 of 3 Data Explorer Command Line Options 8bitcmap Set color map error threshold default 0 1 private shared 0 1 private 1 stored 1 builder Start the Data Explorer Module Builder instead of Data Explorer cache onloff Enable executive cache default on connect host port Start a distributed executive only no user interface data pathlist Override DXDATA environment variable directory dirname Change directory cd to dirname before starting the executive display hostname 0 Set the X display destination E _ colors filename Override DXCOLORS environment variable i NE Appendix C Environment Variables and Command Line Options 295 Table 5 Page 2 of 3 Data Explorer Command Line Options Option syntax dxroot dirname Set the Data Explorer root
25. The neighbors component represents information about the neighbors of each connection element The number of items in this component must match the number of items in the connections component The number of entries in each item must match the number of faces for 3 D or edges for 2 D in the connection element For example each item in the neighbors component for triangle connections has three entries while each item in the neighbors component for tetrahedral connections has four entries For simplexes in n dimensions for example triangles and tetrahedra each item of the neighbors Array consists of n 7 integer indices into the connections Array identifying the n 7 neighbors of the simplex the ith of the n 7 indices corresponds to the face opposite the ith vertex of the simplex For quads cubes and so on each item of the neighbors Array contains 2n integer indices into the connections Array identifying the 2n neighbors of the polyhedron The pointers are in the order X44X1 X24 X 2 X X meaning that the first index points to the neighbor in the x direction the second to the neighbor in the x direction and so on where the x dimension varies fastest in the representation of the point indices in the interpolation element Faces without neighbors are indicated by an index of 1 Box Component The box component consists of 2 n dimensional points where n is the dimensionality of the positions component identifying
26. arg2 Echo sum The third example macro VectorManip implements a function to compute the cross product dot product and cosine of two 3 vectors Note that the returned values do not need to be computed in the order in which they are declared macro VectorManip vectlistl vectlist2 gt dot cross cos cross Compute cross 0 1 vectlistl vectlist2 dot Compute dot 0 1 vectlistl vectlist2 cos Compute 0 mag 1 mag 2 dot vectlistl vectlist2 Chapter 10 Data Explorer Scripting Language 205 10 n m mall o O cr mall o E Q r o E Q e y e D Note that the Data Explorer script language does not allow nested function calls The following example illustrates a syntactically invalid function call Echo Sum argl arg2 10 7 Using Data Explorer Script Commands Sequencer The Data Explorer scripting language provides commands to control the following aspects of the script environment Sequencer These commands set up and control the Sequencer to display a series of frames File inclusion This command lets you include other scripts in your program Prompts These commands let you change the appearance of the prompt in the script environment The Data Explorer commands and parameters if any are complete scripting language statements and are usually terminated with a semicolon There are additional commands that can be executed in the script environmen
27. call whether used as the right hand side of an assignment statement or on its own is Name arglist attribute name value where Name is the name of the function being called and arglist is a list of arguments that are separated by commas the list can be empty Following the function may optionally be a list of attribute name value pairs enclosed in square brackets Each argument s value can be either a variable identifier a constant value an expression or the special identifier NULL Note that nested function calls cannot be passed as arguments The argument values can be passed either by position or by name as described in the following sections Positional Arguments The positional argument passing mechanism is similar to the mechanism found in most programming languages that use subroutines Given a function declared with n input formal parameters the first n values supplied in the function call are assigned to the first n formal parameters If you supply n values in the function call then only the first of the function s formal parameters are assigned the supplied values The missing arguments are assigned the value of NULL IBM Visualization Data Explorer User s Guide By Name Arguments The by name argument passing mechanism provides more flexibility in specifying arguments When an argument is passed by name the following syntax is used for the argument Fname value Fname is an identifier that corres
28. configuration by a means other than Undo Any configurations that have been stored and undone are discarded IBM Visualization Data Explorer User s Guide Resetting the Camera To return the image to a front view that includes the entire object select the Reset option of the View Control dialog box or use the Ctrl F accelerator key You can also use this option if you bring in a new data set and want to create a new camera appropriate for the data Note You can also reset the camera by using the resetCamera parameter to the Image tool see Image in IBM Visualization Data Explorer User s Reference Using Probes Cursors A probe is a list of one or more vectors that represent points in the image You can use them with Data Explorer modules that accept vectors as input such as ClipPlane and Streamline After you execute a visual program and have an image in the Image window you can modify the visual program to include a Probe or ProbeList tool from the Special category The probe tool accepts input from the 3 D cursor tool specifying the points to use as vectors for input into another tool The Probe tool accepts one point as its input the ProbeList tool accepts multiple points as input To use probes to select points for input into tools 1 Execute a visual program to produce an image in the Image window 2 In the VPE place one or more probe tools from the Special category in the visual program connecting the
29. execution The Data Explorer executive schedules module execution It does detailed graph analysis implements distributed processing of the modules and implements the Switch and Route modules It also provides optimization by caching the intermediate outputs of modules For example if you run Import twice in a row with the same inputs Import will not actually run the second time and instead the executive will use the cached output from the previous execution The Image and Display tools also cache their images internally To implement the caching scheme Data Explorer will allocate memory up to some fixed size This memory is referred to as the arena When the arena fills up and more memory is required Data Explorer looks for objects to discard from the cache When it does this it may mean that subsequent executions will have to execute larger portions of the program The arena is of fixed size for any one instance of Data Explorer The size of this arena is chosen by default based on the size of the physical memory in the system For some data sets the default arena size will not be sufficient In those cases one can use the memory option to increase the size of the arena with the limitation that your can t increase the arena size to be larger than the amount of real plus virtual memory page or swap space on your machine Talk to your system administrator if you think you need to increase the amount of swap space on your system
30. interactors To select any of these items simply click on the item In general you can deselect an item by clicking on it again The exceptions are the tool icons and interactors for which you must either click on another part of the canvas or shift click on the item Selecting a Choice in an Option Box An option box contains a list of choices but usually displays only the one currently selected Option boxes are used throughout the Data Explorer interface For example the Selector interactor illustrated in Figure 31 on page 64 can be displayed as an option box Selecting a choice from this box is similar to selecting options from pull down menus To display the possible choices click on the tab on the right side of the option box With the list of choices displayed click on your desired selection The list of options disappears and the option box is updated with the new selection Chapter 5 Graphical User Interface Basics 63 Control Panel 2 J File Edit Execute Panels Options Help Show MapToPlane Ci Figure 31 Example of an Option Box Alternatively you can select an option with the mouse by moving the cursor to the desired option box and pressing and holding the mouse button The list of options appears Then move the cursor to the desired option and release Each option is highlighted as you move the cursor across it Some of the options are accessible using accelerator keys This is indicated to the right o
31. language itself The values for the right side portion of a function call assignment statement are the values returned by a single function call The Statistics function which is used in the following examples returns five values Chapter 10 Data Explorer Scripting Language 199 e Mean of the data e Standard deviation of the data e Variance of the data e he minimum value in the data e he maximum value in the data In the first example all of these values are assigned to variables for later use In the second example the minimum and maximum values are ignored In the third example only the minimum and maximum values are being saved for later use 1 mean sd var min max Statistics data 2 mean sd var Statistics data 3 min min min min max Statistics data 10 5 Invoking Data Explorer Macros and Modules This section describes the procedures and features for invoking macros and modules It describes function call arguments and attributes Function Call Arguments 200 Data Explorer provides a flexible function calling mechanism for invoking macros and modules A macro s definition includes a list of identifiers that are used as its input formal parameters The formal parameters act as names and place holders for the arguments that you supply when the macro is called Modules functions that are compiled into the system have named formal parameters The general form of a function macro or module
32. member 66 value B member 255 value empty attribute font ascent number 0 75 attribute font descent number 0 25 The attributes describe the maximum height above and below the baseline for all characters in this font The values should be positive floating point numbers and they should add to 1 0 Each member of the group must be a field Each field must contain a 2 D or 3 D positions component and a connections component with element type lines or triangles object positions1 class array type float rank 1 shape 3 items 3 data follows 0 1 0 5 0 0 0 3 0 6 0 0 0 5 0 5 0 0 object connections1 class array type int rank 1 shape 2 items 2 data follows 01 12 attribute element type string lines attribute ref string positions The character positions are assumed to have their horizontal X origin at the left edge and their vertical Y origin at the baseline Each field must have a char width attribute describing the character width for Spacing when combining characters into strings object circumflex class field component positions value positions1 component connections1 value connections1 attribute char width number 0 55 Copyright IBM Corp 1991 1997 307 The fields can contain other components such as colors or normals although the standard Data Explorer modules will not process this information Th
33. one similar to that of the Array Object Data are accessed in CDF through an applications programming interface available as C and FORTRAN libraries from the National Space Science Data Center NASA Goddard Space Flight Center Greenbelt MD Data in CDF may be stored in a number of physical formats e g native or portable binary single or multiple files row or column majority but the interface is the same Hence data in a CDF written in a format foreign to the workstation on which Data Explorer is running are converted automatically during the Import process Data Explorer provides support for importing Fields stored as CDF r variables To import data from a CDF specify the CDF name as the name parameter in the Import Configuration dialog box not the file name since the CDF may be in multiple file format If the CDF has more than one variable which is typical Data Explorer categorizes each variable as positions series or data as appropriate Variables that vary in one dimension only and are not record variant are considered positions and become the positions component in a Field Object In many cases these variables may have the CDF variable mnemonics of LATITUDE and LONGITUD which are mapped to the first x and second y components of the positions vector if they exist This mapping permits direct use of these data with cartographic and other tools for the earth and space sciences that are publicly available for use with Data E
34. or by directing the highlighted bar with the keyboard s up and down arrow keys When the desired selection is highlighted press the Enter key Some of the pull down menu options can be selected without accessing the pull down menus using accelerator keys Accelerator keys use the Ctrl key in combination with single keys to provide fast access to frequently used options These keyboard options are displayed on the right side of the pull down menu across from the options that they access Accelerator keys are effective only in the active window that is the mouse cursor must be in the window in which the desired pull down option is located To use an accelerator key to select a pull down option press the Ctrl key in conjunction with the appropriate letter For example the Save option in the File pull down menu can be invoked by pressing the Ctrl key and the S key at the same time A summary of the available accelerator keys and their functions is provided in Appendix G Accelerator Keys on page 315 For information on each windows menu bar and pull down options refer to e VPE Window Menu Bar on page 156 e Control Panel Menu Bar on page 162 e Image Window Menu Bar on page 165 e Colormap Menu Bar on page 168 Selecting and Deselecting Items with the Mouse In the Visual Program Editor VPE and Control Panel windows you use the mouse to select various items such as items in a list tool names tool icons and
35. that is the point IBM Visualization Data Explorer User s Guide where the mouse pointer is located moves more towards the center of the image area View Control Figure 38 Navigate Portion of the View Control Dialog Box Table 4 Look Option Menu Forward 45 Left 45 Right 45 Up 45 Down 90 Left 90 Right 90 Up 90 Down Backward Align If the camera is pointing forward you can use the center mouse button to change your direction Clicking on the center mouse button adjusts your direction and view of the object toward the position of the mouse pointer in the image area With the exception of Align all of the options in the Look option box affect only the direction the camera is pointing Align adjusts the current navigate direction the forward direction to be the same as the current Look value For example if the camera is pointing 45 to the right of the current navigate direction Align changes the navigate direction to be 45 to the right of its current value thereby aligning travel direction with camera direction Chapter 6 Graphical User Interface Important Windows 81 82 Note Switching to another mode such as Rotate from Navigate while the Look value is something other than Forward automatically aligns the navigate direction with the camera direction If the camera is pointing in any direction but forward you can still use the left and right mouse buttons to move forward and backwar
36. that was undone with the Undo button If you wish to return the canvas to its former state i e to the set of tool icons it displayed prior to the first search click on Restore button Note Clicking on Undo Redo or Restore will deselect the tool that is selected in the Tools palette Customizing the VPE Window Under the Options menu bar category are selections for customizing the window Tool Palettes Use as a toggle by clicking to close the palettes and make the working area on the canvas larger Grid A dialog box illustrated in Figure 53 on page 114 appears for you to enter new values Chapter 6 Graphical User Interface Important Windows 113 Figure 53 Grid Dialog Box The Grid option allows you to specify whether the tools you place on the canvas automatically align on a grid pattern You can enable the grid pattern by clicking on one of the following 1D Horizontal 1D Vertical 2D The default is none You can control the spacing of the grid pattern by changing the number of vertical and horizontal pixels Specify how the tools are to be aligned on the grid by changing the alignment toggle buttons For example the dialog box in Figure 53 specifies grid spacing of 50 pixels with the center of a tool being placed at a grid position Adding Comments to a Visual Program 114 For your own documentation purposes you can add comments to your visual program These comments are saved and restor
37. the program executes as fast as possible always using the current settings at the time an execution cycle begins This option is grayed out if the Sequencer is running End Execution Causes the visual program to stop executing Sequencer Causes the Sequencer to display This option is grayed out if there is no Sequencer in the visual program While the Sequencer is running you can change interactors and those changes are reflected in subsequent frames You can pause the Sequencer on a particular frame and explore that frame using the Execute Once and Execute on Change options IBM Visualization Data Explorer User s Guide Using the Sequencer on page 68 discusses the Sequencer in detail While the visual program is executing the Execute label in the menu bar is highlighted and remains so until execution is completed lf Execute on Change is selected the Execute label in the menu bar is highlighted with one color during execution and another color the rest of the time For more information see 5 4 Executing a Visual Program on page 67 VPE Windows Menu The Windows menu allows a user to open and create control panels open previously defined macros included in the visual program open the Image window and open the Colormap Editor These options appear on the Windows menu New Control Panel Opens a new Control Panel If you have selected one or more interactor stand ins on the VPE canvas the new Control Panel contains
38. 0 5 0 5 4 0 0 5 5 0 6 15 0 0 1 5 7 1 5 0 0 4 5 8 2 0 0 5 5 0 9 1 0 0 0 5 0 10 1 0 0 0 1 0 11 Edges array This is a list of connected points by point number All the edges associated with a particular face need to be listed together If points 10 3 and 7 make a triangle the list is 10 3 7 and the 10 is not repeated If there is a hole in the triangle the edges that describe the hole must be listed right before or right after object edge list class array type int rank 0 items 23 data follows SH AE SE SHE 1 0 2 edge point index 0 10 1 2 3 9 6 5 6 10 1 0 11 9 8 4 3 13 11 10 2 17 0 11 2 20 attribute ref string positions Loops array This is a list of connected edges by edge number Each number is the edge index of where the next loop starts object loop list class array type int rank 0 items 7 data follows i i f k i j l 1 i i i 1 r roi i jJ y i i H1 i 1 i f e 1 fo T ET et Figure 94 Example of a Surface Using Faces Edges and Loops 266 IBM Visualization Data Explorer User s Guide 0 loop index 0 3 1 6 2 9 3 13 4 17 5 20 6 attribute ref string edges Faces array This is list of which loops make faces If there are no holes in the faces this is list of all loops If two or more loops actually describe the outside edges and inside hole edges of a face then this list contai
39. 224 Plots and Histograms sx Eo Re om X eee EEE eee 227 Rubbersheet CIT 227 Transformations and Structuring c n 228 Vector Fields ss 2 bus Rh Oe wee OE eee whe boh ded 229 Volume Render exercise BSR ORDERS Ree Eo 231 A 3 Design for Interactive Use 232 Interactors and Control Panels sn 232 Transmitters and Receivers lll 234 DOCUMENTAION a ssa ut S22 SSS St Seek quse ue SS SSS s 235 A 4 Design for Video Output lolo 236 TV Line Resolution 2 isso idas da weet ses 236 TV Color ReEsoluuion ies bet eee eo Awe Seat Bea ee ees 237 Animation and Frame Rates lll 237 A 5 Presentation Issues and Techniques 238 Appendix B Importing Data File Formats 241 B 1 General Array Importer Keyword Information from Data Files 242 B 2 Data Explorer Native Files ollis 244 Overview of the Native File Format css 244 EXAMPICS 2 ese ce ME Nos REED Ete ie Ee Wobei ERU E oa ue d 246 Syntax of the Native File Format 268 OBIGOIS santa Eee reor E ERU DUCES UR ee e SCR S es i Bes 269 OUP ODJECE 3 e286 o aeo X ev Eee d de SS ias ux E 270 Ser s ODISCIS amd hace hee Sodas Gh la ee dese ete eed 4 271 Multigrid Objects lt ao a 4 204 sew kw no Rc mo da 271 Composite PIeld DIGelS e camas Boe oe be eed Sad hee ea Ss 271 Field OBJECT
40. 92 Throttle Dialog Box ls 94 Save Image Dialog Box 2n 95 Print Image Dialog Box e 98 VPE MINdOM uu x xo REOS o EPOR RENE tru Be 100 Example of a Tool Ilcon sms gaia RR S RR RS ds e Ress 101 How TABS WOK estais le due A eek 6 104 Typical Configuration Dialog Box cll 108 Ix 51 Typical Dialog Box for the Compute Module 111 52 Find Tool Dialog Box llle 112 99 Gna Dialog BOX esa dd oe Poe we Ys OUS OR hee os 114 54 Save As Dialog Box a 2 eee 116 55 Open Dialog BOX es 444 4346 052555 244 SEDES 118 56 Fragment of Visual Program Using Colormap 120 67 Golormap EUllOl as derer eR eee cupri debts 121 58 Colormap s Add Control Points Dialog Box 123 59 Generate Waveforms Dialog Box 125 60 Control Panel Window c 129 61 Set Attributes Dialog Box a 135 62 Set Attributes Dialog Box for a Selector Interactor 136 63 Set Interactor Label Dialog Box 137 64 Control Panel Group Dialog Box 2 00 0 0 139 65 Control Panel Access Dialog Box 140 BO ICPP Snes Ss veo So ye pr cet a b Res d ee ae Ge 142 Ors DaFo Me oi 68 ded ak dent se par de dc Be Ses St Sad ee 143 Do SIde SOWIE i uu oe al em Ok BE he Hee he more RRR n ee 143 69 TENSIVE ux dose de Eumene sd do e tan
41. A A Type Z DX errorEnabled Boolean Z DX errorOpensMessage Boolean DX infoEnabled DX infoOpensMessage Z lt lt Boolean N Boolean DX limitImageOptions Boolean DX metric DX noConfirmedQuit DX noCMapOpenMap DX noCMapSaveMap DX noCMapSetNameOption DX noDXHelp DX noEditorAccess DX noEditorOnError limitimageOptions metric Boolean noConfirmedQuit Boolean noCMapOpenMap Boolean noCMapSaveMap Boolean noCMapSetNameOption Boolean noDXHelp Boolean noEditorAccess Boolean noEditorOnError Boolean DX nolmageLoad nolmageLoad Boolean DX nolmageMenus nolmageMenus Boolean DX nolmagePrinting Boolean DX nolmageRWNetFile nolmagePrinting c bj Cc o E h mall o Q e m y cr mall o o E nolmageRWNetFile Boolean DX nolmageSaving nolmageSaving Boolean DX nolnteractorAttribute nolnteractorAttribute Boolean DX nolnteractorEdits nolnteractorEdits Boolean DX nolnteractorMovement nolnteractorMovement Boolean DX noMessagelnfoOption noMessagelnfoOption Boolean DX noMessageWarningOption Boolean DX noOpenAllPanels noMessageWarningOption noOpenAllPanels Boolean DX noPGroupAssignment noPGroupAssignment Boolean DX noPanelAccess noPanelAccess Boolean DX noPanelEdit DX noPanelRWConfig noPanelEdit Boolean noPanelRWConfig noScriptCommand Boolean DXerrorOpensMessage NA Boolean DX noScriptCommand Boolean Co
42. Affects the behavior of the Display module See Display on page 109 in BM Visualization Data Explorer User s Reference for more information cache Attribute Specifies whether the rendered image should be cached Affects the behavior of Display and Image modules See Display on page 109 in BM Visualization Data Explorer User s Reference for more information rendering mode Attribute Specifies the rendering mode to be either hardware or software Affects the behavior of Display and Image modules See Display on page 109 in BM Visualization Data Explorer Users Reference for more information Chapter 3 Understanding the Data Model 27 O y cr y o O D m Arrays rendering approximation render every Attributes Specify hardware rendering characteristics for an object Affect the behavior of Display and Image modules See Display on page 109 in BM Visualization Data Explorer User s Reference for more information pickable Attribute Specifies whether or not an object should be pickable See Pick on page 234 in IBM Visualization Data Explorer User s Reference for more information marked component Attribute Specify which component in an object was previously marked This attribute is set by the Mark module affects the behavior of the Unmark module See Mark on page 214 and Unmark on page 358 in BM Visualization Data Explorer User s Reference for more information Array Objects hold the actual data po
43. An Irregular Grid on page 251 but the data is stored in a file separate from the header If you use this sample header file in a script the results are the same as in Figure 89 on page 252 This file can be found in usr Tpp dx samples data irregirreg2 dx object 1 class array type float rank 1 shape 3 items 24 msb binary data file irregirreg2 bin 0 attribute dep string positions object 2 class array type int rank 1 shape 4 items 30 msb binary data file irregirreg2 bin 288 attribute element type string tetrahedra attribute ref string positions object 3 class array type float rank O items 24 msb binary data file irregirreg2 bin 768 attribute dep string positions object irreg positions irreg connections binary file class field component positions value 1 component connections value 2 component data value 3 end Often you can use this method to point to existing data files To do this your header file must e Describe the coordinate system of the data e Indicate how many data values there are in the data file e Indicate the type of data values float byte scalar vector and so on For example suppose you have an existing data file written in the IEEE floating point format It has the following characteristics e t is on a regular grid 100 x 100 x 15 and the delta in the z direction is 2 while the deltas in the x and y directions are 1 e The origin of the grid is at 50 100 10 e The
44. Arrays in Data Explorer file format 28 isosurfaces 221 issues of visualization presentation 238 iteration using looping 44 L light object in Data Explorer file format 277 lists in scripting language 196 loading modules 183 locating tools 111 look direction for navigating 80 look to point 79 looping constructs advanced 50 iteration using 44 loops component 24 macros in scripting language body 205 definition of 204 example of macro execution 210 examples 205 expansion 208 header 204 variables in 208 326 IBM Visualization Data Explorer User s Guide macros continued in visual programs creating 149 loading 152 naming 151 opening 154 Map 223 matrices in scripting language 195 maximizing windows 65 memory use of 213 Mesh Array Objects in Data Explorer file format 276 in data model 32 Message window 174 menus Commands 173 Edit 173 Execute 173 File 172 Options 173 minimizing windows 65 missing arguments in scripting language 201 modules loading 183 mouse use in Data Explorer 62 moving tools 105 Multigrid Groups 34 Multigrid Objects 34 271 N named arguments 201 naming the image 93 navigating around the image 80 neighbors component 24 netCDF file format complex Fields 282 description 281 examples 286 series data 284 simple Fields 281 networks 13 normals component 24 notation field in a configuration dialog box 108 O object attributes 27 object cache 214 Objects Array 28 definition o
45. Data File Formats 257 ms mall o D ms o 3 y ct tn 1 0 0 1 0 1 1 1 0 4 0 2 1 1 0 2 0 0 1 1 0 1 0 0 152 0 1 0 1 lel 0 0 0 0 0 9 0 0 0 1 attribute dep string positions Object 2 is the data associated with the second frame in the series object 2 class array type float rank 1 shape 3 items 18 data follows 1 1 0 0 O OOOOOOOOOOOOOOO0 RNPPPOP 0DO PPOOMmTDTD c rm co O c ME c M ec E ec E ec E ec A eco E eco ec ec E ec 8 GO ec O O c c5rorLmnm crLccc0c NO c CO CO L2 Lr LL Co Co r n3 rm rmi rLI rc HB N O mr r2 n9 uQO COO CO rm rm n9 P WO Or Co PO 0 2 9 0 attribute dep string positions m Object 3 is the data associated with the third frame in the series object 3 class array type float rank 1 shape 3 items 18 data follows 0 0 0 1 1 0 0 1 0 2 1 0 0 0 0 0 2 0 0 2 0 1 242 0 0 0 1 0 9 0 0 0 2 0 8 0 4 0 1 0 9 0 1 0 2 1 9 0 0 0 1 0 7 0 2 0 1 Lied 0 1 0 0 2 0 0 0 0 3 1 1 0 1 0 1 122 0 5 0 2 1 0 0 1 0 1 2 0 0 2 0 1 1 4 0 1 0 3 0 9 0 2 0 3 1 1 attribute dep string positions 258 IBM Visualization Data Explorer User s Guide Object 4 is the first field in the series The positions and connections are defined by objects 1 and 2 in a separate file pos conn data and the data is given by object 1 in this file object 4 class field component positions value file pos conn data 1 component connections value file pos conn data 2 compon
46. Double click on the tool name in the lower tool palette 2 Click the mouse on the canvas to place one instance of the tool Repeat this step for further instances of the tool 3 To stop placing the same tool deselect the tool s name in the palette by clicking on any tool name Note After you place a tool its icon stays selected until you place another tool or deselect the tool as described in Selecting Moving and Deleting Tool Icons If you place one tool icon on top of another the bottom tool icon is pushed to the right to allow room for the new one To avoid the displacement of tool icons allow enough space for each tool icon you plan to use To deselect a tool name in the lower palette do one of the following e Click on the tool name e Select another tool name e Select another category Selecting Moving and Deleting Tool Icons To select a tool icon click on it To select a group of tool icons use one of these methods e Hold down the Shift key and click on each tool icon in turn e Position the cursor on the canvas near a corner of the group and drag the mouse to draw a selection box around the tool icons you want To select the tool icon you must completely enclose it in the selection box As a tool icon is IBM Visualization Data Explorer User s Guide encompassed by the selection box it is highlighted indicating that it is selected Note If you have tools selected already and you want to select more
47. Limited Warranty a ICS warrants that for thirty 30 days from the delivery to Customer each copy of the Program when installed and used in accordance with the Documentation will conform in all material respects to the description of the Program s operations in the Documentation b Customer s exclusive remedy and ICS sole liability under this warranty shall be for ICS to attempt through reasonable efforts to correct any material failure of the Program to perform as warranted if such failure is reported to ICS within the warranty period and Customer at ICS request provides ICS with sufficient information which may include access to Customer s computer system for use of Customer s copies of the Program by ICS personnel to reproduce the defect in question provided that if ICS is unable to correct any such failure within a reasonable time ICS may at its sole option refund to the Customer the license fee paid for the Product c ICS need not treat minor discrepancies in the Documentation as errors in the Program and may instead furnish correction to the Program d ICS does not warrant that the operation of the Program will be uninterrupted or error free or that all errors will be corrected e THE FOREGOING WARRANTY IS IN LIEU OF AND ICS DISCLAIMS ALL OTHER WARRANTIES EXPRESS OR IMPLIED INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR ANY PARTICULAR PURPOSE IN NO EVENT WILL ICS BE LIABLE FOR ANY IN
48. Object has a class and an identifying numeric or string name whose scope is the file containing the Object The definition of an Object is introduced by an object clause that specifies the Object number or name and its class The class keyword is optional as are many of the keywords in the following list Appendix B Importing Data File Formats 269 ms mall o D ms o ms 3 y cr tn Group Objects 270 IBM Visualization Data Explorer object number class name group series multigrid compositefield field array constantarray gridpositions regulararray productarray gridconnections patharray mesharray xform string light camera clipped screen The numeric or string name definitions of other Objecis forms of an Object is used to refer to that Object in the In general such references can take one of several number name file file file file number file file name An Object that has a string name can be imported with the Import module by specifying that string as the variable parameter of Import All Objects can have any number of named attributes specified by attribute clauses The value of an attribute is an Object The value can be specified as a string or list of strings by using the string keyword in which case a String Object is created to hold the string as a number by using the number keyword in which case an Array Object is created to hold the number or as an
49. Object reference attribute attribute name value string string number number number name file file file file number file file name A Group Object has any number of named or numbered members specified by member clauses The value of the member is specified as an Object name or number in the current file or as an Object name or number in another file Member numbers must be sequential starting at O with no gaps in the numbering User s Guide object number class group name member member name value number number name file file file file number file file name Series Objects A Series Object is a subclass of Group Object in which each member has in addition to its ordinal index a floating point series position The series position can be for example the time stamp for each member in a time series A Series Object has any number of numbered members The value of the member is specified as an Object name or number within the current file or as an Object name or number in another file Member numbers must be sequential starting at O with no gaps in the numbering object number class series name member number position number value number name file file file file number file file name ms mall o D ms o ms 3 y cr tn Multigrid Objects A Multigrid Object is a subclass of Group Object in which each member is constrained to have t
50. Processing Data Explorer provides the capability of distributing the execution of a visual program or a program generated using the scripting language over multiple workstations on a network Distributing the execution provides parallelism and enhanced resource utilization Parallelism is achieved by the simultaneous execution of different portions of the visualization on each of the workstations Enhanced resource utilization can be achieved for example by assigning computationally intensive portions of the visualization to the more powerful workstations or transformation and realization functions that are applied to data located remotely can be distributed to the remote workstations reducing the amount of data transfer Distributed processing is achieved in two ways using outboard modules or placing groups of tools into execution groups These two methods can be used independently or in combination An outboard module is a user written module controlled by the Data Explorer executive but is external to the Data Explorer server program They can be invoked from either a visual program or a script program Execution groups are a set of tools that can be assigned to a workstation Once groups are created they can be assigned to the workstations over which the visualization is to be distributed More than one group can be assigned to each workstation See also 9 1 Using Distributed Computation on page 178 Chapter 4 Data Explorer
51. Reducing Memory Requirements If after using the memory option as described above you find you still lack sufficient memory to perform your visualization there are a number of strategies that can be used to reduce the amount of memory that is required by your program Do Not Render Images A common mistake is to render image data i e 2 dimensional grids using Render Image or Display with a camera input This results in Data Explorer interpreting the image as a very large number of quads in which case much memory and CPU is used Instead one can AutoColor or Color the image and pass it directly to Display without a camera input or for even more memory savings convert the data to unsigned bytes see below and AutoColor or Color the data with delayed colors see below Delayed Colors If you are coloring your objects using AutoColor AutoGrayScale or Colormap Color you might want to use delayed colors To do this convert the data component to unsigned bytes and set the delayed parameter of the coloring module to 1 Using delayed colors means that rather IBM Visualization Data Explorer User s Guide than a 3 vector being used for each data point a single scalar byte is used to index into a color table with 256 entries If you are using Readlmage you may want to set the DXDELAYEDCOLORS environment variable See Readlmage on page 250 in IBM Visualization Data Explorer User s Reference Converting Data Types n ma
52. The pokes picks and pick paths components are created as part of the picking process as implemented by the Pick tool A user writing a module that uses the pick structure output by the Pick tool is expected to use the pick structure manipulation routines as described in BM Visualization Data Explorer Programmer s Heference rather than accessing the pick structure directly The contents of the pick structure are not defined Standard Attributes The standard defined attributes are listed in Table 2 and Table 3 and are further described in the subsequent paragraphs Attributes associated with rendering properties are described under the Display module in Chapter 1 Data Explorer Tools on page 1 in BM Visualization Data Explorer User s Reference Table 2 Component attributes Attribute Mei sep component that this component depends on interpolation method for connections component Oh rammoo O OOOO ras E Chapter 3 Understanding the Data Model 25 O y cr y o O D m Figure 7 Use of Faces Loops and Edge Components Table 3 Page 2 of 2 Object attributes mark every mark scale fuzz ambient diffuse specular shininess shade opacity multiplier color multiplier texture direct color map cache rendering mode rendering approximation render every pickable marked component dep Attribute The Relevant module Plot Plot Display Render Image Display Render
53. The window will shrink or expand vertically as you drag the border e Drag on one of the vertical borders The window will shrink or expand horizontally as you drag the border e Drag on one of the corner borders The window will shrink or expand both vertically and horizontally but not necessarily in a uniform fashion as you drag the border Selecting Pull Down Menus and Pull Down Menu Options 62 To use the mouse to see the list of options a pull down menu offers select the pull down menu s title from the menu bar by moving the cursor to the appropriate title and clicking on it The menu is displayed To then select an option from the window move the cursor to the desired option and click on the option Alternatively select an option with the mouse by moving the cursor to the desired menu title and pressing and holding the mouse button The pull down menu IBM Visualization Data Explorer User s Guide appears Then move the cursor to the desired option and release Each option is highlighted as you move the cursor across it To select a pull down menu with your keyboard press the ATt key in conjunction with the underlined letter of the pull down menu name usually the first letter For example if you want to open the File menu whose title appears in the window as File press ATt F Once the pull down menu is displayed you can select an option by pressing the key corresponding to the underlined letter of the desired option
54. XXIX Changed Modules 0 20000 XXX NEWIMGOCUIES asas E aria y A QU tie XXXi Backward Incompatibilities 0000000008 xxxiii MIME DOCUMENAIOM 42 dae dud v he ee Se ek Oe ES SESS See s XXXIV FIXOS Geldo mo Oe e RS ee Ee o de de se SIR XXXIV Chapter 1 Overview ln 1 1 1 Overview of Data Explorer llle 2 1 2 System Structure 2 ee 3 Graphical User Interface 0 000000 000058 3 EXCCUIINNO uus wet coy de weed PNE eb Be vice da he de edo 4 MOGUIES si xit eodem B REOR ESS d ES B IE tetra di des 4 Data Management lll 4 How the Data Model Facilitates Interoperability 4 Chapter 2 Introduction to Visualization 7 2 1 TEMDO quee pro ROSE EUR S A e ey d Be ADE 8 PIGH sedes nen Spp ce Mad Meets Boe d de a 8 Positions and Connections Dependence 8 Connections and Interpolation cnn 9 Copyright IBM Corp 1991 1997 lii identifying GolecllorS acs X ier oven aph boas eh ewe PSS Set gs 11 Invalid DATA ii mE b RE 445 PEEG Pu ed AR 12 FEIOS siri Se eee es as BOER e MEAS a eee ees 12 2 2 Visual Programming The Basics 13 Chapter 3 Understanding the Data Model 15 3 1 Introduction to the Data Model 16 de ODbIeGF TYDES os ias AE AB Y OA SS 17 nl LIT 17 Du ME TT TET Se So hace
55. a header section a data section or both The header section defines a set of Objects the data for which are contained in the data section or imbedded in the header Each type of object that can be defined is described in the following subsections Header Section The header section of a Data Explorer file consists of a sequence of Object definitions Each Object definition consists of a sequence of clauses beginning with an object clause The clauses defining an Object can be in any order except that the type and size information for an Array must be specified before the data if the data are imbedded in the header A clause consists of a sequence of words separated by one or more blank spaces or new lines Line breaks are not significant except after the follows keyword when data must follow on the next line Multiple clauses can occur on one line and a single clause can be split IBM Visualization Data Explorer User s Guide Objects across lines The following sections describe each of the types of Objects that can be defined In these descriptions the monospace font specifies literals italics non literals square brackets optional items and a vertical list alternatives In the header section and text data sections is the comment character All text from to the end of the line is ignored Data Section The data section is used for Array data when either an offset in the current file or in a separate file is specifie
56. a strawberry as it passes through the gelatin your eyes will detect an orange object with a distinct outline which of course enables us to find the location of the strawberries in the volume of gelatin The strawberry appears orange because its red color is partly occluded by the yellow gelatin nevertheless our brains convert the strawberry color back to red because it is a familiar object If someone has added a fruit unfamiliar to you you will have a hard time identifying the true color of the fruit since our brains are not good at performing subtractive color calculations Volume rendering a data space yields an image something like our bowl of gelatin By default a volume rendering appears somewhat transparent As light passes through from behind the volume toward your eye it is absorbed more in areas of densely concentrated values These areas will appear to be more opaque If you color map your volume according to the data component you will see indistinct colored areas in their relation to each other For more detail on the dense emitter model used by Data Explorer see Opacities Component on page 23 c tn D m mi mall o gt cr tn If we are looking for those areas of rain formation within a rain cloud data volume we do not have a built in conception of the correct color for such an area The colors assigned will come from the color map we construct If we map the 12 degree C area to red as in the e
57. a visualization program to another user Simply look at the top of the net file for the list of referenced macros You can configure Data Explorer to automatically load macros from a specified directory when you begin the Data Explorer program To do this use the macros pathlist option when starting Data Explorer where pathlist specifies one or more paths where the macros can be found Alternatively you can use the DXMACHOS environment variable For more information on how to do this see Using Environment Variables on page 59 and C 1 Environment Variables on page 292 Using Macros in a Visual Program After you have created and loaded a macro you can use it the same way you use other Data Explorer tools Simply select it from the tool palette and place the icon on the canvas Figure 78 on page 154 shows the new icon created for the MapAndDeform macro e c A o E cr o m ma o E D l tn Chapter 7 Graphical User Interface Control Panels Interactors and Macros 153 cade File Edit Execute Windows Connection Options Help E EE NN Macros Tools MapAndDeform MapAndDetorm Figure 78 MapAndDeform Macro Icon The macro has a Configuration dialog box describing the input and output parameters You can open the dialog box by double clicking on the macro icon Viewing and Changing Macros After you place a macro in a visual program it is possible to view the macro contents and to change some
58. also include this module See 9 2 Loading and Using Outboard and Runtime Loadable Modules on page 183 Quit Closes the Menu Bar window Menu Bar Execute Menu This execute menu is identical to that of the Visual Program Editor window See VPE Execute Menu on page 160 for descriptions of the Execute options See also 5 4 Executing a Visual Program on page 67 Menu Bar Connection Menu The Connection menu allows you to monitor and control communication functions between the workstation and the server The Connection menu lists the following options Start Server Connects the user workstation to the server For more information see 9 3 Connecting to the Server on page 183 Disconnect from Server Disconnects the user workstation from the server Reset Server Flushes the cache forcing the visual program to reaccess the data on the server the next time it executes See Resetting the Server on page 185 Execution Group Assignment Displays a dialog box that allows you to assign execution groups to specific machine host names See Assigning Execution Groups to Workstations on page 181 Chapter 8 Graphical User Interface Menus Options and the Message Window 171 Menu Bar Windows Menu The Windows menu allows you to open a VPE window containing the program layout or the Control Panels associated with the visual program All windows created from this Image window become its children Quitting the Im
59. and flexible animation capability The sequencer outputs a frame count which is updated with each new execution The user controls the behavior using a VCR like interactor see Using the Sequencer on page 68 The first time the Sequencer is played it causes the network to be executed with each value for the Sequencer output Each execution which may be time consuming will result in a new image being generated These images are simply the result of a rendering module and will be retained in the cache When the Sequencer is replayed the inputs to the network are the same as they were for one of the frames in the first set of executions Thus the result of the execution an image will be immediately available from the cache Hence Data Explorer provides an automatic mechanism to create real time animations even when the computation of each frame is slower than real time The value produced by the Sequencer can be used in a number of ways The Sequencer may be used to iterate through a time dependent data set causing the visualization to operate on each time step in turn resulting in an animation showing Chapter 4 Data Explorer Execution Model 43 how the data vary with time As another example the Sequencer could be used to drive the isovalue input to the Isosurface module 4 5 Iteration using Looping Figure 21 Example 4 The sequencer provides a basic loop however it has some limitations Only one sequencer
60. and the first occurrence of the data file will be used An example of a statement that sets the DXDATA environment variable in the C shell environment is the following 10 n m mall o O cr mall o E Q r o E Q e y e D setenv DXDATA usr mydirectory mydata usr group groupdata where usr mydirectory mydata and usr group groupdata are two directories that contain data files Multiple directories can be listed with each directory name separated by a colon DXHOST The DXHOST environment variable is the initial machine name of the server on which to run the executive If DXHOST is not specified then a default of localhost is used See 9 3 Connecting to the Server on page 183 for more information on how to connect to the server The host name should be the name that results when you issue the uname n shell command DXINCLUDE f this environment variable is set Data Explorer looks for included scripts first in the current directory and then in each of the directories specified in the colon separated list specified by this variable DXMACHROS The DXMACROS environment variable is a list of the directories in which Data Explorer will look for macros 10 2 Understanding the Script Structure The following example illustrate some of the more important characteristics of scripts a detailed description of each of the elements follows However you may prefer to simply study these examples and perhaps
61. and the name field is grayed out and this input cannot be modified until the connecting line is deleted Value You use the Value field to specify a value for an input Initially the field contains the default value for an input To modify the Value field select the field by clicking on it Then edit it as a normal text field The value must be specified in the syntax described in Chapter 10 Data Explorer Scripting Language on page 187 After you change the field do one of the following e Press Enter which automatically activates the toggle button if it is not already activated e Activate the toggle button by clicking on it e Click on either the OK pushbutton or the Apply button at the bottom of the box see button descriptions in Pushbuttons on page 110 Data Explorer automatically adds the appropriate delimiters for the type of value entered For instance if you specified a string parameter in the Configuration dialog box Data Explorer automatically adds the quotes around it If you specified a scalar list Data Explorer adds braces Note If a source is displayed you cannot modify the Value field If you have modified the Value field and you want to use the default value release the toggle button With the toggle button you can flip between the modified value and the default value Chapter 6 Graphical User Interface Important Windows 109 This button when enabled brings up a list of possible values for t
62. and therefore the outputs of a macro containing GetGlobal are no longer entirely defined by the inputs The outputs from macros with state containing a GetGlobal module are guaranteed to stay in the cache until the inputs for that macro change At that point the results of the previous execution are discarded to make room for the new results This is equivalent to setting the cache attribute of the macro to cache last for each of the outputs These cache settings cannot be overwritten by the user This guarantees coherency when executing macros with state Chapter 4 Data Explorer Execution Model 49 m gt lt D ie S ct mall o le gt o x D 4 7 Advanced Looping Constructs 50 Combinations of the modules described above enable you to create advanced looping constructs These constructs are equivalent to C language constructs such as do while or for loops containing break and continue statements In the following figures the Sum and Increment macros as described above are used as well as a macro named Equals that consists of a Compute where the expression is a b 1 0 if the inputs are equal output 1 otherwise output 0 Illustrated in Figure 25 on page 51 is a macro that computes the sum of numbers from 1 to N If a number in the sequence from 1 to N is equal to an external input x the loop terminates and returns the sum from 1 to x Done in combination with Equals is used to cause early terminat
63. architecture specific README in usr Ipp dx by default Data Explorer will be allowed to grow to use all but 8 megabytes of the physical memory when there is less than 64 megabytes of physical memory If there are more than 64 megabytes of physical memory then Data Explorer will by default be allowed to grow to 7 8 of the amount of physical memory Users may wish to alter this default amount of memory by using the memory option to the dx command or the Memory field of the Connect to Server Options dialog box Paging Space Since it is possible for Data Explorer to use a large amount of virtual memory users should configure systems with paging space at least two or three times the total physical memory in their system If you do not have enough paging space the operating system may kill Data Explorer or other processes sometimes without warning depending on the architecture Your system administrator can increase your paging space Per Process Limits Some systems may enforce per process limits on such things as data segment size stack size and so forth These may need to be adjusted to run Data Explorer with large amounts of memory to avoid paging Your system administrator can adjust your per process limits IBM Visualization Data Explorer User s Guide A 2 Visualization Techniques Animation Now we have our data in a Field Object inside Data Explorer What can we do with it This section discusses some common visualiz
64. as are the second two type is the type of the values and should be one of the following byte int short unsigned byte signed int signed short signed byte unsigned int unsigned short Note that in each of the three groupings shown here the first and second reading down are equivalent to each other bytes lines and marker specify where to begin reading the grid values skip and width are optional and should be used when two pieces of information are on the same line with other information separating them see Example 2 If necessary different portions of the grid specification can be read separately by repeating the bytes lines or marker specification see Example 3 242 IBM Visualization Data Explorer User s Guide Example 1 Suppose that the data file contains the following first line dimensions 100 300 You can specify that this information is to be derived from the data file by the following statement grid lines 0 11 3 1 3 This specifies that O lines are to be skipped Then 11 characters are skipped and the first grid dimension is read from 3 characters Then 1 character is skipped and the second grid dimension is read from 3 characters You could also have used the statement grid bytes 11 which simply specifies that the grid information will be found after skipping 11 bytes in the file Example 2 Suppose the that data file contains the following line not at the top of the file xdim 5 ydim
65. be retrieved by name or by index number the n members of a Group are numbered from O to n 1 Group members can also be stored by index number without a name in which case they can be retrieved only by index number The members of a Group are always numbered consecutively starting at 0 and gaps in the numbering are not allowed In addition to generic Groups used to collect related information there are three subclasses of Group used to combine related Objects with additional semantics Multigrid Groups Composite Field Groups and Series Groups Multigrid Groups It is often necessary to represent a Field as a collection of separate Fields each with its own grid For example this is the case in some kinds of simulations using multiple grids The data structure used to hold such Fields is a subclass of Group called a Multigrid Object It is the same as a generic Group in most respects except that it requires all members to be Fields holding data of the same type The connections component of each member must also be of the same type Grids may be completely disjoint or may overlap For overlapping grids the invalid positions or invalid connections components may be used to define which grid is valid in a particular region 34 IBM Visualization Data Explorer User s Guide Composite Field Groups A Composite Field is another kind of Group that is treated as a single entity For example parallelism in Data Explorer is achieved by ex
66. c2 Camera NULL NULL NULL NULL NULL NULL NULL NULL NULL c3 Camera c4 Camera NULL NULL NULL NULL NULL 0 1 0 NULL NULL c5 Camera up 0 1 0 c6 Camera 5 5 5 0 O 1 NULL to 0 0 0 c7 Camera width 512 width 640 Function Call Attributes Functions may optionally have attributes associated with each invocation of the functions and attributes may also be associated with specific outputs of a module The Data Explorer scripting language provides three function call attributes 202 instance cache IBM Visualization Data Explorer Identifies the instance of a function call This can help you locate errors in scripts To use the instance attribute follow the function call with instance and the instance number separated by a colon and enclosed in brackets For example outl Color surface blue instance 1 out2 Color surface green instance 2 In this example each instance of the Color module is identified uniquely If an error occurs the error message will report the module name in this case Color plus its instance number If the instance numbering was not used the error message will only report the name of the module Specifies whether the system writes the outputs of a module into the cache The cache is a portion of memory in which results of previously executed functions are stored If the inputs to a module do not change the module will not be
67. cache their own data The Display and Image tools are such tools When using software rendering they cache the images they display in the X windows This is an optimization that can be seen when using the Sequencer When this tool starts repeating itself in loop or palindrome mode the images are displayed much faster That is Display or Image is pulling them out of the cache instead of rerendering the input objects each time You can observe this effect by running the example program MovingCamera net with software rendering Most of the time this caching behavior is desirable but in some cases it is better turned off To do that use the Options module to add a cache attribute with the integer value of O zero as follows o Options o cache 0 Display o camera The Image tool s Configuration dialog box has an option menu that lets you control its caching This can be useful when one is running a batch job to generate an animation in which none of the frames will be displayed a second time Note that the cache off command line option mentioned above has no effect on the internal caching that modules themselves perform Note You can use the Data Explorer command line option optimize memory which will automatically set the DXDELAYEDCOLORS and DXPIXELTYPE environment variable to the options that consume the least memory The alternative is optimize precision System Tuning Default Memory Size Except where noted in the
68. calling mechanism e he outputs portion of a macro s header is a list of identifiers separated by commas These identifiers act as place holders for the values returned by the macro when the macro is executed If the macro does not return any values then the right arrow portion gt is not necessary The macro body consists of a sequence of assignment statements and function calls surrounded by braces The functions referred to in these statements need not exist when a macro is defined however they must exist when it is executed Recursive and mutually recursive macro invocations are detected and prevented from executing Statements are not guaranteed to execute in the order given in the macro s declaration although some partial ordering is always preserved Calls to modules that cause external side effects such as Display are always executed in the order in which they were specified Macro Examples The first example macro Sum takes two arguments The macro computes and returns their sum macro Sum argl arg2 gt sum Sum argl arg2 The second example macro PrintSum also takes two arguments and computes their sum However unlike the macro Sum it does not return the computed value Instead it prints out using the Echo module This example illustrates a function call to Echo that either does not return a value or whose return values are ignored macro PrintSum argl arg2 Sum argl
69. children Quitting the Image window causes all of its child windows to close Before the window closes a dialog box appears to request confirmation The Windows menu offers the following options Open Visual Program Editor Opens a VPE window containing the current visual program This option is disabled if you have not loaded a visual program or if the VPE is the anchor window Open All Control Panels Opens all the Control Panels and macro Control Panels for the current visual program unless the macro Control Panels are already contained in another Control Panel This option is disabled if you have not loaded a visual program IBM Visualization Data Explorer User s Guide Open Control Panel by Name Opens a cascade menu from which you can select the name of the control panel to open Open All Colormap Editors Opens all the Colormap Editors for the current visual program See 6 3 Using the Colormap Editor on page 119 Open Message Window Opens the Message Window that displays error and warning information about your execution See 8 2 Using the Message Window on page 174 Image Window Connection Menu The Connection menu allows you to monitor and control communication functions between the workstation and the server The Connection menu lists the following options Start Server Connects the user workstation to the server For more information see 9 3 Connecting to the Server on page 183 Disconnect fro
70. constants have the following characteristics e hey are delimited with double quotes e They can be up to 4000 characters long e They may extend over multiple lines providing that the last character on each line except for the last line is a backslash For example the following lines a 123 456 are equivalent to a 123456 You can use the following escape sequences to include special characters in a string constant Description Character Escape Sequence newline NL LF n horizontal tab HT t vertical tab VT Ww backspace BS Ab carriage return CHR r formfeed FF f audible alert BEL a backslash question mark single quote V double quote octal number 000 ooo hex number hh xhh The following are examples of valid string constants an empty string this a string amp _ Chapter 10 Data Explorer Scripting Language 193 194 Scalar Numeric Constants Scalar numeric constants are sequences of numeric characters that can be used in two ways e As values themselves e As components of a vector matrix tensor or list There are two kinds of scalar numeric constants e Integer e Floating point The following sections describe these constants Integer Integers are the set of counting numbers or their negatives e g 0 1 2 By virtue of their 32 bit internal representation integer values range from 231 to 231 1 They can be prefixed with a minus s
71. contents are ordered as described in Arrays on page 28 Colors Front Colors and Back Colors Components The colors front colors and back colors components are a means of specifying another specialized type of dependent data Specifically the renderer requires that each object in a scene have at least one of these components The front colors and back colors components specify colors to be associated with the front and back sides respectively of a surface The colors component specifies colors to be associated with both sides of a surface or with a volume If only front colors or only back colors are specified then only the front or back sides respectively of the polygons are rendered If present front colors or back colors override the specification of the colors component Each item of a color component Array consists of three floating point numbers specifying the red green and blue component of a color respectively The color components can use the entire floating point range but by convention the range from O to 1 is mapped onto the available range of the output device Like the data component the color components can be position or connection dependent IBM Visualization Data Explorer User s Guide The front of a triangle is defined to be the side such that the path traversing the vertices in the order that they are listed for the triangle appears to go counterclockwise The front of a qua
72. control over a parameter value The user interface ensures that each instance of the interactor is consistent If you change a value in one instance it changes in the others Selecting Moving and Deleting Interactors To select an interactor click on it To select a group of interactors use one of the following methods e Hold down the Shift key and click on each interactor in turn e Position the mouse pointer on the canvas near a corner of the group and drag the mouse to draw a selection box around the interactor you want To select an interactor you must completely enclose it in the selection box As an interactor is encompassed by the selection box it is highlighted indicating that it is selected To deselect an interactor shift click on It To deselect a group of interactors use one of these methods e Shift click on each interactor e Shift drag to draw a box around the interactors you want to deselect As a selected interactor is encompassed in the box it becomes unhighlighted Release the button to deselect the interactors Note Clicking on an empty part of the layout area deselects all selected interactors To move an interactor 1 Depress the mouse button on the interactor and drag it to the desired location While the mouse button is depressed an outline of the interactor follows the motion of the mouse but the interactor remains in the original location 2 Release the mouse button The interactor moves to
73. data 0 0 5 3 O CO Ooo eo 0 0 0 0 0 05 0 5 0 O 0 0 0 0 0 03 netCDF on completely regular grids can be imported directly by Data Explorer without modifying the netCDF file See B 4 netCDF Files on page 281 for more information B 5 netCDF Files Complex Fields For data with more complex structure conventions have been established for netCDF variable attributes as described in the format below The notation used corresponds to that of the netCDL language Irregular Arrays 282 This section describes how to specify netCDF variables for components with irregular values Data To indicate that a netCDF variable contains values corresponding to the data component it must have the following attribute variablel field fieldname Variable is the name of the netCDF variable containing data values to be imported fieldname is the name of the Data Explorer field by which the user refers to the data for example temperature pressure wind If more than one variable is tagged with the same field name each variable is read into a field and the fields are collected into a group The data are read in as an array of values one number per grid point If the data are actually a vector or a matrix at each grid point use one of the following modifiers e variablel field fieldname vector e variablel field fieldname matrix The non scalar data are stored in a
74. display and changes have been made a dialog box appears for applying wanted changes Save As Saves the current Colormap configuration as the name typed into the dialog box that appears Close Closes the Colormap window IBM Visualization Data Explorer User s Guide Colormap Edit Menu The Colormap Edit menu displays the options used to edit the current color map The following options appear on the Edit menu Undo Returns an operation to its previous value Undo retains a stack of 10 operations Copy Copies selected control points to a buffer so that they can be pasted to another field See Copying and Pasting Control Points on page 124 Paste Pastes selected control points to a different field See Copying and Pasting Control Points on page 124 Use Application Default If the Colormap Editor is data driven it is still possible to override its data driven values by explicitly setting them in the Colormap Editor The Use Application Default option restores the data driven values It generates a cascade menu with four suboptions Color HSV Map If a color map was provided to the color map tab of the Colormap tool and was subsequently modified by the user i e adding moving or deleting control points selection of this suboption restores the original color map Opacity Map If an opacity map was provided to the opacity tab of the Colormap tool and was subsequently modified by the user i e adding moving or deleti
75. down menu A dialog box appears similar to the one shown Figure 62 on page 136 3 The procedure for modifying the choices in this list is similar to that for modifying the list elements in a list interactor see List Interactors on page 145 To enter a value in this interactor click on the Value box enter a value and press the Enter key Then click on the Label box type a string and press the Enter key For more information about how to modify add and delete elements see List Interactors on page 145 Note If you wish to change the type of the values in the value field for example entering values other than integers when initially configuring the interactor you must first delete all the entries in the Set Attributes dialog before entering new ones This is required since the type of all values must be the same 4 When you are finished modifying the choices click on OK to apply the changes Because the selector interactor yields both the value and the string as outputs you can use either output or both in a visual program In the selector stand in the output on the left is the value while the output on the right represents the string Changing the Label on the Interactor The default label on any unconnected interactor is the name of the interactor stand in If the interactor is connected to one input the default name of the interactor is the name of the tool followed by the input parameter name f the interact
76. e e La DS de E as 144 70 String Interactor len 144 71 Sample Vector List Interactor rn 145 72 Selector Interactor Radio button Style 146 73 FileSelector Interactor llle 147 74 File Selection Dialog Box llle 148 79 Example or MACIO x ds mess eme PAA ERE A deat 150 76 Input Configuration Dialog Box lll 151 77 Macro Name Dialog Box 152 78 MapAnaDeform Macro Icon 2 2 0000058 154 79 Execution Group Dialog Box 179 80 Execution Group Assignment Dialog Box 182 81 Start Server Dialog BOX 2 2 0 6 66464 lE VI 184 82 Start Server Options Dialog Box 184 83 Data Imbedded in a Header Section 245 84 Header Referring to Data in Another File 245 85 Header and Data in the Same File 246 86 Regular Grid Example 248 87 Regular Skewed Grid Example 249 88 Warped Regular Grid Example 250 89 Irregular Grid Example 252 90 Product Array Example with Irregular Points in the XY Plane 256 91 Product Array Example with Irregular Points in the Z Direction 257 92 Example of Faces Loops and Edges 263 93 Example of Faces Lo
77. execution If so then you can certainly replace your Get and Set by GetLocal and SetLocal and the First module is no longer necessary as GetLocal automatically resets on each new execution See GetLocal on page 151 SetLocal on page 300 GetGlobal on page 149 and SetGlobal on page 299 in BM Visualization Data Explorer User s Reference for more detailed information Assign Get Set Scope gt Convert All modules under the Edit pulldown in the VPE is available for helping change Get Set modules to the new GetGlobal SetGlobal GetLocal SetLocal options New Window Management Functionality The SuperviseWindow and SuperviseState modules see SuperviseState on page 332 and SuperviseWindow on page 336 in BM Visualization Data Explorer Users Reference implement important new functionality for users allowing you much more control over the effect of mouse and keyboard actions in a Display window This allows you not only to define the behavior for given mouse or keyboard events but also allows you to implement direct interaction without the use of the Image tool Thus direct interaction is now possible without the Data Explorer User Interface Hardware Rendering DXLink True transparency is now supported for OpenGL platforms previously only screen door transparency was supported Anti aliasing of lines and multiple pixel width lines is now supported in OpenGL and GL To specify anti aliasing of lines pass the o
78. for you by the Glyph or AutoGlyph modules A vector Field like any Field must have a positions component to identify where the vector valued data was sampled even if the data is connection dependent it still requires positions For Glyph realizations a connections component is not required but it may exist if the Field contained it for other purposes Of course a data component containing a vector quantity is needed Each vector glyph will point in the direction of the vector given by the datum at that point with the base of the vector fixed at the vertex position sample point for position dependent data The base of the vector is located at the center of the connection element for connection dependent data The length of each vector glyph is scaled based on the vector magnitude relative to all the other vectors in the data Field Glyph and AutoGlyph offer a number of modifications you can make to achieve the appearance you desire The effect of glyphing a vector Field is to create a porcupine plot with lots of arrows sticking out in various directions This can become hard to interpret if there are many vector data points or if one area of your data has very large values the vectors may intersect or occlude each other You can use the Reduce module in the Import and Export category to downsample the original data Field and thereby decrease the number of vectors in the image Picking a reasonable reduction factor will permit the vi
79. image is created by applying data as input to a visual program The visual program is a sequence of interconnected functions acting on one or more inputs and producing one or more outputs Typically input is user data and output is a realization of that data in the form of an image Data Explorer consists of the following windows Startup Window You can use the Startup window to access other windows in Data Explorer Visual Program Editor You can use the Visual Program Editor VPE to create and alter visual programs and macros Control Panel You can use Control Panel windows to set and control the input parameters of visual program tools Image You can use the Image window to view an image created by Data Explorer Colormap Editor You can use the Colormap Editor to map colors and opacity to specified data Sequencer You can use the Sequencer to advance through a data series or to step through a changing sequence of input parameters Message Window You can use the Message window to access error and working information about your execution Help You can use the Help window to access online documentation Data Prompter A graphical user interface that simplifies the import of data Module Builder A graphical user interface that simplifies the process of adding modules to Data Explorer For information on the Data Prompter see BM Visualization Data Explorer QuickStart Guide on the Module Builder BM Visualization D
80. in the RGB format by using the Readlmage module This example illustrates the different aspects of header files First describe the positions The image is written such that x varies fastest and the first pixel in the file is the one that is to be displayed at the top left Because x varies fastest the last delta specifies a vector in the x direction Because the first pixel is at the top left the delta in the y direction is 1 object 1 class gridpositions 300 350 origin 0 0 delta 0 1 delta 1 0 Next describe the connections The image is 350 pixels in x and 300 pixels in y Since x is the last delta specified the connections are specified as 300 x 350 object 2 class gridconnections 300 350 attribute ref string positions attribute element type string quads Next indicate that the data can be found in the file cylinder rgb starting at byte 0 There are three bytes red green and blue for each pixel object 3 class array type byte rank 1 shape 3 ieee msb items 105000 data file cylinder rgb 0 attribute dep string positions We read the colors in as the data component This allows us to immediately begin operating on them for example to convert the bytes to floating point colors object image class field component positions 1 component connections 2 component data 3 Syntax of the Native File Format 268 A data file in the Data Explorer native format can contain
81. in which an imported data field is represented So for example you can e create an isosurface contour lines of a mapped isosurface e create an isosurface from an image e map onto glyphs streamlines isosurfaces etc The Data Model also ensures that the fidelity of the original data is maintained throughout the visualization process In particular all of the following are preserved throughout e the original coordinate space of the data e the original range of data values not scaled to O to 255 for example attributes of the data dependency on positions or connections e the presence of missing or invalid data Finally the data model ensures that Data Explorer users and developers can add new components or new attributes without modifying current modules Chapter 1 Overview 5 e lt D m lt mall o D z 6 IBM Visualization Data Explorer Users Guide Chapter 2 Introduction to Visualization 25 Temo tanta e ca ta ete OR GS Shee POP SLE RAS 8 ae PTT 8 E Positions and Connections Dependence 8 a Connections and Interpolation 0 0 0000000004 9 5 Identifying Connections 0000 2 cee ee 11 valid Data stress pes bed be ee oe E Bd eae ee 12 mco WP 12 2 2 Visual Programming The Basics aaa aaa a 0008 13 T Copyright IBM Corp 1991 1997 This chapter is not a substitute for the detailed information in the rest of this Guide but it does summarize
82. interactor stand in on the VPE canvas 2 Press the middle mouse button while the cursor is positioned on the stand in icon 3 Drag the cursor to the Control Panel and release the mouse button 4 The interactor appears at the new location You can add more than one interactor at a time to a Control Panel To do this select multiple interactor stand ins on the VPE canvas then select Add Selected Interactor s in the desired Control Panel After doing this you can use the mouse to place the interactors in the Control Panel one at a time They are placed in the Control Panel in the same order that they were placed initially onto the VPE canvas Similarly you can drag and drop multiple stand ins from the visual program to a Control Panel You can also drag and drop interactors from one Control Panel to another as long as both are associated with the same Data IBM Visualization Data Explorer User s Guide Explorer session For more information on drag and drop see Moving and Copying Tools on page 105 You can put the same interactor in more than one Control Panel and in the same Control Panel more than once For example you may want to have one Control Panel that contains all the interactors for a visual program and another that contains only the most frequently used interactors You can also place multiple instances of an interactor with different styles or step size increments in one Control Panel This provides both coarse and fine
83. is identified by an anchor symbol in the top left corner When this window is closed the Data Explorer session ends architecture The organizational structure of a computer system including hardware and software array In Data Explorer an array structure containing an ordered list of data items of the same type along with additional descriptive information Arrays are either compact or irregular See compact array irregular array assembly An object representing a collection of objects attribute A characteristic of an object Objects can have attributes that are indexed by a string name and have a value that is an object See also component attribute C camera An object that describes the viewing parameters of an image e g width of the viewport viewers location relative to the object and the resolution and aspect ratio of the image A camera may be explicitly defined and passed as a parameter to the Render or Display module It may also be implicitly defined in the use of interactive mouse driven options such as zoom or rotate in the Image window canvas The area of a VPE window used in building and editing visual programs cell centered data Connection dependent data clipping plane A plane that divides a three dimensional object into a rendered and an unrendered region making the object s interior visible Copyright IBM Corp 1991 1997 colormap A map that relates colors to data values The col
84. is used to study a dynamic vector Field Streakline is equivalent to taking a series of snapshots as our styrofoam balls and streamers or just the balls without streamers if you like fly through the vector Field but with the additional fact that each time we take a snapshot we import the next time step of our Field That is at each moment we provide new data for vector direction and intensity at each sample point As a result you would expect the direction and speed of the balls and streamers to change as their flight is affected by the changing Field This technique is often referred to as particle advection Note that both Streamline and Streakline perform interpolation so both modules require that your input vector Field has positions data and a connections component IBM Visualization Data Explorer User s Guide Volume Rendering Another way to examine data collected throughout a volume of space is called volume rendering Imagine a glass bowl full of lemon gelatin Holding it up to a light you can see through the gelatin because it is somewhat translucent Now imagine that you have added strawberries to the bowl of gelatin before it set up You can see the strawberries embedded in the gelatin What is really happening visually Light shines through the mass of gelatin accumulating color If you look through the top corner it will appear somewhat less yellow than if you look through the thickest part If the light strikes
85. menubar mode metric Set the graphical user interface to use metric units whenever possible modules pathlist Set list of directories to be searched for outboard modules morehelp Print complete Help including information about other options optimize Set the environment variables DXPIXELTYPE and DXDELAYEDCOLORS to optimize memory or precision The default is precision EM outboarddebug Enable user to start outboard modules manually pe program filename Start the user interface with visual program filename prompter Start the Data Explorer Data Prompter but not Data Explorer 296 IBM Visualization Data Explorer User s Guide memory precision Option syntax Function O Run the executive only i e in script mode script filename Run the executive only i e in script mode with script filename suppress Do not open any control panels at start up in image or menubar mode only med Start Data Explorer using a timed license EN timing on off Enable module timing default off BN trace on off Enable executive trace default off trialkey Automatically determines the information needed to generate a trial key e tutor Start the Data Explorer tutorial 0 wony Start the user interface only no executive verbose Echo command lines before executing them version Show version numbers of dxexec and dxui Table 6 Page 1 of 2 Command Line Option
86. messages displayed in the Message window Save As Saves the current contents of the Message window to the file named in the dialog box that appears Close Closes the Message window IBM Visualization Data Explorer User s Guide Message Window Edit Menu The Message window Edit menu displays the options used to edit the current Message window The following options appear on the Edit menu Next Error Displays and highlights the next error in the Message window and highlights the tool that reported it Previous Error Displays and highlights the previous error in the Message window and highlights the tool that reported it Message Window Execute Menu This execute menu is identical to that of the Visual Program Editor window See VPE Execute Menu on page 160 for descriptions of the Execute options See also 5 4 Executing a Visual Program on page 67 Message Window Commands Menu The Message window Commands menu displays the options for running specific commands The following options appear on the Commands menu Debug Tracing When enabled displays instance numbers on each tool in a visual program to distinguish between multiple instances of a tool and turns on tracing in the message window so that as each module is run its name and instance number is displayed Execute Script Command Allows commands to be issued directly to the server see Executive on page 126 in BM Visualization Data Explorer User s Reference
87. naming the positions component element type Attribute The element type attribute is an attribute of the connections component It is a String Object naming the type of the interpolation primitives See Connections Component on page 20 for a list of the possible values of the element type attribute label scatter mark mark every mark scale Attributes Specifies characteristics of a plotted line Affects the behavior of the Plot module See Plot on page 237 in IBM Visualization Data Explorer User s Reference for more information fuzz ambient diffuse specular shininess shade Attributes Specifies various rendering characteristics of an object Affects the behavior of the rendering modules Display Render and Image See Display on page 109 in BM Visualization Data Explorer User s Reference for more information opacity multiplier color multiplier Attributes Specifies opacity and color values for volume rendering Affects the behavior of the rendering modules Display Render and Image See Display on page 109 in BM Visualization Data Explorer User s Reference for more information texture Attribute Specifies a texture map which is to be applied to an object Affects the behavior of Display and Image See Display on page 109 in BM Visualization Data Explorer User s Reference for more information direct color map Attribute Specifies whether or not a direct color map should be used when displaying images
88. now be independently controlled You can use this option for example to save or print an image at a much higher resolution than is displayed on the screen You can also specify the number of pixels directly by setting the units of Image Size to pixels note that in this case it is meaningless to set the Output PPI Allows you to specify gamma correction applied to the output image The default is 2 For TIFF MIFF and PostScript image formats allows you to specify whether the image is saved in an image with colormap format For GIF image format this option is required by the format Allows you to choose from the set of available image formats For all formats other than the Postscript formats the following field is available Image Size If the Allow Rerendering button is set this field allows you to set the resolution of the output image to something other than that of the image displayed to the screen If one of the Postscript formats is selected then the following fields are displayed Image Dimensions IBM Visualization Data Explorer User s Guide Allows you to specify the size of the image on the page by default in inches Orientation Allows you to specify the orientation of the image to portrait or landscape or automatic which chooses the best for the given image Input Image Size opecifies the resolution of the image to be printed This field is enabled only if the Allow Rerendering button is toggled on
89. number of Control Panels for one visual program and you can also place a single interactor in multiple Control Panels The configuration of a Control Panel and the values of the interactors are saved when you save the visual program You can also customize Control Panels and save or restore them independently of the visual program e c El A o E ct m o m ma o E D md tn If you are going to control a tool input through an interactor in a Control Panel then you must first connect an interactor stand in to that input in the VPE Using a stand in as a tool input is an alternative to using the module s Configuration dialog box every time you want to change the value of the input Chapter 7 Graphical User Interface Control Panels Interactors and Macros 129 Placing Interactors in a New Control Panel To place interactors in a new Control Panel 1 On the VPE canvas select the interactor stand ins you want in the Control Panel other tools can be selected as well 2 Click on the New Control Panel option of the Windows menu This causes a new Control Panel to appear with the selected interactors in the layout area Each interactor is labeled with the name of the tool to which its output is connected unless its output is connected to more than one tool or not connected to any tool in which case the interactor is labeled with the interactor type e g an integer interactor is labeled with Integer You can also doubl
90. of the tools inside the macro TO open a macro 1 Select the macro icon by clicking on it 2 Select the Open Selected Macro s option from the Windows pull down menu A VPE window is opened with the expanded macro representation You can repeat these steps for any macros contained in the newly opened VPE until only modules are present in the window With the macro opened you can change the tools inside the macro However you cannot change the number or ordering of inputs or of outputs Changing the tool in a macro affects only the current visualization session If you want the changes to be permanent you must save the changed macro using the Save or Save As options lf you want to restore the definition of the macro to the way it was before you modified it close the VPE window containing the macro without saving and reload the macro from the main VPE window 154 IBM Visualization Data Explorer User s Guide Chapter 8 Graphical User Interface Menus Options and the Message Window 8 1 Using the Primary Window Pull Down Menus and Options 156 VPE Window Menu Bar 156 Control Panel Menu Bar len 162 Image Window Menu Bar 165 Colormap Menu Bar 168 Menu Bar Menu Bar 170 Message Window Menu Bar lle 172 8 2 Using the Message Window
91. on page 67 6 1 Using the Image Window on page 74 6 3 Using the Colormap Editor on page 119 7 1 Using Control Panels and Interactors on page 128 Chapter 10 Data Explorer Scripting Language on page 187 presents a more traditional approach to creating data visualizations In this connection see also Chapter 1 Data Explorer Tools on page 1 in BM Visualization Data Explorer User s Heference Appendix A Using Data Explorer Some Useful Hints on page 211 describes some of the ways to use Data Explorer more effectively Appendix B Importing Data File Formats on page 241 discusses various data formats that Data Explorer can import including Data Explorers native format The remaining appendixes contain information of varying interest to different users Appendix C Environment Variables and Command Line Options on page 291 Appendix D User Interface Configuration on page 299 Appendix E Data Explorer Fonts on page 307 Appendix F Data Explorer Colors on page 313 Appendix G Accelerator Keys on page 315 Typographic Conventions Boldface Identifies commands keywords files directories messages from the system and other items whose names are defined by the system Italic Identifies parameters with names or values to be supplied by the user Monospace ldentifies examples of specific data values and text similar to what you might see displayed or might type at a key
92. on the bar between the arrows and move it until the desired portion of the visual program is displayed Scroll bars may also appear in the tool palettes if the list of categories or tools are too long to fit When you place a tool onto the canvas it is represented by an icon Figure 48 illustrates an example of a tool icon Visual Program Editor 2 do File Edit Execute Windows Connection Options Help Categories Untitled Interactor Interface Control Realization Isosurface Figure 48 Example of a Tool Icon The tool icon which has a highlighted border when selected consists of a rectangle displaying the name of the tool plus one or more tabs on the top the bottom or the top and the bottom of the rectangle The rectangle is the active area and is used for selecting and moving the tool The tabs on the top represent inputs to the tool and the tabs on the bottom represent outputs It is possible for a tool to have either no inputs or no outputs Some of a tool s input tabs may be hidden i e not displayed It is possible to reveal the hidden tabs or hide additional tabs It is also possible to add or remove input tabs for tools that allow a variable number of inputs On many tools one or more of the inputs are highlighted with a different color indicating that the input is required These tabs are discussed in more detail in Specifying Values for a Tool s Inputs on page 103 The basic steps in creating a visua
93. operator is applied in turn to each of the elements of the larger list and to that single element to produce a list whose size is the same as the larger list If both of the elements in an operation are the same type either integer or floating point then the result of the operation is also of the same type If however one of the elements is an integer and the other is a floating point value then the result is a floating point value Given this automatic type conversion a simple way to convert an integer value to a floating point value is to add 0 0 to it Operators The operators listed in the following table can be used in arithmetic expressions In the table a horizontal line separates each precedence level and the higher levels are placed above the lower ones Operators with higher precedence are evaluated before those with lower precedence Operators with the same precedence are evaluated from left to right Because expressions in parentheses are evaluated first you can use parentheses to alter the grouping of operands thereby changing the precedence levels p unary minus o e Exponentiation Exponentiation alternate form Multiplication Division Addition E Subtraction The following expressions all have the value 2 0 4 0 8 0 Assignment Statements Assignment statements store values in variables The general form of an assignment statement is left side attribute name value right side attrib
94. outputs the Collect module is an exception it runs even if some of its inputs have been turned off by Route Figure 19 shows an example of a Switch module controlling whether an Isosurface or a MapToPlane is passed to Image In a simple data flow execution model this Visual Program Editor tinp doc tigure2 net MapToPlane Stik ll a i a Chapter 4 Data Explorer Execution Model 41 m gt lt D ie S ct mall o le o x D 42 Switch module will be executed when its inputs are available i e the results of the Isosurface and MapToPlane modules and the value of the selector On execution the Switch module chooses whether to pass the Isosurface or MapToPlane result to the output based on the selection input to Switch In the case of a pure data flow model both the Isosurface and MapToPlane modules execute before the decision as to which will actually be used is known Since both operations can be computationally expensive the execution of both of them is very inefficient Again this problem is handled in Data Explorer within the simple data flow execution module by an examination of the graph prior to execution lf the selection value comes from an external source e g an interactor and is known a priori the selection may be performed by a simple transformation of the graph excising the Switch module altogether and substituting arcs from the selected source either Isosurface or MapToPlane to each o
95. per visual program is allowed and as it executes everything in the visual program executes subject to the optimization for deciding which modules need to be executed discussed above Additional functionality is provided using the ForEachN ForEachMember Done and First modules ForEachN and ForEachMember essentially implement a standard programming language for loop in the case of ForEachN iterating over a specified list of integers and in the case of ForEachMember iterating over the members in a group or the items in a list or array Figure 21 shows a simple loop that outputs the integers 0 to 10 and Echo s them the start and end parameters to ForEachN have been set to O and 10 respectively This is roughly equivalent to the C language statements for i70 i lt 10 i printf d i o TA a tor tnp adoc ipmednetl 44 IBM Visualization Data Explorer Users Guide Data Explorer provides you with two other tools for control looping Done and First Done enables you to exit a loop Examples of its use can be found in Advanced Loop Constructs see below The First module provides a way to recognize the first pass through a loop this is particularly useful for example as a way to reset the GetGlobal module if you are using GetGlobal and SetGlobal see below to store information during the execution of a loop Note that First is not necessary if you are using GetLocal and SetLocal When a loop is present in a visual
96. positioning is not possible with the 3 D cursor tool 5 Repeat the previous three steps for each probe icon in your visual program Reexecute the visual program to implement the probes While in Cursors mode the center and right mouse buttons have the same functions as they do in Rotate mode Note You can also enable Probe cursors mode by using the intrctnMode parameter to the Image tool see Image in BM Visualization Data Explorer User s Reference IBM Visualization Data Explorer User s Guide Using Pick Picking consists of choosing a location on an object in an image using the mouse A chosen location is called a poke Each poke may intersect the object in the image in one or more places the intersections are called picks or may not intersect the object at all For example a poke on a spherical isosurface results in two picks one on the front of the sphere and one on the back Picking differs from using probes in which probes may be present anywhere in a 3 dimensional space while picks always exist on the surface of an object After you execute a visual program and have an image in the Image window you can modify the visual program to include a Pick tool from the Special category The Pick tool accepts input from the mouse and outputs a field that specifies the picked point or points The positions component of this field identifies each picked point on the object in the image The field can be used for example to id
97. programs Macros can help make your visual programs simpler by combining several tool icons into one Creating Macros Macros are themselves visual programs and are created in much the same way For example the macro represented in Figure 75 on page 150 maps data onto a plane colors it and then performs a deformation using the RubberSheet module It is constructed by placing the appropriate tool icons on the VPE canvas and connecting them Note You can also create a macro directly from a visual program in the VPE window See Creating Macros the Easy Way on page 152 Macro s inputs and outputs are represented by the Input and Output tools from the Special category A macro has at least one input or output Note Macros cannot include interactors Sequencers colormaps probes picks Display or Image tools Place the Input icon on the canvas and connect it to the appropriate tool icon input tab The Input type conforms to that of the input tab to which it is connected Like other tools the Input icon can be connected to multiple input tabs You can use the Configuration dialog box for the Input tool Figure 76 on page 151 to specify e Tab position in the macro e Name of the input e Default value for the input e Description of the input e Whether the input is a required parameter e Whether the input has a descriptive default value e c A o E cr o m ma o E D l tn Some of these values are by def
98. represents the color of the object at z and o z represents its opacity at z then the total color of a ray passing through the volume is given by CE f c z exp f oc dz 00 00 Color Map and Opacity Map Components There is an alternative to having the colors component and opacities component explicitly list the color and opacity associated with each position or connection element If each element of the colors and opacities components is a single byte then it is interpreted as an index into the color map or opacity map component The color map component is a 256 element table of three floating point values representing red green and blue typically with values between O and 1 The opacity map component is a 256 element table of floating point values between O and 1 Invalid Positions and Invalid Connections Components The invalid positions and invalid connections components allow positions or connections to be marked as not having valid data This is useful for example for observational data defined on a regular grid but with occasional missing observations or for simulation data defined on a regular grid but with a hole covered by another grid perhaps at a higher resolution The invalid positions component can be an Array of bytes or unsigned bytes one for each position where the component is dependent on positions i e has a dep attribute of positions In that case
99. scalars one entry for vectors two for rank two tensors and so on See also rank shared A term used to indicate the availability of a resource for use by more than one program at the same time specular reflection A reflection from a shiny object stand in See interactor stand in streaklines Lines that represent the path of particles in a changing vector field Also called rakes streamlines Lines that represent the path of particles in a vector field at a particular time Also called flow lines T task A basic unit of work to be accomplished by a computer tetrahedron A volumetric connection element that connects four positions in a field tool In IBM Data Explorer a general term for any icon used to build a visual program specifically module macro or interactor stand in triangle A connection element that connects three points in a field tube A surface centered on a deriving line e g a streamline or streakline Tubes may twist to indicate vorticity U user Anyone who uses the services of a computer system See also user display station V value An instance of an attribute for example blue as the value of the attribute color vector A quantity characterized by more than one component visual program A user specified interconnected set of Data Explorer modules that performs a sequence of operations on data and typically produces an image as output vertex One o
100. session type quit You can also include a script name directly in the script command add the name of the script after the script option Data Explorer will terminate automatically when it has executed the script For example type include usr 1pp dx samples scripts scriptexample You will see a sequence of images created with sequencer commands The directory usr 1pp dx samples scripts contains examples for many modules You may find it helpful to experiment with them to learn how they function Note To ensure that an example program does not exit before you want it to invoke script mode first and then include the program Otherwise some programs will execute and disappear so quickly that you won t be able to identify the image IBM Visualization Data Explorer User s Guide Setting Environment Variables There are several environment variables that you may find useful to customize Data Explorer These can be set in your login profile DXDATA The DXDATA environment variable specifies a list of directories in which Data Explorer will search for data files If the data you wish to import is in one of the directories specified in the DXDATA environment variable you do not need to provide the complete path name to the Import tool Specify the file name and the Import module will look in the specified directories for the data file The directories will be searched in the order in which they are listed in the environment variable
101. specified file This option is useful only for image formats which support series RGB R G B YUV and MIFF For all formats other than the Postscript formats the following field is available Image Size If the Allow Rerendering button is set this field allows you to set the resolution of the output image to something other than that of the image displayed to the screen If one of the Postscript formats is selected then the following fields are displayed Image Dimensions Orientation Input Image Size Page Dimensions IBM Visualization Data Explorer User s Guide Allows you to specify the size of the image on the page by default in inches Allows you to specify the orientation of the image to portrait or landscape or automatic which chooses the best for the given image Specifies the resolution of the image to be saved This field is enabled only if the Allow Rerendering button is toggled on Specifies the size of the page By default this is specified in inches Output PPI Specifies the pixels per inch of the output image Note Unless you specifically care to set the precise pixels per inch you do not typically need to set this Margin Width Specifies a margin width of white space on the page For PostScript formats the printed image will by default fill the page to within Margin Width of the edge of the page If Allow Rerendering is off the pixels in the image will be sized appropriately to scale t
102. start with This is equivalent to setting positions in a Normals module Shade will if necessary create position normals then light the object accordingly Any point on a connection between positions will be lit by calculating an interpolated normal value between the position normals If you choose faceted in Shade the effect is the same as selecting connections in the Normals module In this case each connection element has one normal direction over the entire face As a result every point on a connection element reflects light exactly the same way The image that you see will thus show faceted polygons Once again while this may make the object look less realistic it does more accurately reflect the sampling resolution of your data and may therefore be a more desirable image to show other viewers IBM Visualization Data Explorer User s Guide Plots and Histograms Rubbersheet Data Explorer provides a Plot module that will give you a simple 2 D graphics plot of your data This can be convenient for showing one parameter plotted traditionally while you show a colored 3 D height Field illustrating the same or other parameters in the same scene Histogram regroups your data into a specified number of bins it acts like a form of filler on your data The output of Histogram is a new Field with connection dependent data The connections are the bars on the histogram which can be plotted The height of each histogram bar is prop
103. stop it or pause before quitting VPE Edit Menu The Edit menu lists options for manipulating tools on the canvas Configuration Displays a Configuration dialog box for setting and changing the values of the selected tool See Entering Values in a Configuration Dialog Box on page 107 Find tool Opens a dialog box that lists the tools in the visual network displayed on the canvas Double click on the tool name or type the name in the Chapter 8 Graphical User Interface Menus Options and the Message Window 157 158 Selection field to highlight the corresponding icon in the canvas If the icon falls outside the canvas the canvas will automatically scroll to display the part of the network in which it lies See Locating Tools The Find Tool Dialog Box on page 111 Input Output Tabs Brings up a cascade menu with the following options Add Input Tab Adds input tabs to the selected tool Remove Input Tab Removes input tabs from the selected tool Add Output Tab Adds output tabs to the selected tool Remove Output Tab Removes output tabs from the selected tool Reveal All Tabs Reveals all tabs of the selected tool Hide All Tabs Hides all unconnected tabs of the selected tool Assign Get Set Scope Brings up a cascade menu with the following options Convert All Modules Brings up a dialog which allows you to interactively change all of the Get and Set tools in your visual program to either the Local or Gl
104. stored in the cache In the second example the last result of div is placed in the cache but all results of curl are placed in the cache div curl DivCurl data cache 2 div cache 2 curl DivCurl data In the following example all outputs of Statistics are not cached except for min Since a cache attribute with a value of 2 was associated with min the last result of the min output of Statistics will be stored in the cache mean sd var min cache 2 max Statistics data cache 0 If no cache attribute is associated with the module all results of the outputs will be cached unless an individual output has a cache attribute associated with it The following example is similar to the one above except that all results of module outputs are cached with the exception of min Since a cache attribute with a value of 2 was associated with min only the last result of the min output of Statistics will be stored in the cache mean sd var min cache 2 max Statistics data Identifies which execution group a module belongs to This attribute is used to distribute parts of a visualization across multiple workstations This attribute does not bind a module to a specific workstation but identifies it to be a member of a group that may be assigned to a workstation The assignment of an execution group to a workstation is done using the Executive module see Executive on page 126 in IBM Visualization Data Explorer User s Re
105. taken from the atmosphere Since we have collected data throughout a 3 dimensional space we can identify volumetric elements defined by connecting adjacent grid sample points in three dimensions using a connections component like cubes It now becomes possible to draw isosurfaces rather than isolines An isosurface is that surface cutting through a volume on which all data values are equal to a specified value Depending on the actual distribution of the data isosurfaces may look more or less like flat sheets the isosurface of sea level in a data set of elevations would look like this it might enclose a portion of our space or appear as a whole set of small disconnected surfaces or enclosed spaces To create an isosurface we pick a value of interest Suppose that according to our knowledge of meteorology we know that the dew point at which water condenses from vapor to liquid is 12 degrees C in our sample Although we measured temperatures at only a fixed number of grid points we are interested in seeing where rain formation may begin throughout the atmosphere We could show only the sample points highlighted by themselves but once again we make a reasonable assumption that we have taken discrete samples from a continuous natural volume In other words rain formation will not simply occur at the limited set of discrete points where we have sampled temperatures of 12 degrees C but at all the points in between that are also at 12 degr
106. that are mapped to that range of values The Colormap Editor is discussed in detail in 6 3 Using the Colormap Editor on page 119 Chapter 8 Graphical User Interface Menus Options and the Message Window 161 Open Message Window Opens a window where you can access error and warning messages and working information about your execution See 8 2 Using the Message Window on page 174 VPE Connection Menu The Connection menu lists the following options Start Server Connects the user workstation to the server For more information see 9 3 Connecting to the Server on page 183 Disconnect from Server Disconnects the user workstation from the server Reset Server Flushes the cache forcing the visual program to reaccess the data on the server the next time it executes See Resetting the Server on page 185 Execution Group Assignment Displays a dialog box that allows you to assign execution groups to specific machine host names See Assigning Execution Groups to Workstations on page 181 VPE Options Menu The Options menu allows you to customize tools and window features The Options menu lists the following options Tool Palettes Toggles between displaying the tool palettes and not displaying them You can also use the Ctr1 T accelerator key Control Panel Access Allows you to specify which controls panels and control panel groups are accessible from the VPE See Control Panel Access Groups and
107. that location e c A o E cr o m ma o E D l tn To move a group of interactors 1 Select a group of interactors to be moved 2 Position the mouse pointer on any member of the group and drag it An outline of each interactor appears and follows the mouse 3 Release the mouse button The interactors move to the new location To delete one or more interactors 1 Select one or more interactors to delete 2 Press the Ctrl Delete accelerator key or click on the Delete option of the Edit menu Chapter 7 Graphical User Interface Control Panels Interactors and Macros 131 If you delete an interactor stand in from the VPE the interactor in the Control Panel is also deleted However deleting the interactor in the Control Panel does not affect what is displayed in the VPE Changing the Size of an Interactor You can change the size of interactors in a Control Panel Some interactors e g Selector resize automatically depending on their contents but others e g String do not You can resize any interactor by pressing the control key Ctrl and the left mouse button Locating Interactor Stand ins As you are building and modifying visual programs and Control Panels you may find it desirable to locate that interactor in a Control Panel that corresponds to a specific interactor stand in To locate an interactor corresponding to a stand in 1 Select the desired stand in in the VPE by clicking on it
108. the possibility of deadlock For information about adding modules to the Data Explorer system see BM Visualization Data Explorer Programmer s Reference IBM Visualization Data Explorer User s Guide Chapter 5 Graphical User Interface Basics 5 1 Staring Data Explorer so eaaa eet RS SE GE owed RR S 58 Using Environment Variables 59 5 2 Understanding Data Explorer Windows 60 Looking at Window Structure ss 61 Using the Mouse n 62 Moving and Resizing Windows 62 Selecting Pull Down Menus and Pull Down Menu Options 62 Selecting and Deselecting Items with the Mouse 63 Selecting a Choice in an Option Box 63 Editing Text Fields ren 64 Working with Windows ns 65 5 9 Using Online Help sudo dh 4258 845824 REB asas OO 65 User Defined Help Files cnn 67 5 4 Executing a Visual Program lr 67 Usmo Me Sequence ressanar eU sis ee eae eS Rb ES 68 Using a Data Driven Sequencer 2 0 20008 70 Emor Messages ams ak ut o bee go ge x GE uere he ge s 71 O Copyright IBM Corp 1991 1997 57 This chapter describes how to use the graphical user interface provided with Data Explorer This interface enables you to create and control the visualization of data An
109. the Execute on Change option causes the visual program to execute every time you change an interactor setting If you change values faster than Data Explorer can generate images the system executes the program as quickly as possible always using the current settings at the time an execution cycle begins lf you modify your visual program while Execute on Change is enabled then the option automatically becomes disabled After the changes are made you can reenable it Choosing End Execution while the visual program is executing causes execution to stop after the currently executing module The final Execute menu option is Sequencer If you select this option and a Sequencer tool is present in the visual program the Sequencer appears see Using the Sequencer for more information While the Sequencer runs you can change interactor settings and those changes are reflected in subsequent frames generated by the Sequencer The Execute Once and Execute on Change options are grayed out when the Sequencer is running but when you pause the Sequencer you can use those two options to explore the particular frame the Sequencer paused on While the visual program is executing the Execute option on the menu bar is highlighted It remains highlighted until execution is finished If Execute on Change is selected the Execute option on the menu bar is highlighted with one color during execution and another color outside of execution cycles Using the
110. the Image Window noPanelAccess Remove the Panels menu from the control panel and panel options from the Windows menu of the Image Window noPanelEdit Remove the Edit menu from the control panel noPanelOptions Remove the Option menu from the control panel noPGroupAssignment Remove the Execution Group Assignment option from the Image window s Connection menu noRWConfig Remove the Open and Save As options from the control panel s File menu noScriptCommand Remove the Execute Script Command option from the Message Window s Options menu restrictionLevel Combines options to facilitate building applications for Data Explorer 298 IBM Visualization Data Explorer User s Guide Appendix D User Interface Configuration Data Explorer provides its own set of resources for customizing the user interface in addition to the standard X window and Motif resources These resources see table can be specified in the Xdefaults resource file and a majority can be invoked as command line switches or options For example DX nolmagePrinting true DX restrictionLevel maximum are valid resource file entries The corresponding command line format is dx image nolmagePrinting restrictionLevel maximum The command line switch for a Boolean resource e g noImagePrinting toggles the default value Table 7 Page 1 of 2 Resource Configuration Table Resource Name Command Line Option if available A A
111. the right side list are set to the value NULL In addition if an identifier is repeated in the eft side list then the right side associated with that identifier is the value associated with its rightmost instance 10 n m mall o O cr mall o E Q r o E Q e y e D All identifiers that have not had a value explicitly assigned to them have the value NULL Expression Assignments The values for the right side portion of an expression assignment statement consist of a sequence of constant values variables arithmetic expressions and the value NULL separated by commas The various values need not be of the same kind data type or dimension The following examples all assign the value A string to the variable a the value 2 0 to the variable b and the value NULL to the variable c a A string These 3 lines b 2 2 1e0 constitute a single c NULL example a b C A string 2 0 NULL a b c A string 5 2 5 NULL a b C A string 2 0 a b c d A string 2 0 a b c a 1 O 0 1 2 0 NULL A string 1 2 3 The following example illustrates a simple way to swap values b b a Values are swapped so a 4 b 2 d e e c d c 10 d 6 e 8 Function Call Assignments A function call can refer either to a function defined as a module a function compiled into the system or to a macro a function defined in the scripting
112. their appearance in the variable reading from left to right with successive path names separated by a colon Thus when a file appears in more than one directory Data Explorer will choose the first copy it finds i e in the leftmost directory containing a copy DXDATA specifies directories to be searched for importable data files If the data to be imported is in your current directory or one of the specified directories you do not need to enter the complete path name in the Configuration dialog box for the Import tool given just the file name the Import module will search all of these directories DXINCLUDE specifies directories to be searched for include scripts Data Explorer uses include scripts in script mode It is not necessary to specify this variable in Edit mode See File Inclusion on page 207 for more information DXMACROS specifies directories to be searched for macros when Data Explorer starts up If DXMACROS is not specified you will have to load macros individually see 7 2 Creating and Using Macros on page 149 DXMODULES specifies the directories to be searched for outboard modules Setting a Path Variable Examples Note the colon separating successive path names e To set DXMACROS for both the Bourne sh and the Korn ksh shells DXMACROS usr mydi rectory projectAmacros usr mydirectory projectBmacros export DXMACROS e To set DXDATA for the Korn shell ksh only export DXDATA usr mydirecto
113. those in usr Ipp dx samples scripts and then begin writing your own scripts Example 1 A Simple Script In this example the data found in usr cloudwater is imported and assigned to the variable data Then the Isosurface module is called on data with no other parameters set and the result is assigned to iso A Camera is created using AutoCamera and the isosurface is displayed using Display note that the Image tool is not available in the scripting language data Import usr lpp dx samples data cloudwater iso Isosurface data camera AutoCamera iso Display iso camera Chapter 10 Data Explorer Scripting Language 189 190 Example 2 Setting Parameters Suppose that in the previous example we wished to set the Isosurface number to 3 number is the third parameter to Isosurface We can replace the second line of the script in Example 1 with iso Isosurface data NULL 3 or alternatively iso Isosurface data number 3 Example 3 Using a Macro It is possible to create and use macros in the scripting language A macro is defined using the keyword macro as in the following example macro make iso data isovalue isosurface isosurface Isosurface data isovalue To use the macro simply call it with the required parameters isol make iso data 0 1 iso2 make iso data 0 2 A macro can have as many inputs or outputs as desired Note that it is not necessary t
114. three components positions connections and data The field is given the name irreg positions regular connections object irreg positions regular connections class field component positions value 1 component connections value 2 component data value 3 end The positions are joined in the order last index varies fastest with the connections specified as 4 x 2 x 3 the first 3 positions are joined in a line as are those in each set of 3 following Then the first 6 positions are joined as a set of 2 quadrilaterals as are the next 6 and so on see Figure 88 on page 250 Example 4 An Irregular Grid This example file in usr 1pp dx samples data irregular dx defines an irregular grid and shows how to imbed data as text in a header section The values of the positions and connections components are irregular and must be enumerated See Figure 89 on page 252 Appendix B Importing Data File Formats 251 ms mall o D ms o ms 3 y cr tn Figure 89 Irregular Grid Example The irregular positions which are 24 3 dimensional points object 1 class array type float rank 1 shape 3 items 24 data follows 0 0 0 0 0 1 0 0 2 0 2 0 0 2 1 0 2 2 1 0 841471 0 1 0 841471 i 1 0 841471 2 1 2 841471 0 1 2 841471 1 1 2 841471 2 2 0 9092974 0 2 0 9092974 1 2 0 9092974 2 2 2 909297 0 2 2 909297 1 2 2 909297 2 3 0 14112 0 3 0 14112 1 3 0 14112 2 3 2 14112 0 3 2 14112 1 3 2 14112 2 252
115. use the Edit menu Configuration option or use the Ctrl F accelerator key to open the Configuration dialog box A typical Configuration dialog box consists of four major parts e Notation e Inputs section e Outputs section e Pushbuttons The following sections describe the elements in a Configuration dialog box Notation Field By default the Notation field displays the name of the tool You can use this field to enter a short notation about the use of the tool in the current visual program 1 Select the field by clicking on it 2 Edit the field as a normal text field i e using Backspace Delete and the alphanumeric keys In the case of Transmitter Receiver Probe ProbeList and Pick tools use the Notation field to rename the tool thus changing the name appearing on the tool icon Inputs Section Toggle buttons Specifies whether an input is active that is whether the input tab on the icon is folded in The toggle buttons are the small square buttons on the far left of the dialog box The toggle buttons provide a visual indication of the inputs that have been specified These buttons are analogous to the input tabs on the tool icon and are coherent with the tabs the buttons can be activated and deactivated by clicking on them 108 IBM Visualization Data Explorer Users Guide e When you activate a toggle button the value of the input is either the output of another module specified in the Source field of the dial
116. using the Cache option of Import s Configuration dialog box note however that this will not necessarily cause Import to run every time unless modules downstream from Import are also set to cache no results IBM Visualization Data Explorer User s Guide Note An asynchronous module could be used to monitor a file s status and generate new outputs when the file changes 4 3 Conditional Execution Route and Switch Figure 19 Example 2 Two of Data Explorers mechanisms to control execution flow through a visual program are the Switch and Route modules Switch allows you to switch between one or more inputs to drive a single output Route is the inverse of Switch having a single input that can be routed to zero one or more than one output Switch is typically used to choose between different paths in a visualization program for example to pass an imported data field through either the Glyph module or through Isosurface depending on user choice or characteristics of the data field itself Route is typically used to turn off portions of the visualization program for example to turn off Writelmage or Export or to prevent rendering to an image window unless the user chooses to create an image Switch can be thought of as turning off portions of the visual program logically above Switch Route can be thought of as turning off portions of the visual program logically below Route Note that while Route turns off modules that receive its unused
117. values are invalidated rather than actually removed see Include in BM Visualization Data Explorer User s Reference All Data Explorer modules know to ignore invalid data For example Streamlines will stop when they reach an invalid element and Statistics will ignore data values associated with invalid elements Given the sets of numbers positions connections and data we can define a Field as it is called in Data Explorer The positions identify locations in space the optional connections define logical continuities interpolation paths between positions and the data are the values measured either at each position or within each connection element Data Explorer calls each of these sets of numbers positions connections data a Field component Components are represented as arrays of numbers with some auxiliary information specifying attributes e g type of dependency In addition there are many other types of Field components The Field is the basic unit of information in Data Explorer so it is important to understand how to express your data in these terms A Field can only have one positions and one connections component A Field can have only one component actually named data but you may assign names of your choosing to additional components representing other data sets that are also 12 IBM Visualization Data Explorer User s Guide mapped to the same grid So you can name a data component temperature
118. you can now segment your visual program into pages which are disconnected sets of modules Modules in one page communicate with modules in other pages using transmitters and receivers You can name pages and control the ordering of pages See the Edit menu of the VPE Annotation You can add comments directly onto the canvas of the VPE This option is available from the Edit menu of the VPE Optimizing Caching There is now an option in the Edit menu of the VPE called Output Cacheability gt Optimize Cache If you choose this option Data Explorer will use a heuristic to optimally set the caching behavior of each tool in the visual program XXvili IBM Visualization Data Explorer Users Guide Changes to Get and Set modules In this release the Get and Set modules have been replaced by GetLocal SetLocal and GetGlobal SetGlobal Briefly the difference between these pairs of modules is that the Global pair maintains state between executions while the Local pair do not Remember that a single loop in the visual program is considered a single execution If you do not do anything to modify your visual program any Get Set pairs which you have will be replaced by GetGlobal and SetGlobal and the visual program will run as it did before However in many cases you can replace your Get Set pair by GetLocal and SetLocal for performance advantages One way to know if you can do this is if you are using the First module to reset Get on each
119. you simply Import your volumetric data run it through AutoColor and attach it to Image you will get a colored volume rendering of your data space Appendix A Using Data Explorer Some Useful Hints 231 A 3 Design for Interactive Use Data Explorer is first and foremost designed for interactive exploration using data as the raw material for creating modifying and understanding imagery As such the system is designed to permit operation at several different levels of expertise exploring authoring and programming You can engage in exploring by opening previously created visual programs e g the visual programs provided with Data Explorer and changing values of the Interactors found in Control Panels changing values in the Image window controls or by manipulating the Sequencer if one is provided You author a visual program when you place and interconnect additional modules on the VPE or reorganize connections between modules already present or when you create a new visual program from scratch At the advanced level you can learn how to write and add your own custom modules to Data Explorer This involves writing in a traditional programming language like C taking advantage of a rich function library provided compiling your new module and running your customized version of Data Explorer While it is nice to know you can do this do not worry if you are not a programmer because you may never find a need to write your o
120. your object using the Scale module it might be more convenient to adjust the scale in increments of 0 01 With a little thought you can extend this idea so that the same one and only Sequencer integer series can be converted into several different series of numbers that can simultaneously rotate scale and read in different time steps of data Just a caution though too much changing at the same time will probably not help you visualize your data but instead will cause confusion Is the object getting bigger because the data values are increasing or because you are changing the scale or because you are moving the object closer to you with Translate When you start out keep your animations simple and they will be much more effective It is imperative that good visualizations contain sufficient annotation for a viewer to derive appropriate information from the imagery A colored height field or streamline set with no supporting labeling can make perfectly beautiful utterly meaningless computer graphics Annotating a scene can be done in several ways using Data Explorer modules You can for example provide a ColorBar with numeric values automatically labeled next to the related colors show Text or Caption information to provide textual descriptions of objects or turn on AutoAxes to show neatly labeled and numbered axes around the perimeter of your data space Using the Format module it is possible to create clocks or other meters Fo
121. 0 1 2 4 5 attribute ref string loops data array Dependent on faces object data class array type float rank O items 5 data follows 0 255 12 0 4 1 8 attribute dep string faces m gt Field definition to put the arrays together S object map with hole class field zi component positions position list v component edges edge list component loops loop list component faces face list component data data end Example 11 Three dimensional Faces Loops and Edges The following data file describes a faces loops and edges Object that exists in 3 dimensional space To view the solid g Import solid dx a AutoCamera g 0 2 0 1 1 0 Display g a To look at just the connections s ShowConnections g Display s a Use the first part of the script to view the solid and the second part to view only the connections The data file is given below and the resulting connections are shown in Figure 94 on page 266 This data file can be found in usr 1pp samples data solid dx Example of faces loops and edges components Positions array These are a list of all the vertices of the object no particular order is required here object position list class array type float rank 1 shape 3 items 12 data follows Appendix B Importing Data File Formats 265 5 0 0 0 1 0 point number 0 5 0 0 0 5 0 1 3 0 5 0 5 0 2 4 5 0 0 155 3 4 5 0 0 4 5 4 3 0 4
122. 0 1994 NASA GSFC National Space Science Data Center NASA Goddard Space Flight Center Greenbelt Maryland 20771 USA NSI DECnet NSSDCA CDFSUPPORT Internet CDFSUPPORT NSSDCA GSFC NASA GOV University Corporation for Atmospheric Research Unidata Copyright 1993 University Corporation for Atmospheric Research Permission to use copy modify and distribute this software and its documentation for any purpose without fee is hereby granted provided that the above copyright notice appear in all copies that both that copyright notice and this permission notice appear in supporting documentation and that the name of UCAR Unidata not be used in advertising or publicity pertaining to distribution of the software without specific written prior permission UCAR makes no representations about the suitability of this software for any purpose It is provided as is without express or implied warranty It is provided with no support and without obligation on the part of UCAR Unidata to assist in its use correction modification or enhancement NCSA NCSA HDF version 3 2r4 March 1 1993 NCSA HDF Version 3 2 source code and documentation are in the public domain Specifically we give to the public domain all rights for future licensing of the source code all resale rights and all publishing rights Notices XV XVi We ask but do not require that the following message be included in all derived works Portions developed a
123. 00000 0 700000 point number 12 0 700000 0 600000 point number 13 0 600000 0 600000 point number 14 Edges array This is a list of connected points by point number All the edges associated with a particular face need to be listed together If points 10 3 and 7 make a triangle the list is 10 3 7 and the 10 is not repeated Following a polygon the front of the polygon is determined by the right hand rule object edge list class array type int rank 0 items 25 data follows ESE SS 1 2 6 edge point index 0 0 5 4 3 2 1 edge point index 3 2 3 9 8 6 edge point index 9 11 12 13 14 edge point index 15 hole in third face 3 10 9 edge point index 19 3 4 10 edge point index 22 attribute ref string positions Loops array This is a list of connected edges by edge number Each number is the edge index of where the next loop starts object loop list class array type int rank 0 items 6 data follows 0 loop index 0 3 1 9 2 15 3 19 4 22 f b attribute ref string edges IBM Visualization Data Explorer User s Guide Faces array This is list of which loops make faces If there are no holes in the faces this is list of all loops If two or more loops actually describe the outside edges and inside hole edges of a face then this list contains the starting loop numbers of the list of loops making up a face S Hd de e object face list class array type int rank 0 items 5 data follows
124. 08 Using the Compute Module Configuration Dialog Box The Configuration dialog box for the Compute module illustrated in Figure 51 differs in some respects from the other Configuration dialog boxes lt consists of Notation See Notation Field on page 108 for information Name These fields allow you to enter names for the parameters of the expression By default the names are labeled a and b but you can change them to a name more relevant to the particular computation You can have fewer or more than two inputs to the Compute module see Adding and Removing Input and Output Tabs on page 106 Source See information on Source fields on page 109 Expression The expression is entered in this field See Compute in BM Visualization Data Explorer User s Reference for more information r Compute Notation The Compute tool converts the integers output by the Sequencer to a series of isovalues Inputs Name Source frame Sequencer Expression frame 0 02 0 2 Outputs Name output Type Destination Cache value value list field Isosurface All Results OK Apply Expand Collapse Description Restore Cancel Figure 51 Typical Dialog Box for the Compute Module Locating Tools The Find Tool Dialog Box The Find Tool dialog box provides you with an easy way to locate tools on the VPE canvas You may find this dialog box especially useful if you are editing a large visu
125. 1 frame contains the sequence number of the current frame The keyword sequence identifies the macro that will be run each time frame is incremented and the keyword play will start the sequence The following script will call the macro doit with the values 0 2 4 6 8 10 10 n m mall o O cr mall o E Q r o E Q e y e D startframe 0 endframe 10 deltaframe 2 macro doit i Echo i sequence doit frame play 10 3 Language Delimiters As the preceding examples show the Data Explorer scripting language resembles a conventional programming language Unlike some programming languages that treat all characters as uppercase the scripting language is case sensitive Also you can type statements beginning at any column in the line This allows you to indent sections to clarify the program structure Data Explorer uses the following characters to separate or delimit elements of the scripting language A semicolon terminates a script statement A comma separates keywords arguments lists or vectors Brackets enclose vectors matrices and tensors Braces enclose lists and blocks of statements in macros In some places one or more blank spaces can be used in place of a comma e g in separating elements of a vector Commenting Scripts A comment is defined as two slashes followed by a sequence of characters and terminated by the end of the lin
126. 174 O Copyright IBM Corp 1991 1997 155 8 1 Using the Primary Window Pull Down Menus and Options This section provides illustrations of the primary windows with explanations of the pull down menu options on their menu bars The discussions include e VPE Window Menu Bar e Control Panel Menu Bar on page 162 e Image Window Menu Bar on page 165 e Colormap Menu Bar on page 168 e Menu Bar Menu Bar on page 170 e Message Window Menu Bar on page 172 The Sequencer and Help primary windows have no pull down options so they are not discussed here See Using the Sequencer on page 68 for information about the Sequencer and 5 3 Using Online Help on page 65 for information on the Help window and Help menu options VPE Window Menu Bar 156 The menu bar displays the titles of seven menus e File e Edit e Execute e Windows e Connection e Options e Help The following sections describe the menus and their options For many of the menu options one or more tools on the canvas must be selected in order for the option to be applied If a menu option is grayed out it is unavailable and cannot be selected VPE File Menu The File menu displays the options you can use to create new programs view or edit previously created programs load macros and save programs You must have write permission for a file to save changes directly to that file The following options appear on the File menu New Ini
127. 2 0 delta 0 0 1 object 2 class gridconnections counts 3 2 3 attribute element type string cubes attribute ref string positions end Appendix B Importing Data File Formats 259 260 Example 8 Two dimensional Grid Cell centered Data This example describes a regular 2 dimensional grid In this example unlike other examples presented here the data are dependent on in a one to one correspondence with the connections rather than the positions component Data Explorer interprets this as implying that the data value within each connection element is the constant given by the corresponding data value For example if you used AutoColor and rendered this Field you would see blocks of constant color You can use the following script to render this Object data Import usr lpp samples data datadepconnections dx format dx colored AutoColor data camera AutoCamera colored Display colored camera The data file is located in usr 1pp samples data datadepconnections dx object 1 is the regular positions The grid is 4x4 The origin is at 0 0 and the deltas are 1 in the first dimension and 2 in the second dimension object 1 class gridpositions counts 4 4 origin 0 0 delta 1 0 delta 0 2 object 2 is the regular connections quads connecting the positions object 2 class gridconnections counts 4 4 object 3 is the data which are in a one to one correspondence with the connections d
128. 20 20 20 Uppercase l 20 Double quote accent over o and u AccentHungarian angstrom 0 1 2 3 4 5 6 7 1 Double quote accent over O and U 21 Ligature Ligature Lowercase Uppercase Lowercase Uppercase Lowercase c cedilla Appendix E Data Explorer Fonts 311 312 Table 11 Page 2 of 2 European National Language Symbols and Characters 200 to 1255 220 C cedilla Uppercase C cedilla Looks better than ASCII Circumflex when used as a lowercase accent 221 widecircumflex gt 222 WideCircumflex 223 WideCircumflex 224 WideCircumflex 225 Clicka Uppercase except for and O Uppercase O Uppercase O Used in Lithuanian over C S Z C s and z also called hacek or caron CommaRomanian Used in Romanian under S T s and t 227 enya Lowercase for Spanish n and Portuguese a and o nya ppercase for Spanish N an 230 E U for Spanish N d Portuguese A and O et celandic E decand 232 Eth B Icelandic 233 hookLithuanian Cedilla like hook used under Lithuanian a e and u ihookLithuanian Cedilla like hook used under Lithuanian 1 235 HookLithuanian Cedilla like hook used under Lithuanian A E and U 236 IHookLithuanian NEED Cedilla like hook used under Lithuanian 1 237 dotless Dotless i to be accented with acute grave etc 20 isah Slashed used in Polish 241 Lsash Slashed L used in Polish 242 maxm tower
129. 3 data follows 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 3 0 create a product array of the regular points in the xy plane and the irregular points in the z direction object 3 class product array term 1 term 2 create regular cube connections object 4 class gridconnections counts 4 2 3 the data component object 5 class array type float rank 0 items 24 data follows 1 0 Zak 2 0 1 0 4 5 6 7 8 1 2 0 0 9 0 8 1 0 1 2 1 3 0 1 0 3 3 0 1 2 Sed 4 1 0 9 2 0 1 0 0 9 2 0 IBM Visualization Data Explorer User s Guide object field class field component positions 3 component connections 4 component data 5 end Figure 91 Product Array Example with Irregular Points in the Z Direction Example 7 Series The following file defines the data for a series It defines three data Array Objects and then three Field Objects that are associated with the data The grid definitions are in a separate file pos conn data This first file can be found in usr Tpp samples data regseries dx This example describes a data series with three member fields Object 1 is the data associated with the first frame in the series The data is dep positions or in a one to one correspondence with positions object 1 class array type float rank 1 shape 3 items 18 data follows 1 0 0 1 0 0 1 4 0 2 0 0 1 0 0 0 0 0 2 2 0 1 0 2 1 0 0 0 0 0 2 0 0 0 0 1 0 9 0 1 0 0 1 1 0 4 0 0 1 0 0 1 0 0 122 0 1 0 1 0 3 0 0 0 0 Appendix B Importing
130. 5764706 529412 3098039 6235294 7490196 8274510 8274510 5607843 1960784 0 oO CO CO Lr O O CO coc ccc O CO CO CcOoCcOocCcOocCcocoCco co Coco cocco gt 8588235 0000000 0000000 3725490 1647059 6235294 4980392 2588235 0000000 3098039 3098039 1960784 1372549 3098039 3098039 5764706 3294118 3294118 1372549 5568628 4980392 8588235 7529412 0000000 8588235 7529412 1843137 6235294 8470588 8274510 8274510 5607843 8000000 0 oor Lr O CO oO OOO OO Oo co O oO CO CO CO Coco cocco 5764706 0000000 0000000 6235294 1647059 6235294 0000000 4352941 0000000 1843137 1843137 8000000 5568628 3098039 3098039 8588235 3294118 3294118 1372549 1372549 1960784 4392157 529412 0000000 4392157 529412 1843137 3 25490 8470588 8274510 8274510 372549 1960784 313 IBM Visualization Data Explorer magenta maroon mediumaquamarine mediumblue mediumforestgreen mediumgoldenrod mediumorchid mediumseagreen mediumslateblue mediumspringgreen mediumturquoise mediumvioletred midnightblue navy navyblue orange orangered orchid palegreen pink plum red salmon seagreen sienna skyblue slateblue springgreen steelblue tan thistle turquoise violet violetred wheat white yellow yellow
131. CIDENTAL OR CONSEQUENTIAL DAMAGES INCLUDING WITHOUT Notices XVII xviii LIMITATION LOST PROFITS ARISING OUT OF THE USE OR INABILITY TO USE THE PROGRAM OR DOCUMENTATION 4 Term and Termination The term of this agreement shall be indefinite however this Agreement may be terminated by ICS in the event of a material default by Customer which is not cured within thirty 30 days after the receipt of notice of such breech by ICS Customer may terminate this Agreement at any time by destruction of the Program the Documentation and all other copies of either of them Upon termination Customer shall immediately cease use of and return immediately to ICS all existing copies of the Program and Documentation and cease all use thereof All provisions hereof regarding liability and limits thereon shall survive the termination of this the Agreement 5 U S GOVERNMENT LICENSES If the Product is provided to the U S Government the Government acknowledges receipt of notice that the Product and Documentation were developed at private expense and that no part of either of them is in the public domain The Government acknowledges ICS representation that the Product is Restricted Computer Software as defined in clause 52 227 19 of the Federal Acquisition Regulations the FAR and is Commercial Computer Software as defined in Subpart 227 471 of the Department of Defense Federal Acquisition Regulation Supplement the DFARS The Governm
132. Dissatisfied Overall satisfaction O O O O O How satisfied are you that the information in this book is Very Very Satisfied Satisfied Neutral Dissatisfied Dissatisfied Accurate O O O O O Complete o o o o o Easy to find O O O O O Easy to understand o o o o m Well organized O o O O O Applicable to your tasks O g E d Please tell us how we can improve this book Thank you for your responses May we contact you o Yes O No When you send comments to IBM you grant IBM a nonexclusive right to use or distribute your comments in any way it believes appropriate without incurring any obligation to you Name Address Company or Organization Phone No Readers Comments We d Like to Hear from You SC38 0496 06 Fold and Tape Please do not staple BUSINESS REPLY MAIL FIRST CLASS MAIL PERMIT NO 40 ARMONK NEW YORK POSTAGE WILL BE PAID BY ADDRESSEE IBM Corporation Thomas J Watson Research Center Hawthorne Data Explorer Development P O Box 704 YORKTOWN HEIGHTS NY USA 10598 0704 I l l E Fold and Tape UNITED STATES Cut or Fold Along Line mu A A E CG A A A fi A A A A A A q J lee Fold and Tape Please do not staple SC38 0496 06 Fold and Tape Cut or Fold Along Line E e Printed in U S A Printed in the United States of America G on recycled paper containing 1096 recovered post consumer fiber SC38 0496 06
133. Editor tep doc Tiqure 10 net Fort ach Getl acal Rote Cua pat zero Note that the top level visual program is itself a macro so the same behavior will occur if Done is placed in the top level visual program Illustrated in Figure 29 on page 55 is a macro that computes the Fibonacci Series defined by setting Y 1 Y 1 and by the recursion formula Y Y Y for k 3 4 5 In this example a two vector Y Y is used to store the elements of the series The GetLocal module has its initial value set to 1 1 The first Compute in the macro creates a new two vector consisting of Y Y using the expression a 1 a 0 a 1 The second Compute in the macro extracts Y from the two vector using the expression a 1 To terminate the loop the Y element of the series is checked against an external input x If Y is greater than x the loop terminates GreaterThan is a simple macro consisting of a Compute with its expression set to a gt b 1 0 An equivalent set of C language statements is a 1 b 1 do c b b b a a C while b lt x Chapter 4 Data Explorer Execution Model 53 m gt lt D ie S ct mall o le gt o x D Figure 28 Example 11 Visual Program Editor tep doc Tigqurell net input ForEachN Getl acal Ro site libcressent Outp ut 4 8 External Asynchronous Data Sources 94 Many applications of visualization tools
134. Execution Model 55 4 10 Parallelism for Data Explorer SMP 56 For completeness the notion of module parallelism is discussed here If you are developing visualizations or modules exclusively for use with the IBM Visualization Data Explorer running on a single processor workstation then these concepts are not applicable However if your visualizations or modules are to be run on both the IBM Visualization Data Explorer and IBM Visualization Data Explorer SMP then these concepts are important for achieving higher performance Every module that performs any significant amount of processing is parallelized that is the module makes use of all processors made available to Data Explorer to operate on the data Data Explorer uses explicit data partitioning as the primary framework for parallelism Data Explorer partitions the data into local self contained regions In general visualization modules then generate subtasks corresponding to partitions For more information about partitioning see Partition in BM Visualization Data Explorer User s Reference In general parallel programming is complex To help manage it Data Explorer simplifies the process by providing a simple fork join parallelism model to implement coarse grain shared memory parallelization data parallel Using data partitions read only objects and a single fork join mode simplifies the module writing task by avoiding the explicit use of locks in modules thereby reducing
135. File menu When an error occurs during the execution of a module the errant module can be located in the VPE by double clicking on the line in the Message window s text window containing the error message This selection causes the VPE s canvas to shift so that the indicated module is within the canvas s scrolled viewing area Errors for the last execution can also be located using the Next Error and Previous Error commands of the Message window s Edit menu These commands expose and highlight errors that occurred before or after the currently highlighted error If no error is currently highlighted then Previous Error indicates the last error during execution and Next Error indicates the first error The Message window can be configured so that it does not display certain message types in the text window by using the Error Messages Warning Messages and Information Messages buttons in the Message window s Options pull down menu If a toggle button is activated colored the corresponding message type is displayed The default behavior is to display all error warning and information messages You can change this default behavior with the infoEnabled IBM Visualization Data Explorer User s Guide warningEnabled and errorEnabled configuration options described in Appendix D User Interface Configuration on page 299 By default the Message window pops up when an error is displayed in the text window and does not automatically pop up when i
136. IBM Visualization Data Explorer User s Guide The irregular connections which are 30 tetrahedra object 2 class array type int rank 1 shape 4 items 30 data follows 10 3 4 1 3 10 9 6 10 1 7 6 6 1 3 10 6 1 0 3 10 1 4 5 5 1 8 10 8 5 2 1 10 8 7 1 5 8 11 10 15 6 9 10 10 6 13 15 13 10 7 6 15 13 12 6 10 13 16 15 17 10 11 8 10 17 16 13 17 8 14 13 13 8 10 17 13 8 7 10 n 22 15 16 13 15 22 21 18 22 13 19 18 S 18 13 15 22 zi 18 13 12 15 7 22 13 16 17 17 13 20 22 20 17 14 13 22 20 19 13 17 20 23 22 attribute element type string tetrahedra attribute ref string positions The data which is in a one to one correspondence with the positions object 3 class array type float rank 0 items 24 data follows 2 49 aon o0 de Los 9 4 e A PO W N 010 A Ww B amp B Co W 09 L OF Ww A 1 1 Es az 3 attribute dep string positions the field with three components positions connections and data object irregular positions irregular connections class field component positions value 1 component connections value 2 component data value 3 end Appendix B Importing Data File Formats 253 254 Example 5 Header and Data in Separate Files The following example uses a header file that contains no data Instead it refers to another file irregirreg2 bin that contains the data in binary format This example contains the same information as Example 4
137. IBM Visualization Data Explorer ee ee verre User s Guide Version 3 Release 1 Modification 4 sl IBM Visualization Data Explorer User s Guide Version 3 Release 1 Modification 4 SC38 0496 06 Note Before using this information and the product it supports be sure to read the general information under Notices on page xiii Seventh Edition May 1997 This edition applies to IBM Visualization Data Explorer Version 3 1 4 to IBM Visualization Data Explorer SMP Version 3 1 4 and to all subsequent releases and modifications thereof until otherwise indicated in new editions Make sure you are using the correct edition for the level of the product Order publications through your IBM representative or the IBM branch office serving your locality Publications are not stocked at the address given below A form for readers comments appears at the back of this publication If the form has been removed address your comments to IBM Corporation Thomas J Watson Research Center Hawthorne Data Explorer Development P O Box 704 Yorktown Heights NY 10598 0704 USA If you send information to IBM you grant IBM a nonexclusive right to use or distribute that information in any way it believes appropriate without incurring any obligation to you O Copyright International Business Machines Corporation 1991 1997 All rights reserved Note to U S Government Users Documentation related to restricted rights Use duplication or d
138. Image Display Render Image Display Render Image Display Render Image Display Render Image Display Render Image Display Render Image Display Image Display Display Image Display Image Display Image Display Image Pick Mark Unmark 0 1 2 3 4 5 6 7 8 9 dep attribute specifies which component the given component depends on The dependent component is specified by a String Object naming the component it depends on For example if the data is position dependent it has a dep attribute that is a String Object naming the 26 IBM Visualization Data Explorer User s Guide positions component A component with a this attribute is expected to be in a one to one correspondence with the component named in the attribute ref Attribute The ref attribute specifies which component the given component refers to The referent component is specified by a String Object naming the component it refers to For example the connections component generally has a ref attribute that is a String Object naming the positions component A component with this attribute consists of indices into the component named in the attribute der Attribute The der attribute specifies that a component is derived from another component and so should be recalculated or deleted when the component it is derived from changes For example the box component has a der attribute that is a String Object
139. Interface For Advanced Users 179 a 1ND ms o I x lt w gt e D O c A D A Creating an Execution Group To create an execution group 1 Select the tools on the VPE canvas that are to be placed in a single execution group This can be done by a rubber band selection or using a shift click selection or a combination of both 2 Open the Execution Group dialog box by selecting the Edit menu Execution Group option 3 In the Group Name text field enter a name for the execution group 4 Click on the Create button The newly created execution group will appear in the list of execution groups Note If a tool is a member of an existing execution group and it is placed into a new group the tool is automatically deleted from the existing group A single tool can not be a member of two execution groups Modifying Execution Groups Execution groups can be modified by adding new tools to the group or removing tools from the group To add tools to an Execution Group mb Select the tool or tools to be added to a group Open the Execution Groups dialog box by selecting the Edit menu Execution Groups option Select the name of the execution group to which the tool s are to be added Click on the Add To button NO E CO To remove tools from an Execution Group 1 Select the tool or tools to be removed from a group 2 Open the Execution Groups dialog box by selecting the E
140. Menu The options in this menu are discussed in 5 3 Using Online Help on page 65 Menu Bar Menu Bar A menu bar is displayed as the anchor window when the user specifies the menubar option on the command line to Data Explorer The menu bar displays the titles of five menus e File e Execute e Connection e Windows e Help 170 IBM Visualization Data Explorer User s Guide Menu Bar File Menu The File menu lists the following options Open Displays a dialog box for specifying a file path name to load a visual program or if the path name ends in a directory to show a list of visual programs in that directory To select a program click on the name See File Selection Dialog Boxes on page 116 for more information Program Settings Brings up a cascade menu with two choices e Save As saves the current settings for the visual program e g window placement interaction mode camera viewpoint interactor setup etc The settings are saved in a cfg file e Load loads previously saved settings from a cfg file Load Macro Loads a macro for use making it available in the tool palette A file selection dialog box appears for you to specify the desired macro file name See Loading Macros on page 152 Load Module Definition s Loads a module definition for use making it available in the tool palette A file selection dialog box appears for you to specify the desired module file name The executable you are using must
141. Represent interactors that output vector lists Selector stand ins Represent interactors that output values and strings representing a choice of one from many Selector list stand ins Represent interactors that output values and strings representing a choice of none one or more among many FileSelector stand ins Represent interactors that output both a fully qualified path name and an individual file name IBM Visualization Data Explorer User s Guide Reset stand ins Represent interactors that output one value when executed the first time after being set and another value thereafter Toggle stand ins Represent interactors that output one of two values Data Explorer allows the visual programmer to associate comments with each Control Panel To access these comments use the On Control Panel option of the Help pull down menu in the Control Panel about which you want to learn If no comments exist for the Control Panel the On Control Panel option is grayed out Building Control Panels Figure 60 illustrates the organization of a Control Panel Control Panel a J File Edit Execute Panels Options Help Show Map ToPlane off number of contour lines active only when Show MapToPlane is on E a Figure 60 Control Panel Window The menu bar discussed in Control Panel Menu Bar on page 162 contains categories of available menu options The open area is called the layout area You can create any
142. Rotation Globe Enables and disables the wire framed globe display in many of the view control options While the toggle button is pressed in the globe display is enabled See Rotating the Object on page 77 Rendering Options Displays a dialog box allowing you to choose hardware or software rendering options See Rendering Options on page 91 Image Depth opecifies the number of bits 8 12 or 24 per color See Image Depth on page 93 Throttle opecifies the minimum number of seconds to display each frame See Changing the Rate of Frame Display Throttle on page 93 Change Image Name Opens a dialog box in that you can specify a new title for the Image window See Changing the Title of an Image Window on page 93 Control Panel Access Allows you to specify which control panels and control panel groups are accessible from the Image Window s Open All Control Panels option under the Windows menu See Control Panel Access on page 94 Help Menu The options in this menu are discussed in 5 3 Using Online Help on page 65 Colormap Menu Bar 168 The Colormap menu bar displays the name of five menus you can use e File e Edit e Execute e Options e Help Colormap File Menu The Colormap File menu provides the following options New Replaces Colormap Editor values with default values Open Opens an existing Colormap as specified in the dialog box that appears If a current Colormap is on
143. S 9 zb Re REUS Se Xon doe Een EE ES ed 272 Array ODJECIS casam owe eon E DAL op DEE Y AUR CES EH d 272 Constant Array Objects 200000000002 ee 273 gridpositions Keyword len 274 Regular Array Objects 0 0 00 a 274 Product Array Objects dg dace badd seh but Ee ae EM EL 275 gridconnections Keyword len 275 Path Array Objects sua 24465 bk aa Ree Bee OM 0 d 276 Mesh Array Objects cf sede oboe neck mex B oa SEE XS oed 276 MIOMM ODCCIS Leu aa ee brides dep ub ande du qo de doge ee wha e cbe 277 SWING ODISGIS du ot ee ade oes o SE E a ee eg edes 277 LIGNPODCCIS d ri i Drm deed oce ok eae oe ke SE SS Db oe 277 Gamers ODIGGIS e da ove ica Ge a e 278 GIIBBed ODIGOCIS aaas Sore aia e 278 Screen OBECIS e uh de te Bee a E A 278 Data Mode Clause rn 278 Default Gla sG nus setas ua hop A QUE Ge Ud Ew d 279 O Scce tid a Rod eu e yt d i bust s dene dor Bat dis UT dt ed 279 B 3 CDP FICS dag dm eh Si oe ie 8 pe RUE GA e du bob es 279 BA NeEICDE FIGS cum zum tuna E das Lex nib Suet EE ANS H 281 Regular GIGS es sra ge Ee ce EUR B de dy tx ra e a 281 Contents VII viii B 5 netCDF Files Complex Fields susana A ER Irregular Arrays 2408444264864 4 644 POR EO Dh See RA Rs SONS DAS per de Od ae EB Re ee EXAMPOS econ Sie ee Da aed a le cosh is E eee ele A BHO FICS cassou 2 oS OSE eke Gas as Appendix C Environment Variables and Command Line Options C 1 Environment Va
144. Save Current Continuous Saving If Allow Rerendering is toggled on then the currently displayed image will be rerendered at a new resolution based on the settings of Output PPI and Image Size which can now be independently controlled You can use this option for example to save or print an image at a much higher resolution than is displayed on the screen You can also specify the number of pixels directly by setting the units of Image Size to pixels note that in this case it is meaningless to set the Output PPI Allows you to specify gamma correction applied to the output image The default is 2 For TIFF MIFF and PostScript image formats allows you to specify whether the image is saved in an image with colormap format For GIF image format this option is required by the format Allows you to choose from the set of available image formats Allows you to specify the file name to which the image should be written An appropriate extension for the chosen format will be added if you do not provide one Allows you to use a File Selection dialog to specify the output image file name Allows you to specify that the current image should be saved when the Apply button is pressed Allows you to save a series of images If you do not want the current image to be saved be sure the Save Current button is not set before pressing Apply When Continuous Saving is activated each image displayed in the image window will be saved to the
145. Sequencer 68 The Sequencer allows you to animate a visual image and is very easy to use The process is rather like running a video cassette tape You can play it forward or backward stop it pause and so on The Sequencer Control panel consists of 8 buttons as shown in Figure 33 Figure 33 Sequence Control Panel The first two buttons at top left are Loop and Palindrome The others are Step Counter Back 4 Forward e Stop 1 and Pause IBM Visualization Data Explorer User s Guide The button starts the animation sequence and plays forward The lt button plays the sequence in the opposite direction The button stops the animation and resets the animation to the beginning of the sequence while the button pauses the animation at the current frame The Loop button causes the animation to loop that is to go from beginning to end reset to beginning play to end and so on until terminated by either pause or stop The Palindrome button causes the sequence to be played from beginning to end and then from end to beginning Loop and Palindrome can be pressed simultaneously resulting in an continuous forward and reverse animation The button causes the behavior of the gt and lt buttons to become single step mode Each time one of these buttons is pressed the animation advances one frame in the specified direction The button opens the Frame Control dialog The Frame Contro
146. SetLocal preserving state 45 setting interactor attributes See interactor attributes setting output cacheability 214 setting render options 91 shape of an Array item 28 shared components 19 simplex vertices ordering 20 standard attributes color multiplier 27 dependence dep 26 derived der 27 element type 27 opacity multiplier 27 reference ref 27 standard components attributes dependence dep 26 derivative der 27 element type 27 reference ref 27 box 24 color map 23 colors front colors and back colors 22 connections 20 data 22 data statistics 24 edges and polylines 25 faces loops and edges 24 invalid positions and invalid connections 23 neighbors 24 opacities 23 opacity map 23 pokes paths and pick paths 25 positions 20 tangents normals and binormals 24 Start Server option 183 state preserving explicit 45 stopping execution 212 string constants in scripting language 193 String Objects in Data Explorer file format 277 structuring in modules 228 328 IBM Visualization Data Explorer User s Guide T tabs connecting 104 deleting 105 moving 105 tangents component 24 techniques for presentation 238 techniques visualization 217 television color resolution 237 line resolution 236 tensors in scripting language 196 Throttle option 93 Toggle interactor 147 tool icons 101 tools deleting 103 icons 101 moving 103 moving a group 103 placing 102 requesting general information 65 selecting 102 se
147. The DXDATA environment variable specifies a list of directories in which Data Explorer will search for data files If the data you wish to import are in one of the directories specified in the DXDATA environment variable then you do not need to specify the complete path name to the data in the Configuration dialog box for the Import tool You can simply specify the file name and the Import module will look in the specified directories for the data file The directories are searched in the order in which they are listed in the environment variable and the first occurrence of the data file is used An example of a statement that sets the DXDATA environment variable in the C shell environment is the following setenv DXDATA usr mydirectory mydata usr group groupdata where usr mydirectory mydata and usr group groupdata are two directories that contain data files Multiple directories can be listed with directory names separated by a colon DXHOST The DXHOST environment variable is the initial machine name of the workstation on which to run the executive If DXHOST is not specified then a default of localhost is used See 9 3 Connecting to the Server on page 183 for more information on how to connect to the server The host name should be the name that results when you issue the uname n shell command The rest of the environment variables and start up options are discussed in Appendix C Environment Variables and Command Line Optio
148. VPE you may drop the tools on a VPE in another Data Explorer session or in another VPE i e macro editor of the same Data Explorer session Interactors in control panels can only be dragged and dropped between panels in the same visual program If you drag a set of tools to an inappropriate window e g from a control panel to a VPE no action will occur If you drag a set of tools that includes transmitters the latter along with their corresponding receivers will be renamed to wireless 1 wireless 2 and so on Note To include an existing net file in the VPE use the Insert Visual Program option of the Edit pull down menu in the VPE The inserted visual program is placed to the right of the rightmost tool in the existing network Using Transmitters and Receivers It is possible to create large visual programs in Data Explorer Data Explorer provides two tools Transmitter and Receiver to maintain the modularity and readability of large programs These tools allow connections between input and output tabs without using a visible connecting line Using the Transmitter and Receiver tools allows you to separate visual programs into logical blocks For example the output of several logical blocks can be transmitted to another block that receives them collects them and produces the image Macros described in 7 2 Creating and Using Macros on page 149 provide another way to structure visual programs into logical blocks To remotely c
149. WARRANTY OF ANY KIND EXPRESS IMPLIED OR OTHERWISE INCLUDING WITHOUT LIMITATION ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE IN NO EVENT SHALL SAM LEFFLER OR SILICON GRAPHICS BE LIABLE FOR ANY SPECIAL INCIDENTAL INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE DATA OR PROFITS WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE AND ON ANY THEORY OF LIABILITY ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE Compuserve Incorporated The Graphics Interchange Format is the copyright property of Compuserve Incorporated GIF SM is a Service Mark property of Compuserve Incorporated Integrated Computer Solutions Inc Motif Shrinkwrap License READ THIS LICENSE AGREEMENT CAREFULLY BEFORE USING THE PROGRAM TAPE THE SOFTWARE THE PROGRAM OR THE ACCOMPANYING USER DOCUMENTATION THE DOCUMENTATION IBM Visualization Data Explorer User s Guide THIS AGREEMENT REPRESENTS THE ENTIRE AGREEMENT CONCERNING THE PROGRAM AND DOCUMENTATION POSAL REPRESENTATION OR UNDERSTANDING BETWEEN THE PARTIES WITH RESPECT TO ITS SUBJECT MATTER BY BREAKING THE SEAL ON THE TAPE YOU ARE ACCEPTING AND AGREEING TO THE TERMS OF THIS AGREEMENT IF YOU ARE NOT WILLING TO BE BOUND NY THE TERMS OF THIS AGREEMENT YOU SHOULD PROMPTLY RETURN THE CONTENTS WITH THE TAPE SEAL UNBROKEN YOUR MONEY WILL BE REFUNDED 1 License ISC remains the exclus
150. a Group Name Color and Opacity Add Delete Modify Close Figure 64 Control Panel Group Dialog Box The right side of the dialog displays the list of Control Panels Associated with each Control Panel is a toggle button to the left and an ellipsis toggle to the right The left side of the dialog is a list of the existing groups This list remains empty until a group is created At the bottom of the dialog box is a series of pushbuttons that are used for creating modifying and deleting groups Clicking on the ellipsis causes the corresponding Control Panel to be opened or raised to the front if it is already opened Clicking on the ellipsis when it is depressed closes the corresponding Control Panel and releases the toggle To create a Control Panel group e c El A o E cr m o m ma o E D md tn 1 Select the Control Panels that you want in the group by activating the corresponding left toggle button 2 Enter the name of the group in the text field next to Group Name Although it is not required select a name that is unique compared to the names of other Control Panels or other groups 3 Click on the Add pushbutton at the bottom of the dialog box The new group is added to the list of groups displayed on the left side of the dialog box The group is also added to the list of named Control Panels that is displayed by the Open Control Panel by Name option in the Windows menu Chapter 7 Graphical User I
151. a Group To import a particular dataset specify a number corresponding to that dataset as the variable parameter 0 corresponds to the first dataset The format parameter must be hdf 288 IBM Visualization Data Explorer User s Guide If dimension scales are specified Data Explorer uses these to construct positions otherwise positions have an origin of 0 0 and deltas of 1 0 along each dimension Data Explorer automatically constructs regular connections for either case m n mall o D T1 o ms 3 y cr un Appendix B Importing Data File Formats 289 290 IBM Visualization Data Explorer User s Guide Appendix C Environment Variables and Command Line Options C 1 Environment Variables 292 Path VanableS cs da amp amp ort HERB e RE EUR Sedo de E MEUS E 292 Other Environment Variables 292 C 2 Command Line Options 058 295 Copyright IBM Corp 1991 1997 291 lt o m mall o o o al D tn O ct mall o o E tn C 1 Environment Variables Path Variables The environment variables described in this section can be set in your login profile to customize Data Explorer Note also that these variables can be overridden on the command line see C 2 Command Line Options on page 295 Path variables specify a directory or directories to be searched for files Directories are searched in the order of
152. a control point simply drag it to the desired location Control points cannot be moved past each other this facilitates the creation of step functions They can be moved as a group by doing the following 1 Draw a selection box around the points you want in the group 2 Position the mouse pointer on any one of them and drag it to the desired location All of the control points move together within the constraints of the unselected points above and below The movement of control points can be constrained either horizontally or vertically by selecting the Constrain Horizontal or Constrain Vertical option from the Colormap Edit menu see Colormap Edit Menu on page 169 By constraining horizontally after adding a precise control point you can move the point to change the color or opacity mapped to specific value without changing the value itself Chapter 6 Graphical User Interface Important Windows 123 124 Creating Waveforms To create waveforms select the Generate Waveforms option from the Edit pull down menu The Generate Waveforms dialog box appears Figure 59 on page 125 This dialog box allows you to e Choose the shape of the waveform from an options box Waveforms can be step square or sawtooth e Choose the range of the waveform from an options box Full creates a waveform that runs the full length of the selected area Selected creates a wave that runs the distance between two selected control points
153. a is stored explicitly isosurface A surface in three dimensional space that connects all the points in a data set that have the same value isovalue The single value that characterizes each and every point constituting an isosurface By default this value is the average of all the data values in the set being visualized item A single piece of data in an array J join An operation that merges two or more computation paths L line An element that connects two positions in a field macro In IBM Data Explorer a sequence of modules that acts as a functional unit and is displayed as a single icon Macros can also be defined in the Data Explorer scripting language member An individual unit or object in a group A collection of members makes a group menu bar In windows a horizontal bar that displays the names of one or more menus or tasks When the user selects a menu a pull down list of options for that menu is displayed mesh array A compact array that encodes multidimensional regularity of connections lt is a product of path arrays In a mesh array which positions are connected to one another is implicitly rather than explicitly defined module 1 In IBM Data Explorer a primitive function such as Isosurface 2 In a VPE window the icon for a module 3 A program unit that is functionally discrete and identifiable i e it can be assembled compiled combined with other units and so on N
154. a multipage panel See also scroll palette A displayed grouping of available selections such as functions modules or colors in a user interface window palindrome In Data Explorer a mode of running an entire sequence first in one direction then in the opposite direction panel A formatted display of information on a display screen See also window Synonymous with display Glossary 319 e O o Ye Y m lt partitioned field A composite field created by partitioning a single field into a collection of separate fields used for parallel processing and data management purposes path array A compact array that encodes linear regularity of connections It is a set of n 1 line segments where the ith line segment joins points and 1 pixel Picture element In computer graphics the smallest element of a display surface that can be independently assigned color and intensity polygon 1 Any multisided planar figure 2 A face of a three dimensional object position dependent data Data that are in one to one correspondence with positions positions component A component that consists of a set of dimensional points in a field probe A list of one or more vectors that represent points in a graphical image Probes can be used with Data Explorer tools that accept vectors as input such as ClipPlane and Streamline or to control the view of an image product array A compact array that encodes
155. ables corresponding to the output formal parameters are initialized to NULL Those variables corresponding to the input formal parameters are initialized in the manner described in the preceding section If an input and an output formal parameter both have the same name then they share a single parameter and are initialized to the value passed as input when the function is called Macro Expansion When the function being called is a macro the macro is effectively expanded in line after first constructing the necessary environment for its input and output parameters This guarantees that the partial orderings defined by macros are maintained Variables Used in Macros 208 The Data Explorer allows you to use variables on both the left and right sides of a function assignment that is as both left side and right side Variables as Left Side Values All assignments in a macro s environment affect variables that are local to the macro These variables if they do not already exist are created in the macro s environment when they are first used on the left hand side of an assignment expression Thus a variable outside of a macro cannot be modified with that macro IBM Visualization Data Explorer User s Guide The only way to make such a change is to propagate a new value out of the macro using its output formal parameters and to use this returned value in an assignment statement in the enclosing environment Given these semantics it i
156. ackets Each of the vectors contained in a matrix must have the same length as all of the others The following are all valid matrices 1 0 0 o 0 1 0 O O 0 1 O O 0 O 1 a 4x4 identity matrix 0 707 0 707 0 000 a 45 degree rotation 0 707 0 707 0 000 about the Z axis 0 000 0 000 1 000 1 1 1 1 2 2 2 2 a 2x4 matrix Tensors Tensors are a generalization of the concept of vectors On one hand the elements in a tensor have meanings that are independent of the coordinate system in which they are embedded On the other hand one can associate certain metrics to them that vary among coordinate systems In general a rank n tensor can be formed by surrounding k rank n 1 tensors with square brackets Note that scalars vectors and matrices are rank 0 1 and 2 tensors respectively As with the matrices all of the subtensors must have the same shape The following are valid tensors LEEL Oxabcd 111 a 1x1x1x1x1 rank 5 tensor 1 0 0 a 3x3x3 rank 3 tensor with 0 0 0 l s on the diagonal 0 0 0 o 0 0 0 1 0 o 0 0 o 0 0 0 0 0 o 0 1 Lists Unlike the vector matrix and tensor constructions that aggregate several lower dimensional data elements into a single higher one the ist construction collects several homogeneous elements together so that they can be handled as a single entity while still retaining their individuality Lists are constructed by enclosing a sequence of
157. acro files are saved as visual programs and therefore have net extensions it may be helpful to organize them in a separate directory to distinguish them from other visual programs Creating Macros the Easy Way For use in other visual programs or to simplify the network that appears in the VPE canvas you may want to combine some of the tools of a visual program in a single macro This can be done directly and easily in the VPE window if the selection includes only allowed tools See preceding Note page 149 1 On the VPE canvas use the left mouse button to create a selection box around the tool icons to be included in the macro It may be necessary to first reposition some of the icons in order to simplify this boxing process Note Alternatively you can shift click on all the desired tools 2 Select Create Macro from the Edit pull down menu 3 In the Create Macro dialog box that appears enter the required information macro name category description and file or path name The default category macro and description new macro can be changed or left as they are 4 Click on 0K Unless you specified otherwise the macro will be saved in the directory from which Data Explorer was started under the name you specified input and output names can be changed by editing this saved file using the Visual Program Editor The new macro will appear in the category specified under the name specified in the
158. actor to a Transmitter Then pick up this channel with Receivers throughout the visual program for instance as an input to a Format module the Format template must include a s as a place holder for a string input You will find this especially convenient when you give your visual program to a colleague who will naturally place the visual program and data files in a differently named subdirectory on your colleague s workstation By simply changing the name in the Interacior to identify the name of the work directory on the new machine the visual program will be back in business If you had hard coded the name of the path into several modules on your visual program the new user would have to hunt down all these references and do a lot of extra typing Documentation When you author a visual program or create a macro a special kind of visual program discussed in Creating Macros on page 149 you should describe its function using the Comment capability found on the Edit menu in the VPE This Comment will be viewable by other users or yourself when they run your visual program and choose the Help menu item Application Comment Another brief kind of documentation is available in each module Double click a module and its default name is shown in the Notation box at the top of the module description dialog box You can add to or change this notation This is particularly helpful in Compute modules to describe the meani
159. age to zoom in or out depending on which mouse button is pressed If the left button zoom in is pressed the portion of the image inside the rectangle is enlarged to fill the Image window If the right button is pressed zoom out the image displayed in the Image window is reduced to the size of the rectangle Note You can also enable Zoom mode by using the intrctnMode parameter to the Image tool see Image in BM Visualization Data Explorer User s Reference For both orthographic and perspective projection zooming in makes the object appear larger in the Image window while zooming out makes it appear smaller However the way that this is accomplished is different depending on which projection method is selected e While using perspective projection Zooming in or out changes the view angle without changing the look from point e While using orthographic projection zooming in or out adjusts width of the image The camera look from point does not change because with orthographic projection the look from parameter merely specifies a direction not a location in space For more information about the projection methods see Changing the Projection Method on page 76 IBM Visualization Data Explorer User s Guide Changing the Look to Point Data Explorer maintains the look to point at the center of the Image window You can use the Roam mode to change the look to point To change the look to point 1 Select the Roam mode by u
160. age window causes all of its child windows to close Before the window closes a dialog box appears to request confirmation The Windows menu offers the following options Open Visual Program Editor Opens a VPE window containing the current visual program This option is disabled if you have not loaded a visual program or if the VPE is the anchor window Open All Control Panels Opens all the Control Panels and macro Control Panels for the current visual program unless the macro Control Panels are already contained in another Control Panel This option is disabled if you have not loaded a visual program Open Control Panel by Name Opens a cascade menu from which you can select the name of the control panel to open Open All Colormap Editors Opens all the Colormap Editors for the current visual program See 6 3 Using the Colormap Editor on page 119 Open Message Window Opens the Message Window that displays error and warning information about your execution See 8 2 Using the Message Window on page 174 Help Menu The options in this menu are discussed in 5 3 Using Online Help on page 65 Message Window Menu Bar 172 The Message window menu bar displays the names of five menus e File e Edit e Execute e Options e Help Message Window File Menu The Message window File menu provides the following options Clear Clears the Message window Log Allows you to designate a file that will receive all subsequent
161. ageSize resource If this is set to zero the default then the Print Image dialog box chooses the resolution Appendix D User Interface Configuration 303 c s Cc o E h mall o Q e o cr mall o e E DX printImageSize Specifies the default size of PostScript images printed from the Print Image dialog box available from the Image window If specified this option overrides the printImageResolution option The value is a string in the same format as that accepted by the dialog box for example 8 8x x10 8x10 Units are those indicated by the metric option The default value is determined by printImageResolution option DX restrictionLevel Combines options to make it easier to build applications on top of Data Explorer The string value must be one of the following minimum intermediate maximum DX savelmageFormat Combines the restrictions implied by the following options noEditorAccess noInteractorEdits noInteractorMovement limitImageOptions noScriptCommand noCMapSetNameOpt i on Combines the restrictions implied by minimum restriction level plus the following options noImageRWNetFile noOpenAI I Panels noImageLoad noPanelEdit noPanelOptions noPGroupAssignment Combines the restrictions implied by the intermediate restriction level plus the following options noPanelRWConfig noImageSaving noPanelAccess noCMapOpenMap noCMapSaveMap opecifies the default file f
162. aints on an axis choose the None option While in Roam mode the center and right mouse buttons have the same functions as they do in Rotate mode Panning and Zooming into and out of the Image You can zoom into or out of the image and change the look to point at the same time using the Pan Zoom mode In this mode the left and right mouse buttons work the same as they do in Zoom mode except that the point on the image where you initially click becomes the new look to point and therefore the center of your zoom action As you move the mouse pointer away from the point where you initially clicked the rectangle enlarges As you move the mouse pointer towards the point where you initially clicked the rectangle shrinks For information about the Zoom mode see Zooming into and out of the Image on page 78 To select Pan Zoom mode select its option from the Mode option box or use the Ctr1 G accelerator key Note You can also enable Pan Zoom mode by using the intrctnMode parameter to the Image tool see Image in BM Visualization Data Explorer User s Reference Navigating in a Scene You can move your camera within the scene in all directions using the Navigate mode As well as being able to change your view direction like the other modes Navigate also lets you move through an object and view it from the inside out When you use Navigate mode the camera is automatically changed to perspective rendering You can also move your camera
163. aking it available in the tool palette A file selection dialog box appears for you to specify the desired module file name The executable you are using must also include this module See 9 2 Loading and Using Outboard and Runtime Loadable Modules on page 183 Save Image Displays a dialog box that allows you to save the image and specify the format layout resolution and page size of the image See Saving an Image on page 94 Print Image Displays a dialog box that allows you to specify the format layout resolution and page size of the print See Printing an Image on page 97 Close or Quit Closes the Image window If you opened the Image window from the VPE Close appears is the option If you started Data Explorer with the Image window as the anchor Quit is the option Quit is grayed out if the Execute menu title is highlighted You must select the End Execution option in the Execute pull down menu or if the Sequencer is running you must stop it or pause before quitting Image Window Execute Menu This execute menu is identical to that of the Visual Program Editor window See VPE Execute Menu on page 160 for descriptions of the Execute options See also 5 4 Executing a Visual Program on page 67 Image Window Windows Menu The Windows menu allows you to open a VPE window containing the program layout or the Control Panels associated with the visual program All windows created from this Image window become its
164. al Symbols 1001 1035 apostrophe curly open apostrophe curly close backslash bullet copyright cross product degree emdash endash exclamation franc guillemet open guillemet close guillemet single open guillemet single close infinity integral interrogatory minus 310 IBM Visualization Data Explorer User s Guide Table 10 Page 2 of 2 Additional Symbols 1001 1035 The octal values for the English and Greek character sets in the pitman or area font are the same as those illustrated in Table 8 on page 309 and Table 9 on page 310 European National Languages characters are provided using single octal values or using a combination of values see Table 11 For example a is produced using 252a and 1 is produced using 12211237 Additional special symbols are provided with octal values 001 to 035 see Table 10 on page 310 LEES ER E E The following illustrates how you could produce a caption that contains the string Jag r h r p semester caption Caption Jag 252ar h 252ar p 213a semester font pitman camera AutoCamera caption Display caption camera Table 11 Page 1 of 2 European National 1255 Language Symbols and Characters 1200 to accentAcute To type a acute enter 201a To type acute enter 201 237 E AccentAcute Uppercase except enter 202A Uppercase except AccentAcute Uppercase Acute To type A acute accentGrave AccentGrave 20 20 20 20
165. al program The dialog box can also be used to locate transmitters and receivers by the names you give them You open this dialog box by selecting the Find Tool option from the Edit pull down menu Chapter 6 Graphical User Interface Important Windows 111 112 Find Tool Figure 52 Find Tool Dialog Box Figure 52 illustrates the layout of the Find Tool dialog box The dialog consists of three parts Tool list Selection Pushbuttons Displays an alphabetized list of all the tools in the visual program currently displayed on the VPE canvas If the visual program contains transmitters receivers probes or picks then the tool name e g Transmitter is displayed instead of the user supplied name Displays the current tool to be located When the dialog first appears this field is blank To change the selected tool either click on the desired tool name or click on the Undo or Redo buttons or type the name of the tool transmitter or receiver directly in the selection text field The next time you open the dialog box the selection field will display the last selection you made Find initiates the search for the selected tool Undo undoes the last find and updates Selection Redo redoes an undone find and updates Selection Restore restores the canvas to the location at the time the dialog box was opened Close closes the dialog box To locate a particular tool on the canvas 1 Click on the tool name 2 Click
166. al tools are 0 Chapter 4 Data Explorer Execution Model 47 rm X D ie cr mall o le gt o O D o itm si tk e o PE ui ua T Fort achbMembes Measure Output SetLocal Figure 23 Example 6 Illustrated in Figure 24 on page 49 is a visual program that saves the current camera settings for use in the next execution of the program The initial value of GetGlobal is NULL The Inquire module checks to see that the output of GetGlobal is a valid camera object If it s not a camera object then Route is used to ensure that the Display module is not scheduled to run When a new camera is chosen for example by rotating the object in the Image window the Display window will show the image using the previous execution s camera settings 48 IBM Visualization Data Explorer Users Guide Figure 24 Example 7 Visual Program Editor tinp doc savecamera net maguire Palito Colors Image SetGlodal As mentioned previously in a true data flow implementation all modules are pure functions i e their outputs are fully defined by their inputs Hence processes are stateless with no side effects A macro in Data Explorer is considered to be a function with its outputs being fully defined by its inputs This is no longer true when a GetGlobal module is added to a macro GetLocal maintains state information only within one execution of the macro GetGlobal maintains state information between executions
167. ame from a Control Panel Image window and VPE To open a Control Panel by name from any of these three primary windows do the following 1 Select the Open Control Panel by Name option from the Windows pull down menu in the VPE and Image window or from the Panels pull down menu in the Control Panel This reveals a cascade menu with a list of the existing Control Panels 2 Click on the name of the Control Panel you wish to open The desired Control Panel appears Adding Comments to a Control Panel If other people are going to use the visual programs you create it may be desirable to document how the interactors are used You can associate comments with the Control Panel to describe how it uses the interactors to control input values in the visual program To add comments to a Control Panel 1 Select the Comment option from the Edit pull down menu in the Control Panel A dialog box appears with a large text field in which you can type the comments f a comment has been entered previously for this Control Panel it is displayed in the text field 2 Enter your comments in the text field editing the same way as with any text field This text field has multiple lines you can break the lines using the Enter key or allow them to flow automatically as you type 3 Click on OK to store the comments e c A o E cr o m ma o E D l tn These commenis can be viewed but not edited by using the On Control Pan
168. an SGI will no longer fail due to lack of resources resulting from fork SelectorList interactors can now contain more entries Cache management has been improved It is now possible to save texture mapped images both from the Image window and by capturing the output of Display See ReadlmageWindow on page xxxii XXXIV IBM Visualization Data Explorer User s Guide Chapter 1 Overview 2 E 1 1 Overview of Data Explorer sacs tee bak o oS sadias oe DAS 2 p dice SYSICMMOUUCINTe pucca woos DES Ge ey e EEUU od s 3 Graphical User Interface 0 00 00 000000008 3 EXGCUIVG pasaga hos dees Ee XXE Se kie duh AVE RUE ROSS Red 4 MOQUIES oacs 2544434540408 4444436824245 b 8442445 4 Data Management 2 lll 4 How the Data Model Facilitates Interoperability 4 O Copyright IBM Corp 1991 1997 1 This book describes the IBM Visualization Data Explorers which you can use in a workstation environment Data Explorer is a visualization system that can be used in many application areas and with a variety of data representations to extract useful information from complex data 1 1 Overview of Data Explorer 2 The Data Explorer graphical user interface allows end users to perform tasks at various levels of sophistication For example a user can use the user interface to apply data and adjust input values to an existing visualization process A slightly more advanced user can construct a new vi
169. an by using the Frame Control panel If the Sequencer is data driven then the information transmitted by connection or set in the Configuration dialog box overrides values set in the Frame Control panel A data driven Sequencer allows you to create visual programs that will work with a variety of input data sets without your having to reset Sequencer attributes For example if the Sequencer minimum is set to zero and its maximum to the number of steps in a series it can be used to drive the Select module to select each member of the series in turn The inputs are summarized in the corresponding module description in BM Visualization Data Explorer User s Reference Each time an input to a data driven Sequencer is changed for example by importing a new data set the Sequencer is reexecuted updating its attributes IBM Visualization Data Explorer User s Guide Error Messages If Data Explorer encounters an error in your visual program while executing it an error message is displayed in the Message window see 8 2 Using the Message Window on page 174 The name of the tool in which the error occurred is shown in the window Pull down menu options enable you to quickly locate the tool that caused the error The title of the tool icon in the visual program that caused the error is displayed in a different color in the VPE until you execute the program again When the error occurs execution stops only in the path where the error is othe
170. and another wind velocity or you can just use the default name data if you only have one data component The dx file format provides the most flexibility for describing data sets to Data Explorer But many researchers produce fairly straightforward arrays of numbers mapped onto regular or deformed regular grids If your data are already written out in such a form you may not need to convert your data files into the native dx file format Instead Data Explorers General Array Importer can read your data directly given a small header file that you create to tell the General Array Importer the name of your data file and its dimensions see Chapter 5 Importing Data on page 61 in BM Visualization Data Explorer QuickStart Guide lt mall o tn o mall o N o cr mall o o E This shorthand description is enough for Data Explorer to convert your data structure into a Field when it reads your raw data file You will still find it valuable to understand the components of a Field because once you begin using the Data Explorer visual programming language you will have direct access to these components Much of the power and flexibility of the visual programming language is derived from our ability to access and manipulate Field components in a variety of ways 2 2 Visual Programming The Basics The Field description represents a mapping between your actual data sampling space and the Data Explo
171. anels Interactors and Macros 147 148 File Selector Filter lusrilpp dx samples data dX Directories Files FacesLoopsEdges dx usr lpp dx samples data FacesLoopsEdges hole dx Polylines dx cloudwater dx datadepconnections dx datawithattribute dx deformedreqular dx z group dx R 7 5 9 Rp z Selection fusrilppidxfsamplesidataf OK Filter Close Apply Figure 74 File Selection Dialog Box If an interactor is data driven then the information transmitted via connections or set in the Configuration dialog box overrides the values set via the Set Attributes dialog box and causes the corresponding values in the Set Attributes dialog box to be grayed out Data driven interactors allow you to create visual programs that will work with a variety of inout data sets without the need to reset the interactor attributes to be in a range appropriate for the data being used For example a scalar interactor controlling an isosurface value can be data driven by connecting the input data field to it The interactor is then automatically set so that its minimum and maximum span the range of the data Data driven interactors have a data input to which an input data field may be connected In this case the interactor automatically chooses the minimum maximum and increment However if you would like to have more control over the exact values that are used the interactors allow you to specify them directly throu
172. ap front colors back colors opacities opacities opacity map tangents normals binormals connections invalid connections pick paths pickpaths neighbors box data statistics float 3 surface or volume colors char color index see color map float 3 color map indexed by colors component float 3 colors of front of surface float 3 colors of back of surface float opacity of surface or volume char Opacity index see opacity map float Opacity map indexed by opacities component float 3 float 3 float 3 curve tangent curve or surface normal second curve normal int A interpolation elements char which interpolation elements are invalid faces described as a collection of loops loops described as a series of edges edges described as a series of points picks paths pickpaths int p pointers to connection neighbors float 2n Zn corners of a bounding box statistics for data component Positions Component The positions component is an Array Object specifying a set of n dimensional positions For data on a grid with regular positions the positions can be encoded compactly by Hegular and Product Arrays which are described in Arrays on page 28 Connections Component The connections component provides a means for interpolating data values between the positions Each item of the connections Arra
173. apped with the same tool as a meteorologists 3 D volume but the visual output will be appropriately different for the different inputs Similar to Isosurface s contour lines is the output of the Band module This yields filled regions between contours these bands can be colored by a color map or AutoColor to yield the kind of image frequently used to show temperature distributions on a weather map IBM Visualization Data Explorer User s Guide Mapping There is a very useful module called Map in Data Explorer that permits you to map one data set onto a Field defined by another data set For example in our rain cloud data we have measured temperature and cloud water density throughout a volume We learned earlier how to make an isosurface of temperature equal to 12 degrees C Now it may be instructive to observe the cloud water density associated with this temperature isosurface The operation we wish to perform is to use our temperature isosurface with its arbitrary data defined shape as a sampling surface to pick out the values of cloudwater density as they occur throughout the volume That is conceptually we will dip the temperature isosurface into the cloudwater volume Wherever the isosurface comes in contact with the cloudwater volume the values that stick to the isosurface represent the values of cloudwater density that occur at that intersection But remember that the isosurface was created using temperature data The isosurface o
174. ar Fields e The connections component depends on the dimensionality of the data variable such that O none 1 lines 2 quads 3 cubes and so on e Each positions variable is considered a term of a Product Array to form the positions component e All variables of 0 dimension are imported as the data component of a Field with no positions and no connections If the LATITUDE and or LONGITUD variables exist the other variables are considered data components of Fields with positions and no connections where the positions are those latitude and longitude variables You can construct an appropriate Field with positions and connections from the variables that are imported through modules like Construct Regrid and Connect e All variables of 1 dimension are imported as the data component of a Field of lines where the positions would typically be a scalar i e the one independent variable If the LATITUDE and LONGITUD variables exist then the positions are a 2 vector constructed from the latitude and longitude Arrays but still a line One dimensional variables in CDF may be of one of three distinct classes which are NOT distinguished in the way they are stored in a CDF file 1 true 1 dimensional or line data 2 indexed point data or 3 indexed mesh data You must know which class the variable belongs to in order to ensure that Data Explorer processes the data in an appropriate fashion The first class is handled correctly For the secon
175. arameters see the preceding description of grid The syntax for the positions keyword is in addition to the syntax given in 5 3 Header File Syntax Keyword Statements on page 85 in BM Visualization Data Explorer QuickStart Guide bytes n positions format type lines n skip width marker string This syntax may be used only if you are specifying regular positions origin and delta pairs for each dimension As described in BM Visualization Data Explorer QuickStart Guide the origins and deltas are specified as origint delta1 origin2 delta2 etc format is the format in which the grid values will be found and must be one of the following binary ieee text or ascii The first two parameters are synonymous as are the second two For type and the other parameters see the description of grid above A question mark signifies that the default should be used origin 0 or delta 1 for a particular origin or delta value This would be used if only the origins or only the deltas are to be found in the file B 2 Data Explorer Native Files The Data Explorer native file format encapsulates the Data Explorer data model on disk or on standard output as the result of an external conversion program This file format is comprehensive and flexible in that it can represent any of the Objects created in Data Explorer Thus any Object can be exported at any point A data file in this format can be imported into a Data E
176. are the fundamental Objects in the Data Explorer data model A Field represents a mapping from some domain to some data space The domain of the mapping is specified by a set of positions and generally a set of connections that allow interpolation of data values for points in the domain between specified positions The mapping at all points in the domain is represented implicitly by specifying data that are dependent on located at the sample points or on the connections between the sample points cell centered data This simple abstraction is sufficient for representing a wide range of things For example you can describe 3 dimensional volumetric data whose domain is the region specified by the positions and whose data space is the value associated with each position Two dimensional images have a domain that is the set of pixel locations and a data space that consists of the pixel color Two dimensional surfaces imbedded in 3 space that is traditional graphical models can have a domain that is the set of positions on the surface and a data space that is for example the set of data values on that surface If the data are dependent on the given positions then a data value at a point other than those given is found by interpolation within the connection in which the point resides If the data is dependent on connections then the data value is assumed to be constant within each connection lf no connections are specified then there is no
177. art of the execution of a script or network The definition of a Camera Object is included here for completeness object number class camera type orthographic name from number number number to number number number width number resolution number aspect number up number number number angle number color number number number color name Clipped Objects Screen Objects A Clipped Object represents one Object specified by the of keyword clipped by another Object specified by the by keyword Generally Clipped Objects are not specified in input data files but rather are generated as a result of using the ClipPlane or ClipBox module object number class clipped by number of number name name name file file file file file file number file file number file file name file file name Screen Objects represent an Object transformed so as always to face the camera See Chapter 15 Rendering on page 149 in the IBM Visualization Data Explorer Programmer s Reference for more information specifically 15 5 Screen Class on page 154 object number class screen world J behind of number name viewport inside name pixel infront file file stationary file file number file file name Data Mode Clause You can specify a default data section format using the data mode clause This clause can be used as part of an Array Object definition or as a stand alone clau
178. arting value until the resultant value passes the ending value Each of the following produces the same list 11357 9 1 9 2 l1 9 2 1 10 2 Note Spaces are required around the operator Lists specified using this notation will be represented as a Regular Array of 1 vectors See Arrays on page 28 for a discussion of Array types 10 4 Building Expressions and Statements You can use the basic elements of the Data Explorer scripting language to build expressions and assignment statements Most statements in the scripting language are assignment statements however a special group of script commands with their options can form a statement These commands are described in 10 7 Using Data Explorer Script Commands on page 206 The following sections tell you how to write Data Explorer script expressions and statements Arithmetic Expressions You can combine scalar values and variables that contain values with the arithmetic operators listed below to derive new values Lists of scalars can also be combined if the lists have the same cardinality number of elements or if one of the lists has just a single element If the two lists being operated upon have the same number of elements then the operator is applied to the corresponding element pairs in each list to produce a new list of the same cardinality If one of the lists has just a Chapter 10 Data Explorer Scripting Language 197 single element then the
179. at 20 then 10 would have a color halfway between blue and red On the default color map this would be green When we ask Data Explorer to color map our data it examines each data value performs a linear interpolation between the minimum and maximum values to find the color associated with that interpolated value in the color map and colorizes the object at all points containing that data value with that color If we change the maximum value in the color map to 30 the measured data value of 10 taken from the same data set as above will now map to a cyan color part way between blue and green On the other hand we could keep our same extreme values but manipulate the color map s color distribution in such a way that any value has any color we like You can learn the details about this capability in 6 3 Using the Colormap Editor on page 119 The best way to learn about the power of color mapping is to take some sample data color map it then manipulate the settings in the Colormap Editor you have connected to the Color module your data Field passes through Note Choose Execute on Change from the Colormap Editor Execute menu and you will see the data change colors as soon as you make a change in the Colormap Editor For instance you can create sharp color discontinuities by placing two control points close together vertically on the Hue control line then dragging one horizontally away from the other This can be used to indicate a sha
180. ata Explorer Programmer s Reference 5 1 Starting Data Explorer To run Data Explorer using a workstation you must have e An account on the workstation e f the executive portion of Data Explorer is to be executed on a remote workstation then a rhosts file in your home directory should contain the name of the machine on which the user interface will run The permissions for the rhosts file should be set to 600 read and write only by the owner 58 IBM Visualization Data Explorer User s Guide You can start Data Explorer in any of several modes n all cases you must first do the following 1 Log on to your workstation 2 Start an X Window System running with the Motif or the appropriate window manager If you are going to create modify and execute visual programs start Data Explorer initially in the Visual Program Editor and connect to the executive server by typing dx edit program where program which is optional names an existing visual program If you plan to execute a previously created visual program start Data Explorer initially in the Image window and connect to the executive server by typing dx image program Or dx menubar program where program is the name of an existing visual program You may want to start the user interface without connecting to the executive For example you may want to work on a visual program or macro but may not plan to execute it until some later time In that case
181. ate pair and the data values may encode such things as surface reflectance in the ultraviolet By associating each data value with a latitude longitude position we produce position dependent data This implies that data values should be interpolated between positions using the connections grid if one is present Data Explorer works equally well with position dependent and connection dependent data see Figure 1 on page 10 Generally the decision about which dependency the data has is made by you at the time of data collection or simulation There is a simple way in Data Explorer to convert either dependency to the other See Post on page 242 in IBM Visualization Data Explorer User s Reference We can extend our data sampling into three dimensions where appropriate In that case we identify each grid position with three coordinates These coordinates form the corners of volumetric elements and the entire sample space is called a volume A volumetric element may be a rectangular prism like a cube or a tetrahedron a solid with four triangular faces not necessarily equilateral Connections and Interpolation In the cases just discussed we made the implicit assumption that there is a logical connectivity between adjacent members of our 2 dimensional or 3 dimensional grid positions The path connecting grid positions is called a connection in Data Explorer For a surface 2 or 3 dimensional positions connected by 2 dimensional conn
182. ation techniques and the Data Explorer modules associated with them e Animation e Annotation on page 218 e Color Mapping on page 219 e Contours and Isosurfaces on page 221 e Mapping on page 223 e Normals and Shading on page 224 e Plots and Histograms on page 227 e Rubbersheet on page 227 e Transformations and Structuring on page 228 e Vector Fields on page 229 e Volume Rendering on page 231 The Sequencer tool is the primary device used in Data Explorer to produce animation or motion control There are two basic types of animation show a series of steps one after another or cause an object to move or rotate or change scale in order to study it from different points of view Since many data sets are measured at a series of different times your data may have a time value associated with each measurement set There are two ways to read in these time step data files in order to study the dynamic process you have measured In one scheme you can collect all your data files into a Series a special Group of Fields understood by Data Explorer Each Series member can represent a data collection event at a certain time Series do not have to be based on time you may have a set of experimental measurements made at different voltages e g a voltage series Each series member is assumed to have the same type scalar vector etc and the same dimensionality 2 D 3 D etc but the data and e
183. ator jumps to the mouse pointer location and the value changes accordingly Isosurface controls 4 J File Edit Execute Panels Options Help Scalar 45 00000 Figure 67 Dial Style The dial indicator can move clockwise or counterclockwise as many times as determined by the increment values and minimum and maximum that are set These limits can be set in the Set Attributes dialog box which you can display by selecting the Set Attributes option on the Options menu When the interactor reaches the limit it can no longer be turned in that direction Slider The Slider Figure 68 enables you to enter a value by either moving the tab on the Slider typing in a number or clicking on one of the arrow buttons to increase right arrow or decrease left arrow a displayed value Isosurface controls Ea ig File Edit Execute Panels Options Help Scalar Sjaueg 042U0 219 S 45 00000 Figure 68 Slider Style Text The Text style Figure 69 on page 144 enables you to simply type in a value For more information on how to enter and modify text in a field see Editing Text Fields on page 64 Chapter 7 Graphical User Interface Control Panels Interactors and Macros 143 Isosurface controls Scalar 445 0 Figure 69 Text Style String Interactor The string stand in has one style of interactor which cannot be changed This interactor consists of a text field Figure 70 For information on h
184. ault inherited from the input tab to which the Input tool is connected but many of them can be changed from the Configuration dialog box The fields in the Configuration dialog box for the Input tool are Position Specifies the tab position this input occupies on the resulting macro icon By default the tab positions are assigned in the order that you select the Input icons from the tool palette For example the first icon you drag over to the canvas has position 1 the second has position 2 and so on If an input is deleted from a macro the position of the other inputs are not automatically changed For example if the input at position 2 of a macro with three inputs is deleted the other two inputs Chapter 7 Graphical User Interface Control Panels Interactors and Macros 149 Figure 75 Example of a Macro 150 Name Type Default Value Description Visual Program Editor Map oPlane AutoC otor HubberSheet Output remain at positions 1 and 3 with position 2 left empty Each input must have a different value for position Specifies the name of the input This field must begin with a letter and no spaces or special characters except for the at symbol and the underscore character _ are allowed Specifies the type of the input The type conforms to the inputs that the Input tool is connected to When connecting it to more than one input the Input tool assumes the type of the most restrictive input t
185. ave Image dialog box will be grayed out as appropriate if the corresponding parameter is set using these parameters to the Image tool See Image on page 160 in BM Visualization Data Explorer User s Reference If you select specify an existing file and select one of the RGB MIFF or YUV formats the image will be appended to the existing file If you select TIFF or PostScript formats the existing file will be overwritten by the new image When you want to save another image you need only click on Save Current specify a new file name and click on Apply To save a continuous sequence of images 1 Open the Save Image dialog box using the File menu Save Image option IBM Visualization Data Explorer User s Guide save Image _ Allow Rerendering Gamma Correction 2 00 J Delayed Colors Format RGB gt Image Size 640x480 Output file name image Select File Save Current Continuous Saving Apply Restore Close Figure 45 Save Image Dialog Box 2 Select the name of the file into which the sequence will be written or enter a file name into the Output File Name text field 3 Select the image format either RGB R G B MIFF or YUV 4 Depress the Continuous Saving toggle by clicking on it 5 f you do not wish to include the currently displayed image in the sequence be sure the Save Current toggle button is not depressed 6 Click on the Apply button Each
186. ave a data drop out or a simulation may for whatever reason produce an invalid entry Of course if you are explicitly listing your positions or connections you can simply leave those positions out when you create your data file However if you have a regular grid for which you simply list the origin of the grid and the delta in each dimension this is not convenient Data Explorer has a way to easily handle this situation using invalid positions and invalid connections components These components are discussed in Chapter 3 Understanding the Data Model on page 15 but briefly when present in a Field they instruct any module processing that Field to completely ignore any position or connection identified in that component For example an invalid positions component may list the integers O 15 and 23 This instructs Data Explorer to ignore the positions 0 15 and 23 and the data associated with those positions You can create these components in a Data Explorer format file see Appendix B Importing Data File Formats on page 241 or often more easily using the Include module For example suppose in your data file drop outs are indicated with a data value of 9999 while all valid data lies in the range 0 100 Then set the max parameter of Include to 9998 Include will then remove or invalidate all of the positions with the value 9999 Note that it is usually preferable to set the cull flag of Include to 0 so that the data
187. ayed out during software rendering and during hardware rendering that is not Dots or Wireframe approximations IBM Visualization Data Explorer User s Guide Note Do not use the Options module to set hardware rendering options if you intend to use the Rendering dialog box options set by the Options module are overridden by those set through the dialog box see Display on page 109 in BM Visualization Data Explorer User s Reference Image Depth This option determines the maximum number of possible colors or shades of color that Data Explorer can use in creating an image With greater numbers gradations are smoother and edges are sharper The image is clearer The choices are the number of bits available for specifying colors 8 256 colors 12 4096 and 24 more than 16 million Data Explorer supports 8 bits With the appropriate graphics card it will process 12 and 24 bits Changing the Rate of Frame Display Throttle You can specify a maximum rate of speed to display new frames This rate is specified as a number of seconds per frame i e the minimum number of seconds that any frame will be displayed before advancing to the next frame To change the rate of display do the following 1 Select the Throttle option from the Options pull down menu in the Image window A dialog box appears as illustrated in Figure 44 on page 94 2 Edit the Seconds per Frame text field changing it to the minimum number of seconds you
188. bject to be rendered through the Options module setting an attribute of antialias with a value of lines To specify multiple pixel width lines pass the object to be rendered through Options setting an attribute of line width with value set to the number of pixels A number of new routines which allow execution of named macros and control over window management e g opening and closing image windows have been added See Chapter 16 DXLink Developers Toolkit on page 157 in IBM Visualization Data Explorer Programmer s Reference New Features in Data Explorer Version 3 1 4 Xxix Changed Modules XXX This section contains only summaries See BM Visualization Data Explorer User s Reference for details AutoAxes There are new inputs to AutoAxes which allow you to explicitly specify tick locations and optionally to specify labels to be associated with those locations Thus for example if one of your axes represents the months with integers 1 to 12 you could indicate to AutoAxes to place ticks at each integer from 1 to 12 and to label them jan feb Plot and ColorBar similarly now allow you to specify tick location and label AutoAxes no longer scales the input object This should make using probes in an image which includes axes easier There is a break with backward compatibility in that for some viewpoints the axes may not lie completely within the image you will need to change the viewpoint to be slightly fa
189. board or that you might write in a program Related Publications and Sources IBM Publications IBM Visualization Data Explorer User s Guide SC38 0496 Details the main features of Data Explorer including the data model data import the user interface the Image window and the visual program editor and the scripting language Of particular interest to programmers chapters on the data model and the scripting language IBM Visualization Data Explorer User s Reference SC38 0486 Contains detailed descriptions of Data Explorer s tools Note Consult this reference if you are creating visual programs or scripts IBM Visualization Data Explorer Programmer s Reference SC38 0497 About This Guide XXIII Contains detailed descriptions of the Data Explorer library routines Note Consult this reference if you are writing your own modules for Data Explorer Non IBM Publications The following treat various aspects of computer graphics and visualization Adobe Systems Incorporated PostScript Language Heference Manual 2nd Ed Addison Wesley Publishing Company Massachusetts 1990 Aldus Corporation and Microsoft Corporation Tag Image File Format Specification Revision 5 0 Aldus Corporation Washington 1988 Arvo Jim ed Graphics Gems l Academic Press Inc Boston Massachusetts 1991 Foley J D van Dam A Feiner S K Hughes J F Computer Graphics Principles and Practice Addison Wesley Publishing Company Mas
190. button This action selects and copies the text To paste the selected text in a text field position the mouse cursor at the point you want to insert the text and click on the center mouse button The pasted text is inserted at the mouse cursor position If the amount of text entered into a text field cannot be fully displayed you can use the keyboard to scroll the cursor through the text Pressing the left or right arrow key moves the cursor one character to the left or right respectively Also pressing 64 IBM Visualization Data Explorer User s Guide the Control key Ctrl at the same time as either the left or right arrow key moves the cursor one word to the left or right respectively The Home key will move the cursor to the beginning of the text field The End key will move the cursor to the end of the text field Working with Windows Your window manager allows you to Stack and raise windows Minimize windows Maximize windows Close windows These functions can be invoked using the menu minimize and maximize buttons on the title bar of Data Explorer windows You can use the X Window System or the appropriate window system manager to customize the way these options work For more information see BM AlXwindows User s Guide or another appropriate window system overview 5 3 Using Online Help The online Help facility offers the following options in its pull down menu Context Sensitive Help can help you with a specific t
191. by using attributes if you are using the Data Explorer scripting language see Chapter 10 Data Explorer Scripting Language on page 187 Once the execution groups are created you assign each group to the workstations over which you wish to distribute the visual program You can assign more than one group per workstation Note that if more than one group is assigned to a given workstation the groups will not be run as separate processes Data Explorer uses this two part approach of creating groups and assigning groups to make it easier for you to change the set of workstations over which you distribute your visual programs This utility is especially convenient if you share visual programs with other users When you execute a visual program for the first time the Data Explorer executive is started on each workstation over which the program is to be distributed Each executive plans the execution and executes each of the execution groups assigned to it This means that not only is the computation and data flow distributed but the control flow is distributed as well One of the workstations is a master the workstation to which the user interface is connected The master creates and initiates the communication between the other workstations and distributes commands from the user interface to all the workstations The master also executes any execution group that is not assigned to another workstation in addition to its own assigned groups C
192. call for a direct interface to external data sources especially ones that generate data to be studied e g a computational simulation The execution model of Data Explorer provides the framework for real time visualization of data generated asynchronously by such a process An external data source is linked into a Data Explorer network by incorporating a communications module which receives data from the external source often across a socket and passes the resulting data object to the module s output This module and its descendents will only run when the external data source has indicated that new data are available see 10 2 Asynchronous Modules on page 84 in IBM Visualization Data Explorer Programmer s Reference Data Explorer also provides a mechanism for direct manipulation of the executive e g mode passing data error handling etc and the user interface e g window visibility and mode from an external application This allows control of Data Explorer from other software and peer to peer communications see Chapter 16 DXLink Developers Toolkit on page 157 in IBM Visualization Data Explorer Programmer s Reference IBM Visualization Data Explorer User s Guide doc Tiqure12 net Visual Program Editor tmp Geli ocal Compute Input Computo SetLocal 2 n m gt lt D ie S ct mall o le o x D Outpat Dose Figure 29 Example 12 4 9 Parallelism using Distributed
193. can be modified with the options Label and Separator under Add Element in the Edit pull down menu of the Control Panel These will add the specified element to the panel at the point where the mouse cursor is positioned Separators can be made vertical using the Set Layout option of the Edit menu The size of the separator can be controlled using the mechanism described in Resizable Interactors on page 134 The color and font of labels can be specified using the dialog box that appears when the label is created These can be changed by selecting the label and choosing Set Attributes from the Edit menu of the Control Panel Once the Control Panel has been created select Dialog Style in the Options pull down menu to create the dialog box The size of the box will vary to accommodate the interactors The empty canvas to the right of the interactors will be truncated The placement of the interactors will also change if the box size is changed to maintain the same relative positions n editor mode the Close button returns to an editable Control Panel In image or menubar mode the Close button closes the dialog box To enable a dialog style dialog box save the visual program with the Control Panel in dialog style format Control Panel Access Groups and Hierarchies 138 You may wish to organize your Control Panels into groups or hierarchies depending on how the interactors in the Control Panels relate For example you may have a few Co
194. caso 243 Macon Uppercase 247 Overdot Dot placed over Polish Z and z thorn celanaic mo thom fe ela 252 umat o Lowercase also called diaresis miaut ppercase except for an ms Umit qu or Land O 254 Umlaut l umlaut 255 OUmlaut os O umlaut IBM Visualization Data Explorer User s Guide Appendix F Data Explorer Colors The following list of defined colors is internal to Data Explorer and is accessed when the colors txt file is unavailable see Colo on page 75 in IBM Visualization Data Explorer User s Reference Data Explorer accepts these names as valid strings for specifying colors to a visual program Each color is followed by the corresponding RGB vector aquamarine black blue blueviolet brown cadetblue coral cornflowerblue cyan darkgreen darkolivegreen darkorchid darkslateblue darkslategray darkslategrey darkturquoise dimgray dimgrey firebrick forestgreen gold goldenrod gray green greenyellow grey indianred khaki lightblue lightgray lightgrey lightsteelblue limegreen Copyright IBM Corp 1991 1997 0 O OOO OOOO OO OC oO co oor O O O CO CO CO CO CO O Cc cocco CO 4392157 0000000 0000000 6235294 0470588 3 25490 0000000 2588235 0000000 1843137 3098039 6000000 4196078 1843137 1843137 4392157 3294118 3294118 5568628 1372549 8000000 8588235 7529412 0000000
195. ch that the viewer is looking straight down on it Connect the second wire from Import to Rubbersheet and then use a second Color module but run wires from the same Colormap as you used to color the first copy The second copy a 3 D colored height Field can then be rotated into a perspective view The result will be a Field both colorized according to the data values and also elevated into the third dimension according the same data values This redundancy is often more instructive than either visualization technique used alone Transformations and Structuring 228 Rotate Scale Translate and Transform are all special types of operations that change the location orientation or size of objects in your scene These operations can be performed anywhere in a visual program You can create hierarchical motion by attaching Rotates and Translates to individual objects then Collect these objects together and attach another Rotate and Translate to the Group output of Collect In this fashion you can individually rotate members of the group independently of each other or you can rotate the entire group as one By default many modules operate on the data component We have been treating data as a special kind of numeric Array separate from positions and connections We mentioned earlier that you can have several different data components but each must have a unique name for example your input data file can contain positions
196. ct as being parallel Orthographic Orthographic projection provides a less realistic view of an object than perspective projection However orthographic projection does preserve exact scale measurements and parallel lines One way to think about orthographic projection is that it is as if the distance between the front and back of an object is small relative to the distance between the object and the camera Orthographic is the default projection method It is quicker to render an object in orthographic projection than in perspective The differences between these two methods become evident when using the view controls in certain modes For example the Zoom mode behavior depends on the projection method as does the behavior of the 3 D cursor Roam and Cursors modes The differences are discussed in the sections that discuss these modes For more information about these projection methods consult a computer graphics text You can select the projection method by using the Projection option box on the View Control dialog box Setting the View Angle f you select Perspective then you can also specify the view angle in degrees The vertex of the view angle is located at your camera and the end points are the left and right sides of the image area Thus the wider the viewing angle the more image space you can fit in your viewing area opecify the view angle by adjusting the View Angle stepper in the View Control dialog box Unless
197. cteristics of the Image widow by using input parameters to the Image tool These parameters are hidden by default but can be accessed with the Expose button in the Image tool s Configuration dialog box which itself is accessed by selecting the Configuration option in Edit pull down menu of the Visual Program Editor For more information see Image in the BM Visualization Data Explorer User s Reference Controlling the Image View Control 74 You can change your view of an object in the Image window by using the View Control option of the Image window Options menu The way an object appears in the Image window is controlled by a camera The camera specifies the look from point the look to point the field of view the size and shape of the window and whether the rendering method is orthographic or perspective If you are using orthographic projection the field of view is controlled by a parameter called width which specifies the width of the Image window in world coordinates For perspective projection the field of view is controlled by the camera look from position and the view angle of the camera The differences between these two projection methods is discussed in Changing the Projection Method on page 76 You can change the camera settings with direct interactors which let you use the mouse in conjunction with dialog box options to manipulate the view of the object directly and which provide immediate visual feedback for y
198. ctions Moving and Copying Tools o Using Transmitters and Receivers Adding and Removing Input and Output Tabs Entering Values in a Configuration Dialog Box Revealing and Hiding Input Tabs llle Using the Compute Module Configuration Dialog Box Locating Tools The Find Tool Dialog Box Customizing the VPE Window s Adding Comments to a Visual Program Ls Adding Annotation to a Visual Program ww ww we aa aa a Creating pages in the VPE seduce wiii BREESE Saving and Restoring a Visual Program lll 6 3 Using the Colormap Editor 004 Entering Values in a Colormap Editor Using Data Driven Colormap Editors Chapter 7 Graphical User Interface Control Panels Interactors and MACIOS e P 7 1 Using Control Panels and Interactors Building Control Panels s aces ws HARE AE SER Be Sh E Placing Interactors in a New Control Panel Adding Interactors to an Existing Control Panel Selecting Moving and Deleting Interactors Changing the Size of an Interactor llis Locating Interactor Stand ins 0 000 000 0508 D leung Gontrol Panels o Sus ae Bo eo been XU E RP Eu Saving and Restoring Control Pan
199. ctor field naxes 3 ndeltas 2 variables float lat_axis ndeltas naxes float lon_axis ndeltas naxes float level axis tlvl naxes float temp time tlat tlon tlvl temp field temperature scalar series temp positions lat axis product compact lon axis product compact level axis product float sali time tlat tlon tlvl sali field salinity scalar series sali positions lat axis product compact lon axis product compact level axis product ms mall o D ms o ms 3 y cr un float wata time tlat tlon tlvl wata field water parage scalar series wata positions lat axis product compact lon axis product compact level axis product float conv time tlat tlon tlvl conv field covective index scalar series conv positions lat axis product compact lon axis product compact level axis product float vel time tlat tlon tlvl vsize vel field velocity vector series vel positions lat axis product compact lon axis product compact level axis product data lat axis 14 667 0 0 052935 Dus 053 lon axis 0 0 99 8 0 0 0 0 0 5 0 0 level axis 0 0 0 0 17 5 0 0 0 0 53 425 0 0 0 0 5374 98 temp 3 sali AE wata ENTRE conv ds E Vel Appendix B Importing Data File Formats 287 B 6 HDF Files Irregular Surface This example is the netCDL description of a netCDF for an irreg
200. d descriptions of functions see Appendix D User Interface Configuration on page 299 Option syntax Function S noEditorOnError Turn off default behavior of popping up a VPE when an error occurs Instead a dialog box will ask whether a VPE should be opened noExecuteMenus Remove Execute menu from all Windows intended for use with DXLink applications noExitOptions Changes quit to Close intended for use with DXLink applications nolmageLoad Remove both Load options from the Image window s File menu nolmageMenus Remove menus from all Image and Display windows nolmagePrinting Remove the Print Image option from the Image Window s File menu nolmageRWNetFile Remove Open Save and Save As options from the Image Window s File menu nolmageSaving Remove Save Image option from the Image Window s File menu nolnteractorAttributes Remove Set Attributes option from the Image Window s File menu nolnteractorEdits Remove four set options from the control panel s Edit menu nolnteractorMovement Restricts the ability to move interactor instances within a control panel noMessagelnfoOption Remove the Information Messages toggle button from the Message window s Options menu noMessageWarningOption Remove the Warning Messages toggle button from the Message window s Options menu noOpenAllPanels Remove Open All Panels option from the Panels menu of the control panel and from the Windows menu of
201. d the trajectory of your movement is the same as it was when you last traveled forward n this case the center mouse button has no effect 3 he Navigate mode uses two values to control its precision These are controlled by the two sliders on the View Control dialog box They are Motion Controls the speed of execution as you move the camera forward and backward The higher the number the faster the speed and the faster your camera appears to move In addition to using the slider you can use the up and down arrow keys to adjust this value be sure the cursor is in the Image window Pivot Controls the increment of the turn angle when you turn using the center mouse button The higher the number the more drastic the turn In addition to using the slider you can use the left and right arrow keys to adjust this value be sure the cursor is in the Image window Precise Camera Settings In addition to using direct interactors to change camera settings Data Explorer lets you specify exact values to the camera for more precise results You can also use this feature to learn the exact camera settings that result from your use of direct interactors These settings correspond to parameters of the Camera module See Camera on page 49 in IBM Visualization Data Explorer User s Reference To access the camera settings select the Camera mode using the Mode option box in the View Control dialog box or the Ctrl K accelerator key The cam
202. d and third class the connections component IBM Visualization Data Explorer User s Guide of any imported Field s may be meaningless You can use the Remove module to eliminate it and treat the Field as scattered or point data i e use Regrid or Connect to create a more appropriate mesh Treating such data as a collection of points is consistent with the original design philosophy of CDF and CDF applications The third case actually represents an irregular mesh which Data Explorer can support directly Unfortunately the connectivity information i e the mesh structure is typically not stored in the CDF so Import cannot directly reconstruct the original mesh Hence the data must be treated as point data unless you have information external to the CDF that can be used to recreate the original mesh structure B 4 netCDF Files Regular Grids Data Explorer supports the importation of data in netCDF format a data abstraction for self describing multidimensional Arrays It represents a simpler data model than that of Data Explorer one similar to that of the Array Object Data are accessed in netCDF through an application programming interface available in C and FORTRAN libraries from the Unidata Program Center in Boulder Colorado Scalar data on a regular grid can be imported from a standard netCDF file To import vector data data on irregular grids or time series data additional attributes must be added to the netCDF file T
203. d in the Array Object definition All other Objects including Array Objects whose definitions use the data follows specification are self contained their definitions include all necessary information These Objects do not use a data section The Data Explorer file format is flexible enough to describe many existing data formats without having to reformat the data It allows you to specify byte order which index varies fastest whether the data type is floating point or byte and whether the file format is binary or ASCII For data that is not in a format accepted by the Data Explorer native file format you can either reformat the data so it is acceptable or import the data using a general importer specification see 5 1 General Array Importer on page 63 in BM Visualization Data Explorer QuickStart Guide The data section consists of a set of data items specified as text or binary by the data clauses in the various Array Object definitions Text and binary can be mixed in the same data section because the data clauses specify portions of the data section by byte offsets Binary representations can be in most significant byte first msb or least significant byte first 1sb format as specified by the relevant data or data mode clause Binary floating point numbers currently must be in IEEE format If a Data Explorer file does not begin with a valid header at least an end clause it is assumed not to have a header section Every
204. d is the side from which the vertex numbering appears Figure 5 on page 21 The interpretation of colors differs between surfaces and volumes For surfaces the color values in the range from O to 1 are mapped onto the range of colors values possible for the display For volumes the interpretation of colors follows the dense emitter model described in the next section Opacities Component The opacities component plays a role similar to that of colors components except that it specifies a floating point opacity for rendering Its interpretation differs depending on whether the connections represent a surface triangles or quads or a volume tetrahedra cubes and so on In the surface case the opacity is a number from 0 to 1 specifying the opacity of the surface In the volume case the opacity represents the instantaneous attenuation of light per unit distance traveled Like the colors components it can be position or connection dependent The interpretation of colors and opacities differs between surfaces and volumes For surfaces a surface of color c and opacity o is combined with the color c of the objects behind it resulting in a combined color co c 1 o For volumes the dense emitter model is used in which the opacity represents the instantaneous rate of absorption of light passing through the volume per unit thickness and the color represents the instantaneous rate of light emission per unit thickness f c z
205. d use the rules of design mentioned above including proper legible annotation reasonable choices for colors and so on These things are determined partly by the medium you are working in and partly by the rules of good layout and design But what color is a magnetic field What color is hot What color is high How fast should molecules vibrate How quickly should a metallic surface move as it changes phase These decisions must be made by the program author Probably the three most critical choices are color scale and speed In visualization color is used precisely because it is not realistic That is to emphasize an area of interest red is commonly used Or a strong contrast color can be used against a field of fairly neutral colors However there are some cultural color choices that you may find inappropriate to violate For historical and to some degree natural reasons we tend to make color gamuts that indicate red as the highest and blue the lowest Particularly with temperature we can associate blue with cool or water ice color and red with hot or flame sun color To some degree this gamut is related to the color of heated metal but of course the metal color does not pass through green at the midway point and the color scale does not end at white like white hot metal so this too is only a loose analogy But try inverting a color map of temperature to make red cool and blue hot and you will probably find you have to per
206. dditional dimensions for the variable For a static three dimensional 3 vector the three components are stored in a fourth dimension of size 3 IBM Visualization Data Explorer User s Guide If the data have both regular connections and regular positions no other attributes are required A regular grid is assumed with the origin at 0 0 and a spacing of 1 0 along each axis The number of axes will be determined from the number of dimensions in the data array Positions If the locations of the data values in variable do not form a regular lattice with origins at 0 0 and spacings of 1 0 the name of a netCDF variable that contains the position information must be specified as an attribute for variable There are five different types of position specifications none completely regular completely irregular and two types of partially regular Completely irregular is assumed if the following attribute is specified variablel positions variable2 where variable2 is an array of vectors one for each grid point defining its location The dimensionality of the data space is determined by the number of items in a vector Regular positions can be specified with just the origin and spacing between grid points along each axis in compact form The following attribute is used variablel positions variable2 compact where variable2 is the name of a nx2 array containing origin delta pairs for the spacing and location of positions al
207. dialog box Loading Macros For a macro to be available for use it must be loaded into the tool palette To load a saved macro 1 Select the Load Macro option from the File pull down menu in the VPE A file selection dialog box appears For information about how to use the dialog box see File Selection Dialog Boxes on page 116 152 IBM Visualization Data Explorer User s Guide 2 Use the dialog box to locate the macro you want to load and select the desired file The macro name appears on the tool palette under its assigned category 3 You can also load all the macros in a selected directory by clicking on Load A11 Macros in the dialog box Note If the macro you loaded has the same name as a macro previously loaded the new macro replaces the earlier one whether or not they were assigned to the same category When the new macro is available for use it is listed in the tool palette as a member of the category you assigned it to For example the MapAndDeform macro would be listed under the MyMacros category When you save a visual program which uses a macro the path to the macro is saved in the visual program When you reload the visual program the macro will automatically be loaded for you from the same location so it will only be necessary to explicitly load the macro if it has been moved to a new location You can also easily see what macros need to be included with a visual program if for example you are sending
208. directory default usr lpp ax echo edit Echo the command lines without executing them Start the user interface in edit mode default exec filename Use the specified executive execonly Start the executive only no user interface in remote mode execute Execute the visual program automatically at start up execute on change Go into Execute On Change mode at start up full Start the full Data Prompter See also file and prompter file filename Start the Data Prompter with header file filename See also full and prompter help Print the abbreviated help message highlight on off Enable node execution highlighting default on host hostname Start the executive on machine hostname hwrender gl opengl if both GL and OpenGL are supported set the type of hardware rendering used Start the user interface in image mode Override DXINCLUDE environment variable image include pathlist license runtime Request that the user interface use only the develop timed indicated functional type local Start the executive on the current machine default log on off Enable executive and user interface logging default off macros pathlist Set list of directories to be searched for macros Use mdf file filename in addition to the default mdf file mdf filename memory Mbytes Set the amount of memory the executive uses menubar Start the user interface in
209. dit menu Execution Groups option 3 Select the name of the execution group from which the tool s are to be removed 4 Click on the Remove From button Deleting an Execution Group To delete an execution group 1 Open the Execution Groups dialog box by selecting the Edit menu Execution Groups option 2 Select the name of the execution group to be deleted 3 Click on the Delete button Displaying the Tools in an Execution Group Data Explorer provides you with the ability to display all the tools that are members of an execution group To display the tools 1 Open the Execution Groups dialog box by selecting the Edit menu Execution Groups option 2 Select the name of the execution group to be displayed 3 Click on the Show button IBM Visualization Data Explorer User s Guide I9 The tools that are members of the execution group become selected If the selected tools are not part of the currently displayed portion of the visual program the VPE will be updated so that the selected tools will be displayed m o ms gt x lt w 5 O D a c uo D uo Assigning Execution Groups to Workstations Once you have decomposed your visual program into execution groups you can assign these groups to workstations or hosts If you do not specify a host for a particular execution group the group will be executed on the master Execution groups are assigned to a host using the Execution Group Ass
210. double duty out of your visualization Record and play it at one rate and viewers will see one aspect of your data play it faster or slower and different details will be Appendix A Using Data Explorer Some Useful Hints 237 c tn D m mi mall o gt cr tn noticed And often it is good practice to let an animation loop a few times allowing the viewer to observe the entire process from beginning to end The Sequencer also can generate palindromic motion in which the object swings back and forth rather than jumping from the end of a series back to the beginning Be sure that you use this feature in a meaningful way time steps shown in reverse order imply time running backward Annotation is definitely required in this case A 5 Presentation Issues and Techniques 238 Visualization is used to represent natural phenomena that are inherently visual themselves but probably more often it is used to visualize non visual phenomena The process of making something visual means making choices on the part of the program author or designer Clearly without a sound scientific basis for these choices this can become a purely artistic venture While computer graphics can be used to make beautiful artwork that is presumably not the point of using visualization to help study analyze or understand data This does not mean that you should forego good design in making your visualization scene understandable Remember an
211. driven the information transmitted via the connections or set in the Configuration dialog box overrides values set in the Colormap Editor Data driven Colormap Editors allow you to create color maps that are appropriate for a variety of input data sets without the need to reset the minimum and maximum of the color map The Colormap tool has a data input to which an input data field may be connected In this case the Colormap Editor is automatically set so that the minimum is the minimum of the data set and the maximum is the maximum of the data set However if you would like to have more control over the exact values that are used the Colormap tool allows you to specify the minimum and maximum directly through other input tabs that are by default hidden You can also pass a color map or opacity map directly to the Colormap tool The inputs for the Colormap tool are summarized in the corresponding module description in BM Visualization Data Explorer User s Reference Each time an input to a data driven Colormap Editor is changed e g by importing a new data set the interactor is reexecuted updating its attributes Chapter 6 Graphical User Interface Important Windows 125 126 IBM Visualization Data Explorer User s Guide Chapter 7 Graphical User Interface Control Panels Interactors and Macros 7 1 Using Control Panels and Interactors 128 Building Control Panels o 129 Placing Interact
212. e Comments have no effect on the script other than to enhance its readability For example This is a valid comment Chapter 10 Data Explorer Scripting Language 191 Naming Variables and Macros 192 You can name the variables and macros with identifiers Identifiers are sequences of characters selected from the following e Uppercase alphabetic characters A Z e Lowercase alphabetic characters a z Numerals 0 9 Special characters Underscore _ Single quote At sign 8 All identifiers must start with either an alphabetic character an underscore or an at sign Remember that the Data Explorer script language is case sensitive identifiers that differ in the case of at least one character are considered to be different identifiers Identifiers are currently limited to a length of 200 characters Note IBM reserves the definition and use of most identifiers that begin with However there are some built in variables that you can set these are discussed in 10 7 Using Data Explorer Script Commands on page 206 The following are valid unique identifiers ComputeSine Compute Sine cOmpute sine compute slne compute sine Identifiers can be used as e variable names e function names Some identifiers are reserved and cannot be used as a variable or a function name Every other identifier can be used both as a variable and as a function name The proper use of the identi
213. e points Array identifying one vertex of an edge the other vertex of an edge is the next entry in the edges Array except that the last edge in a loop that connects the last point to the first point is not listed explicitly This is illustrated in Figure 7 on page 26 It is assumed that the first loop for each face is the enclosing loop and that subsequent loops if any are holes in the face If this is not true then set the DX NESTED LOOPS environment variable see Other Environment Variables on page 292 However setting this environment variable will cause a decrease in performance when processing faces loops and edges data Edges and Polylines Polylines are a way of collecting a set of line segments into a single object with which data can be associated They are implemented much as faces loops and edges are see above An edges component contains the indices of the vertices along polylines A polylines component contains the indices of the first element in the edges component of each polyline sequence In other words the element of the polylines component is the index in the edges component at which the sequence of vertex indices of polyline starts The sequence corresponding to polyline continues to the beginning of the next polyline sequence or to the end of the edges component Polyline data may be dependent on either polylines or positions Pokes Picks and Pick Paths Components
214. e Options He Edit Execute Options File Edit Execute Options He 2 2 5000000 RGB Saturation Value Opacity 2 488h3 r min max min max min Figure 57 Colormap Editor Entering Values in a Colormap Editor The Colormap Editor specifies color in the hue saturation and value HSV color space Hue refers to the color for example blue red or yellow The range of the hue goes from red to green to blue back to red again Saturation refers to the purity of the color and is a value between O and 1 A saturation of 1 is pure color as saturation decreases the color becomes more pastel becoming white when saturation is O Value is the brightness of the color and is a value between 0 to 1 A value of 1 is maximum brightness as value decreases the color becomes darker becoming black when value is O For a thorough understanding of color and the color elements of hue saturation value and opacity and other elements of computer graphics that might relate to the Colormap characteristics you may want to refer to a computer graphics text You can display the Colormap Editor by selecting the Open All Colormap Editors option on the Windows menu of the Image window or by double clicking on the Colormap tool in the VPE window The Colormap Editor displays default settings for each of the three HSV color space parameters as shown in the first three boxed areas on the right hand side of the window These three areas labeled Hue Sa
215. e Pick tool set to O or 1 subsequent executions may or may not use the last pick point or points chosen If persistent is set to 0 then pick points are not saved between executions if persistent is set to 1 then pick points are saved between executions Note You can also enable Pick mode by using the intrctnMode parameter to the Image tool see Image in BM Visualization Data Explorer User s Reference Undo Redo and Reset These options are almost self explanatory Undo and Redo both restore images either by undoing the current image or by redoing the image that has just been undone The Reset option returns the Image window to its initial state i e before the image was first modified See also Restoring Images on page 84 Chapter 6 Graphical User Interface Important Windows 87 AutoAxes 88 This option generates an axes box around an image Select AutoAxes from the Options pull down menu The AutoAxes Configuration dialog box appears as illustrated in Figure 41 on page 89 The dialog box consists of eight parts Enabled Input groups Axes Labels Miscellaneous Annotation Colors Corners Cursor Ticks IBM Visualization Data Explorer User s Guide The first part consists of a single toggle button AutoAxes enabled This button must be activated depressed to make an axes box appear the next time the visual program is executed The button is automatically ac
216. e axes in each dimension The Cursor section allows you to place a cursor marker at a specific location in the axes box Allows you to specify number or locations of ticks If the option menu to the right of Ticks is set to All then you can specify the approximate total number of ticks in the All field AutoAxes Figure 41 AutoAxes Configuration dialog box If the option menu to the right of Ticks is set to Per Axis then you can specify the approximate number of ticks on each axis If the option menu to the right of Ticks is set to Values then you can use the Ticks Values section to set exact tick locations and labels You can also specify the direction of the ticks to point inward or outward using the buttons at the bottom of this section Ticks values This section is only enabled if the option menu to the right of Ticks is set to Values By using the buttons you can add Tick Location Tick Label pairs for each axis See AutoAxes on page 27 in IBM Visualization Data Explorer User s Reference for more information buttons 0K and Apply both confirm option changes which appear the next time the visual program is executed OK also closes the dialog box Restore and Cancel both restore values that were present when you opened the dialog box or last clicked on the Apply button Cancel also closes the dialog box For more details on the AutoAxes configuration see the corresponding module descr
217. e click on one of the selected interactor stand ins to create a new Control Panel automatically When a new Control Panel is created with the selected interactors the interactors are placed in a vertical column in the order in which their stand ins were placed on the VPE canvas Note If you select a group that includes tools other than interactor stand ins only the interactors appear in the Control Panel Therefore the quickest way to place all the visual program s interactors in one Control Panel is to use the Select ATI option of the Edit pull down then select the New Control Panel option of the Windows pull down menu Adding Interactors to an Existing Control Panel 130 To add an interactor to an existing Control Panel 1 Open the Control Panel 2 Select the interactor stand in on the VPE canvas 3 In the Control Panel window click on the Add Selected Interactor s option of the Edit menu 4 Move the cursor to where you want to position the tool in the Control Panel Note that the style of the cursor changes when you move it onto the panel This is similar to how tool icons are placed on the VPE canvas Exact placement of the interactor depends on the grid settings see Changing the Alignment of Interactors in the Control Panel on page 134 5 Click the mouse The interactor appears at the specified location Alternatively you can use drag and drop to add an interactor to an existing Control Panel 1 Select the
218. e compatible with the input tab will change color 4 Place the pointer over the input tab you want and release the mouse button If you release the mouse button in the rectangle area of the icon the line automatically connects to the leftmost of the newly colored tabs When you release the mouse button the white temporary line is replaced with a black line and the corresponding tabs fold in Note Sometimes when tools are placed too close together on the canvas a connection that you made is not visible In this case the affected input tabs are still folded in and a dark line is visible on each one but the connecting line is not visible To correct this move one of the affected tools to another spot on the canvas You can connect an output tab to more than one input tab either on different tool icons or on the same tool icon Therefore you can make a connection from an output tab even though the output tab is folded in An input tab can receive a value from only one source either from a connection to an output tab or from a value entered in a Configuration dialog box Once an input tab folds in you cannot make a new connection to the tab until the tab is released Because output tabs can have multiple destinations connections can only be moved or deleted from an input tab To delete a tab connection 1 Depress the mouse button on the input tab 2 Drag the cursor to an empty space on the canvas away from the active area
219. e data flow execution model seems a natural mechanism for the execution of visual programs a closer examination reveals that real world problems are more complex In order to function efficiently it is vital that the system avoid unnecessary work In general there are two reasons why modules present in a visual program may not need to be executed when their turn comes 1 their results are not actually required by a result of the network and 2 their inputs are unchanged from the last time the module was executed i e the result will be the same The outputs of a visualization network occur in modules that have side effects They produce results outside of the visual program itself such as the display of images on a workstation or the creation of output files Unless the result of a module ultimately affects a module that produces a side effect that module does not need to be executed Eliminating modules that are not ancestors i e not upstream of modules with side effects is done in Data Explorer by preprocessing the network before the actual Chapter 4 Data Explorer Execution Model 39 m gt lt D ie S ct mall o le gt o x D data flow network evaluation commences This is done by traversing the graph bottom up beginning at each module known to have side effects and flagging each module as it is encountered Once this is complete modules that have not been flagged do not have to be executed Note that
220. e executive to run You might change this field if you want to run a customized version of Data Explorer Working Directory Specifies the default directory to search for files ms o ms gt x lt w 5 O D a c uo D uo Memory Size Specifies the amount of memory to use in megabytes Options opecify options in this text box as you would on the command line when invoking Data Explorer that is each option must be preceded by a dash cache on saves the state of the visual program in memory after an execution lf the visual program changes Data Explorer reexecutes only the portion of the program affected by the change If cache off is specified Data Explorer must reexecute the entire program for each change The default setting is on trace on displays each execution step as it happens in the Debug window It is mainly used for debugging purposes The default setting is off log on saves all communication between the server and the user interface to a file The default setting is off Other options are listed in C 2 Command Line Options on page 295 Connect to already running server radio button Specifies that the user interface should connect with a server that was started earlier You might use this option to set up a connection to a debugging session for a customized version of the Data Explorer executable You can specify the port number in using the stepper below the button Note that whe
221. e features of a window manager the appearance of your windows may differ slightly from those in the figures and examples e Chapter 1 Overview on page 1 describes IBM Visualization Data Explorer an integrated visualization environment and its main features e Chapter 2 Introduction to Visualization on page 7 introduces the basic terminology and working principle of Data Explorer e Chapter 3 Understanding the Data Model on page 15 presents a formal description of Data Explorer s underlying data model Users who do not require such a description however should find the informal treatment in Chapter 2 Introduction to Visualization on page 7 sufficient for their purposes e Chapter 4 Data Explorer Execution Model on page 37 describes the Data Explorer execution model e The next five chapters deal with various aspects of the Data Explorer graphical user interface Chapter 5 Graphical User Interface Basics on page 57 Chapter 6 Graphical User Interface Important Windows on page 73 Chapter 7 Graphical User Interface Control Panels Interactors and Macros on page 127 XXli IBM Visualization Data Explorer User s Guide Chapter 8 Graphical User Interface Menus Options and the Message Window on page 155 Chapter 9 Graphical User Interface For Advanced Users on page 177 If you intend to use only existing visual programs see 5 4 Executing a Visual Program
222. e state is reset for the next execution of the loop To save state in a program that uses a Sequencer module you should use GetGlobal and SetGlobal since each iteration of the Sequencer is 46 IBM Visualization Data Explorer Users Guide a separate execution of the program as described in 4 5 Iteration using Looping on page 44 Illustrated in Figure 22 on page 46 is a simple macro that sums the numbers from 1 to N where N is an input parameter The start parameter to ForEachN has been set to 1 GetLocal and SetLocal are used to accumulate the sum Sum is a trivial macro consisting of a Compute where the expression is a b On the first iteration of the loop GetLocal will output its initial value which has been set to O On subsequent iterations GetLocal will output the accumulated value SetLocal saved during the previous iteration When the loop terminates the final accumulated value is the output of the macro This macro is roughly equivalent to the following C language statements b 0 for a 1 a lt 10 a b bta If the macro were run again on the first iteration of the loop GetLocal would again output its initial value Note that the macro will only run again if the input to the macro changes or the output of the macro has been removed from cache If you replaced the GetLocal and SetLocal in Figure 22 on page 46 with GetGlobal and SetGlobal it would be equivalent to the following C language statements int a Stat
223. e ta Sb da ied 204 Macro BOM uz ks boe Rue ite DESA eu Xd o ien 205 Macro Examples vo RU RR Ro bee X Y owe e bad 205 10 7 Using Data Explorer Script Commands 206 Sequencer 2 2 222222252 22 Ss 206 PICUINGIUSION CL 207 PROMOS TFC 207 10 8 Understanding the Script Execution Model 208 Top level Environment srl 208 FUMCHOMIEXCCUUOM ubuntu tee ws a m Xo tg 208 Macro Expansion s sou and obo qo 844444484 45 oe an Gus 208 Variables Used in Macros 20000000024 ee 208 Assignment and Function Call Semantics 209 Execuliori EXAMPIC rotar dodo men delete eo he ELAS E 210 10 9 Running net files in script Mode 210 Appendix A Using Data Explorer Some Useful Hints 211 A 1 Using Data Explorer Effectively o 212 Common Problems su scarico s as de SLE dede 444 212 What is the Difference Between Image and Display 212 How do get more information 213 Memory USC ps sad dod dod e y uh aa o dede e 213 IBM Visualization Data Explorer User s Guide A 2 Visualization Techniques oll n 217 ANIMATION sedeo mp SIR Eug ue Ane dee ee headed es 217 ANNOUOM zorg eden e om uus Xon T ORG de sos ee eee wR SEB x 218 Color Mapping es 219 Contours and Isosurfaces 2L 221 Mapping DP 223 Normals and Shading lll
224. e to absorb it looping the entire sequence is usually helpful You do not want to bore the viewer to death but visualization is not a TV commercial cutting to a new scene every two seconds is not a good editing technique for communicating difficult visual information As we discussed in the section on Animation showing the same sequence at more than one speed helps a viewer notice different information in the very same scene Appendix A Using Data Explorer Some Useful Hints 239 c tn D m mi mall o gt cr tn 240 Visualization allows users fortunately to wildly distort time scales One video may show the movement of tectonic plates another the gyrations of atoms in a gas One scale is millions of years the other billionths of seconds but both are brought into the video scale of one frame every thirtieth of a second Clearly you must use some kind of clock annotation especially if you plan to change playback rates and even more importantly if you plan to show different data sets using the same type of animation The user must be given a proper sense of how two animations compare in their duration if sense is to be made of these animated sequences However humans are not particularly good at visual comparison from memory We are good at pattern recognition and comparison but we have inadequate temporal rate memories we do not remember detail in relation to time because we do not have good time keeping refere
225. ead Evaluation and verification of operation in conjunction with other products except those expressly designated by IBM is the user s responsibility IBM may have patents or pending patent applications covering subject matter in this document The furnishing of this document does not give the user any license to those patents License inquiries should be sent in writing to International Business Machines Corporation IBM Director of Licensing 500 Columbus Avenue Thornwood New York 10594 USA Trademarks and Service Marks The following terms marked by an asterisk at their first occurrence in this publication are trademarks or registered trademarks of the IBM Corporation in the United States and or other countries AIX IBM IBM Power Visualization System RISC System 6000 Visualization Data Explorer The following terms marked by a double asterisk at their first occurrence in this publication are trademarks of other companies AVION Data General Corporation DEC Digital Equipment Corporation DGC Data General Corporation Graphics Interchange Format GIF CompuServe Inc Hewlett Packard Hewlett Packard Company HP Hewlett Packard Company IFOR LS Apollo Computer Inc Motif Open Software Foundation NetLS Apollo Computer Inc Network Licensing Software Apollo Computer Inc OpenWindows oun Microsystems Inc OSF Open Software Foundation Inc PostScript Adobe Systems Inc X Window System Massachusetts In
226. ections we could choose to make triangular or quadrilateral connections i e triangles or quads Quads require four positions for each connection and triangles three Data Explorer supports these element types as well as cubes tetrahedra and lines Suppose we first choose to link adjacent positions in the botanists sample area with ine connections The grid markers were 1 meter on a side Given a sampling area of 5 meters by 3 meters the entire sample would be 15 meters square there would be 24 positions 6 in X and 4 in Y On such a plot we see that a position located at x 0 y 0 is connected to its neighbor at x 1 y 0 We can imagine that it is meaningful to draw associations between data values at adjacent grid positions considering that so many natural phenomena are continuous rather than discrete Chapter 2 Introduction to Visualization 9 10 a A Image tmp doc dependency net 213 File Execute Windows Connection Options position dependent data connection dependent data Figure 1 Examples of Data Dependency We assume that the grasses are free to spread across the area and the wind is free to blow in any direction over the area Previously we assumed that samples were measured at the center of each grid square that is the botanist used quad connections to associate sets of four positions into 4 sided elements then measured data values at the center of each connection element yielding connection dep
227. ed as you save and restore the program To add a comment to the visual program 1 Select the Comment option from the Edit pull down menu A window opens with space for a large text field If a comment has been entered previously it is displayed in the text field IBM Visualization Data Explorer User s Guide 2 Enter the desired comment in the text field Edit the field the same way you edit any text field This text field has multiple lines you can generate line breaks using the Enter key or type continuously and have the line breaks added automatically You can view these comments by using the Comment option of the Edit pull down menu in the VPE or by using the Application Comment option of the Help pull down menu in any primary window Adding Annotation to a Visual Program You can also add annotation directly to the canvas Select the Add Annotation option from the Edit pull down menu A cursor appears Click on the canvas where you would like to place annotation You can modify the text in the annotation by double clicking on the annotation A text entry dialog appears By default the annotation text is visible on the canvas You can choose the Hide Text option on the text entry dialog in which case only a marker appears on the canvas Creating pages in the VPE You can structure your visual program to make it more readable by using pages A visual program can consist of a number of pages Each page contains a se
228. ed to the output of Unmark Unmark also copies back all values from saved data into the data component Then you can Mark temperature as data and perform operations on it if you like Since positions are also 2 D or 3 D vectors you can Mark positions perform operations on the grid itself then Unmark positions to perform operations on the data With a little knowledge of the correct matrix operations it is possible to simulate the effects of rotations translations and scalings using this Mark technique You can warp flat grids into cylinders or polar coordinate systems or create more complex objects like cones In fact there are already many macros available in the Data Explorer Repository that handle these types of operations using this technique which you may wish to download and use yourself For the Data Explorer Repository see Other sources of information on page xxiv Vector valued data sets occur very frequently in visualization Data Explorer offers three ways to visualize vector Fields vector glyphs streamlines and streaklines For this example assume that we acquired data on wind velocity and direction in the atmosphere Recall that a glyph is a visual object a Field of glyphs is made by copying a generic object positioning each copy appropriately and scaling or coloring each copy according to the data associated with that sample point Vector glyphs resemble arrows or rockets and are generated
229. ees How do we find all those in between points By interpolating through the volumetric elements between adjacent sample points And in fact the Isosurface module will do this automatically The resulting isosurface will represent all values of 12 degrees C throughout our volume of sampled space The actual image depends on the distribution of the data of course If the outside of a rain cloud were at exactly 12 degrees C we would see a shape resembling a cloud in the sky But if rain formed at an altitude where the temperature was 12 degrees C we would instead expect to see a flat sheet Or we may not know what to expect that is one of the uses of visualization as well for discovery not just for verification Generally the vertices that describe the mesh positions of an isosurface will not coincide with the original grid points It is important to realize that an Isosurface is a new and valid Data Explorer Field with positions and connections and a data component in which all data values are identical You can treat this Field just like any data Field you have imported Color mapping such a Field is not particularly useful since all the data values are identical so you will get the same color for every point To draw contour lines on a 2 dimensional grid you also use the Isosurface module Data Explorer figures out the dimensionality of the visualization by looking at the input data Thus a biologists 2 D grid can be easily contour m
230. el option of the Help pull down menu in the Control Panel To edit the comments you must use the Comment option of the Options pull down menu Chapter 7 Graphical User Interface Control Panels Interactors and Macros 133 134 Changing the Alignment of Interactors in the Control Panel You can specify whether the interactors you place in the Control Panel automatically align on a grid pattern To do this select Grid from the Options pull down menu The Grid dialog box appears it works the same way as it does in the VPE see Customizing the VPE Window on page 113 Changing the Interactor Style A particular default interactor might not be the most desirable style for your particular application For some interactor types you can change this in a Control Panel at any time by using the following procedure 1 Select the interactor 2 Click on the Edit menu Set Style option Note Be sure to highlight the interactor in the panel before selecting this option Otherwise most of the options will appear grayed out If the interactor is not a type whose style can be changed the style option will remain grayed out A cascade menu appears for you to choose a new style Resizable Interactors You can change the size of the interactors in a Control Panel Some interactors e g Selector resize automatically others e g String do not To resize any interactor press the Control key and then drag the border of the interactor
231. els lll Customizing a Control Panel lll Control Panels as Dialog Boxes 2 2 Control Panel Access Groups and Hierarchies Creating Modifying and Deleting Control Panel Groups Restricting Control Panel Access 005 Specifying a Startup Control Panel Opening Existing Control Panels Using InteraotofS ox shew et E eee SRE Shae SES SE eu Using Data Driven Interactors o 7 2 Creating and Using Macros lll ln Creating Macros aa EOSGIBO MAacI s ma deed ic erp thes dem E eoe od der rer de We hae Be g Using Macros in a Visual Program Viewing and Changing Macros llle Chapter 8 Graphical User Interface Menus Options and the Message WIndOW auk dox ESGUEGCUEGLESX ed dae SR oed uod 8 1 Using the Primary Window Pull Down Menus and Options VPE Window Menu Bar Control Panel Menu Bar 0002 Contents V vi Image Window Menu Bar 165 Colormap Menu Bar 168 Menu Bar Menu Bar 170 Message Window Menu Bar len 172 8 2 Using the Message Window 174 Chapter 9 Graphical User Interface For Advanced Users 177 9 1 Usin
232. en by Compute functions that might in turn be connected to a Sequencer or other data Fields or data components in a Field As just a simple example a Sequencer could emit a series of integers from O to 360 a Compute can turn the integers into floating point angles in the range from 0 0 to 1 0 then make this new number the first component of a 3 vector a 360 0 1 0 1 0 then Convert can change this HSV vector into RGB Connect the output of Convert to a Vector Interactor and feed the interactor output to Color The result is that the Sequencer will make the color of an object attached to this Color module pass through the entire spectrum of hues simultaneously you can watch the RGB values change on the Vector interactor in the Control Panel You can have as many Control Panels associated with a visual program as you like Furthermore a handy feature is that the same stand in the Interactor module that appears in the visual program can have multiple interactor instances associated with it This means you can have both simple Control Panels and elaborate Control Panels with commonly needed interactors appearing in both When you do set things up like this you will notice that the multiple instances of the interactors will always maintain the same value as you change the value in one Control Panel s the associated interactor s in the other Control Panel will stay in perfect agreement Control Panels can be named and accessed by na
233. endent data Now assume that the botanist measures temperature values at each grid position Temperature would then be position dependent data It s perfectly acceptable to have both kinds of data in the same data set We will see how this works when we discuss Fields Assume that the first grid position sampling point lies precisely at the position coordinate x 0 y 0 We take a measurement and record the value Then we measure the temperature at x 1 y 0 Later we ask what was the temperature at x 0 5 y 0 Quite honestly we do not know because our sampling resolution was not fine enough for us to give a definitive answer However if we make the assumption very often a perfectly reasonable assumption but not always that our grid overlaid a continuous set of values we can derive the expected data value by interpolation between known values If we use ine connections to connect adjacent points we realize by looking at our mesh that a straight line connects the grid point x 0 y 0 and x 1 y 0 and that halfway along this line lies the grid point x20 5 y20 We can further assume that the data value at this midpoint is the average of the data values at known sample points bordering this location By linear interpolation we calculate a reasonable value for the temperature at x20 5 y 20 IBM Visualization Data Explorer User s Guide We need to define polygonal connections over the 2 D grid if we wish to find the value at the poin
234. ent data value 1 Object 5 is the second field in the series The positions and connections are defined by objects 1 and 2 in a separate file pos conn data and are in fact the same positions and connections as those of the first field and the data is given by object 2 in this file object 5 class field component positions value file pos conn data 1 component connections value file pos conn data 2 component data value 2 Object 6 is the third field in the series The positions and connections are defined by objects 1 and 2 in a separate file pos conn data and are in fact the same positions and connections as those of the first field and the data is given by object 3 in this file object 6 class field component positions value file pos conn data 1 component connections value file pos conn data 2 component data value 3 ms mall o D ms o ms 3 y cr tn Here we create the series object with three members The members are objects 4 5 and 6 which we defined above Each has a position tag associated with it for example a time tag object series class series member 0 value 4 position 1 3 member 1 value 5 position 2 5 member 2 value 6 position 4 5 end The following file defines the grid for this time series This file can be found in usr lpp samples data pos conn data object 1 class gridpositions counts 3 2 3 origin 0 0 0 delta 1 0 0 delta 0
235. ent agrees that i if the software is supplied to the Department of Defense the software is classified as Commercial Computer Software and that the Government is acquiring only Restricted Rights in the software and its documentation as that term is defined in Clause 252 227 7013 c 1 of the DFARS and ii if the software is supplied to any unit or agency of the Government other than the Department of Defense then notwithstanding any other lease or license agreement that may pertain to or accompany the delivery of the computer software and accompanying documentation the rights of the Government regarding its use reproduction and disclosure are as set forth in Clause 52 227 19 c 2 of the FAR All copies of the software and the documentation sold to or for use by the Government shall contain any and all notices and legends necessary or appropriate to assure that the Government acquires only limited right in any such documentation and restricted rights in any such software 6 Governing Law This license shall be governed by and construed in accordance with the laws of the Commonwealth of Massachusetts as a contract made and performed therein OMRON Corporation NTT Software Corporation and MIT Copyright 1990 1991 by OMRON Corporation NTT Software Corporation and Nippon Telegraph and Telephone Corporation Copyright 1991 by the Massachusetts Institute of Technology Permission to use copy modify distribute and sell th
236. ent operations on it To see all of these visual outputs in the same scene you use the Collect module to gather all the subnet output wires back together The single output from Collect called a Group can be attached to the input of the Image module The Collect module shares a handy feature with some other modules in that you can easily add new inputs to it if you need more than the two default input tabs See Appendix A Using Data Explorer Some Useful Hints on page 211 for discussions of the following e Visualization techniques including animation color mapping and shading e Creating good visualization programs for interactive use e Creating good visualizations for video IBM Visualization Data Explorer User s Guide Chapter 3 Understanding the Data Model 3 1 Introduction to the Data Model 16 oe JODIGGLTVDOS gruas d oo are wae oe CR P jeg PY RH Eee eee 17 mo MT ye Oe E an SA wt ee ee ee ee ee 17 AWAVS woe weak A ERO RS eue ee Yee RR RES de 28 CLOUDS 265224454445 48454 BSA gtd ede de x eke ends 34 O y o D 15 Copyright IBM Corp 1991 1997 3 1 16 This chapter describes the concepts and terminology of the data model for data stored in the Data Explorer system whether in memory or on disk A complete understanding of this chapter is not required for the effective use of Data Explorer and the brief discussion of a Field in Chapter 2 Introduction to Vi
237. ent server model the user interface is the client The executive modules and data management componenis often referred to collectively as the executive make up the server portion The user interface client can be on a different platform from the server executive and the executive can run on multiple platforms simultaneously distributed processing Data Explorer allows you to switch among servers running on different hardware platforms The Data Explorer system can be thought of as consisting of four layers each with its own defined interface These layers are described in the order in which you are likely to encounter them e Graphical user interface e Executive e Modules e Data management Graphical User Interface The graphical user interface is built upon the X Window and Motif standards These tools manage multiple application windows that allow a user to create and control the visualization process easily and effectively The graphical user interface provides two levels of service First non programmers or users with fixed requirements can execute previously created visual programs These visual programs may consist of various menus dials sliders and other interactors that provide fixed functions Second programmers can create customized visualizations by using the interface to interconnect modules in flexible ways and to create new combinations of modules in the form of macros The Data Explorer graphical user int
238. entify all picked points with a glyph or to start streamlines at each picked point In addition the field output by the Pick tool can be used by a user written module to perform a variety of operations on the object in the image e g coloring each picked object a particular color BM Visualization Data Explorer Programmer s Reference includes a sample module that uses the pick structure in this way To use picking to select points on objects 1 Execute a visual program to produce an image in the Image window 2 In the VPE place one or more pick tools from the Special category in the visual program connecting them to the tools for which you want to provide input The pick icons are numbered as you place them on the canvas For example the first pick icon you place is labeled Pick 1 the second Pick 2 and so on You can change the label of the icon by using its Configuration dialog box 3 In the View Control dialog box select Pick mode from the Mode option box or use the Ctrl I accelerator key The dialog box changes to add the Pick controls Select the pick tool you want by choosing the Pick s option box This opens an options menu with a list of the available picks from which to select 4 Select a point or points as input to the tool connected to the Pick icon To choose a point click on a point in the image A small square box appears marking the point Depending on whether you have the persistent parameter to th
239. ep on connections object 3 class array type float rank 0 items 9 data follows 1 3 4 5 2 did Ju 0 3 4 5 4 0 attribute dep string connections A field is created with three components positions connections and data object regular positions regular connections class field component positions value 1 component connections value 2 component data value 3 end Example 9 Faces Loops and Edges Faces loops and edges are used to define polygons For example you may wish to define regions of a map with polygons A positions component identifies the vertices of the polygons an edges component identifies how to connect positions a loops component identifies the beginning of each loop by referring to the first edge of the loop and a faces component identifies which loops make up a face A face may have more than one loop if the face has one or more holes in it For more information about faces loops and edges see Faces Loops and Edges Components on page 24 Note that some modules do not accept this kind of data However the Refine module can be used to convert faces loops and edges IBM Visualization Data Explorer User s Guide data to triangles See Refine on page 258 in IBM Visualization Data Explorer User s Reference The following example describes a simple 2 dimensional data set consisting of five polygons None of the polygons has holes To view the data you can use the following scri
240. er s Reference for details AutoGrid This module provides much of the function of the existing module Regrid However it automatically will construct a grid for you rather than requiring you to create one Categorize Categorizes data replacing the categorized component by a list of indices into a lookup component Among other things allows string data to be categorized CategoryStatistics Computes statistics on categorical data ChangeGroupMember Allows you to insert a new member into a group or replace a member of a group ChangeGroupType Allows you to change the type of a group for example from a generic group to a series New Features in Data Explorer Version 3 1 4 xxxi xxxii CopyContainer Allows you to copy the header of an object Describe This module is used to describe an input object For example it will tell you the structure of the object how many data points the bounding box etc It can also tell you whether or not it is ready to be rendered i e is a valid input to the image tool DXLInputNamed Similar to DXLInput but allows you to specify the name of the DXLink variable by passing it into the module rather than via the configuration dialog box for the module ImportSpreadsheet Imporis tabular spreadsheet data Legend Creates a legend bar which is similar to a color bar but which associates colors with strings The Legend module also accepts a colormap for the second parameter c
241. era controls appear on the View Control dialog box as illustrated in Figure 39 on page 83 IBM Visualization Data Explorer User s Guide View Control indo Cine Medo Ciri D Mode Camera Set View Mone Projection Orthographic View Angle d 30 000 fm X 1 08133 Y 0 00000 1 00000 Window Width 640 Window Height 470 Camera Width 3 40057 Close Reset Ctrl F Figure 39 Camera Settings Portion of the View Control Dialog Box Note that these camera controls are not direct interactors so changing their values does not cause the visual program to reexecute automatically To see the effect of your changes you must specify Execute or Execute on Change in the VPE Control Panel or Image window Changing the Look to Point Look from Point and the Up Vector You can adjust your view of the image by specifying values for these settings look to point vector The point around which the displayed image is centered The point is specified as a vector in world coordinates look from point vector The position of the camera The point is specified as a vector in world coordinates up vector The rotation tilt of the camera Only the direction of this vector is important not the magnitude For instance if you are looking at the object from a positive z direction an up vector with a negative value for x tilts the camera counterclockwise The option box near the center of the View Control
242. erface lets you create or work with a visual program to easily realize sample select and transform data during visualization You can use the Visual Program Editor VPE to create new scenarios by simply connecting module icons on the screen in any logical sequence Data Explorer provides the following primary windows Visual Program Editor Lets you create and alter visual programs Control Panel Lets you set and control the variable input parameters of the tools used in a visual program Image Window Displays the image created by a visual program and allows direct interaction with the visualized image Help Window Provides online access to the Data Explorer user manual and context sensitive help information Data Explorer provides a Colormap Editor window that lets you map colors to specified data values and display the results in the visual image The system also provides a Sequencer window which has many uses including controlling how a sequence of images is displayed with forward and backward direction repetition and so on Chapter 1 Overview 3 Executive Modules These windows are discussed in detail in Chapter 5 Graphical User Interface Basics on page 57 In addition Data Explorer provides two stand alone utilities Data Prompter a point and click interface for describing a data set for importing See IBM Visualization Data Explorer QuickStart Guide Module Builder a point and click interface for describing
243. es 271 Composite Field Objects 2 2 0 2002002020 008 4 271 Field ODIECIS xut ob uu bee eR Ge A A Eae s 272 Amay ObIeGlS seu ms bot dede qo d deg weed e 272 Constant Array Objects ses deseos See Ro wot SD de e 273 gridpositions Keyword ole 274 Regular Array Objects scs aca X TERES EHE 8S eee EC RUE dos 274 Product Array Objects ee ee 275 gridconnections Keyword 2e 275 Path Array Objects 276 Mes Array ODJEC S au da 0836 e ue oa EA S 276 Xform Objects 0 a 277 3 SINO ODJECE uda A hu BES E qa RES E E 277 4 Light Objects sos aoc ics Bode max ore Pave die Sapa EE ia 277 Z Camera Objects a ce 278 Clipped Objects a a a a a R E T A ya h 278 Screen ODISCIS mis gas Sis we don EV e io we ied eed 278 Data Mode Clause rn 278 Detault CIAUSO raas eona oom ee dw ete Se ESSES I EIE exe 279 End CANSO oiu mucus a d i tube Pp IE up be mo E ee Se Hades 279 BS GORROS cido eck duni m ete bees m O q DS s iu 279 BA NEICDR FIGS 4 645 2 2068 a AIN cas Ws 281 Regular GdS ima sd sad 440880464 5o 5 0044 04 Barks 281 B 5 netCDF Files Complex Fields lt 24 65 vs 282 megla AMAS coso ara ara d dom he ns Bs 282 Bcc owe tenn bone TET 284 EXAMmMples as Sich Conr de Nod er dn E ah we Ta Tu de De ee de SO eR d 286 Bo HOF ECS vuimeobeuesuhmmaeundsee ds ec eke Bee mque Ex 288 O Copyright IBM Corp 1991 1997 241 Importing your data into Data Explorer w
244. esolution directly At the same time this surface can be colored or color mapped either by connection dependent or position dependent data The other type of normals are created by the Normals module when you enter positions as the method this is the default method in fact In this case the surface will be much smoother in appearance yielding a more aesthetically pleasing surface at the expense of being able to directly perceive the grid resolution It is sometimes less confusing to use position normals in place of connection normals IBM Visualization Data Explorer User s Guide because the object is less busy looking You must be the judge of what is the appropriate way to observe your own data You can also show your data first with connection normals to illustrate the sample resolution then switch to position normals in order to better show some other aspect of your data Normals are used by various modules in Data Explorer One use of this information is that it is required by the image renderer the Image Render and Display modules all incorporate the image renderer to calculate the amount and direction of light falling on an objects surface we will discuss this in more detail below Rubbersheet assumes that the input grid or line is flat if there is no normals component in the input Field and projects the values in a perpendicular direction However you may wish to create your own normals or modify an existing normals c
245. ess you are running Data Explorer in script mode In Data Explorer script mode you can also perform tasks that would be awkward with a visual program e g facilitation of batch processing or debugging of a module 10 1 Starting Data Explorer in Script Mode 188 To run Data Explorer in script mode on a workstation you must have an account on that workstation To start Data Explorer follow these steps 1 Start the X Window System session on the workstation 2 Type dx script When script mode starts you will see a prompt symbol dx gt indicating that Data Explorer is ready to accept input Ilf you want to change the prompt symbol see 10 7 Using Data Explorer Script Commands on page 206 All of the command line options for Data Explorer are described in C 2 Command Line Options on page 295 You can type commands directly at the command line but you may find it more convenient to create a script and submit it to Data Explorer for execution To submit a script type include scriptname at the prompt where scriptname is the name of the script Once you have submitted a script Data Explorer will process the commands it contains Note that none of the direct interactor options are available in script mode you must use the Image tool in the graphical user interface to take advantage of those options After the included script has been processed you can include another script To terminate your Data Explorer
246. ewer to see the overall vector Field direction s while reducing the visual clutter You can also use the Sample module to extract a subset of points of the data Field For example you can select a subset of points lying on an isosurface these data Appendix A Using Data Explorer Some Useful Hints 229 c tn D m mi mall o gt cr tn 230 points can then be fed to Glyph The effect in this case is to show the vector Field direction and magnitude sampled at the surface of constant value This is another technique to reduce the number of vectors glyphed at the same time and may make it easier to perceive the structure of the vector Field Another technique for visualizing a vector Field relies on the concept that there exists a potential flow direction through the Field Imagine releasing some very light styrofoam balls into our wind Field each ball has a streamer attached to it Gravity and friction are ignored by the visualization tool of course you may have accounted for these forces in the simulation that modeled the vector Field if these forces are relevant to your science We release the balls at one instant on one side of our Field and after they have passed through the Field we take a snapshot of the streamers This type of image is essentially what you get with the Streamline module Streamline is used to visualize a flow Field at an instant in time it assumes that you have a particular measure of a vector F
247. f 16 Field 17 Group 34 in Data Explorer files 244 Objects Array compact constant 33 in Data Explorer file format 244 Objects Array continued compact continued mesh 31 path 31 product 29 regular 29 irregular 28 items in 28 octal numbers in scripting language 194 on line help Context Sensitive Help 65 in a Control Panel 67 133 in a visual program 67 Overview of Window 65 Table of Contents 65 Technical Support 65 Tutorial 65 user defined 67 Using Help 65 opacities component 23 Opacity map component 23 Opacity multiplier attribute 27 operators in scripting language 198 options box 63 ordering of vertices 20 21 orthographic projection method 76 outboard modules loading 183 output cacheability setting 214 P panning 80 See also look to point parallelism 55 56 Path Array Objects in Data Explorer format 276 in the Data Model 31 paths component in the Data Model 25 perspective projection method 76 pick paths component 25 picking 25 87 Plot 227 pokes component 25 positional arguments in scripting language 200 positions component 20 positions dependence 8 17 positions definition 17 preserving explicit state 45 printing an image 97 probes 85 Product Array Objects in Data Explorer format 275 in the Data Model 29 projection methods 76 pull down menus selecting 62 R rank of an Array item 28 Receiver tool 106 234 Redo action 84 reference ref attribute 27 Regular Array Objects in Data Explo
248. f axes and the wire framed globe if enabled also rotate providing instant feedback to your actions Note If you do not have Execute on Change enabled only the set of axes and the globe are updated as you move the mouse providing preliminary feedback to your rotation actions If Execute on Change is enabled then the object rotates as you move the mouse 3 When you release the mouse button the object is rotated according to the new position of the axes and globe Note You can also enable Rotate mode by using the intrctnMode parameter to the Image tool see Image in BM Visualization Data Explorer User s Reference The point around which the object rotates is the look to point which you can change by selecting Roam see Changing the Look to Point on page 79 Alternatively you can select Pan Zoom in the Mode pull down menu see Zooming into and out of the Image Zooming into and out of the Image To zoom in or out relative to the center of the Image window 1 Select the Zoom mode in the Mode option box or use the Ctr1 Z accelerator key 2 o zoom in press the eft mouse button to zoom out press the right mouse button Drag the mouse in the image area This causes an overlay image of a rectangle to appear As you move the mouse pointer away from the center of the window the rectangle enlarges As you move the mouse pointer towards the center of the window the rectangle shrinks Releasing the mouse button causes the im
249. f font that includes European National Language characters script fonts a script single line font The default font directory is usr lpp dx fonts For user added fonts the DXFONTS variable can contain a colon separated list of directories to search for fonts before searching the default directory A font file name must be the same as the font name For example the font cursive should be stored in the cursive dx file and the font parameter to the Caption module should be cursive to use this font The names of user supplied fonts should be all lowercase Since font files are in the standard Data Explorer file format in addition to being used by Caption Plot AutoAxes and ColorBar they can be read into Data Explorer with Import and processed like any other group Individual characters can be selected with Select colored with Color and displayed with ShowConnections Newly constructed fonts can be exported with Export Table 8 and Table 9 on page 310 illustrate those characters that are part of the roman ext font The appearance of a character may differ from that illustrated in the tables Table 8 roman ext Font Characters Part 1 AR e e gt u u lt i 7 Je wo go we o le He gt Appendix E Data Explorer Fonts 309 Table 9 roman ext Font Characters Part 2 Octal Value E amp ro po Table 10 Page 1 of 2 Addition
250. f temperature the input Field to Map in this example had only one data value 12 degrees C at every position but the mapped isosurface the output of Map will contain arbitrary patches of data corresponding to the distribution of cloudwater density If we AutoColor this output isosurface we will see an arbitrary geometric surface with a patchy color scheme The surface is the location of all 12 degree temperatures and the patchy color corresponds to the distribution of different cloudwater densities sampled on that surface Of course if cloudwater density happened to have the same value at all points on the 12 degree temperature surface we would see only one color Naturally you can do the opposite First make an isosurface of cloudwater density say at the mean value of density The mean value of a Field is taken as the default value by the Isosurface module this is convenient when you start exploring a new data set and do not know what the extreme values are Now map the temperature data onto the cloudwater isosurface Run the output through AutoColor The result will look very different This time you have dipped the cloudwater isosurface into a bucket of temperature data Once again this serves as a reminder that you must indicate to an observer exactly what kind of operation you performed if your visualization is to bear any meaning You can also dip the cloudwater isosurface into the temperature colors To do this first AutoCo
251. f the modules that in the original network received the result of the Switch module This leaves the unselected module dangling It and any of its ancestors that are therefore made unnecessary will not be executed A different procedure is used if the controlling value is not static e g if it is determined elsewhere in the network as shown in Figure 20 on page 43 Suppose either an isosurface or a set of vector glyphs is selected depending on whether the data are scalar or vector The determination of the type of the data is made using the Inquire module i e at run time In this case the selection value for the Switch module cannot be determined before the execution of the graph Instead the graph must be evaluated in stages 1 determine the selection value 2 determine the necessary input to the Switch module and 3 evaluate the remainder of the graph Since dynamic inputs may themselves be descended from other non static inputs e g computed in the network this process may have to be performed repeatedly IBM Visualization Data Explorer User s Guide Visual Program Editor tip doc figure3 net Import Isosurtace E mauire Pato Giyph m gt lt D ie S ct mall o le o x D Figure 20 Example 3 4 4 Iteration using the Sequencer Caching of intermediate results is particularly useful in conjunction with the Data Explorer Sequencer module The Sequencer provides Data Explorer with a very simple
252. f the option in the options list much like it is in the pull down menus Editing Text Fields Many of the dialog boxes in Data Explorer include text fields that you can change You can place a text cursor in the box by clicking on the box With the cursor in the box you can use the keyboard to alter the text The number of times you click on the text box depends on how you want to edit it Single Click Places the text cursor at the point on which you clicked in the existing text field All text you type is then inserted in the field after the selected point You can also use the Delete and Backspace keys Double Click Places the text cursor at the start of the word on which you clicked in the existing text field and highlights that word When you type the highlighted text is replaced with the new text you enter Pressing the Backspace key deletes the highlighted text Triple Click Highlights the entire text field When you type the entire field is replaced with the new text you enter Drag Highlights the portion of the text field that you drag the cursor over When the mouse button is released the text remains highlighted Typing anything replaces the highlighted text with what you type pressing the Backspace key deletes the highlighted text Data Explorer allows you to copy and paste text within text fields To copy text select the desired text by double clicking triple clicking or dragging the cursor over it with the left mouse
253. f the positions that define a connection element visual program editor IBM Data Explorer window used to create and edit visual programs and macros See also canvas volume The amount of three dimensional space occupied by an object or substance measured in cubic units To be distinguished from an object s surface which is a mathematical abstraction volume rendering A technique for using color and opacity to visualize all the data in a 3 dimensional data set The internal details visualized may be physical such as the structure of a machine part or they may be other characteristics such as fluid flow temperature or stress vorticity Mathematically defined as the curl of a velocity field A particle in a velocity field with nonzero vorticity will rotate W window On a visual display terminal information in a framed area on a panel that overlies part of the panel See also anchor window primary window secondary window wireframe Connected lines that represent a surface Glossary 321 e O Y un y m lt 322 IBM Visualization Data Explorer User s Guide Index Special Characters variables 192 206 207 Numerics 3 D cursor 79 85 A accelerator keys 63 adding comments to a visual program 114 adding input tabs 106 advanced looping constructs 50 align for navigating 80 aligning interactors in a Control Panel 134 aligning tools in the VPE window 113 anchor symbol 60 angle fo
254. fect will be to make the scaled object disappear That is usually not desirable set the minimum permitted scale value to be a positive value greater than 0 0 if you do not want to confuse users of your visual program Some interactors can be used in a different mode than interactive these are called data driven interactors Scalar Integer and Vector interactors and their respective List types all have input tabs of their own By default all the numeric interactors have arbitrary ranges preset to 1 000 000 to 1 000 000 Clearly these will rarely be the appropriate ranges for your data As part of good interactive visual program design you the visual program author would like to restrict these ranges to the correct values for the input data sets But if you are building a visual program for use by others you won t know in advance the ranges of data sets the user will import If you build your visual program such that the data IBM Visualization Data Explorer User s Guide Field the output of Import for example connects to the input tab on one of these interactors the correct maximum and minimum values will be automatically set the first time the visual program is executed and they will be updated appropriately as the input data set changes Thereafter the user cannot accidentally exceed the range of values by turning a dial or sliding a slider too far in one direction or the other Data driven interactors can be directly driv
255. ference The following example illustrates how the group attribute can be used cwater Import cloudwater iso Isosurface cwater wind Import wind group group2 x Compute 0 x wind group group2 mapped Map iso x colored Color mapped camera Camera colored Display colored camera The second Import and the Compute will be placed into an execution group called group2 All other modules will be placed into one default execution group Chapter 10 Data Explorer Scripting Language 203 10 n m mall o O cr mall o E Q r o E Q e y e D You can combine the various attributes for a single function call by separating them with commas as in the following examples wind Import wind instance 2 group group2 Colored Color iso blue instance 1 cache 2 Colored Color iso green instance 2 cache 2 group group one shot Represents the script language implementation of the Reset interactor in the user interface It sets the value of a variable to one value for the first execution and a different value resetvalue there after The syntax IS xloneshot resetvalue value 10 6 Defining Macros Macro Header Macros are higher level processing functions that are constructed from simpler ones A macro definition consists of two parts e A macro header e A macro body The following sections define these parts The macro header define
256. field use the stepper controls or select the field and enter the new value or use the End marker If you change the value in the Max field then the End field is set to that new value If you are working with a saved program then the Max and End fields are set to the values that were saved Current Displays the current frame number Increment By default set to 1 To change the increment use the stepper controls or select the field and enter the new value Next By default set to the value in the Start field in a new program You can set the Next field to any value between the Start and End values the Sequencer will begin running at that value When the Sequencer is in loop mode subsequent loops begin at the value in the Start field Min and Max Specify the allowed range of sequence values These are text fields that can be altered Data Explorer ensures that the value in the Start field is greater than or equal to the Min value and the value in the End field is less than or equal to the Max value Note f the images change more quickly than you would like use the Throttle option see Changing the Rate of Frame Display Throttle on page 93 Using a Data Driven Sequencer 70 The Sequencer can be data driven meaning that its minimum maximum and step values can be set by connecting the output of a tool to the input of a Sequencer in the VPE or by a value typed into the Sequencer s Configuration dialog box rather th
257. fier is determined by its context Reserved Words The identifiers in the following list cannot be used for variable or function names Those marked with asterisks are reserved for use in future releases and loop repeat backward macro or cancel not sequence elsex off step falsex on stop for palindrome then forward pause truex if play until include quit while The identifier NULL is a reserved variable name It can be used to initialize other variables or function arguments to have no value assigned to them IBM Visualization Data Explorer User s Guide Specifying Values in a Script You can specify values in a Data Explorer script as any of the following e String constants e Scalar numeric constants e Vectors matrices and tensors e Lists You can use any of the formats described in the following sections to specify values to Data Explorer To have Data Explorer use a particular format to echo these values to you you must first format a string with the Format module as described in Format on page 146 and then echo the string using the Echo module 10 n m mall o O cr mall o E Q r o E Q e y e D String Constants String constants consist of a sequence of any characters delimited by the double quote character However a null character in a string delimited by double quotation marks for example str Oing causes the string to be terminated at the null character otring
258. first three bytes of the file are the number of elements in the x y and z directions e The data values are listed in an order such that z varies fastest Given all these conditions the following Data Explorer header file imports the data substituting the data file name for data file name object 1 class gridpositions counts 100 100 15 origin 50 100 10 delta 1 0 0 delta 0 1 0 delta 0 0 2 object 2 class gridconnections counts 100 100 15 attribute element type string cubes attribute ref string positions IBM Visualization Data Explorer User s Guide It skips the first three bytes before reading the data values object 3 class array type float rank 0 items 150000 ieee data file data file name 3 object field class field component positions value 1 component connections value 2 component data value 3 end Example 6 Product Arrays The following examples show how to use Product Arrays to define positions that are composed of products of arrays Such positions may be regular in one or more dimensions and irregular in one or more dimensions The resulting product array is found as a product of all possible combinations of the terms comprising the Array The first data file defines data that has irregular positions in the xy plane but regular spacing in the z dimension This file can be found in usr Tpp dx samples data productl dx Figure 90 on page 256 shows the resulting image define a set of irregular p
259. following options noInteractorEdits noInteractorAttribute noEdi torAccess noInteractorMovement By restricting the ability to highlight interactors with a mouse click this option in effect also disables interactor movement DX noRWConf ig Removes the Open and Save As menu commands from the File menu DX noScriptCommand Removes the Execute Script Command menu command from the Message window s Options menu DX printImageCommand Specifies the default print image command to be used use in the Print Image dialog box available from the Image window DX printImageFormat Specifies the default file format to be used in the Print Image dialog box available in the Image window The following values are recognized PSCOLOR Color PostScript PSGHEY Gray level PostScript EPSCOLOR Encapsulated Color PostScript EPSGREY Encapsulated Gray level PostScript DX printImagePageSize Specifies the default page size that PostScript images should be centered on when printing images from the Print Image dialog box available from the Image window Units are those indicated by the metric option DX printImageResolution Specifies the default resolution that PostScript images should be printed with when printing images from the Print Image dialog box available from the Image window Resolution is in dots per inch unless the DX metric resource is set in which case dots per centimeter is used This resource is overridden by the printIm
260. form mental gymnastics to interpret it correctly If you are mapping altitude however red is not necessarily best associated with the high point after all the highest altitudes are snow covered and lower altitude deserts are frequently red hot Actually color mapping altitude is almost purely an artistic endeavor but at least it has a long history and literature in cartography Consulting the traditional textbooks for a field may indicate how users in that discipline prefer things to be mapped It is generally unwise to start a new schema for your visualization if you wish it to be immediately accessible to other viewers familiar with the discipline But relating new ways of visualizing data to the old methods may be a good way to provide new insights for everyone involved Remember that to use interpolation the basis of your assumptions is that the phenomenological space studied is continuous and linear lf you have reason to believe the sampling was not done over a domain that can be linearly interpolated you should certainly not be using linear interpolated images to understand the data IBM Visualization Data Explorer User s Guide You may need to collect more data on a finer grid to resolve such problems Since Data Explorer supports irregular grids this is not a problem for the software as long as you provide the correct data sampling Also be aware that trying to read too much detail out of an image is an error You cann
261. formation box appears when Data Explorer requires more information in order to complete a task or when a user requests more information A dialog box option is indicated by an ellipsis at the end of its title Using the Mouse In Data Explorer the mouse is one of the primary input devices Some operations can be done using the keyboard but many rely on the mouse The mouse related terms used in this guide are Click One press and release of a mouse button Double click Two rapid presses and releases clicks of a mouse button Triple click Three rapid presses and releases clicks of a mouse button Drag A press and hold on a mouse button For example with the button depressed a selected item can be moved dragged to another part of the screen by moving the mouse pointer to the desired location and releasing the mouse button Shift Click A press and release of the mouse button while depressing the Shift key Shift Drag A drag of the mouse pointer while depressing the Shift key Most of the Data Explorer operations use the left mouse button The exceptions are the Online Help function and the image direct interactors which use two or three mouse buttons Moving and Resizing Windows You can move windows and adjust their sizes on the screen To move a window drag the window name portion of the title bar to the desired screen location To resize a window do one of the following e Drag on one of the horizontal borders
262. frequent change You can use interactors as an easy method for controlling those input values nteractors which appear only in Control Panels are the interactive devices that you use to manipulate inputs to a visual program in order to change the image that is produced see Using Interactors on page 142 for detailed descriptions Interactor stand ins are used to indicate which input to a module a given interactor is to control While you are building the network in the VPE you select interactor stand ins from the tool palettes and place them on the canvas as you do with other tools Like any tool the output of an interactor stand in can be connected to more than one input Interactor stand ins are named in general after the type of data they output Integer stand ins Represent interactors that output whole numbers Scalar stand ins Represent interactors that output real numbers String stand ins Represent interactors that output text strings Value stand ins Represent interactors that output scalars vectors and tensors Vector stand ins Represent interactors that output vectors Integer list stand ins Represent interactors that output integer lists Scalar list stand ins Represent interactors that output scalar lists String list stand ins Represent interactors that output string lists Value list stand ins Represent interactors that output value lists e g vector and scalar lists Vector list stand ins
263. g Distributed Computation 178 Creating Modifying and Deleting Execution Groups 178 Displaying the Tools in an Execution Group 180 Assigning Execution Groups to Workstations 181 PCSIIGHONS cite ene ee ee te eee eS ke Re ee ee q E 182 9 2 Loading and Using Outboard and Runtime Loadable Modules 183 9 3 Connecting to the Server 0200000200004 183 Resetting the Server 0000000 a e ee 185 Chapter 10 Data Explorer Scripting Language 187 10 1 Starting Data Explorer in Script Mode 188 Setting Environment Variables cles 189 10 2 Understanding the Script Structure 189 10 3 Language Delimiters 00000000058 191 Commenting Scripts e 191 Naming Variables and Macros 0 200004 192 Specifying Values ina Script ln 193 10 4 Building Expressions and Statements 197 Arithmetic Expressions 2 0 197 Assignment Statements ooo llle 198 Function Call Assignments 0 000000000 2 ae 199 10 5 Invoking Data Explorer Macros and Modules 200 Function Call Arguments 0 0000000 2 ee eee 200 Function Gall AUIDUIeS a ax Bs Gy dux Des e eR Se ee RS 202 10 6 Defining Macros ees 204 Macro Header picas V eee BY Ede debe dom ur De
264. g example show how to set these variables Note that this example shows the Data Explorer prompts as they would be displayed in the executive Chapter 10 Data Explorer Scripting Language 207 10 n m mall o O cr mall o E Q r o E Q e y e D dx prompt DATA EXPLORER gt DATA EXPLORER gt cprompt more gt If after these commands an incomplete statement was entered Data Explorer would respond as follows DATA EXPLORER a more gt 3 5 10 8 Understanding the Script Execution Model An execution model is applied to the constructs defined by the Data Explorer scripting language This model consists of the environment structure that is maintained during function calls the behavior associated with macro expansions the scope rules used for locating the value associated with a variable and the semantics associated with assignment statements and function calls Top level Environment All global assignment statements and initial function invocations occur in the top level environment This environment is special in that all assignment statements and function invocations initiated in this environment are always executed Function Execution When either a macro or a module function is executed a new dynamically scoped environment specific to that function call is created Variables that correspond to the function s input and output formal parameters are created in this new environment The vari
265. g values 121 menus Edit 169 Execute 170 File 168 Options 170 moving control points 123 selecting control points 123 using 119 colors component 22 comments adding to a visual program 114 in a Control Panel 67 in a data file 269 in a script 191 in a visual program 67 user defined 67 Compact Arrays 29 component attributes 26 component sharing 19 323 component definition 17 Composite Field Groups 35 Composite Field Objects in Data Explorer file format 271 configuration dialog box buttons 110 entering values in 107 for Compute module 111 notation field 108 toggle button 108 value field 109 connecting to the server 183 connection dependence 8 20 connections 9 20 Constant Array in Data Explorer file format 273 Constant Arrays 33 constants in scripting language scalar numeric 194 string 193 constraints on 3 D cursor tool 79 85 constructs advanced looping 50 contours 221 Control Panels 232 access 138 adding interactors 130 building 129 customizing 133 deleting 132 Groups 138 139 menus Edit 163 Execute 164 File 163 Options 164 Panels 164 placing interactors 130 saving and restoring 132 Control Panels dialog style 135 controlling view of an image See image controlling view of copying tools 105 cuboid vertices ordering 21 cursor constraints 79 85 customizing the VPE window 113 D data component 22 Data Explorer Data Model 16 environment variables 59 292 file format examples See examples of Data Exp
266. gamma correction is a nonlinear adjustment of the pixel values to compensate for this difference and produce a more accurate representation on the screen By default except for 8 bit windows on the sgi architecture the correction factor exponent is 2 two on the assumption that the display is not otherwise gamma corrected The DXGAMMA variable allows you to override this default In particular if the display device is already gamma corrected set the variable to 1 one See Display in BM Visualization Data Explorer User s Reference and README sgi in usr Ipp dx DXGAMMA_8BIT DXGAMMA_12BIT and DXGAMMA_24BIT set the gamma correction for software rendered images displayed to the screen in 8 12 or 24 bit windows by a Display or Image tool This variable overrides the value set by DXGAMMA DXHOST specifies the machine name of the server on which the executive is to be run The default is localhost See 9 3 Connecting to the Server on page 183 for information on how to connect to the server To determine the host name enter the command uname n Appendix C Environment Variables and Command Line Options 293 lt o m mall o o o al D tn e cr mall o o E tn 294 DXHWGAMMA sets the gamma correction for hardware rendered images displayed to the screen by a Display or Image tool On many display devices a given change in the digital brightness of the image is not reflected in a corresponding change i
267. gh other input tabs that are by default hidden For example you may wish to set the minimum and maximum for an interactor to go from the minimum of the data values to the midpoint of the data values rather than to the maximum In this case you can use the min and max input tabs of the interactor rather than the data tab The interactors that can be data driven are Integer Scalar Vector IntegerList ScalarList VectorList Selector SelectorList and Toggle In Chapter 2 Functional Modules in BM Visualization Data Explorer User s Reference the inputs for each of these interactors are described on the manual page corresponding to that interactor IBM Visualization Data Explorer User s Guide Each time an input to a data driven interactor is changed for example by importing a new data set the interactor is reexecuted updating its attributes If the current setting of the interactor lies within the new range allowed the interactor value does not change If the current setting is outside the new allowed range the current setting is reset to the midpoint of the new minimum and maximum 7 2 Creating and Using Macros In general macros are higher level processing functions that are constructed from simpler ones A Data Explorer macro is a sequence of modules collected together that you can use as a single tool This is useful if you have a sequence of modules that provide a function that you need frequently in your visual
268. grams These tutorials will familiarize you with the user interface as well as some of the commonly used Data Explorer modules Creating a Visual Program To create a visual program use the Visual Program Editor VPE window in which you place and connect tools and specify values for those tools Figure 47 illustrates the VPE window and a sample visual program Visual Program Editor usr ipp dx sammles tutorial example net Figure 47 VPE Window A Ort o Part ion Sequence Compute EDS STADT ea un Map I oF tare Geadiem AuitoColor Integer Colorssap Isosurtace Selector Color Color Collect Image The title bar of the VPE displays the name of the current visual program file On the left side of the window are two palettes The top palette contains tool categories When you select a category from the top palette the bottom palette displays the tool names in that category The large area on the right side of the 100 IBM Visualization Data Explorer Users Guide window is called the canvas You place tools on the canvas to construct a visual program In some cases the visual program may be too large to be displayed all at once on the canvas On the right and bottom sides of the canvas are scroll bars which allow you to move the display to different parts of the visual program To display a different part of the visual program click on the arrows at the end of the scroll bars or click and hold the button
269. grams and tips and tricks you discover as you learn and master Data Explorer On the Internet the newsgroup comp graphics apps data explorer is used by customers around the word to share information and ask questions This newsgroup is also followed by Data Explorer developers IBM Visualization Data Explorer User s Guide If you have access to the World Wide Web you can find the Data Explorer home page at http www almaden ibm com dx About This Guide XXV XXVI IBM Visualization Data Explorer Users Guide New Features in Data Explorer Version 3 1 4 User nt rlace 2 5 9 BAS Renee MDA Reve PUES A e ERES New Startup Behavior New Save Image Dialog in Image Window New Data Prompter 0 0048 Pages ud uueRe5 Ade E Eu dies rd Annotation 00 0 Optimizing Caching ccn Changes to Get and Set modules New Window Management Functionality Hardware Rendering lr DAGOK 24 338 tot ra s ae eee eee es oF ESOS MSS Changed Modules New Modules sek de Wn PEG E oed fei eS Backward Incompatibilities HTML Documentation FIXES ai i at a DR Se es I a ce DO e ds A Copyright IBM Corp 1991 1997 XXVIII XXVIII XXVIII XXVIII XXVIII XXVIII XXVIII XXXIV xxvii User Interface New Startup Behav
270. green User s Guide OSSO lt P lt P OOOO Oe Oe Oe corn O 0000000 5568628 1960784 1960784 4196078 9176471 5764706 2588235 4980392 4980392 4392157 8588235 1843137 1372549 1372549 0 8000000 m 0000000 0 8588235 oO CO CO CO CO CO O CO Ho O O m 5607843 7372549 9176471 0000000 4352941 1372549 5568628 1960784 0000000 0000000 1372549 8588235 8470588 6784314 3098039 8000000 8470588 0000000 0000000 0 6000000 O Coco Ccococococococo O SO coco O CO Ho O O m 0000000 1372549 8000000 1960784 5568628 9176471 4392157 4352941 0000000 0000000 8588235 4392157 1843137 1372549 1372549 1960784 0000000 4392157 372549 5607843 6784314 0000000 2588235 5568628 4196078 6000000 4980392 0000000 4196078 5764706 7490196 9176471 1843137 1960784 8470588 0000000 0000000 0 8000000 O Cocco Lco OOOO OC OF O O CO r2 CO CO CO O CO Ho O O 0000000 4196078 6000000 8000000 1372549 6784314 8588235 2588235 0000000 0000000 8588235 5764706 3098039 5568628 5568628 1960784 4980392 8588235 5607843 5607843 0176471 0000000 2588235 4196078 1372549 8000000 0000000 4980392 5568628 4392157 04 0588 9176471
271. h one module after another Some modules add new components others remove or change components However an essential point to keep in mind is that unless a module is designed to operate on a specific component it does not affect any other part of a Field That is to say if you feed a Field into a module that does not operate on the positions component then from the output of that module will come a Field with the identical unchanged positions component And that means that another module further downstream in the visual program can operate on that positions component if need be This differs in a critical way from traditional languages which explicitly specify all return values from a function In Data Explorer assume that everything that goes into a module comes out though often changed whereas in a traditional language ignoring side effects bad programming practice usually only those values specifically indicated as return values are returned when the function exits The descriptions in BM Visualization Data Explorer User s Reference identify the components that are changed deleted or added by each module It is also very often useful to branch a visual program Any module input can only have one wire tab connection attached to it at a time However any module output can feed several different module inputs This allows you to run copies of the same Field through different subnets to perform several differ
272. he corresponding parameter is set using the recordFormat recordRes or recordAspect parameters to the Image tool Print Image Options Allow Rerendering allows you to specify whether or not the currently displayed image should be rerendered at a new resolution or aspect ratio If Allow Rerendering is toggled off then the Image Size is completely determined by the resolution of the currently displayed image Image Size and Output PPI cannot be independently controlled and you can not change the aspect ratio of the image from that of the currently displayed image If you attempt to change the aspect ratio of the image size e g by specifying a size of 8x8 when the original image is not at an aspect ratio of 1 1 the new image size will not be accepted by the Image Size text field If you change only one component of the image size e g by specifying 8 x then the other component of the image size will be computed by Chapter 6 Graphical User Interface Important Windows 97 98 Print Image We Figure 46 Print Image Dialog Box Gamma Correction Delayed Colors Format comparing it to the current aspect ratio and Output PPI will be adjusted such that the number of pixels of the image remains that of the currently displayed image If Allow Rerendering is toggled on then the currently displayed image will be rerendered at a new resolution based on the settings of Output PPI and Image Size which can
273. he parameter This list is for convenience only you may enter values other than those listed as long as they are valid inputs for that parameter For example the button for the color parameter to the Color module lists red green and blue Outputs Section Name Type Destination Cache Specifies the name of an output parameter You cannot modify this field opecifies the type of an output parameter You cannot modify this field Displays the name of the tool or tools to which the output tabs are connected Specifies the number of results for this output of the tool that are eligible for caching Cache can be All Results in which all results are eligible for cache Last Result in which only the last value of the output is eligible or No Results in which no results from the module should be cached See Cache Control Executive on page 215 Pushbuttons The seven buttons at the bottom of the Configuration dialog box are labeled boxes that perform an action when you click on them The buttons are OK Apply Expand Collapse Description Restore Cancel Applies new values and closes the box Saves newly entered values Once you click on the Apply button you can no longer restore previous values Causes all hidden inputs to be displayed in the Configuration dialog box You can then unhide hidden tabs using the Hide toggle button Causes all hidden input tabs to be removed from display
274. he Selector This interactor lets you construct a pop up menu containing one or more string items each associated with a value either a scalar including integer scalar vector or a string Selector has two outputs the value and the string you have entered This allows you to present a menu that Appendix A Using Data Explorer Some Useful Hints 233 c tn D m mi mall o gt cr tn describes clearly what choices the user has and when the user picks an item Selector outputs both the value through its left hand output tab and the string choice through the right hand output tab The right hand output can be attached to modules that accept string input Remember Format You can use this technique to change a caption depending on the user s current Selector choice If you use integers as the values in your Selector the left hand output will be the currently selected integer You can direct this numeric output of Selector to any module that takes an integer a common use is to connect the integer output of Selector to a Switch module The Switch module in the Structuring category uses a number to pick which of several inputs to pass to its output Suppose you have connected an Isosurface to the first input the second tab of Switch and a ShowConnections to the second input third tab You have also constructed a Selector menu to offer the three choices O Both off 1 Show Isosurface and 2 Show Connectio
275. he following are examples of valid floating point numbers all of which have the value 95 0 95 95 0 95e0 9 5E1 950e 1 9 50e 1 Vectors Matrices and Tensors Vectors matrices and tensors are higher dimensional mathematical entities that are used for the representation of specific kinds of data Vectors A vector is a quantity that has both magnitude and direction in n dimensional space It corresponds to a directed line segment whose length represents the magnitude of the vector and whose orientation corresponds to its direction Vectors are composed of a sequence of scalar values enclosed by square brackets The scalar values can be separated by commas if desired although this is not necessary If the elements of a vector are not homogeneous e g if they are both integer and floating point elements then the integer elements are converted to floating point The following are all valid vectors 0 0 0 0 0 0 the origin of a 3 D space 0 0 1 an axis in a 3 D coordinate system 1 1 0 1 1 0 1 a vector in a 5 D space Matrices Matrices are 2 dimensional collections of scalars They are used to represent among other things the coefficients of a set of simultaneous equations or a transformation of a vector Chapter 10 Data Explorer Scripting Language 195 10 n m mall o O cr mall o E Q r o E Q e y e D 196 Matrices are constructed from a sequence of vectors enclosed by square br
276. he image to fill the page but the same number of pixels as in the currently displayed image will be used If this results in a grainy image set Allow Rerendering on and enter a different Input image size For example if the displayed image is 640x480 and you want to double the resolution just enter 1280 in the Input image size field and Data Explorer will recalculate the new value of y 960 and the new higher value for Output PPI By default Image Dimensions Page Dimensions and Margin Width are specified in inches However you can use the DX metric resource or the metric command line option to use centimeters instead See Table 7 on page 299 Pushbuttons Apply causes the currently displayed image to be saved if the Save Current toggle button is depressed Restore restores settings in the dialog to what they were the last time the Apply button was depressed Close causes the dialog to be closed without saving an image Note lf you are not using the Image window this functionality is available with the Writelmage module See Writelmage on page 374 in IBM Visualization Data Explorer User s Reference Printing an Image You can print images displayed in the Image window by choosing the Print Image option from the File menu of the Image window Selecting this option causes a Print Image dialog box to be opened see Figure 46 on page 98 Note that portions of the Print Image dialog box will be grayed out as appropriate if t
277. he noisy values may be the best visualization technique When you lower opacity below 1 0 you will see two stripes one white and one black or a checkerboard pattern of black and white behind the sample color strip in the Colormap Editor These are useful when you manipulate Opacity to check the apparent color against both a light and dark background As with the color tools you can turn on Execute On Change and interactively play with the Opacity of the selected object until you get the effect you want Contours and Isosurfaces Given a set of samples taken over a presumably continuous region it is meaningful to consider drawing smooth lines connecting together the locations on the grid containing the same data values You are probably familiar with topographic maps that show contour lines connecting together the same values of elevation of the Earth s surface features such as hills and valleys These lines are called contour lines or isolines iso means same or equal In most cases the places on the surface of the sample grid that have identical data values will not coincide with the grid sample points This is another case where the connections component is required for Data Explorer to determine where on the grid the same value occurs say the value 5 2 in order to create lines connecting together all these locations Appendix A Using Data Explorer Some Useful Hints 221 222 To return to our 3 dimensional data set
278. he numbers using a height map But it is not correct to say then that the data values so shown were collected from these 3 dimensional positions that would imply the botanist counted grass species growing in mid air This might be true in the Amazon but not in Kansas That is we may have counted 2 species at the grid point x 0 y 0 If we Rubbersheet using the species count as the Z deflection value our 3 D height map will now have a point at x 0 y 0 z 2 if the Rubbersheet scale is 1 0 and the minimum count in our data set is 0 The data was not collected at that point but rather at x 0 y 0 z 0 For our convenience Data Explorer maintains the original data values as if they were attached to the original grid lt is your responsibility to remember and if necessary make it clear to other viewers that the representation of the data in 3 D is not a realistic image of the original 2 D sampling space Rather Rubbersheet is used to visualize the ups and downs in the data Field as actual differences in height This is a very powerful visualization technique because of our familiarity with actual heights in everyday experience One simple way to show viewers the difference is to make two copies of the Field by taking two wires from the output tab of the Import module you use to import the data Field Connect one wire to a Color module with a Colormap attached but leave the Field 2 dimensional Arrange the 2 D colored grid su
279. he output of each Switch to a Collect add inputs to Collect as needed then to Image This way you have a whole panel of Switches allowing you to turn off and on each object in the scene This will decrease the amount of time you wait for all objects to be rendered if you know that certain ones are OK but wish to test new ones in the scene This technique is easier than connecting and breaking wires too Transmitters and Receivers 234 In the Special category there are two modules Transmitter and Receiver that should be used in larger visual programs Each Transmitter can broadcast to any number of identically named Receivers The name you choose for the Transmitter is analogous to a radio station s broadcast frequency Receivers with the identical name are like radios tuned to that channel Like radios more than one Receiver can receive from a single Transmitter more than one Transmitter can broadcast each on a different frequency requiring differently named tuned Receivers This means you reduce the clutter of wires looping all over the screen in the VPE But the real advantage of Transmitters and Receivers is that you the visual program author can provide meaningful names that then appear on the modules in the IBM Visualization Data Explorer User s Guide visual program This is a handy way to provide some visual documentation of the way the visual program is wired Although you can add Transmitters and Receivers to your
280. he same data and connections type This is used for representing a Field as a collection of primitive Fields Fields may be spatially disjoint or they may overlap A Multigrid Object has any number of named or numbered members specified by member clauses The value of the member is specified as an Object name or number within the current file or as an Object name or number in another file Member numbers must be sequential starting at 0 with no gaps in the numbering object number class multigrid name member member name value number number name file file file file number file file name Composite Field Objects A Composite Field Object is a subclass of Group Object in which each member is constrained to have the same data and connections type In addition Fields must be spatially disjoint and abutting with boundary positions replicated exactly A Composite Field Object has any number of named or numbered members specified by member clauses The value of the member is specified as an Object name or number in the current file or as an Object name or number in another file Member numbers must be sequential starting at 0 with no gaps in the numbering Appendix B Importing Data File Formats 2 1 Field Objects Array Objects object number class compositefield name member member name value number number name file file file file number file file name A Field Object has an
281. he sequence backward This command sets the backward direction of the sequence palindrome on off The palindrome command with its parameters sets or unsets the palindrome mode When you display frames in the palindrome mode the current direction changes at the first or last frame in the series loop on off The loop command with its parameters sets or unsets the loop mode When you display frames in the loop mode the series of frames repeats using the settings of the forward backward and palindrome commands include The include command is used to interpose the contents of a file into the input stream being sent to Data Explorer The file being included can contain both scripting language constructs and executive commands This means an included file can in turn include other files There is currently a limit of 32 nested levels of inclusion after which the include commands are ignored To include the file my script issue the following command include my script Gprompt and cprompt There are two at sign variables that you can set in the executive or in a script to customize the Data Explorer script prompt Gprompt and continuation prompt cprompt The continuation prompt appears when you enter an incomplete command in the script environment It indicates that you must complete the command before it can be acted upon The default prompt and continuation prompt are dx and respectively The followin
282. hese attributes allow you to specify the data positions and connections components of your data set See B 5 netCDF Files Complex Fields on page 282 for more information about these attributes To import scalar data on a regular grid specify the netCDF file name as the name parameter By default all netCDF variables are imported and collected into a Group To import one or more particular variables specify their names as the variable parameter The format parameter must be netCDF Data Explorer automatically constructs positions and connections for each variable with an origin of 0 0 and spacings of 1 0 along each dimension For data that is logically a vector Field but whose values are stored in three separate netCDF variables each component of the vector can be imported separately the Compute module can then be used to create a single vector Field For data that is logically a vector Field but whose values are stored as an n 1 dimensional regular grid use the Slice and Compute modules to separate the components of the vector and then recombine them into a single vector Field Example of a Regular Grid The following file describes a 3 x 3 x 3 regular grid at origin 0 0 O with deltas of 1 0 along each axis netCDF volume dimensions nx 33 ny 3 nz 3 Appendix B Importing Data File Formats 281 ms mall o D ms o ms 3 y cr tn variables float field data nx ny nz data field
283. hold down the Shift key and either click on a single icon or drag the selection box over several icons to select them To select all icons on the canvas use the Select A11 option of the Edit pull down menu To deselect an icon shift click on it To deselect a group of tools use one of these methods e Shift click on each icon e Shift drag to draw a box around the tools you want to deselect As a selected tool is encompassed in the box it becomes unhighlighted Release the button to deselect the tools Note Clicking on an empty part of the canvas deselects all selected tools To move a tool icon 1 Press and hold the left mouse button on the tool icon and drag it to the desired location While you are dragging the tool an outline of the tool icon follows the motion of the mouse but the tool icon remains in the original location 2 Release the mouse button at the desired location The tool icon moves to that location Any lines connecting to other tools are rerouted to the tool s new location To move a group of tool icons 1 Select a group of tool icons to be moved 2 Position the cursor on any member of the group and drag it An outline of each tool icon follows the motion of the mouse 3 Release the mouse button The icons representing the tools move to the new location Any affected connections are rerouted To delete tool icons 1 Select the tool icon or group to be deleted 2 Press the Ctrl Delete accelerato
284. iated with the visual program this menu option is grayed out Also you cannot modify the comments when using this option only view them The user can also access the comments for the visual program from the Open or Load Macro file selection dialog boxes even before the visual program is opened For information on how to do this see Restoring a Previously Created Program on page 118 To access comments for a specific Control Panel select the On Control Panel option from the Help pull down menu in the Control Panel about which you want to learn A dialog box opens with the comments Note If there are no comments associated with the Control Panel this menu option is grayed out Also you cannot modify the comments when using this option only view them 5 4 Executing a Visual Program After you set up a visual program in the VPE window and build any desired Control Panels or after you open an existing visual program file you can execute the visual program program The resulting image appears in the Image window This section explains how to execute a visual program Section 6 1 Using the Image Window on page 74 describes how to manipulate images in the Image window by using direct interactors You can also manipulate images in the Image window using interactors in the Control Panels the Colormap Editor and the Sequencer For more information on these tools see 7 1 Using Control Panels and Interactors on page 128
285. ible because the Arrays are Objects with a reference count stored in the Array header Figure 3 Shared Components among Different Fields For example this sharing allows members of a time series defined on a fixed grid and represented by two Fields to share positions and connections while each has different data In addition sharing is vital to an efficient implementation of the data flow programming model in which a module may not modify its inputs In the example in Figure 3 the first Field might represent the input to a module e g a vector Field while the second Field might represent the output from a module that computes the length of each vector The module has constructed a Field with a separate data component representing the calculated result but has not had to copy the portions of the Field that remained the same positions and connections because they could be shared between the input and output Fields Standard Components The standard defined Field components are listed in Table 1 and further described in the subsequent paragraphs Table 1 Page 1 of 2 Standard Field Components data user s data dependent variable positions float n n space sample points invalid positions char which sample points are invalid Chapter 3 Understanding the Data Model 19 U y cr y o O D mal Table 1 Page 2 of 2 Standard Field Components component type MO colors colors color m
286. ic int b 0 for a 1 a lt 10 a b b a While when SetLocal is used the sum is reset each time the macro is run if SetGlobal is used the sum of a previous execution is added to the sum of the current execution For example let macro local be the macro shown in Figure 22 on page 46 and macro global be the same macro but with SetGlobal and GetGlobal substituted for SetLocal and GetLocal If the input to both macros is 10 then both macros will output 55 the sum of numbers 1 to 10 the first time they are run If an execution takes place without the input to the macros changing then neither macro will run again and the value 55 will be used as the output again If you change the input to 3 then macro_local will output 6 and macro_global will output 61 55 6 Illustrated in Figure 23 on page 48 is a macro that returns the accumulated volumes of the members of a group and the number of members in the group ForEachMember is used to iterate through the group Measure is used to determine the volume of a member and the GetLocal and SetLocal pair on the left side of the macro is used to accumulate the volumes For illustrative purposes a loop containing GetLocal SetLocal and Increment is used to count the number of members in the group Inquire also provides this function as does the index output of ForEachMember Increment is a trivial macro consisting of a Compute where the expression is set to a 1 The initial values to both GetLoc
287. ide List Interactors Data Explorer provides six types of list stand ins and interactors e Integer e Scalar e Selector e Vector e String e Value With the exception of Selector these list interactors can have two styles list editor and text The text style list interactor is similar to that of the value interactor The list editor style list interactors consist of the following parts e Title e List of values e Pushbuttons for adding and deleting elements e A single stepper for integer and scalar lists three steppers for a vector list or a text field for string and value lists Figure 71 shows an example of a Vector list interactor For the SelectorList interactor see Selector and SelectorList Interactors on page 146 iaa Control Panel 4 oJ File Edit Execute Panels Options Help VectorList 0 00000 0 00000 0 00000 Delete a c El A o E ct m o m ma o E D md tn 4 000000 b 4 000000 b 4 000000 Figure 71 Sample Vector List Interactor Chapter 7 Graphical User Interface Control Panels Interactors and Macros 145 The top portion of the list interactor shows the current list of values If the list exceeds the length of the display area a vertical scroll bar is provided If the list values exceed the width of the display a horizontal scroll bar is provided Modifying an Element in the List To modify an element select it by clicking on it The stepper or text f
288. ie in perfect rings around the outside of the tubes Which of the above two representations is correct Both are accurate Which you choose to show depends on the point you are trying to make In the first case you are illustrating the values of data precisely as they occur along the Streamlines the Tubes are used to make these very thin lines more visible In the second case you wish to sample the data volume at a specified radius away from a given otreamline By varying the radius of the Tubes you can investigate phenomena such as the rate of change of the data Field as you move further away from the Streamline itself Normals and Shading 224 Another Field component used in Data Explorer is the normals component normals are unit vectors that tell the computer graphics program and the image renderer which direction is up or out Several tools like Isosurface automatically create a normals component so you do not have to calculate these numbers yourself There are two types of normals provided in Data Explorer connections normals and positions normals Connection based normals are vectors perpendicular to each connection element on the surface They are created by the Normals module when you set the method input to connections The resulting surface reveals the underlying polygonal grid structure of your sample grid Frequently this is a valuable way to show your data as any observer can then see the grid r
289. ield and wish to study the shape of that static Field otreamline produces a set of lines that show the flight path of each ball and streamer You can indicate the starting positions of these paths in a number of ways essentially any kind of object with positions can be the designated start point or points for Streamline For example you can use the Sample module to extract an arbitrary subset of positions from an isosurface then treat this subset of positions as valid starting points for Streamline You would see a set of streamlines that began on an isosurface and then traversed your vector Field If you want to visualize the streamers associated twist use the Ribbon module and use the curl and flag parameters of Streamline to force computation of the vorticity field Streamlines can also start from a Grid a list of positions or a Probe The Probe is a handy way to interactively investigate a vector Field Probe tools are selected from the Special category They are manipulated in the Image window select View Control from the Image window s Options menu then choose Cursors from the Mode pop up menu Any Probes that you have placed in your visual program will be listed in another pop up menu so you can pick the one you wish to interactively manipulate By dragging the probe through the vector Field the Streamline starting point will follow the mouse pointer again use Execute on Change to see this happen interactively Streakline
290. ield is updated to show the element s values Use the stepper or text field to change the values of the elements Appending an Element to the List To append a value to a list make sure that no list elements are selected An element can be deselected by clicking on it Use the steppers or text field at the bottom of the interactor to specify the value then click on the Add button Adding an Element to the Middle of the List To add an element to the middle of the list select the element following the position you want the new value to occupy Click on the Add button A copy of the selected element is added to the list becomes selected and the steppers or text field display its current value Use the steppers or text field to adjust the value of the new element Deleting an Element from the List To delete an element from the list select it by clicking on it then click on the Delete button After deleting the item the next item in the list becomes selected Selector and SelectorList Interactors The Selector interactor Figure 72 can be used as a switch control in a visual program It can appear as an option menu with only the current choice shown or as a radio button interactor with all possible choices shown and only the current choice highlighted in the radio button next to the label The SelectorList interactor always appears as a list of toggle buttons Control Panel 4 File Edit Execute Panels Options Help Select
291. iewer The n dimensional cuboids are represented by connections components with element type attributes of lines 1D quads 2 D cubes 3 D cubes4D and so on in the format cubesnD where n represents the number of dimensions Each item of such a connections component is a list of 2 integer indices referring to items in the positions component representing the 2 vertices of an n dimensional cuboid The ordering of these vertices is illustrated in Figure 5 For cubes the parity of all cubes in a given Field must be consistent In addition for quads there is a convention that determines the front face r V q S S front t p r quads q u cubes Figure 5 Order of Vertices in Quads and Cuboids Note Figure 5 does not indicate the correspondence between the edges of the cubes or quads and the spatial dimensions For example the cubes or quads can be irregular in which case the positions of each vertex are specified explicitly Regular positions components can specify an arbitrary correspondence between the spatial dimensions and the edges of the cube as illustrated in Figure 10 on page 30 For data on grids with regular connections the connections can be encoded compactly by Path and Mesh Arrays which are described in Arrays on page 28 and in more detail in Appendix B Importing Data File Formats on page 241 Figure 6 on page 22 illustrates the various type
292. ights an object Diffuse light is light emanating from a direct light source like the default Light in any Data Explorer network or from Light modules you place in your network Think of diffuse light as the light coming from a light bulb and falling on an object surface like a light in your office shining directly on your desk This property is called diffuse because it represents the way light bounces off a surface depending on the roughness of the surface The rougher the surface the more the light rays are scattered diffused An extremely smooth surface tends to bounce light more uniformly to the eye Ambient light is light that is indirect for example daylight coming through a window bouncing off white walls and then impinging on your desk Data Explorer automatically places an AmbientLight value in any scene or you can override this value by placing your own AmbientLight module in a network Ambient light is best thought of as a sort of glow emanating from a non point source of light and therefore illuminating even the parts of objects that face away from the point light sources in a scene If you remove the ambient light the apparent shadows on an object lit only by a point source of light are much harsher Like Normals the Shade module can light an object in two fundamentally different ways f you enter smooth in the how input to Shade the surface will appear smoothly rounded assuming it is not completely flat to
293. ign to represent a negative number Integers in Data Explorer can be represented in the following base systems Decimal Decimal notation base 10 is the most common notation for integers Decimal numbers are constructed from sequences of numerals 0 1 9 Octal When a sequence of numerals begins with the numeral zero 0 followed by a numeral from O to 7 Data Explorer treats it as an octal or base 8 number If a numeric sequence starts with a zero but contains either an 8 or 9 then these digits are identified as invalid octal digits They are however correctly converted For example although the following octal numbers are both converted to the decimal number 17 the first produces an error message but the second does not 019 021 Hexadecimal Hexadecimal or base 16 numbers can be constructed from both the numerals 0 to 9 and the extended hex digits a to f or A to F To differentiate them from decimal and octal integers hexadecimal numbers start with either the sequence 0x or the sequence 0X the numeral zero followed by the letter X The following are examples of valid integers all of which have the value 95 base 10 95 0137 Ox5f Floating Point Floating point numbers are used to represent the set of real numbers These numbers encompass both rational and irrational numbers By virtue of their 32 bit IEEE single precision internal representation they lie in the range of 3 4028 x 1038 The smallest
294. ignment dialog box Figure 80 on page 182 The dialog box consists of three parts Groups and Hosts Displays the name of an execution group and the host on which the group is executed If a host name is not given then localhost is displayed as the host name Host Name A text field for specifying the name of a host on which an execution group is to be executed Pushbuttons 0K causes the assignments of executions groups to host names and closes the dialog box Options opens a dialog box that allows you to specify startup options e g memory size or the Data Explorer executive that will be started on the host Chapter 9 Graphical User Interface For Advanced Users 181 Restrictions Execution Group Assignment lune BEER 1 Apply Close Figure 80 Execution Group Assignment Dialog Box To assign an execution group to a workstation 1 Open the Execution Group Assignment dialog box by selecting the Connection menu Execution Group Assignment option in either the Visual Program Editor or Image Window Select the execution group that you wish to assign to a host by clicking on its name Enter the host name in the Host Name text field and hit Enter Click on the Options button to specify any options for the host for example memory size If there are more groups to assign to hosts repeat Steps 2 through 4 otherwise click on OK In general you can place any to
295. ility Brings up a cascade menu with the following options All Results Highlights all tools for which all results are cached Last Result Highlights all tools for which only the last result is cached No Results Highlights all tools for which no results are cached See Cache Control Executive on page 215 Delete Deletes the selected tools and connections to other tools Cut Deletes the selected tools but places them into a buffer so they can be pasted Copy Copies the selected tools and places them into a buffer so they can be pasted Paste Pastes the tools from the buffer into a selected location Add Annotation Adds annotation text to the canvas see Adding Annotation to a Visual Program on page 115 Insert Visual Program Brings up a file selection dialog box for selecting a visual program The selected program will be inserted to the right of all the tools in the current program Create Macro Creates a macro from the currently selected tools See Creating Macros on page 149 for more information Chapter 8 Graphical User Interface Menus Options and the Message Window 159 160 Page Brings up a cascade menu with the following options Create Empty Page creates an empty page Create with Selected Tools creates a new page containing the currently selected tools Delete deletes the currently displayed page available only if there is more than one page Configure brings up a dialog which allows you t
296. ill be the first step in creating a visualization of that data In order to take this step you should have some understanding of the Data Explorer data model and a working knowledge of a Field An informal description of a Field is provided in Chapter 2 Introduction to Visualization on page 7 A formal description is given in Chapter 3 Understanding the Data Model on page 15 A number of methods for importing data are available for use with Data Explorer the General Array Importer Data Explorer native file format netCDF CDF and HDF B 1 General Array Importer Keyword Information from Data Files In addition to the syntaxes for the grid points and positions keywords described in IBM Visualization Data Explorer QuickStart Guide it is also possible to derive information for these keywords directly from the data file This allows you to write filters for specific applications that output their data in a set format which includes the grid size within the file The syntax for the grid keyword is in addition to the syntax given in 5 3 Header File Syntax Keyword Statements on page 85 in BM Visualization Data Explorer QuickStart Guide bytes n bytes n grid format type lines n skip width skip width lines n marker string marker string where format is the format in which the grid values will be found and must be one of the following binary ieee text or ascii The first two parameters are synonymous
297. ill brighten up again What looks kind of pink on the RGB workstation monitor will usually be much redder on TV Of course if you are producing images for another medium like a color printer you can set the color saturations appropriately fully saturated may be correct in that case the tips in this section are to help you make better video recordings Frame Rates In making animation for TV you must be aware of frame rate Just like all the other references to sampling in the discussion above TV samples time at 30 frames per second 25 in PAL That means that at most you can have 30 time step changes per second of video unless you choose to skip some time steps in your data Generally you may want to show many fewer changes than that or the phenomenon may go by too quickly for the viewer to comprehend On the other hand when you rotate an object you want to make as many small changes as you can afford The result will be smooth animation rather than jerky cartoon like movement One rule of thumb is to rotate no faster than 3 degrees per frame That means that your object would rotate 90 degrees in one second or 360 degrees in 4 seconds Like any rule of thumb this can be adjusted depending on the case at hand For example it is often useful to record the rotation at more than one speed The human visual system will detect different levels of detail in an object depending on its motion rate This can be used to your advantage to get
298. implied information about data values at positions other than those given The information in a Field is represented by some number of named components Each component has a value that is an Object In general components are Array Objects described in more detail in the next section For example the positions component is an Array specifying the set of sample points the connections component is an Array specifying a means to interpolate between the positions and the data component is an Array specifying the data values Chapter 3 Understanding the Data Model 17 O y cr y o O D m a E pe arbitrary E data type float 3 type int 4 type float 3 items 8 items 100000 items 150000 data data data Figure 2 Example of a Field Object Figure 2 shows an example of a Field Object with four components The data component specifies the users data as an Array of data of arbitrary type e g integer which is dependent on i e in one to one correspondence with the positions component the positions component specifies the sample points as an Array of 3 dimensional vectors the connections component specifies a set of tetrahedra as vectors of four integers that refer to the positions component and the box component lists the eight points that define the bounding box of the positions i e of the Field itself A complete list of defined compo
299. in one direction while looking in another direction For instance you can move forward past the left side of an object while looking to the right enabling you to see the object as you move past it Unlike the Roam and Rotate modes which appear to adjust the object to change your view or the Zoom mode which appears to adjust the camera lens to change your view the Navigate mode appears to actually move your camera around the scene while the objects you are viewing remain stationary Note Because Data Explorer does not support perspective rendering of volumes you cannot navigate software rendered volumes To move your camera within the scene 1 Select the Navigate mode from the Mode option box This adds some controls illustrated in Figure 38 on page 81 to the View Control dialog box 2 The mouse buttons control the navigate motion of the camera while the setting of the Look option box controls the direction the camera is pointing The Look options are illustrated in Table 4 on page 81 Note You can also enable Navigate mode by using the intrctnMode parameter to the Image tool see Image in BM Visualization Data Explorer User s Reference With Look set to Forward you have more control over the trajectory the camera moves along in the scene To move forward click on the left mouse button To move backward click on the right mouse button The position of the mouse pointer on the image indicates the angle at which you travel
300. in the Configuration dialog box Displays a window with descriptions of the input and output parameters of the tool Restores previous values that were present when you opened the box or when you last clicked on the Apply button Restores previous values that were present when you opened the box or when you last clicked on the Apply button and then closes the box Revealing and Hiding Input Tabs Most of the tools have more input tabs than are displayed when a tool icon is initially displayed For example the Isosurface module has six inputs but when an Isosurface tool icon is initially placed on the canvas only three input tabs are displayed The displayed tabs represent those that are most frequently used 110 To reveal the hidden input tabs 1 Select the tool icon by clicking on it 2 Select the Reveal All Tabs option from the Edit pull down menu You can also use the Ctr1 L accelerator key IBM Visualization Data Explorer User s Guide Once the input tabs have been revealed they can be hidden To hide input tabs 1 Select the tool icon by clicking on it 2 Select the Hide All Tabs option from the Edit pull down menu You can also use the Ctr1 H accelerator key Hiding input tabs in this way will cause all tabs that are not connected to another module to be hidden If you wish to hide or reveal individual inputs use the hide toggle button in the Configuration dialog box see Inputs Section on page 1
301. in the specified area e Specify the number of steps to be created in the range of the waveform by using the stepper The number of steps specified can be between 2 and 100 Copying and Pasting Control Points Control points can be copied and pasted from one Colormap area to another using the Copy and Paste options of the Edit window 1 Select the control point or control points you wish to copy 2 Click on Copy 3 Select the area to which you wish to copy the control points and then click on Paste Display Control Point Values The data values of control points are displayed by default You can control which data values are displayed using the Display Control Point Data Value cascade menu in the Options menu f off is specified no data values are shown If selected is chosen only the data values for the selected control points are shown and if all is selected the data values for all control points in the selected area are shown Axis Display You can control how the Colormap Editor axis is displayed by using the Options menu Axis Display option You have three choices for the display Ticks the default Histogram and Log Histogram Histogram will cause the histogram of the data to be displayed Log Histogram will cause the log of the histogram to be displayed If the Colormap Editor is not data driven these two options will be grayed out The number of histogram bins can be controlled using the Edit menu Number of hi
302. ing 178 180 modifying 178 180 execution model 38 execution stopping 212 explicit state preserving 45 expression assignments in scripting language 199 F faces component 24 Field attributes color multiplier 27 opacity multiplier 27 Field Objects 17 18 272 Fields Data Explorer file format 244 Data Model 16 general discussion 12 file format CDF 279 Data Explorer 244 HDF 288 netCDF 281 Find Tool dialog box 111 flow control 38 flow data 38 frame display rate 93 237 front colors component 22 function call assignments in scripting language 199 function call attributes 202 function call conventions in scripting language by name arguments 201 function call example 201 introduction to 200 missing arguments 201 positional arguments 200 G GetGlobal preserving state 45 GetLocal preserving state 45 graphical user interface 58 74 128 156 178 graphics card hardware rendering options 91 grid types 21 gridconnections keyword in Data Explorer file format 275 gridpositions keyword in Data Explorer file format 274 Groups 34 Composite Field 35 general description 34 in Data Explorer file format 270 Multigrid 34 271 Series 35 H header section of the Data Explorer file format 268 help Context Sensitive Help 65 in a Control Panel 67 133 in a visual program 67 Overview of Window 65 Table of Contents 65 Technical Support 65 Tutorial 65 user defined 67 Using Help 65 hexadecimal numbers in scripti
303. ing model in which the intensity of values of incident illumination on a polygon are interpolated from intensity values at the vertices of the polygon Contrast with flat shading graphical user interface A set of panels and dialogs for interacting with an application group A collection of objects icon A displayed symbol that a user can point to with a device such as a mouse to select a particular operation or software application image window IBM Data Explorer window that displays the image generated by a visual program Associated with the Image window are special interactors for 3 D viewing interactor A Data Explorer device used to manipulate data in order to change the visual image produced by a program See also data driven interactor interactor stand in interactor stand in An icon used in the VPE window to represent an interactor Stand ins are named after the type of data they generate e integer e scalar e selector outputs a value and a string e string e value e vector interpolation element An item in the connections component array Each interpolation element provides a means for interpolating data values at locations other than the specified set of sample points See positions component invalid A classification of an array item typically positions or connections An invalid item is not to be rendered or realized irregular array n contrast to a compact array an array in which the dat
304. inguish them Each filenameN is the name of the netCDF file that contains the data variables for that step In the first format the spacing of the steps is 1 0 In the second format the float value is the value of each step All other specifications are the same as for simple fields This format can be used to create short term series within a file and then have a series of these smaller series Appendix B Importing Data File Formats 285 ms mall o D ms o ms 3 y cr tn Examples This section shows examples of netCDF files in the netCDL description language See the documentation supplied by UCAR for more information on netCDL and the ncgen and ncdump utilities Compact Specifications of Regular Dimensions This example describes a single two dimensional scalar field on a latitude longitude regular rectangular grid The example data are temperature on a one degree grid with global coverage Because Data Explorer array objects can be specified compactly you can use this method to specify a netCDF with regular dimensions For each dimension you need to specify its value at the origin and its spacing along the dimension In this example two variable attributes are defined for the netCDF variables field specifies the rank of the parameter and positions specifies where the information containing the locations of the data is space is located dimensions lon 360 lat 180 naxes 2 ndeltas 2 variable
305. interactor setup etc The settings are saved in a cfg file e Load loads previously saved settings from a cfg file Load Macro Loads a macro and makes it available in a tools palette A file selection dialog box appears for you to specify the desired macro file name See also Loading Macros on page 152 Load Module Definition s Loads a module definition and makes it available in a tool palette A file selection dialog box appears for you to specify the desired module file name he executable you are using must either include this module or this module definition must refer to an outboard or run time loadable module See 9 2 Loading and Using Outboard and Runtime Loadable Modules on page 183 Print Program Prints or saves to a file a representation of a visual program If the Label Set Input toggle button is activated then any parameter value s set in the configuration module s Configuration dialog box will also be printed next to the corresponding tab s if scale allows Quit or Close Closes all windows created from the current VPE window If you have made changes since the last save a dialog box appears so you can save changes lf you opened the VPE from the Image window or with the Open Macro option Close appears as an option instead of Quit Quit is grayed out if the Execute menu title is highlighted You must select the End Execution option in the Execute pull down menu or if the Sequencer is running you must
306. invoked in subsequent executions rather the module results are retrieved from the cache If the module results are not found in the cache because they were purged in order to make room for some other result or they were never stored in the cache the module will be reexecuted The cache attribute can have one of three values cache 0 Do not cache the module outputs cache 1 Cache all the results of the modules outputs cache 2 Cache only the results of the modules outputs for the last execution of the module The cache attribute can be associated with the individual outputs of a module with the entire module affecting all the outputs or a combination of both When output associated and module associated User s Guide group cache attributes are used in combination the output associated attributes override the effects of the module associated attributes The following two examples illustrate how the cache attribute can be used In the first example the attribute is associated with the module In the second example the attribute is associated with the module output The results of both of these examples are identical since Isosurface has only one output iso Isosurface data value cache 0 iso cache 0 Isosurface data value The following examples look similar to those above but there is a difference because DivCurl produces two outputs In the first example only the last result of both outputs of DivCurl are
307. ion of the loop Done causes the loop to terminate after all the modules in the macro have executed if the input to Done is nonzero The macro illustrated in Figure 25 on page 51 is equivalent to the C language statements sum 0 E do 1 t sum sumti while i lt n amp amp i x Now consider a macro in which the sum of numbers from 1 to N is computed but if a number is equal to an external input value x it is excluded from the sum To achieve this result using C language statements you would use a conditional with a continue statement sum 0 for i21 i lt n i if i x continue Sum sumti IBM Visualization Data Explorer User s Guide Figure 25 Example 8 VA 20 r1 m Editor tmp doc tmuwre8 net A bd Inu ForF ach Gel oc al Output As illustrated in Figure 26 on page 52 you would use Route to create this macro using Data Explorer The selector input of Route is being controlled by the output of Compute The Compute has its expression set to a b 0 1 if a and b are equal output 0 otherwise output 1 This is similar to the Equal macro used earlier but the expression differs slightly Therefore if the iteration variable is equal to x Compute outputs a 0 causing Route to disable the execution of all the modules downstream from it This implies that Sum and SetLocal will not run therefore during the next iteration GetLocal will retrieve the same value as the curren
308. ior With this release when you type dx a different initial panel will appear giving you access to various parts of Data Explorer such as the Data Prompter the Tutorial the Visual Program Editor etc To bypass the Startup window and go directly to the Visual Program Editor as in previous versions of Data Explorer either type dx edit at the prompt or set your DXARGS environment variable to edit New Save Image Dialog in Image Window The Save Image dialog has been improved to make it easier for users to save images at a specific size on the printed page New Data Prompter The Data Prompter has a new initial window which allows you to specify what kind of data you have dx format image format You can access the Data Browser from this window to view your data before attempting to import it If you have general array format data then choose the Grid or Scattered file button which will lead to the interface which was called the Data Prompter in previous versions of Data Explorer Once your data has been imported there is an option to either describe or visualize your data If you choose the Test Import option then the data will be imported and characteristics about it such as dimensionality number of points will be reported to you If you choose the Visualize Data option then a general purpose visual program will be run on your data You can then inspect and modify this visual program Pages In the VPE
309. iption in BM Visualization Data Explorer User s Reference Note lt is also possible to set AutoAxes parameters using input parameters to the Image tool see Image in BM Visualization Data Explorer User s Reference Set Background Color This option displays a dialog box that will accept either a color name string or an RGB vector as the specification of a background color for the Image window Valid strings are listed in a user specified lookup table or a file supplied with Data Explorer see Color in IBM Visualization Data Explorer Users Reference f neither is available Data Explorer uses a smaller internal list see Appendix F Data Explorer Colors on page 313 Chapter 6 Graphical User Interface Important Windows 89 AutoAxes Configuration Figure 42 Expanded AutoAxes Configuration Dialog Box The box lists seven options not visible in the default version Figure 41 Notes 1 Although each defined color has a corresponding RGB vector the range of possible vectors is continuous from black 0 O 0 to white 1 1 1 Thus you can specify an RGB vector for which there is no corresponding string i e no defined color Nonetheless Data Explorer will accept the vector as valid and generate the corresponding color 90 IBM Visualization Data Explorer Users Guide 2 Data Explorer supplies double quotation marks for color name strings and brackets commas and terminal zeros for vectors For example ei
310. is software and its documentation for any purpose is hereby granted without fee provided that the above copyright notice appear in all copies and that both that copyright notice and this permission notice appear in supporting documentation and that the names of OMRON NTT Software NTT and M I T not be used in advertising or publicity pertaining to distribution of the software without specific written prior permission OMRON NTT Software NTT and M I T make no representations about the suitability of this software for any purpose It is provided as is without express or implied warranty IBM Visualization Data Explorer User s Guide OMRON NTT SOFTWARE NTT AND M I T DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS IN NO EVENT SHALL OMRON NTT SOFTWARE NTT OR M I T BE LIABLE FOR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE DATA OR PROFITS WHETHER IN AN ACTION OF CONTRACT NEGLIGENCE OR OTHER TORTIOUS ACTION ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE Notices XIX XX IBM Visualization Data Explorer User s Guide About This Guide Who Should Use It How To Use lt Related Publications and Sources IBM Publications Non IBM Publications Other sources of information Copyright IBM Corp 1991 1997 Typographic Conventions xxi This manual is a g
311. isclosure is subject to restrictions set forth in GSA ADP Schedule Contract with IBM Corp Contents FIQUEOS os oue Dio fcd noe ra did AP HUE BR edd en SD Beds E IX FADIS separar ss LENTES a da e xi NOlICGS 2 4 Se beech dB DRE Se ESA ERS dd MS pe a Ops des xiii Products Programs and Services 0 o xiv Trademarks and Service Marks o xiv OoDyHght BollGeS quis s i dp Bore HOS ede dem mb eS we a XV About This Guide s xxi Who Should USE 2 4 0 8 doge Sd Se eo EEN EUR e ert ad xxii HOW TOUSE E uua doter um deum adem do gee A xxii Typographic Conventions a xxiii Related Publications and Sources aoaaa aaa a xxiii IBM PUDIICAUONS 2 0 6e k Settee E TEA E R LS xxiii Non IBM Publications enn XXIV Other sources of information 0 2020004 XXIV New Features in Data Explorer Version 3 1 4 XXVII User Interiace engi dk ok ea bee eee ew eed AESA pa gd de xxviii New Startup Behavior ls xxviii New Save Image Dialog in Image Window xxviii New Data Prompter 2n XXVIII gc c A PPP XXVIII ANOTA lO PETERE PT xxviii Optimizing Caching escorts dass E cte he wa se eat d xxviii Changes to Get and Set modules l l Xxix New Window Management Functionality Xxix Hardware Rendering aa XXIX DALOK canta E Ee A NINE A
312. ist class array type int rank 0 items 21 data follows SHS SHS SHS SH SHE SH HS SE 1 2 6 edge point index 0 0 5 4 3 2 1 edge point index 3 2 3 9 8 6 edge point index 9 3 10 9 edge point index 15 3 4 10 edge point index 18 attribute ref string positions Appendix B Importing Data File Formats 261 ms mall o D ms o ms 3 y cr un 262 Loops array This is a list of connected edges by edge number Each number is the edge index of where the next loop starts object loop list class array type int rank 0 items 5 data follows 0 loop index 0 3 1 9 2 15 3 18 4 attribute ref string edges Faces array This is list of which loops make faces If there are no holes in the faces this is list of all loops If two or more loops actually describe the outside edges and inside hole edges of a face then this list contains the starting loop numbers of the list of loops making up a face E Sh SME SHE E object face list class array type int rank 0 items 5 data follows 0 1 2 3 4 attribute ref string loops data array Dependent on faces object data class array type float rank 0 items 5 data follows 0 2 5 1 2 0 4 1 8 attribute dep string faces Field definition to put the arrays together object map class field component positions position list component edges edge list component loops loop list component faces face lis
313. it can simply retrieve its results from the cache Otherwise the module reexecutes placing its new result into the cache Data Explorer extends this notion by incorporating a cache implemented by the module scheduler rather than by the modules themselves for all partial results This cache retains results from not only the previous execution of the network but from all prior executions this is the default behavior the user can also control cache settings for modules The saving of objects in the cache is subject to memory limitations and a least recently used cache eviction strategy items used the longest time ago are first to be discarded from the cache The caching behavior for each output of a module may also be explicitly set by a user to optimize memory utilization See A 1 Using Data Explorer Effectively on page 212 The caching of partial results means that in general the output of Import is held in the cache Usually this is highly desirable as it avoids needing to reimport the data every time the visual program is run However if you modify your file on disk e g by editing it Data Explorer will not know that the file has been changed and will continue to use the cached version To force Data Explorer to reimport the data use the Reset Server option of the Connection menu This will cause all items in the cache to be discarded and Import will reaccess the file on disk You may also set Import to cache no results by
314. iteration using the looping modules preservation of state using the pairs GetLocal SetLocal or GetGlobal SetGlobal creating advanced looping constructs using combinations of tools asynchronous data sources and parallelism The tools that control the flow of execution of a visual program are found in the Data Explorer category Flow Control In a true data flow implementation all modules are pure functions i e their outputs are fully defined by their inputs Hence processes are stateless with no side effects When a module s inputs are received it runs and when finished it distributes its results to modules waiting downstream Note that in Data Explorer results are communicated between modules by passing pointers to data objects not by copying Of course when running in distributed mode or when using outboard modules data must be sent by socket since the processing may occur on another host Consider the example illustrated in Figure 18 on page 39 38 IBM Visualization Data Explorer User s Guide Figure 18 Example 1 Visual Program Editor tinp doc figure 1 net Map of lane Sein ll a ie The Collect module waits for inputs from the Isosurface and MapToPlane modules Import would send its results to the waiting Isosurface and MapToPlane modules In effect this execution model is entirely data driven and top down the execution of modules is dependent solely on the passage of data through the system While this simpl
315. ive owner of the Program and the Documentation ICS grant to Customer a nonexclusive nontransferable except as provided herein license to use modify have modified and prepare and have prepared derivative works of the Program as necessary to use it 2 Customer Rights Customer may use modify and have modified and prepare and have prepared derivative works of the Program in object code form as is necessary to use the Program Customer may make copies of the Program up to the number authorized by ICS in writing in advance There shall be no fee for Statically linked copies of the Motif libraries Statically linked copies are object code copies integrated within a single application program and executable only with that single application Run Time copies require payment of ICS then applicable fee Run Time copies are copies which include any portion of a linkable object file o file library file a file the window manager mwm manager the U I L compiler a shared library or any tool or mechanism that enables generation of any portion of such components other copies will require payment of ICS applicable fees TRANSFERS TO THIRD PARTIES OF COPIES OF THE LICENSED PROGRAMS OR OF APPLICATIONS PROGRAMS INCORPORATING THE PROGRAM OR ANY PORTION THEREOF REQUIRE ICS RESELLER AGREEMENT Customer may not lease or lend the Program to any party Customer shall not attempt to reverse engineer disassemble or decompile the program 3
316. l 50 4 8 External Asynchronous Data Sources 54 4 9 Parallelism using Distributed Processing 55 4 10 Parallelism for Data Explorer SMP 56 rm X D ie cr mall o le gt o O D Copyright IBM Corp 1991 1997 37 4 1 Data Flow Data Explorer s execution model is based on the data flow concept However features are provided that extend the data flow concept to allow you to create a visual program that could not be supported by simple data flow For example there are tools that allow you to explicitly save partial results of a visual program to be used in a subsequent execution Data Explorer also provides you with various tools to control the flow of execution of your visual programs Most of these tools are analogous to constructs found in commonly used programming languages For example tools are provided that perform the function of IF statements CASE statements and FOR or DO loops This chapter discusses flow control tools with several examples of their use both individually and in combination Although it is not necessary to understand all the details of the Data Explorer execution model in order to build and run visual programs you may find it helpful as you build visual programs Other topics in this chapter include caching of intermediate results conditional execution using the Route and Switch modules iteration using the Sequencer simple
317. l dialog box see Figure 34 is used to specify the first next and last end frames the number of frames and the increment between successive frames If a frame is being displayed the current frame number appears in the Frame Control dialog box next to the word Current and a corresponding colored marker is shown on the slide bar A colored marker indicating the position of the next frame is also shown Black markers indicate the positions of start and end relative to the next range of min to max Frame Control Y Start Next Y End ao das Das Y Current 0 y Y lt 1 gt in ncrement ax Figure 34 Sequencer Frame Control Dialog Box Values for the Start Next and End frames are set by e Entering a value in the text field of the stepper buttons e Using the stepper controls e Moving the position marker Start The starting value for the sequence By default set to the value in the Min field in a new program To change the Start field use the stepper controls or select the field and enter the new value or use Chapter 5 Graphical User Interface Basics 69 the Start marker If you change the value in the Min field then the otart field is set to that new value If you are working with a saved program then the Min and Start fields are set to the values that were saved End The ending value for the sequence By default set to the value in the Max field in a new program To change the End
318. l program are Chapter 6 Graphical User Interface Important Windows 101 102 Select and place the desired tools on the canvas Connect tool outputs to inputs Set values for the tools If you plan to change input parameters frequently while viewing an image e g an isosurface value then you should build a Control Panel and set interactors see Building Control Panels on page 129 and Using Interactors on page 142 BON Placing Tools on the Canvas The tools are divided into categories and a list of these categories appears in the top palette on the left side of the VPE window To locate a tool 1 Click on a desired category The names of the tools in that category appear in the lower tool palette All palette lists are presented in alphabetic order 2 Select the appropriate tool name from the bottom palette by clicking on the tool s name Clicking on an already selected tool deselects that tool To place one instance of the selected tool on the canvas 1 Move the cursor to where you want to position the tool on the canvas Note that the style of the cursor changes when you move it onto the canvas Exact placement of the tool depends on the grid settings see Customizing the VPE Window on page 113 2 Click the mouse The tool icon appears at the specified location When you have placed the tool its name is no longer highlighted in the lower palette To place multiple instances of the tool 1
319. least one invalid point IBM Visualization Data Explorer User s Guide New Modules Inquire Has several new inquiries is image is connection object tag connection type valid count invalid count Integer IntegerList Scalar ScalarList Vector VectorList Each of these data driven interactors now has a refresh input This input resets the interactor as if it is running for the first time regardless of the current output value with respect to the range of the current input to the interactor Pick Has new inputs locations and camera These inputs are intended for use when picking is done in an image window created using SuperviseWindow rather than the Image tool Plot Has new inputs which allow you to specify precise tick locations and labels for the ticks see AutoAxes on page xxxiii Readlmage Readlmage supports miff images If the miff file contains a sequence of images they will be read in as an image series Readlmage has a new input colortype which allows control over the pixel format used internally to represent the loaded image It also has a new input delayed which specifies whether images stored in image with colormap format should be imported as a delayed colors image Writelmage Supports MIFF output which is a run length encoded format that supports image sequences Supports GIF output of any image This section contains only summaries See BM Visualization Data Explorer Us
320. lect the Program Settings Save As option on the File menu anchor window bar You can retrieve Control Panels in the anchor window by using the Program Settings Load option If you have made changes that you do not want to keep click on the Program Settings Load option of the File menu and select the file again without saving This procedure restores the original configuration 132 IBM Visualization Data Explorer User s Guide Customizing a Control Panel This section describes the customization that can be done while building the Control Panel from the VPE window or while actually viewing the image in the Image window The Control Panel Options menu provides several possibilities for further customizing the Panel and its interactors as described in Control Panel Options Menu on page 164 Changing the Name of a Control Panel Every Control Panel is given the default name of Control Panel as shown in the title box across the top of the window If you want to customize the name in any particular Control Panel you can do so by clicking on the Change Control Panel Name option on the Options menu and entering a new name in the dialog box that appears The new name can contain any number of characters including any letter number symbol or space that you find on the keyboard If you have several Control Panels in your visual program you should assign names to them Data Explorer allows you to open each one individually by n
321. lecting a group 102 special 218 specifying values for inputs 103 transformation modules 228 Transmitter tool 106 234 type of an Array item 28 types of Arrays 28 U Undo action 84 use of memory 213 user interface 58 74 128 156 178 using the Sequencer 68 V vector Fields 229 vectors in scripting language 195 vertex ordering 20 21 video output 236 video output design 236 view angle for perspective rendering 77 view direction changing 76 view of an image controlling See image controlling view of Visual Program Editor VPE customizing 113 finding tools 111 menus Connection 162 Edit 157 Execute 160 File 156 Visual Program Editor VPE continued menus continued Options 162 Windows 161 tool palette 100 visual program definition 99 visual programming 13 visual programs creating See tools executing 67 restoring previously created programs 118 saving a previous file 117 in general 115 to a different directory 118 visualization techniques 217 volume rendering 231 W waveforms in the Colormap Editor 124 X xform Objects in Data Explorer file format 277 Z zooming into and out of an image 78 Index 329 Readers Comments We d Like to Hear from You IBM Visualization Data Explorer User s Guide Version 3 Release 1 Modification 4 Publication No SC38 0496 06 Overall how satisfied are you with the information in this book Very Very Satisfied Satisfied Neutral Dissatisfied
322. les and data management components E face 1 Any planar surface that three dimensional object 2 A polygon bounds a field A self contained collection of data items A Data Explorer field typically consists of the data itself the data component a set of sample points the positions component a set of interpolation elements the connections component and other information as needed flat shading A shading model in which each face of an object is shaded with a single intensity value Contrast with Gouraud shading fork An operation that causes a program to branch into two or more parallel concurrent paths 318 IBM Visualization Data Explorer User s Guide fork join parallelism A programming mechanism that supports parallel processing The fork statement splits a single computation into multiple independent computations The join statement recombines two or more concurrent computations into one G general array format A data importing method that uses a header file to describe the data format of a data file This format makes it possible to import data in a variety of formats glyph A graphical figure used to represent values of a particular variable The length angle or other attribute of the glyph is some function of the value of that variable Each occurrence of a glyph represents a single value of the variable Gouraud shading Also called intensity interpolation shading A shad
323. licitly set to local Vector interactors The Set Attributes dialog box for vector interactors has an additional field Selected Component included at the top of the box You can use this field to set different attributes for the different components of a vector Do this by changing the component number with the stepper and setting the attributes desired for that component Repeat this process for all components of the vector To assign common attributes to all components of a vector interactor set the option box at the top of the dialog box to All Components When you do this the component stepper is disabled and any attributes you set are applied to all components of the vector Chapter 7 Graphical User Interface Control Panels Interactors and Macros 135 e c El A o E cr m o m ma o E D md tn 136 Setting Selector and SelectorList Interactor Attributes The Set Attributes dialog box for the Selector and SelectorList interactors Figure 62 on page 136 differ from the dialog box for other types of interactors because the behavior of those interactors is different from other types of interactors The Selector and SelectorList interactors are similar to an option menu with the current choice s displayed by the interactor The Selector offers a one of many choice the SelectorList a choice of none one or more among many Each choice on the interactor represents a pair of outputs a value and a string The stri
324. lines and streaklines indicate vorticity S sample point A point that represents user data Data is interpolated between sample points by interpolation elements connections A figure derived from lines e g from Ribbons may twist to scalar A non vector value characterized by a single real number scatter data A collection of sample points without connections screen An illuminated display surface e g the display surface of a CRT or plasma panel scripting language The IBM Data Explorer command language Used for writing visual programs to manage the execution of modules and to invoke visualization functions scroll To move all or part of the display image vertically or horizontally to display data that cannot be observed in a single display image secondary window Any window generated by another window A secondary window always appears on top of its parent window and is automatically minimized or closed when the parent window is minimized or closed Synonymous with child window sequencer An IBM Data Explorer tool for creating animated sequences of images series In IBM Data Explorer used to represent a single field sampled across some parameter e g a simulation of a CMOS device across a temperature range Members of a series have a position A copy of the position is found in the series position attribute shape A list of the dimensions of a structure the list contains nothing for
325. long the same direction as any of the axes When you have moved the point to the desired area release the left mouse button Note that since perspective projection does not preserve parallel lines the directions in the axes diagram do not necessarily correspond with the direction Chapter 6 Graphical User Interface Important Windows 85 86 Image tmp doc 3dcurs net 2 de File Execute Windows Conn 0 857606 0 0364668 1 0093 Figure 40 3 D Cursor with a Selected Point that the point moves in the Image window However these axes do correspond with the values of the coordinates While using orthographic projection the movement of the point in the Image window corresponds to the directions of the axes diagram To delete a point double click on it with the left mouse button You can restrict the movement of the 3 D cursor with the Constraints option Selecting the Constraints option box reveals an options menu that lets you choose which of the three axis projections to that movement is constrained For example if the x axis is selected from the cascade menu you are able to move only the x projection in the 3 D cursor box When cursor movement is constrained the portion of the wire frame box that corresponds to the selected axis is highlighted To remove movement constraints on the cursors select None from the options menu Constraining is useful for more precise positioning of the cursor Note that exact
326. lor the temperature data set Then use Mark to mark the colors as data this temporarily renames the colors component to data while saving the original data component Then use Map to map this marked Field into the cloudwater isosurface colors component lt is necessary to mark the colors as data before mapping because Map always maps from the data component An example visual program that performs each of these mapping operations can be found in usr 1pp dx samples programs UsingMap net Note that we changed the order of the modules slightly in the third example In the second case we Mapped data values from the map Field cloudwater density onto the input Field the temperature isosurface then AutoColored the resulting Field In the third case we AutoColored the map Field temperature then mapped color values onto the input Field cloudwater density This illustrates some of the flexibility of both the Map module itself and Data Explorer in general In this case the output image would be similar whether you colored by temperature then mapped or mapped temperature first then colored by temperature There will be color differences if the range of values that mapped onto the isosurface is different from the entire data range used to AutoColor the entire temperature Field Appendix A Using Data Explorer Some Useful Hints 223 c tn D m mi mall o gt cr tn You could avoid this problem by substitu
327. lorer file format overview 2 scripting language 188 starting Data Explorer 58 324 IBM Visualization Data Explorer User s Guide Data Explorer continued system structure 3 windows Colormap Editor 119 Image 74 pull down options 62 structure 61 using on line help 65 VPE 99 working with windows 65 data flow 38 data mode clause in Data Explorer file format 278 Data Model Data Explorer 16 data section of Data Explorer file format 269 data statistics component 24 data structures supported 16 data driven interactors 147 debugging visual programs 212 decimal notation in scripting language 194 default values in configuration dialog box 109 in scripting language 204 deforming a surface field 227 dependence dep attribute 27 dependence data 8 17 derivative der attribute 26 description button in configuration dialog box 110 dialog style Control Panels 135 distributed computation 3 178 drag and drop 105 E edges component 24 element type attribute 27 end clause of the Data Explorer file 279 environment variables 59 292 error messages 71 examples of Data Explorer file format faces loops edges and polylines 25 260 263 265 header and data in separate files 254 image files 268 irregular grid 251 Product Arrays 255 regular grid 247 regular skewed grid 248 series 257 two dimensional grid 260 warped grid 249 executing a visual program 67 execution Groups 178 assigning Groups to workstations 181 creating 178 180 delet
328. ls the Data Explorer executive not the user interface immediately You can restart using Start Server in the Connection menu In addition modifying a visual program for example by disconnecting an arc or adding a new tool will cause execution to stop after the currently executing module How to orient yourself in the Image window If you find yourself lost in the Image window for example you have a black picture and don t know where your data object is you can always reset the camera by using the Reset Camera option in the View Control dialog box of the Image window This zooms out so that you can see all of your object from a front and center view It is also often helpful to use ShowBox to display the bounding box of your entire data set Collect this with the rest of your visualization and then you will be able to see how the part you are looking at relates to the entire data set What is the Difference Between Image and Display 212 Image Display and Render all render an object i e create an image Render given an object and a camera creates as output an image This image can be sent directly to Display for display to the screen sent to Writelmage to be written to a file or collected with other images into a single window using Arrange Display given an object and a camera both renders the object using the camera and displays it to the screen IBM Visualization Data Explorer User s Guide Displa
329. m Server Disconnects the user workstation from the server Reset Server Flushes the cache forcing the visual program to reaccess the data on the server the next time it executes See Resetting the Server on page 185 Execution Group Assignment Displays a dialog box that allows you to assign execution groups to specific machine host names See Assigning Execution Groups to Workstations on page 181 Image Window Options Menu The Options menu provides the following options which are available only when the Image tool is used in a visual program View Control Opens a dialog box with various view control options For more information on this menu option see Controlling the Image View Control on page 74 Undo Returns to the view of the image that was displayed before the most recent action effectively undoing the action See Restoring Images on page 84 Redo Restores the view of the image that was displayed before the last Undo action See Restoring Images on page 84 Reset Resets the camera to its initial position and direction See Restoring Images on page 84 AutoAxes Places axes around the image the next time you execute the visual program See AutoAxes on page 88 Chapter 8 Graphical User Interface Menus Options and the Message Window 167 Set Background Color Sets the background color of the image See Set Background Color on page 89 Display
330. m a menu of waveforms The waveforms can be applied to the full range of hue saturation value or opacity or to a selected range See Creating Waveforms on page 124 Delete Selected Control Points Deletes selected control points in the selected area of the Colormap Select All Control Points Selects all the control points in the selected area of the Colormap Colormap Execute Menu This execute menu is identical to that of the Visual Program Editor window See VPE Execute Menu on page 160 for descriptions of the Execute options See also 5 4 Executing a Visual Program on page 67 Colormap Options Menu The Colormap Options menu displays the options used to edit the current color map The Colormap Options menu lists the following options Set Background Style to Checkerboard or Stripes Changes the background bar from two vertical stripes to a checkerboard Note The opacity must be less than 1 to make this pattern visible Axis Display Allows you to choose between Ticks Histogram and Log Histogram See Axis Display on page 124 Number of histogram bins Allows you to select the number of histogram bins See Axis Display on page 124 Display Control Point Data Value Allows you to specify which control point values will be displayed See Display Control Point Values on page 124 Change Colormap Name Sets the name of the Colormap Editor See Changing the name of the Colormap Editor on page 124 Help
331. m of the origins of the terms An example of a Product Array Object is illustrated in Figure 10 on page 30 A Product Array can Chapter 3 Understanding the Data Model 29 e y ct y o O D have terms that are Regular Arrays irregular Arrays or any combination of Regular and irregular Arrays Irregular rray type float real vector 2 items n Product Array Regular Array type float real vextorL2 items m origin Cun data Lug Val Figure 10 Example of a Product Array The example in Figure 10 represenis in compact form the same information as the following irregular Array Lx Ug yg Vol xy Ug t Ug VYot Vat Val Lx Uy 2U VotVot 2Vyl X4 U Y4 Vo x Uo Ug Y4 Vo Vg x 4 ug m 1 uy yay 4 Vo m 1 v4 An important special case of the more general Product Array Object is the n dimensional geometrically regular grid Figure 11 on page 31 is an example that shows two ways to describe a Product Array composed of two Regular Arrays 30 IBM Visualization Data Explorer User s Guide The order of the specification of the counts and deltas implicitly creates a list of positions X is the fastest varying dimension Regular Array type float real vector 2 tems 3 origin 0 0 delta 0 1 Regular Array type float real vector 21 items lorigin 0 0 A delta 1 0 X This represents in compact form the same information a
332. m to the tools for which you want to provide input The probe icons are numbered as you place them on the canvas For example the first probe icon you place is labeled Probe 1 the second Probe 2 and so on You can change the label of the icon by using its Configuration dialog box 3 In the View Control dialog box select Cursors mode from the Mode option box or use the Ctr1 X accelerator key A wire frame appears around the object The dialog box changes to add the Probe controls Select the probe you want to set by choosing the Probe s option box This opens an options menu with a list of the available probes from which you can select the desired probe 4 Use the mouse to select a point or points to use as input to the tool connected to the Probe or ProbeList icon To add a point double click on the eft mouse button inside the wire frame box A small square box appears marking the point Note The Probe tool allows only one point while the ProbeList allows several To move a point select the point by pressing the left mouse button with the mouse pointer positioned on it When the left mouse button is depressed on the point the three projections one for each axis appear inside the wire frame box as dots and the values for the x y and z coordinates are displayed on the right side of the Image window menu bar as illustrated in Figure 40 on page 86 You can move the point by dragging the selected point inside the box a
333. me This allows you to set up hierarchies or even rings of Control Panels You might choose to make a simple panel with only the most commonly used interactors then create additional panels with less used interactors The main panel can then be set up to access the subpanels by name using the Control Panel s Panels menu Select Open Control Panel by Name to see the list of other Control Panels accessible by the current panel It is very important to create sensible labels for the interactors in your Control Panels Data Explorer will automatically assign a name to a new interactor that reflects the name of the module and input to which you have attached the interactor stand in in the visual program However this name tends to be too generic especially if you have several interactors connected to several similar modules For example you connect a Scalar Interactor to the value input of an Isosurface module The interactor label in your control panel will acquire the title Isosurface value But if you also place another Scalar connected to a different Isosurface you will end up with two interactors with identical names So it is incumbent upon you the visual program author to change the names of your interactors to reflect their function in your visual program See 7 1 Using Control Panels and Interactors on page 128 and Using Interactors on page 142 for the instructions on using Control Panels and Interactors A very handy interactor is t
334. mines the dimensionality of the grid The last item in this list corresponds to the fastest varying dimension A grid has an origin which can be specified by an origin clause which lists the n coordinates of the origin If the origin clause is not present the origin defaults to 0 The origin clause can be followed by n delta clauses listing the deltas for each dimension Each delta clause has n elements The last delta clause corresponds to the fastest varying dimension Example 1 A Regular Grid on page 247 shows how to use the delta clause to specify a grid in which z varies fastest If the delta clauses are not specified the deltas default to unit vectors in each dimension with the last dimension varying fastest object number class gridpositions counts number name origin number delta number delta number The gridpositions keyword does not actually correspond to a primitive Object type in the system but instead is a convenient way of representing an important special case of the more general product Product Array Object of n 1 dimensional Regular Arrays Regular Array Objects For most purposes the gridpositions keyword is sufficient and more convenient The more primitive Regular and Product Arrays are described next Regular Array Objects 274 A Regular Array Object is a compact encoding of a linear sequence of equally spaced points in n space t is often combined in a Product Array with other
335. mple of a Mesh Array is illustrated in Figure 13 Path rray type int real vector 2 items n Mesh Array 1 Path Array type int real vector 2 c2 items m Figure 13 Example of a Mesh Array This example represents in compact form the same information as the following irregular Array 0 1 m m 1 1 2 m 1 m 2 m 2 m 1 2m 2 2m 1 m m 1 2m 2m 1 An important special case of the more general Mesh Array Object is the n dimensional cuboidal connections of a regular grid Figure 14 on page 33 is an example that shows a Mesh Array composed of two Path Arrays See Appendix B Importing Data File Formats on page 241 for a detailed description of how to specify these compact Arrays IBM Visualization Data Explorer User s Guide The order of the specification of the counts implicitly creates a list of position indices in the order of ast index varies fastest The location in space of each vertex is determined by the value of the position referred to by that index Path rray Path rray type int real 2 int real vector 2 PS corto items 5 items 3 Path Array Path Array type int real a int real vector 2 A Weetor 2 items 3 items 5 This represents in compact form the same information as the following irregular Array 013 4 1245 This represents in compact form the same 346 7 p p information as the following irregular Array
336. mponent positions value 1 component connections value 2 component data value 3 end Figure 86 Regular Grid Example The argument off front has been substituted for off diagonal in the script used to generate this figure see Examples on page 246 Example 2 A Regular Skewed Grid This example is similar to the previous one However the positions component is changed slightly so that the Objects and data describe a regular skewed grid This file is found in usr lpp dx samples data regularskewed dx Figure 87 on page 249 shows the resulting structure This example describes a regular grid where the axes are non orthogonal object 1 is the regular positions where the deltas is non orthogonal object 1 class gridpositions counts 4 2 3 origin 0 0 0 delta 1 0 2 0 delta 0 2 0 delta 0 0 1 object 2 is the regular connections object 2 class gridconnections counts 4 2 3 IBM Visualization Data Explorer Users Guide object 3 is the data which is in a one to one correspondence with the positions dep on positions object 3 class array type float rank 0 items 24 data follows 1 3 4 5 2 3 4 5 1 0 3 4 5 1 2 3 4 1 2 1 6 8 9 1 2 3 4 5 5 3 0 4 3 1 2 1 2 3 0 3 2 attribute dep string positions the field contains three components positions connections and data object regular positions regular connections class field component positions value 1 component connections value 2
337. mport then use the Select module Select takes an integer input from Sequencer for example to choose the appropriate series member If you choose to use separate files for separate data samples you would likely want to use the Sequencer as an input to a Format module The Format module could construct the filename with a format string like s 03d s along with three inputs myfield the output of the Sequencer and dx Then when the Sequencer emits the integer 2 the output string from Format becomes myfield 002 dx This can be fed into Import as the name of the dx file to read The result is that you can use the Sequencer to specify either any specific file or a whole series of files to import and image one after another Another common type of animation is to use the Sequencer to control object motion Usually this requires that you run the output of Sequencer through at least one Compute module For instance you can rotate an object around the Y axis one full revolution by employing the Rotate module The smaller the angular increment the smoother the animation will appear but there is a trade off in apparent motion rate if your graphics workstation is not very fast So you may have to adjust the incremental angular amount to your liking You will find the technique of wiring Interactors to Compute modules useful for converting the output of Sequencer to arbitrary floating point values If you wanted to vary the Scale of
338. multidimensional positional regularity It is the set of points obtained by summing one point from each of the terms in all possible combinations In the simplest case each term is a regular array pull down In windows the list of options displayed when a task is selected from the menu bar Q quad An element that connects four positions in a field R rank The number of dimensions in an array Rank zero corresponds to scalars e g the number 3 Rank one corresponds to vectors e g 1 5 3 7 and 2 9 4 0 6 0 Rank two corresponds to matrices or rank two tensors e g the matrix 1 3 8 5 7 2 1 O 1 Higher ranks correspond to higher order tensors See also shape realization A description of how raw data is to be represented in terms of boundaries surfaces transparency color and other graphical image and geometric characteristics 320 IBM Visualization Data Explorer User s Guide reference A component attribute One component is said to refer to another ref if the items in the first array are integer indices into the second array The connections component references the positions component regular array A compact array that is a set of n points lying on a line with constant spacing between them which can represent one dimensional regular positions rendering The generation of an image from some representation of an object such as a surface or from volumetric information ribbon stream
339. n screen brightness A gamma correction is a non linear adjustment of the pixel values to compensate for this difference and produce a more accurate representation on the screen By default the correction factor is 2 on the assumption that the display is not otherwise gamma corrected The DXHWGAMMA variable allows you to override this default In particular if the display device is already gamma corrected set the variable to 1 DXHWMOD if both GL and OpenGL are supported you can override the default library which is platform specific please see the appropriate README file for your architecture in usr 1lpp dx by using this environment variable It should be set to either DXhwad o for GL or DXhwddOGL o for OpenGL DXMDF specifies the name of the mdf file that contains custom added modules for customized versions of Data Explorer DXMEMORY sets the amount of memory in megabytes that can be used by the executive DX NESTED LOOPS for faces loops and edges data if set allows loops other than the enclosing loop for a face to be listed first However there is a consequent decrease in performance if this environment variable is set DXPIXELTYPE sets the image type to either 24 bit color images or floating point based 96 bit images the default This affects the behavior of Render and Readlmage This variable can be set to either DXByte 24 bits or DXFloat 96 bits Setting this variable to DXByte will result in images taking up le
340. n 198 a Function Call Assignments 0 00 00 002 ae 199 10 5 Invoking Data Explorer Macros and Modules 200 Function Call Arguments 000000000 eee ee 200 Function Call Attributes 0000058 202 10 65 Defining Macros 3 dere de Ae uh tb ae SR ee cni s 204 Macro Header os 44 542 hae Sao Pah de oium ELE UE AL eR 204 MCGB am in e arte ar Rodi eb ee eet y ae gout a Ur es Sa T 205 Macro Examples 5 det a ada Db ve EUER P eRe e o 205 10 7 Using Data Explorer Script Commands 206 SEQUENCE isidro REOR aha ovo Reo pus bad pad 206 File INCIUSION umma RU ee wee eee du eee ewes MESES x 207 xia d ae a de os a A A a a 207 10 8 Understanding the Script Execution Model 208 Top level Environment rre 208 FUNCION EXECUII N z p deu Ss dive dao a A nur m te e cU e rere G ee 208 Macro EXDaFISIOD s cs 2 2 ce ke ea a a EA aaa 208 Variables Used in Macros 2er 208 Assignment and Function Call Semantics 209 Execution Example goias po Mad ede a oe we bug wwe gu Med 210 10 9 Running net files in script Mode 210 Copyright IBM Corp 1991 1997 187 When you create a visual program with the graphical user interface Data Explorer saves the program in a net file This saved version is actually a set of scripting language commands You do not need to understand the script language unl
341. n a macro is expanded its statements are first analyzed to determine whether they need to be executed The rule of thumb for determining if a statement will be executed is that it must contribute either directly or indirectly to e One of the values passed into a module that has a side effect e A value assigned to a top level variable using a macro s formal output parameters There are two kinds of side effect modules e Those that do not produce any Object outputs Display and Writelmage are examples of this kind of module because they modify things such as monitors and files which are outside of the language s domain and control This type of module is represented in the graphical user interface as having no output tabs e Those that make use of internal executive features These modules are specially marked in their mdf module description files as ones that can cause side effects Chapter 10 Data Explorer Scripting Language 209 Side effect modules are always executed For information on the SIDE EFFECT flag see 10 1 Module Description Files on page 80 in BM Visualization Data Explorer Programmer s Heference Execution Example The macro sum3 in the following example computes both the sum of its first two arguments and the sum of all three of its arguments When the top level assignment statement on line 7 is executed the statements in lines 3 and 4 are both executed resulting in the values 11 and 111 being assigned t
342. n curve Equalize is useful to reduce extreme values back to a range similar to the majority of data values You may also wish to experiment with other data compression and expansion techniques by connecting your data Field to Compute and applying a function like In a or a2 where a is the input Field Another technique used to visualize data collected on a 2 dimensional grid is sometimes called a height map In Data Explorer the Rubbersheet module will generate this for you Conceptually a height map is drawn by elevating the 2 D grid into the third dimension Call it the Z dimension with our original grid lying in the X Y plane The height or Z value given to each vertex of the original grid is proportional to the specified scalar data value at that vertex If the data were vector data you could elevate the grid by the magnitude of the vector since magnitude is a scalar value The result usually resembles something akin to a relief map of the surface of the Earth with hills and valleys However this brings up an important point that will occur elsewhere in Data Explorer and visualization in general Remember that the original data were collected on the X Y plane for example our grass counting botanist s data It is one thing to indicate the different distributions of grass species by showing a 3 D Appendix A Using Data Explorer Some Useful Hints 227 c tn D m mi mall o gt cr tn plot of t
343. n of the whole grid and the origin of this grid object number class gridconnections name counts number meshoffsets number The gridconnections keyword does not actually correspond to a primitive Object type in the system but instead is a convenient way of representing an important special case of the more general mesh Mesh Array Object of n 1 dimensional paths path Array Objects For most purposes the gridconnections keyword is sufficient and more convenient The more primitive Mesh and Path Arrays are described next Path Array Objects A Path Array Object encodes linear regularity of connections It is often combined in a Mesh Array with other Path Arrays to obtain a grid of connections in such a case it is generally more convenient to use the gridconnections keyword described earlier A Path Array is a set of n 7 line segments joining n points where the ith line segment joins points and 7 The number of points n is specified by the number following the optional count keyword object number class patharray count number name Mesh Array Objects 276 A Mesh Array is a compact encoding of a generalized notion of a regular grid of connections It is frequently used to describe a rectangular grid of connections as a product of Path Arrays in such a case it is generally more convenient to use the gridconnections keyword described earlier A Mesh Array encodes multidimensional regularity of con
344. n this button is toggled on all other fields in this dialog box become disabled Resetting the Server If the data set your visual program is using changes e g by being edited during your Data Explorer session and the cache is enabled the default condition it may be necessary to force Data Explorer to reinitialize the server executive to access the new data To do this select the Reset Server option from the Connections pull down menu The action of resetting the server flushes the executive cache The next time you execute the visual program it executes the entire network not just the portions affected by changes internal to the Data Explorer session and will thus reaccess the data set Chapter 9 Graphical User Interface For Advanced Users 185 186 IBM Visualization Data Explorer Users Guide Chapter 10 Data Explorer Scripting Language 10 1 Starting Data Explorer in Script Mode 188 Setting Environment Variables llle 189 10 2 Understanding the Script Structure LL 189 10 3 Language Delimiters ossueesemeve ds de oA eer RE 191 sj Commenting Scripts ce ee 191 Naming Variables and Macros 0 2000000 192 Specifying Values ina Script o 200 8 193 10 4 Building Expressions and Statements 197 by Arithmetic Expressions 0 0 00000 eee ee 197 e Assignment Statements o se
345. n unlimited dimension that corresponds one for one with the data array An example using this method is provided in Partially Regular Grids and Time Series on page 286 284 IBM Visualization Data Explorer User s Guide Separate Variables When there are separate netCDF variables defined for each step in the series but all variables are in the same file use the following global attribute tags seriesxxx fieldname variablela variablelb variablelx Or seriesxxx fieldname variablela float value variablelb float value variablelx float value where the global tag must have the first 6 characters series Global tags must be unique so additional characters can be added to distinguish them Each variabletx is the name array containing the data for that step In the first format the spacing of the steps is assumed to be 1 0 In the second format the float value is the value of each step All other specifications are the same as for simple fields Separate Files When there are netCDF variables in separate files that make up the steps of a series use the following global attribute tags seriesxxx fieldname files filenamel filename2 filenameN Or seriesxxx fieldname files filenamel float value filename2 float value filenameN float value where the global tag must have the first 6 characters series Global tags must be unique so additional characters can be added to dist
346. nal faces rather than single lines Data Explorer provides a font called area or pitman which uses polygonal faces Another tip about text is that due to the much lower resolution of TV you must be careful to keep text large Ideally use a size that permits only about 30 to 40 characters to fit across the width of the screen Fine detailed text annotations may look good on the workstation but will become blurry little globs on TV defeating the whole purpose of annotating your video for your viewers Try making some text in different sizes then dub to VHS videotape Can you still read the text f so the size is probably sufficient for general use If it is too mushy to read increase the size For best legibility use white or yellow colored text TV Color Resolution Animation and Standard TV is simply not capable of correctly rendering fully saturated colors like red in particular or blue Large areas of fully saturated colors will pulse and bleed that is they will smear to the right due to the direction the TV raster scan is moving This smears any sharp edges on your objects and will severely degrade the quality of your visualization The color problem can best be dealt with by never using fully saturated colors Instead when building your color maps lower the entire Saturation curve to about 0 8 Although this will look much more pastel than you might prefer once you have converted the images to TV these colors w
347. navigate To move the camera changing the to and from points around the image scene using the mouse netCDF Network Common Data Form network In Data Explorer the set of tool modules interactor stand ins and connections that constitute a visual program In the VPE window a network appears as a set of icons connected by arcs Network Common Data Form netCDF A data format that stores and retrieves scientific data in self describing multidimensional blocks netCDF is not a database management system however netCDF is accessible with C and FORTRAN normal 1 Perpendicular to a surface 2 In IBM Data Explorer a vector that is perpendicular to a face or surface of an object A normal may depend on connections or positions A connection dependent normal results in flat shading a position dependent normal results in Gouraud shading O object In IBM Data Explorer any discrete and identifiable entity specifically a region of global memory that contains its own type identification and other type specific information opacity The capacity of matter to prevent the transmission of light For a surface an opacity of 1 means that it is completely opaque an opacity of O that it is completely transparent For volume opacity is defined as the amount of attenuation of light per unit distance P page 1 That portion of a panel displayed by a user interface 2 To move back and forth through the pages of
348. nce systems in our brain That implies that you must either choose to show comparisons based on precisely the same time duration and playback rate thus factoring out the time dimension or much better show two motion sequences at the same time in the same picture One way to accomplish this is to render two sets of images then use the Arrange module to construct an animation showing the two sequences side by side This technique is important if the two phenomena vary in a scientifically critical way during the process for example if one phase change event is virtually complete after 4096 of the entire time step series and another phase change after 6096 this may represent one of the important findings of your research But if you show the viewer first one sequence then the other very few people will be able to make a solid visual comparison from their memory It is much more visually impressive to show the two phase change simulations side by side starting at the same time and proceeding for the same number of time steps Animation must also proceed quickly enough for the mind s eye to perceive it as animation Imagine taking each time step of your simulation making a 35mm slide and loading up a slide carousel with ninety slides A viewer who is shown each slide for 5 seconds is unlikely to perceive the motion Put on videotape the same sequence of images takes only 3 seconds This may be too fast the entire event may flash by too fast f
349. nections It is a product of connection Arrays The product is a set of interpolation elements where the product has one interpolation element for each pair of interpolation elements in the two multiplicands and the number of sample points in each interpolation element is the product of the number of sample points in each of the multiplicands interpolation elements A Mesh Array is specified by a list of term clauses naming the Arrays that form the product The last term varies fastest in the resulting list of connections object number class mesharray name term number name file file file file number file file name IBM Visualization Data Explorer User s Guide Xform Objects String Objects Light Objects An xform Object specifies another Object transformed for example by a rotation scaling or translation The Object to be transformed is specified by an of clause and the transform itself is specified by a 3x3 matrix specified by a times clause and a 3 vector specified by a plus clause object number class xform of number name name file file file file number file file name times abcdefghi plus jkl This Object represents the Object specified in the of clause where each point x y z in the Object has been transformed to the new point x y z according to wO jk 1 Q Q Y 3 DO x y z Ix y 2 A String Object encapsulates a text string as an Object For example
350. nent types is given in Standard Components on page 19 Field components and Objects in general can have attributes associated with them For example the dep attribute of a component records the dependency of that component on another component thus the data component will have a dep attribute of positions or connections depending on whether the data are associated with the sample points or with the connections between them A component can also have a ref attribute indicating that it refers to another component Typically the connections component has a ref attribute of positions signifying that the items in the connections component refer to the positions component A connections component must have an element type attribute naming the type of connections such as triangles quads or tetrahedra A complete list of defined attributes is given in Standard Attributes 18 IBM Visualization Data Explorer User s Guide on page 25 the complete list of element types is given in Connections Component on page 20 Note that Fields can share components This allows for example several Fields to share the same positions and connections while having different data colors and so on Figure 3 illustrates two such Fields that share 3 dimensional positions and tetrahedral connections but each of which has separate but still both position dependent data The sharing is poss
351. net at any time and do not have to add them in pairs you will find it is easier to add one or more Receivers to a net right after you place and name the corresponding Transmitter because Data Explorer automatically gives Receivers the same name as the most recently placed Transmitter However if you decide to add a Receiver later just be sure to double click the Receiver module and set its name to the name of the Transmitter you wish it to receive from Changing the name of any Transmitter will automatically change the names of all associated Receivers but changing the name of a Receiver affects only that specific module A good way to use Transmitters is to broadcast global variables to use the terminology of traditional programming For example you are allowed only one Sequencer per visual program but as discussed earlier the output of Sequencer may be used by many subnets to perform various functions You may find it most convenient to place the Sequencer connected to a Transmitter you name sequencer near the top of your visual program the lowercase s helps remind you of the function of this Transmitter but you may use any name you like Then wherever in the net that you need to receive the current value of the Sequencer attach a Receiver named sequencer c tn D m mi mall o gt cr tn Another global that you may want available is the path name of your current work directory Attach a String Inter
352. nformation or warning messages are displayed You can also change this default behavior with the infoOpensMessage warningOpensMessage and errorOpensMessage configuration options described in Appendix D User Interface Configuration on page 299 Lastly when connected to the server the Execute Script Command command of the Message window s Options menu allows commands to be issued directly to the server However only advanced users should use this feature as the results of the commands entered can upset the state of the visual program This command brings up the Execute Script Command dialog box which will accept a single command in a 1 line text window Any messages that result from this command appear in the Message window s text window Chapter 8 Graphical User Interface Menus Options and the Message Window 175 176 IBM Visualization Data Explorer User s Guide E G eme o E a Chapter 9 Graphical User Interface For Advanced Users a 9 1 Using Distributed Computation 178 Creating Modifying and Deleting Execution Groups 178 S Displaying the Tools in an Execution Group 180 Assigning Execution Groups to Workstations 181 HOSIHCIOFIS uva deo domo b exea eU dor A RE Re P eed 182 9 2 Loading and Using Outboard and Runtime Loadable Modules 183 9 3 Connecting to the Server 000000200004 183 Resetting the Ser
353. ng control points selection of this suboption restores the original opacity map Minimum If the minimum was set either by a field passed to the data tab of the Colormap tool or by a value passed to or set for the min parameter of Colormap and was subsequently modified by the user in the Colormap Editor this suboption restores the original value Maximum If the maximum was set either by a field passed to the data tab of the Colormap tool or by a value passed to or set for the max parameter of Colormap and was subsequently modified by the user in the Colormap Editor this suboption restores the original value A11 Restores all values to their data driven settings Minimum amp Maximum Restores both the minimum and the maximum values of the original color map Add Control Points Brings up a dialog box in which you can enter the exact numerical location for control points to be added as the data value and as the value for either the Hue Saturation Value or Opacity area of the color map See Adding Control Points on page 122 Constrain Horizontal Constrains the horizontal movement of all control points in all areas of the Colormap See Moving Control Points on page 123 Constrain Vertical Constrains the vertical movement of all control points in all areas of the color map Chapter 8 Graphical User Interface Menus Options and the Message Window 169 Generate Waveforms Displays a dialog box that allows you to select fro
354. ng for all subsequent data clauses to be the most recently defined data encoding The default data encoding is text or ascii on all currently supported systems The ieee keyword specifies the ANSI IEEE standard 754 data format If binary or ieee on all currently supported systems is specified the default byte order depends on the platform on which Data Explorer is running On the DEC 272 IBM Visualization Data Explorer User s Guide Alpha the default byte order is 1sb least significant byte first On all other platforms the default byte order is msb most significant byte first The data mode clause can be used outside an Array Object definition see Data Mode Clause on page 278 for more information object number class array name type unsigned byte signed byte unsigned short signed short unsigned int signed int hyper float double string category real complex rank number shape number items number mn msb text data mode offset 1 Isb ieee file file offset 1 binary follows S ascii zi tn If byte short or int are not prefixed with either signed or unsigned by default bytes are unsigned shorts are signed and ints are signed For compatibility with earlier versions char is accepted as a synonym for byte Note For string type data the Array rank should be 1 and the Array shape should be the length of the longest string plus 1 Constant Array Objects A Con
355. ng is what appears as the choice on the interactor The value can be a string integer scalar vector or matrix All the values must be of the same type By default the values are integers A value is associated with a string using the Set Attributes dialog box Figure 62 EE i set Selector Attnbutes Figure 62 Set Attributes Dialog Box for a Selector Interactor You can use the Selector or SelectorList interactor for many purposes A common use is as a switch control in your visual program You can use an integer output for example as input to the Switch module to switch easily among several objects You can use a string output for example as input to the Select or Import modules allowing you to easily select different members or data file names You can also use a string output as input to the Caption module to annotate the image with the current selector setting A discussion on how to use the Selector and SelectorList interactors can be found in Selector and SelectorList Interactors on page 146 IBM Visualization Data Explorer User s Guide The default choices for the Selector and SelectorList interactors are e 1 on 0 off To modify the choices do the following 1 Open a Control Panel with the selector interactor in it 2 Open the selectors Set Attributes dialog box by double clicking on the interactor or by selecting the interactor and then choosing the Set Attributes option in the Edit pull
356. ng language 194 hiding input tabs 110 hints for using Data Explorer 212 Histogram 227 in Colormap Editor 124 identifiers in scripting language 192 Image Window changing the name of 93 menus Connection 167 171 Execute 166 171 File 165 171 Options 167 Windows 166 172 organization 165 image controlling view of changing look to point roaming 79 changing view direction 76 navigating 80 panning 80 resizing 84 rotating 77 selecting view mode 74 zooming 78 import changing data 185 importing data 242 include command 207 input tabs adding and removing 106 input tabs revealing and hiding 110 instance attribute in scripting language 202 interactive use 232 interactor attributes in general 134 incrementing 135 label 137 layout 134 Style 134 updating 135 interactor stand ins 128 interactors adding and moving to existing Control Panel 130 and Control Panels 232 changing the label 137 Index 325 interactors continued changing the layout 134 changing the size of 132 changing the style 134 deleting 131 Dial 142 Integer 142 List 145 moving a group 131 moving single interactor 131 placing in Control Panel 130 radio button 146 Reset 147 Scalar 142 selecting a group 131 Selector 136 146 SelectorList 146 Slider 143 Stepper 142 String 144 Toggle 147 use of 130 147 Value 144 Vector 144 interface user 58 74 128 156 178 interpolation 9 invalid positions and invalid connections components 23 irregular
357. ng of the expression for example square root of pressure per cubic inch And any time you do something tricky with a module enter a note to yourself in the Notation box for later reference Compute also offers a useful way to document the terms of an expression Each input to Compute can be given a meaningful name the default names are simply a and b If you like you can change the input letter names to words like pressure and scale then use an expression like sqrt pressure scale 0 5 You may Appendix A Using Data Explorer Some Useful Hints 235 add more inputs to Compute by simply pressing Ctrl A when you have selected the Compute module You can also add annotation text directly to the canvas using the Add Annotation option of the Edit menu of the VPE see Adding Annotation to a Visual Program on page 115 And you can segment your visual program with pages see Creating pages in the VPE on page 115 A 4 Design for Video Output Video production is only one useful output from a Data Explorer visual program Videotape has the advantage of portability you can send a video to almost anyone these days because of the proliferation of consumer VCRs But video has the great disadvantage that you can no longer make interactive changes in the images you cannot explore any more once you have committed your images to videotape Unfortunately high definition digital television is not widely available yet lt is very imp
358. ns The left hand output of Selector is connected to the first tab the selector of Switch Now when the user chooses item 1 on the menu in the Selector interactor located on a control panel of course the number 1 is emitted and received by Switch Switch then lets the isosurface pass through One more trick you may want to allow both the Isosurface and the ShowConnections images to appear at the same time Use a Collect module just before the Switch Attach the Isosurface output both to Switch input 1 and to Collect similarly attach the ShowConnections output to Switch input 2 and to the Collect Now add a fourth choice to the Selector menu 3 Show both Attach the output of Collect to input 3 of Switch and you have provided this new capability to the user By the way the value 0 will always turn off all output from the Switch you do not need to provide a 0 valued choice if that is not appropriate in other words if you always want Switch to pass at least one item The default settings for Selector are O off 1 on You may find this handy as you begin to develop more complicated visual programs containing a number of objects in the Image window As you develop each subnet that is a branch of the visual program that yields a particular visual object attach it to a Switch and add an on off Selector Change the label of the Selector interactor in the Control Panel to identify the object it controls Run t
359. ns on page 291 5 2 Understanding Data Explorer Windows 60 The Data Explorer user interface is built on the X Window System and Motif standards These tools manage the windows used with Data Explorer The windows you use depends upon how you choose to use the system The primary windows are listed and described at the start of this chapter The primary window in which you begin a Data Explorer session either the Visual Program Editor or Image window is called the anchor window You can also have a menu bar as your anchor window by specifying menubar on the command line This is the window that if closed ends the Data Explorer session The anchor window is identified by a symbol resembling a ship s anchor located in the top left corner as illustrated in Figure 30 on page 61 Descriptions of the primary window pull down menu options are located in Section 8 1 Using the Primary Window Pull Down Menus and Options on page 156 Secondary windows such as dialog boxes or informational boxes appear when they are needed to complete a task You can move secondary windows but you cannot put them behind the primary window from which they came See BM AlXwindows User s Guide or the appropriate window system overview for more information on how to manipulate windows In this chapter when references are made to the X Window System it means any window server that supports X11 protocol including Sun s OpenWindows The Motif window manger m
360. ns the starting loop numbers of the list of loops making up a face object face list class array type int rank O items 5 data follows 0 1 3 5 6 attribute ref string loops Colors array To get flat shaded surfaces there should be one color per face and one normal per face These are Red Green Blue values between O no color and 1 fully saturated u object color list class array type float rank 1 shape 3 items 5 data follows S 0 6 0 3 0 6 zi 0 8 0 8 0 1 n 0 9 0 4 0 9 0 4 0 8 0 7 0 8 0 8 0 8 attribute dep string faces Normals array object normal list class array type float rank 1 shape 3 items 5 data follows 0 93 0 37 0 0 0 0 0 0 1 0 0 0 1 0 0 0 0 93 0 37 0 0 0 0 0 63 0 78 attribute dep string faces Field definition to put the arrays together object solid class field component positions position list component edges edge list component loops loop list component faces face list component colors color list component normals normal list end Appendix B Importing Data File Formats 267 Example 12 Image Files This Data Explorer header file reads an image cylinder rgb The image is 350 x 300 and consists of RGB colors 3 vectors You can read this image in and display it using the visual program usr 1pp dx samples programs ReadImage net This file can be found in usr 1pp dx samples data image dx Note It is easier to import a file
361. nteractor to the Control Panel for each stand in that is selected in the VPE window See Adding Interactors to an Existing Control Panel on page 130 Show Selected Interactor s Shows the relation between a selected interactor stand in in the VPE and the interactors in the Control Panels See Locating Interactor Stand ins on page 132 Show Selected Tool Shows the relation between a selected interactor stand in in a control panel and interactor stand ins in the VPE Comment Opens a dialog box with a text field You can use this text field to document the use of the Control Panel See Adding Comments to a Control Panel on page 133 Control Panel Execute Menu This execute menu is identical to that of the Visual Program Editor window See VPE Execute Menu on page 160 for descriptions of the Execute options See also 5 4 Executing a Visual Program on page 67 Control Panel Panels Menu The Panels menu allows you to open one or all existing control panels The Panels menu has the following options Open All Control Panels Opens all existing control panels Open Control Panel by Name Opens a cascade menu from which you can select the name of the control panel to open Control Panel Options Menu The Options menu allows you to customize the Control Panel The Options menu contains the following options Change Control Panel Name Displays a dialog box where you can enter a new name for the current Control Panel
362. nterface Control Panels Interactors and Macros 139 Once a Control Panel group is created it can be modified Modifying a Control Panel group can include changing its name adding new Control Panels and removing Control Panels from the group To modify a Control Panel group 1 Click on the Control Panel group name that is to be modified This causes the name of the Control Panel group to be displayed in the group name text field and causes the toggle buttons of the Control Panels that are members of the group to be activated All other Control Panel buttons are released 2 You may now change the name of the group by editing the text field Add a new Control Panel by clicking on its toggle button this causes the toggle button to be activated To remove a Control Panel from the group click on its toggle button to release it 3 Once you have made the desired changes to the Control Panel group click on the Modify button at the bottom of the dialog box This causes the change to take effect To delete a Control Panel group 1 Select the group by clicking on its name 2 Click on the Delete button at the bottom of the dialog box Restricting Control Panel Access Access to Control Panels is restricted using the Control Panel Access dialog box This dialog box is opened by selecting the Control Panel Access in the Option menu of the VPE Image or Control Panel windows The Control Panel Access dialog is used to restrict certain Con
363. ntrol Panels that are tightly related and wish to have them treated as a group Data Explorer provides you with the means of placing these Control Panels into a group so that they can be opened together If you have a master Control Panel that should be open before any other controls Data Explorer provides you with the capability of restricting access to these Control Panels from any Data Explorer window except the master Control Panel Access to Control Panel groups can be done in a similar fashion Restricting access to Control Panels in this way allows you to build Control Panels into hierarchical structures A special type of Control Panel access can be achieved by specifying which Control Panels are automatically opened when Data Explorer is started with the Image window or menu bar as the anchor using the image or menubar option IBM Visualization Data Explorer User s Guide Creating Modifying and Deleting Control Panel Groups The following describes how to create Control Panel groups restrict access build hierarchies and specify which Control Panels are open at startup Control panel groups are created using the Control Panel Group dialog box The dialog box is opened by selecting the Control Panel Groups option under the Options menu in the VPE window Figure 64 Control Panel Group Groups Panels Color and Opacit F Color controls Pe Realization 3 Isosurface controls F Opacity controls p
364. ny cases it may be acceptable to convert your data components to smaller sized types using Compute For example you might change your floating point data to bytes This has the advantage that all downstream modules will require less memory Working with Series Data When working with series data if you are importing the entire series and then selecting members out of the series it may be that your program can be changed so that you only import one member at a time Do this using the start and end parameters to Import This reduces memory requirements by not having the whole series in memory at once Glyphs f you are using glyphs AutoGlyph or Glyph you may want to use less spiffy glyphs A less spiffy glyph is one that has fewer positions and connections facets and therefore consumes less memory To use less spiffy glyphs use the type parameter of either AutoGlyph or Glyph and set it to speedy or to a small fraction of 1 Reducing Grid Resolution f you can sacrifice resolution in your data set you may want to use the Reduce module usually just after Import to reduce the number of points in your data set Reduce filters the data set before reducing the number of points Remember that it is of little use to process 5000x5000 points if your final image is only 1000x1000 pixels 24 Bit Images You can create 24 bit images instead of the default 96 bit images by setting the environment variable DXPIXELTYPE to DXByte See
365. o I get more information e n the Help Menu Application Comment presents comments if provided on the current visual program Table of Contents presents the table of contents of the user documentation You can use hypertext links to go to a particular topic Context Sensitive Help presents a cursor just click on a tool icon or other feature to learn more e Samples Sample Visual Programs usr lpp dx samples programs See also the subdirectories there grouped by topic Sample Scripts usr Ipp dx samples scripts e Information available electronically Data Explorer user group on the internet comp graphics apps data explorer DX Home Page on world wide web http www almaden ibm com dx Data Explorer Repository at Cornell anonymous ftp ftp tc cornell edu look for directory pub Data Explorer gopher ftp tc cornell edu port 70 Memory Use Appendix A Using Data Explorer Some Useful Hints 213 214 Data Explorer Object Cache Data Explorer uses an object cache to store intermediate results of modules Caching systems are intended to fill up and then reclaim memory by throwing things out of the cache The size of the cache defaults to a large percentage of the physical memory on the machine You can control the size of the cache with the memory command line option to the dx command The minimum cache size needed is on the order of the maximum amount of memory required for a program
366. o its background Maximum opacity shows the color calculated by the hue saturation and value fields minimum opacity calculates colors so that the image is faintly visible in front of the background In summary the Colormap Editor enables you to e Control the range of data values over which the mapping occurs e Select the colors that are mapped to the range of values e Select the opacities that are mapped to the range of values When the Colormap stand in from the Special category is connected to the Color tool as shown in the visual program fragment in Figure 56 on page 120 the combination can be used in place of the AutoColor tool Chapter 6 Graphical User Interface Important Windows 119 Visual Program Editor Figure 56 Fragment of Visual Program Using Colormap To use the Colormap Editor 1 Double click on the Colormap tool in the VPE window or select either the Open Selected Colormap Editors option from the VPE or the Open A11 Colormap Editors from the Image window Windows menu Note From the VPE this option is Open Colormap Editor For this option to be available the Colormap icon must be selected 2 The Colormap Editor appears Make necessary adjustments to values as described in Entering Values in a Colormap Editor on page 121 Figure 57 on page 121 illustrates the organization of the Colormap Editor window 120 IBM Visualization Data Explorer Users Guide Colormap Editor 4 1 File Edit Execut
367. o pass parameters into a macro the parameters will be found in the environment outside of the macro if necessary However it is necessary to pass any parameters out of the macro that are intended to be used outside of the macro Example 4 Using Route in the Script Language The Route module is used to choose between different destinations for a particular object For example you could choose to either write an image to a file or display the image to the screen In order to use Route in a script the Route module and the tools that consume the outputs of Route must be contained in a macro data Import usr 1pp dx samples data cloudwater iso Isosurface data camera Autocamera iso image Render iso camera macro do which which image image to display image to write Route which image Display image to display WriteImage image to write do which 1 image The call to the macro do which with a value of 1 causes the first output branch Display to be executed Writelmage is not executed If do which had been called with a value of 2 however then Writelmage and not Display would have been executed IBM Visualization Data Explorer User s Guide Example 5 Using the Sequencer You can use the Sequencer in script mode The special variables you use are startframe the starting integer of the sequence Qendframe the ending integer of the sequence deltaframe the increment between frames default
368. o specify the name of the page specify whether or not the page is included in PostScript output through the Print Program option of the File menu and specify the tab position of the page Macro Name Displays a Configuration dialog box for naming a visual program as a macro See Creating Macros on page 149 for more information Execution Groups Displays a dialog box for creating and modifying execution groups See 9 1 Using Distributed Computation on page 178 Comment Displays a dialog box for documenting the function of a visual program or macro See Adding Comments to a Visual Program on page 114 VPE Execute Menu You can use the Execute menu to execute the current visual program in various ways This menu is the same as the Execute menus in control panels the Image window the Colormap Editor and the Message window The options in the Execute pull down menu are grayed out when there is no connection to the server The Execute menu lists the following options Execute Once Causes the visual program to execute only once using current values and configuration settings Subsequent interactor value changes do not cause program reevaluation until this command is reexecuted This option is grayed out if the Sequencer is running Execute on Change Causes the visual program to execute each time a value or configuration setting is changed If you are changing values faster than Data Explorer can generate images
369. o the top level variables x and y respectively When the top level assignment statement on line 8 is executed only the statement on line 3 is executed Since the value in the output variable e is not assigned to anything in the calling environment the statement on line 4 need not be executed macro sum3 a b c d e Jf A 2 d a b 3 e d 4c 4 5 6 x y sum3 1 10 100 LI X sum3 1 10 100 8 10 9 Running net files in script mode 210 When you create a visual program using the User Interface the net file saved is a script so you can run it in script mode User Interface specific information such as placement of tools on the canvas is saved as comments in the script If you have a sequencer in your visual program the User Interface adds a play command as the last line of the net file Thus you can edit this line out and add your own options if you want to do something other than play forward through the sequence once see Sequencer on page 206 If you do not have a sequencer in your visual program the User Interface adds a call to main the main macro which is defined to be your top level visual program If you do not want the program to automatically execute when you read it in as a script remove or comment out the call to main If your visual program uses macros the user interface will add an include line so that the macros will be included when the visual p
370. o which it is connected For example if the Input tool is connected to two inputs an object and a scalar the Input tool type would become a scalar type Specifies a default value for the input If the descriptive value toggle button is activated the default value field of the macro is treated as a description not an actual value You can use this to indicate to users of the macro what sort of parameter this input should be Provides a short description of the input for your own documentation purposes This description is used to generate the Description window for the resulting macro tool which you can access through its Configuration dialog box IBM Visualization Data Explorer User s Guide Input Position lt 4 Type Default Value no defa 0000 Description Do Options _ required parameter PF descriptive value J hide tab by default Outputs Name Type Destination Cache parameter scalar RubberSheet Ad Results n OK Apply Expand Collapse Description Restore Cancel Figure 76 Input Configuration Dialog Box Options The required parameter toggle button when activated indicates that the input is required for the macro The corresponding input tab of resulting macro icon is highlighted with a different color This option is inherited from the input to which the Input tool is connected The descriptive value toggle button is used with the Default Value field as described above
371. oZg Dx ygzo then the order of the delta clauses would be reversed and the counts would be specified as 3 2 4 When using the gridconnections keyword it is not necessary to specify the element type or ref attribute as these will automatically be set for you This example describes a regular grid object 1 is the regular positions The grid is 4 inx by 2 iny by 3 inz The origin is at 0 0 0 and the deltas are 1 in the first and third dimensions and 2 in the second dimension object 1 class gridpositions counts 4 2 3 origin 0 0 0 delta 1 0 0 delta 0 2 0 delta 0 0 1 object 2 is the regular connections object 2 class gridconnections counts 4 2 3 attribute element type string cubes attribute ref string positions object 3 is the data which is in a one to one correspondence with the positions dep on positions The data are matched to the positions in the order last index varies fastest i e x0 y0 z0 x0 y0 zl x0 yO z2 x0 yl z0 etc object 3 class array type float rank 0 items 24 data follows 1 3 4 5 2 3 4 Fal 0 9 4 5 1 2 3 4 1 2 1 6 8 9 1 253 4 5 5 3 0 4 3 1 2 1 2 3 0 3 attribute dep string positions Appendix B Importing Data File Formats 247 ms mall o D ms o ms 3 y cr un 248 A field is created with three components positions connections and data object regular positions regular connections class field co
372. oard modules For an outboard or runtime loadable to be available for use its module description file must be loaded into the tool palette To load a module description file 1 Select the Load Modules Description s option from the File pull down menu in the VPE A file selection dialog box appears For information about how to use the dialog box see File Selection Dialog Boxes on page 116 2 Use the dialog box to locate the description file for the module you want to load and select the desired file The module name appears on the tool palette under its assigned category Note If the module description you loaded has the same name as an module description loaded previously the more recent description replaces the less recent regardless of whether they were assigned to the same category When the new module is available for use it is listed in the tool palette as a member of the category you assigned it to You can configure Data Explorer to automatically load module descriptions when you begin the Data Explorer program To do this use the mdf filename option when starting Data Explorer where filename specifies one or more module definitions Alternatively you can use the DXMDF environment variable For more information on how to do this see Using Environment Variables on page 59 and C 1 Environment Variables on page 292 9 3 Connecting to the Server Before you can execute a visual program your workstation mus
373. obal variety Set Selected Gets Sets Local Sets all of the selected Get and Set modules to the Local variety Set Selected Gets Sets Global Sets all of the selected Get and Set modules to the Global variety For additional information on the Get Set tools see 4 6 Preserving Explicit State on page 45 Select Deselect Tools IBM Visualization Data Explorer Brings up a cascade menu with the following options Select All Selects all tools on the canvas Select Connected Selects all tools connected to the currently selected tool Select Unconnected Selects all tools not connected to the currently selected tool Select Upward Selects all tools modules that directly or indirectly provide input to the selected tool Select Downward Selects all tools modules that directly or indirectly accept output from the currently selected tool Deselect All Deselects all selected tools Select Unselected Selects all unselected tools User s Guide Output Cacheability Brings up a cascade menu with the following options Optimize Cacheability Uses a heuristic for automatically selecting the optimal cache setting for each module in a visual program Set Output Cacheability Brings up a cascade menu with the following options Cache All Results Caches all results of the selected tool s Cache Last Result Caches only the last result of the selected tool s Cache No Results Caches no results Show Output Cacheab
374. ode RR RESUME DS Sede 64 Working with Windows rns 65 5 3 Using Online Help 0000000000000 0008 65 User Defined Help Files cnn 67 5 4 Executing a Visual Program lr 67 Using the SCQUCNCE xad oe eB nu eub e eee SEE AL rid ard sts 68 Using a Data Driven Sequencer 20 2000 4 70 Eror Messages were eamm BRED Bee Ee AY ees SERA TO 71 Chapter 6 Graphical User Interface Important Windows 73 6 1 Using the Image Window 74 Controlling the Image View Control 74 Undo Redo and Reset o 87 AUIDAXOSUE adro Sop a te br pas a ub i ee ut 88 det Background ColOfus 2n 0 205 44446 24 698 AA 89 Display Rotation Globe 0000000000000 08 91 Renden OPUS esa resta d dhe rida ds eet ands 91 Image Depth oes 93 Changing the Rate of Frame Display Throttle 93 Changing the Title of an Image Window 93 IBM Visualization Data Explorer User s Guide Control PanelJACCBSSas Soranus Se A dws E ded Saving an Image eii oe e608 Seb CARS be ASRS GAO Nes Printing an Image 2 2246 oS e Xedkhe x be a eee Pee a ee x 6 2 Using the VPE 22203 SG ew xe memo Fal ou S emm A Creating a Visual Program 2 2 len Specifying Values for a Tool s Inputs Creating Deleting and Moving Tab Conne
375. of the tool A white line from the output tab follows the mouse pointer If you decide at this point not to break the connection you must place the cursor back on the input tab where the connection was and release the mouse button 3 Release the mouse button The connection is deleted and the input tab released To move a tab connection 1 Depress the mouse button on the input tab 2 Drag the cursor to an empty input tab one that has not already been folded in 3 Release the mouse button The connection is rerouted to the new input tab Moving and Copying Tools The Drag and Drop capability provided by Data Explorer allows you to move or copy selected tools within a Data Explorer window e g the VPE or a control panel or between different Data Explorer windows i e between two different VPE windows You can also drag interactor stand ins to control panels to create interactors To initiate a drag and drop first select the tools you want to move or copy either by rubber band or shift selection Then place the mouse cursor over one of the selected tools and press the middle mouse button Keeping the button pressed move the cursor to an empty spot on the canvas and release the button A copy of Chapter 6 Graphical User Interface Important Windows 105 the selected tool will be placed where the mouse button was released To do a cut and drop move use Shift middle mouse button When dragging and dropping tools from the
376. of the FileSelector interactor and leaves the file selection dialog box open An alternate way of specifying or modifying a file name in the FileSelector text field is to directly type into the field See Editing Text Fields on page 64 on how to enter and modify text in a text field The FileSelector interactor produces two outputs the first output is the contents of the text field typically a fully qualified path name set from the file selection dialog box The second output is the name of the file as it appears in the directory that is excluding any directory name Reset Interactor The Reset interactor outputs one value for the first execution after its toggle is set and a different value thereafter This interactor appears only as a toggle button e c El A o E ct m o m ma o E D md tn Toggle Interactor The Toggle interactor outputs one of two possible values The values can be strings scalars vectors or matrices This interactor appears only as a toggle button Using Data Driven Interactors Most of the interactor types may be data driven meaning that their attributes such as minimum maximum increment and label may be set by connecting the output of a tool to the input of the interactor stand in in the VPE or by a value typed into the interactor stand in s Configuration dialog box rather than by using the Set Attributes dialog box for the interactor Chapter 7 Graphical User Interface Control P
377. og box or the value specified in the Value field e When you deactivate a toggle button the input parameter is unbound and the tool uses its default value for the input Name Specifies the name of an input parameter You cannot modify this field This field is grayed out if the name is specified with tab connections Hide Indicates whether an input tab is to be hidden When you activate the Hide toggle button the corresponding tab on the tool icon is removed If a tab is connected to another tool it cannot be hidden Once a tab is hidden it can be removed from display in the Configuration dialog box by using the Collapse button To reveal individual input tabs first click on the Expand button This will cause the Configuration dialog box to resize displaying all of the tool s inputs Then deactivate the Hide toggle buttons of the desired inputs by clicking on the toggle buttons As the inputs are revealed the tool icon is updated to reflect the additional inputs Once you have revealed all the desired tabs you can click on the Collapse button to remove the remaining hidden tabs from being displayed in the Configuration dialog box See also Revealing and Hiding Input Tabs on page 110 Type opecifies the type of an input parameter You cannot modify this field Source Displays the name of the tool connected to the input if a connection exists If the name of a tool is displayed in the source field the toggle button is activated
378. ogically above a SetLocal When GetLocal runs it checks if an object has been saved in the cache If no object was saved Chapter 4 Data Explorer Execution Model 45 Figure 22 Example 5 LA i aon P fe r Visual Program Editor tmp doc fmquwre6 net input Output Sel oca as would be the case if SetLocal has not yet run or the reset parameter to GetLocal is set GetLocal outputs an initial value that you can set using the initial parameter Otherwise GetLocal retrieves the saved object from the cache and outputs it When SetLocal runs it saves its input object in the cache and then indicates that its paired GetLocal should simply be scheduled during the next iteration of a loop or the next time an execution is called for Note that if GetLocal is inside a macro it will be executed only if the macro needs to be executed that is if the macro s inputs have changed or there is a side effect module in the macro GetGlobal and SetGlobal are paired in the same way as GetLocal and SetLocal They also save and retrieve items from the cache The main difference is that GetGlobal and SetGlobal will preserve state over more than one execution of a program However recall that a complete loop takes place within a single execution Using GetGlobal and SetGlobal is comparable to using a static variable in C language programming GetLocal and SetLocal are good for saving state inside of a looping construct Once the loop is terminated th
379. oint does not move Because of this the movement of the look to point is constrained to six directions i e the positive and negative directions for each of the three axes Note that since perspective projection does not preserve parallel lines the directions in the axes diagram do not necessarily correspond to the direction that the point moves in the Image window However these axes do correspond with the values of the coordinates While using orthographic projection the movement of the point in the Image window corresponds with the directions of the axes diagram The Constraints option appears in the View Control dialog box when you select Roam mode You can further restrict the movement of the look to point by using the Constraints option This allows you to constrain movement of the point to two directions i e the positive and negative directions of a particular axis Select an axis to restrict movement to by clicking on the Constraints option box and selecting the desired axis X Y or Z Once this is done you are able to move the look to point along only the selected axis while the values of the other two axes remain constant You may want to position the cursor in two steps using different views for each step For example you can position the x and y coordinates using the front view and the z coordinate using the side view Chapter 6 Graphical User Interface Important Windows 19 80 To release the constr
380. oints in the xy plane object 1 class array type float rank 1 shape 3 items 8 data follows 0 0 0 0 0 0 0 0 Teck 0 0 1 0 0 2 0 0 1 1 3 0 0 2 2 0 2 0 0 225 I 0 0 355 0 1 0 0 3 4 1 0 0 0 define a set of regular points in the z direction object 2 class regulararray count 3 origin 0 0 0 0 0 0 delta 0 0 0 0 1 0 create a product array of the irregular points in the xy plane and the regular points in the z direction object 3 class product array term 1 term 2 create regular cube connections object 4 class gridconnections counts 4 2 3 the data component object 5 class array type float rank 0 items 24 data follows 1 0 2 1 2 0 1 0 4 5 6 7 8 1 0 9 0 8 1 0 1 2 1 3 0 1 0 3 1 2 Dae 4 1 0 9 2 0 1 0 0 9 object field class field component positions 3 component connections 4 component data 5 end Appendix B Importing Data File Formats 255 NM OO PO O O ms mall o D ms o ms 3 y cr un 256 Figure 90 Product Array Example with Irregular Points in the XY Plane The next data file defines a regular grid that is regular in the xy plane but has irregular positions in the z direction This file can be found in usr Tpp dx samples data product2 dx Figure 91 on page 257 shows the resulting image define a set of regular points in the xy plane object 1 class gridpositions 4 2 1 define a set of irregular points in the z direction object 2 class array type float rank 1 shape 3 items
381. ol in any execution group alter the members of an execution group at any time or change the assignment of an execution group from one host to another at any time The exceptions to these rules deal with e Modules maintaining state e g Streakline e Hardware rendering e The Pick Module Modules that maintain internal state information using private cache objects cannot be freely moved between hosts Doing so will cause the module to lose its state 182 IBM Visualization Data Explorer User s Guide I9 information or obtain old state information If you do reassign a module maintaining state to another host you should reset the server using the Connection menu Reset Server option to ensure correct execution The only Data Explorer module provided with the system that maintains state information is Streakline ms o ms gt x lt w 5 O D a c uo D uo When you are using the hardware rendering option with either the Display or Image tools the tool should be assigned to execution on the host physically connected to your display The Pick module must be run on the same host as the Image tool 9 2 Loading and Using Outboard and Runtime Loadable Modules Data Explorer allows the following types of user written module inboard modules are compiled and linked into the Data Explorer Executive outboard modules are run as separate processes runtime loadable modules are loaded at runtime and effectively become inb
382. ol points are used to define the value of hue saturation value and opacity for a given data value The number and position of control points can be different in each of the areas The control points appear as small squares on the vertical scale marks in each of the four areas Adding Control Points Control points can be added to an area using one of four different methods e double clicking directly in the area e using the Add Control Points dialog box e using the Generate Waveforms dialog box or e copying and pasting control points from another area To add a new control point by double clicking place the cursor on the location where you want the new control point then double click The values between control points are linearly interpolated by the Colormap If a new point is added as the bottom or top most point on the line the new line continues vertically from the new point to the min or max value respectively When a new control point is added its data value is displayed by default To specify exact values for new control points click on the Add Control Points option on the Edit menu The Add Control Points dialog box appears as illustrated in Figure 58 on page 123 The Add Control Points dialog allows you to specify values using two steppers The Data value stepper allows you to specify a control point value between min and max The second stepper displayed in the dialog will reflect that area Hue
383. olorlist If a colormap is given then the colors corresponding to the integers 0 n 1 where n is the number of items in the stringlist first parameter are assumed Lookup Use one object to lookup the value of another object in a field This module is especially useful with categorical data Quantizelmage Allows you to create a delayed colors image from any image You specify the number of colors to use and the module will choose the best set of colors to represent the image ReadimageWindow Allows you to obtain the image that is the field of pixels from a Display or Image window ReadlmageWindow is called internally by the Image tool when necessary to save a displayed image ScaleScreen Scales all screen objects i e captions color bars text glyphs by a specified amount Used internally by the Image tool to make sure that rerendered images remain WYSIWYG SimplifySurface Reduces the number of triangles in a surface SuperviseState Used with SuperviseWindow to create and manage windows This pair of modules allows you to directly specify what actions should take place for a given mouse or keyboard event in the window This is in contrast to the use of the Image window where mouse actions are predefined by Data Explorer i e rotation or pan zoom mode SuperviseWindow See SuperviseState on page xxxii IBM Visualization Data Explorer User s Guide Backward Incompatibilities There are a few backward incom
384. olumetric connection element that connects eight positions in a data field cutting plane An arbitrary plane in three dimensional space onto which data are mapped 317 e O o Ye Y m lt D data driven interactors Interactors whose attributes such as minimum and maximum are set by an input data field Data Prompter An interface that enables a user to describe the format of the data in a file The prompter creates a General Array Format header file that is used by the Import module to import the data dependence A component attribute One component is said to be dependent dep on another if the items in their component arrays are in one to one correspondence to each other dialog box The window displayed when the user selects a pull down option that offers or requires more detailed specification display 1 To present information for viewing usually on a terminal screen or a hard copy device 2 A device or medium on which information is presented such as a terminal screen 3 Deprecated term for panel E element Connection item element type An attribute that describes the type of connection element for example cubes tetrahedra or lines executive The component of the Data Explorer system that manages the execution of specified modules The term often refers to the entire server portion of the Data Explorer client server model including the executive modu
385. ome Useful Hints 225 c tn D m mi mall o gt cr tn 226 those that face away Data Explorer like other computer graphics rendering programs takes the normal directions of the object surfaces into account when calculating the angle between the object the light s in the scene and the viewer s eye point the camera in the scene In the real world different materials react to incident light differently For example many metals scatter light causing the specular reflection to be more spread out than it is on shiny plastic surfaces The specular highlight is the highlight many types of cloth and other dull surfaces have no specular brightest spot on a shiny surface Think of how the sun sometimes bounces off the hood of your car at just the right angle and makes a bright sharp reflection By adjusting the specular and shininess inputs to the Shade module you can make your object appear more metallic or more plastic lf you turn the specular value all the way to 0 0 you eliminate the specular reflection This can be important if you are trying to make sense of color mapped data since the specular highlight will be a bright white area on the surface of the object assuming the incident light color is white This white spot or area could confuse a viewer who is trying to interpret the color mapping of the data Two other inputs in the Shade module diffuse and ambient are also used by Data Explorer when it l
386. omponent using the Compute module for example and Rubbersheet will then use the modified normals to control the direction of projection of the surface or line After performing the Rubbersheet projection you may want to insert another Normals module This will take the projected object and generate real surface normals before rendering resulting in better looking shading on you projected surface See RubberSheet on page 277 in IBM Visualization Data Explorer User s Reference for a full description Isosurface will also generate normals automatically to do so lsosurface either calculates or reads the previously calculated Field gradient depending on the setting of the gradient input flag Therefore the normals generated by Isosurface are not necessarily perpendicular to the connection elements generated by the Isosurface module but better indicate the actual Field direction than simple perpendicular normals If you wish to understand Normals better you can use the Glyph module to visualize them First use Mark to mark the normals component This makes Data Explorer treat the normals component as if it were the data component Then Glyph the Field Finally Unmark the normals to restore the previous data component to its proper place By showing the normals as vector glyphs in conjunction with a surface you should be able to see how different modules like Rubbersheet and Isosurface deal with these vectors Normals are al
387. on the Find button This will initiate the search for the first occurrence of the tool icon on the canvas When the tool is found the portion of the canvas that is displayed may be updated to include the located tool icon Note The located tool icon is selected IBM Visualization Data Explorer User s Guide If you wish to find another occurrence of the same tool simply click on Find again This can be repeated as many time as you desire When no more occurrences of the tool can be found a message is displayed If you click on the Find button again the search will be reset and the first occurrence of the tool icon will be located If the selected tool is a transmitter receiver probe or pick occurrences of the tool will be found independently of the user supplied name To locate a transmitter receiver probe or pick tool by name 1 Enter the name of the transmitter receiver pick or probe in the Selection text field 2 Click on the Find button You can initiate the search for a different tool at any point If you wish to retrace your steps the Find dialog provides an Undo button allowing you to undo up to 10 previous searches When you click on the Undo pushbutton the name of the tool or transmitter or receiver that was previously located will appear in the Selection text field and the canvas is updated to reflect the location of the tool icon The dialog box also provides a Redo button This enables you to repeat a search
388. ong each axis The number of positions along each axis is determined from the shape of variable 1 Positions that can be specified as the product of arrays containing the location of points along each axis can be input in product form Use the following attribute variablel positions variable2a product variable2b product variable2x product where the variable2s are each the name of an array containing a list of positions along that axis The number of items in each array must match the length of the corresponding axis in the original variable1 data array If any of the axes in an partially regular product array are actually regular they can be specified in compact form variablel positions variable2a product compact variable2b product variable2x product where variable2a is the name of an origin delta array and the rest are position lists as before Appendix B Importing Data File Formats 283 ms mall o D ms o ms 3 y cr tn Series Data Connections If the connections between positions is a regular lattice no additional attributes are necessary For 1 D data connections of lines is assumed 2 D data implies quads 3 D data implies cubes and for higher dimensions hypercubes is assumed If the connections are irregular use one of the following attributes e variablel connections variable3 tetrahedra e variablel connections variable3 triangles e variablel connec
389. onment variable or an input parameter See Headlmage on page 250 in BM Visualization Data Explorer User s Reference for more information Transmitters and Receivers Version 3 1 4 prevents Transmitter and Output nodes and Receiver and Input nodes from sharing names These name collisions were permitted in earlier versions and could lead to incorrect behavior Now colliding nodes will be renamed automatically and you will be notified Save Image from Image Window By default Savelmage in PostScript format will now nearly fill the page and will automatically choose portrait or landscape orientation Writelmage and Image A gamma correction factor of 2 is applied to all images when they are written out This can be changed if desired by using the format parameter of Writelmage or the Savelmage dialog of the Image tool Previously images were not gamma corrected when saved DXSHMEM environment variable In versions of Data Explorer prior to 3 1 4 DXSHMEM if set to anything would force shared memory to be used In version 3 1 4 DXSHMEM must be set to anything other than 1 for shared memory to be used if New Features in Data Explorer Version 3 1 4 xxxiii set to 1 then the data segment will be extended for architectures for which this is permissible HTML Documentation For the HTML version of the complete Data Explorer documentation point your web browser at DXROOT html index htm Fixes Creating an outboard module on
390. onnect input and output tabs 1 Select the Transmitter tool which appears under the Special category in the tool palette and place it near the output tab 2 Connect the tool s output tab to the input tab of the Transmitter 3 Select the Receiver tool also in the Special category and place it near the input tab to be connected to the output tab above 4 Connect the Receiver s output tab to the receiving tool icon s input tab The Receiver automatically assumes the same name as the Transmitter There can be multiple instances of a Receiver corresponding to a single Transmitter These Receivers assume the same name until a new Transmitter is selected The name of a Transmitter and Receiver can be changed using the notation field of the Configuration dialog box as described in Entering Values in a Configuration Dialog Box on page 107 When you change the name of the Transmitter all Receivers that share a name with that Transmitter also change their names However when you change the name of a particular Receiver the associated Transmitter and the other Receivers are not affected Adding and Removing Input and Output Tabs 106 Most of the tools have a fixed number of inputs and outputs but some such as Collect and Compute allow the number of inputs to vary For example the default number of inputs for Compute is two but you may want to use the output from an expression that has six inputs Data Explorer lets you change such t
391. ool or feature of Data Explorers graphical user interface After you select this option and the cursor has changed to a question mark click on the item you want help with For example try clicking on a particular module in the VPE window or on an interactor in a Control Panel Note You can also position the mouse cursor over an object and press the F1 key to select an object in any window including the options in a pull down menu and icons on a VPE canvas Overview of Window gives an introductory description of the window from which this option was requested Table of Contents presents a list of the main topics and subtopics of the Data Explorer user manuals Select the desired item by clicking on its box once Using Help explains how to use the online facility itself Product Information gives the version of Data Explorer that is currently running Technical Support gives information on how to get technical support Tutorial presents a list of tutorial topics which can be accessed directly Application Comment presents a comment on the currently loaded visual program if one was supplied by the user who created the program Figure 32 on page 66 depicts a sample Help window Chapter 5 Graphical User Interface Basics 65 Figure 32 Sample Help Window In addition an HTML version of the documentation is available Point your browser at usr lpp dx html index htm For Future Reference e In the Help wind
392. ools to accommodate the extra inputs IBM Visualization Data Explorer User s Guide To add input tabs to a tool on the canvas 1 Select the tool icon by clicking on it 2 Select the Add Input Tab option from the Input Output Tabs option from the Edit pull down menu You can also use the Ctr1 A accelerator key Note If the tool you selected has a fixed number of inputs the Add Input Tab option is grayed out The appropriate number of input tabs are added to the tool icon Typically the Add Input Tab option adds one tab to the icon In the case of some tools such as CollectNamed that require inputs in pairs two input tabs are added To add multiple tabs repeat the previous steps When you change the number of input tabs on the tool icon the tool s Configuration dialog box is updated to reflect the change To remove input tabs from a tool on the canvas 1 Select the tool by clicking on it 2 Select the Remove Input Tab option from the Input Output Tabs option from the Edit pull down menu You can also use the Ctr1 R accelerator key Note If the tool you selected has a fixed number of inputs or if the icon has only the minimum number of tabs required for that tool the Remove Input Tab option is grayed out The appropriate number of input tabs are removed from the right side tool icon If the tabs that are removed previously had connections to them those connections are broken It is possible for some tools to have ze
393. ops and Edges with a Hole 263 94 Example of a Surface Using Faces Edges and Loops 266 X IBM Visualization Data Explorer User s Guide Tables ee ilu Mr ou quce o O Copyright IBM Corp 1991 1997 Standard Field Components Component attributes Object attributes Look Option MEN eo isso dia de AA RR Data Explorer Command Line Options Command Line Options for Developers Resource Configuration Table roman_ext Font Characters Part 1 roman_ext Font Characters Part 2 Additional Symbols 1001 10B5 European National Language Symbols and Characters 1200 to 1255 Summary of Data Explorer Accelerator Keys xi Xli IBM Visualization Data Explorer Users Guide Notices Products Programs and Services 2l lll Trademarks and Service Marks 0 200000000 eee CODVAGHENOGHCES 2544 4 62824644808 etaed D soho o SE d Copyright IBM Corp 1991 1997 xiii Products Programs and Services References in this publication to IBM products programs or services do not imply that IBM intends to make these available in all countries in which it operates Any reference to an IBM product program or service is not intended to state or imply that only IBM s product program or service may be used Any functionally equivalent product program or service that does not infringe any of IBM s intellectual property rights may be used inst
394. or on Figure 72 Selector Interactor Radio button Style Setting Selector and SelectorList Interactor Attributes on page 136 describes how to configure the selector interactor for your visual program and also describes its various uses FileSelector Interactor The FileSelector interactor can be used to select a file from within the file system Figure 73 on page 147 146 IBM Visualization Data Explorer User s Guide Control Panel 4 J File Edit Execute Panels Options Help FileSelector NULI Eq Figure 73 FileSelector Interactor The interactor consists of a text field containing a string and a button labelled with an ellipses Clicking on the button causes a file selection dialog box to be opened The file selection dialog box illustrated in Figure 74 on page 148 functions in a similar manner to other file selection dialog boxes for a description on how to use file selection dialog boxes see Saving and Restoring a Visual Program on page 115 with the exception of the buttons at the bottom of the dialog box OK causes the file name in the Selection area to be set in the text field of the FileSelector interactor and closes the file selection dialog box Filter applies the filter string specified in the Filter area Close closes the file selection dialog box without any modification to the FileSelector interactor text field Apply causes the file name in the Selection area to be set in the text field
395. or is connected to more than one input its default name is the name of the interactor stand in You can change the default name by doing the following 1 Click on the Set Interactor Label option on the Control Panel Edit menu 2 Enter a new name in the dialog box that appears Figure 63 Imm M Set Interactor label Interactor Label Scalar OK Figure 63 Set Interactor Label Dialog Box Chapter 7 Graphical User Interface Control Panels Interactors and Macros 137 e e El A o E cr m o m ma o E D l un The new name can contain any number of characters including any letter number symbol or space that you find on the keyboard If you want a blank label enter O for the name The interactor label can have multiple lines type n where you want a line to break For example First Line nSecond Line Setting Toggle and Reset Attributes You can set the output of Toggle and Reset interactors for both their button down set and button up unset states The output value can be string integer scalar or vector and the set and unset outputs do not have to be of the same type Control Panels as Dialog Boxes It is possible to customize Control Panels so that they appear as dialog boxes This is intended for building applications to be used in image or menubar mode i e with the Image window or menu bar as the anchor window The appearance of the dialog box
396. or the viewer to see any change You may need to double record each image i e slowing things down by one half making the video take 6 seconds Another way more computationally expensive is to generate twice as many raw data files and twice as many images This will yield smoother animation but may be too costly for your resources Of course some events can be shown in 3 seconds maybe everything stays the same for 1 5 seconds then oops into a new configuration Slowing this down too much might hide the importance of the sudden transition to a new state Again you the user familiar with the field and with the phenomenon become a judge and a designer You have to make wise decisions based on a desire to accurately and honestly depict the behavior under study with the purpose of illuminating other viewers not impressing them with spectacular computer graphics displays IBM Visualization Data Explorer User s Guide Appendix B Importing Data File Formats B 1 General Array Importer Keyword Information from Data Files 242 B 2 Data Explorer Native Files 244 Overview of the Native File Format 0 244 EXAMPIOS sit ad awe eke oe A e A RC E d 246 Syntax of the Native File Format 268 Sua c r 269 Group ODJe6IS 2 04 2 xS Sib mon SAS S E mde 9 Bie c Sawa eg 270 Senes OBEC gs midis de qr re e oy US Ue ee ees we 271 Multigrid Objects o
397. ormat to be used in the Print Image dialog box available in the Image window The following values are recognized PSCOLOR PSGREY EPSCOLOR EPSGREY RGB R G B TIFF DX saveImagePageSize Color PostScript Gray level PostScript Encapsulated Color PostScript Encapsulated Gray level PostScript rgb format r g b format TIFF format Specifies the default page size that PostScript images should be 304 IBM Visualization Data Explorer User s Guide centered on when saving images from the Save Image dialog box available from the Image window Units are those indicated by the metric option DX savelImageResolution opecifies the default resolution that PostScript images should be saved with when saving images from the Save Image dialog box available from the Image window Resolution is in dots per inch unless the DX metric resource is set in which case dots per centimeter is used This resource is overridden by the savelmageSize resource If this is set to zero the default then the Save Image dialog box chooses the resolution which may be specified inside the visual program DX saveImageSize Specifies the default size of PostScript images saved from the Print Image dialog box available from the Image window If specified this option overrides the saveImageResolution option The value is a string in the same format as that accepted by the dialog box for example 8 8x x10 8x10 Units are tho
398. ors are carried in the map s data component and the data values to which each color applies in its positions component colormap editor A special tool for mapping precise colors to specified data values the results of which are displayed in a visual image compact array Any of five types of compact encoding of array data constant array mesh array path array product array regular array component A basic part of a field such as positions data or colors each component is indexed by a string e g positions and its value is typically an array object e g the list of position values See also component attribute component attribute A characteristic of a component Components of a field can have attributes that are indexed by a string name and have a value that is an object composite field A grouping of like fields for processing a single spatial entity See also partitioned field connection Component of an IBM Data Explorer data field that specifies how a set of points are joined together Also controls interpolation connection dependent data Cell centered data The data value is interpreted as constant throughout the connection element contour On a surface a line that connects points having the same data value e g pressure depth temperature control panel An IBM Data Explorer window that facilitates setting and changing the parameters of visual programs cube A v
399. ors in a New Control Panel 130 Adding Interactors to an Existing Control Panel 130 Selecting Moving and Deleting Interactors 131 Changing the Size of an Interactor 2 132 Locating Interactor Stand ins oll 132 Deleting Control Panels llle 132 Saving and Restoring Control Panels lll 132 Customizing a Control Panel ll 133 Control Panels as Dialog Boxes 00 138 Control Panel Access Groups and Hierarchies 138 Creating Modifying and Deleting Control Panel Groups 139 Restricting Control Panel Access 0 2 140 Specifying a Startup Control Panel 141 Opening Existing Control Panels 2 00 141 Using Interactors 00 ores 142 Using Data Driven Interactors lll 147 7 2 Creating and Using Macros llle 149 Creating MACIOS crisis GUESS SABERES CAES 149 Loading MACIOS ama pm eR eae ed ae eb E ED BRE E OS DS Sa d 152 Using Macros in a Visual Program 153 Viewing and Changing Macros llle 154 e c A o E cr o m ma o E D l tn O Copyright IBM Corp 1991 1997 127 7 1 Using Control Panels and Interactors 128 As you create a visual program you may have inputs whose values are subject to
400. ortant to be aware of the technical limitations of standard analog television especially as it differs from workstation monitors The two biggest problems encountered in moving images created on a high resolution workstation to a consumer television monitor or VCR are the loss of resolution and the inability of consumer TV to accurately render color These remarks are basically true for both the American NTSC TV system and the European PAL system This is not meant to be a technical description of either system TV Line Resolution 236 Resolution losses are most evident if you use single width lines Workstations have both a higher number of vertical and horizontal lines on the screen and a much higher refresh rate than consumer TV However on TV the alternating lines odd numbered even numbered are refreshed or painted on the monitor at slightly different times As long as the scene contains objects that span more than one of these lines our eye brain system is fooled into believing that the entire object is always present due to the phenomenon of persistence of vision But when you use single line width horizontal lines the lines will visibly flash clearly showing that they are being drawn only half of the time Related to this problem is the condition in which you rotate a grid of single width lines slightly away from horizontal This will generate an optical effect called a moire pattern in which curved lines appear whe
401. ortional to the number of samples of original data that occur in the range covered by that bar You can feed the output of Histogram through AutoColor then Plot to get a colored plot of the data distribution If the aspect ratio of the Plot is distorted you can correct it in the Plot module This will stretch the Plot out in either the X or the Y direction until you achieve the look you want Visual designers recommend an aspect ratio of approximately 4 units wide to 3 units high since this is also the aspect ratio of television your image will be ready both for video and for print Be aware that binning your data with Histogram can sometimes create rather arbitrary distributions It is important to make this clear to the viewer of your visualization For example by carefully selecting bin size you may turn a unimodal distribution into a bimodal one Which distribution is correct for the phenomenon under study must be determined by the underlying science not by the arbitrary picture you create On the other hand if you wish to actually redistribute your data rather than just show a histogram of its distribution you can use the Equalize module The output of this module is essentially the same scalar Field you fed into it but the data values have been changed to fit the specified distribution By default the data values are changed to approximate a uniform distribution but you can create your own custom distribution like a normal Gaussia
402. ose ASCII codes for which there is no representation should be empty fields object empty class field A space character can be generated by making an empty field with a positive width object wide class field attribute char width number 0 3 object myfont class group member 32 value wide Overstrike characters can be generated by making a field with a zero or negative width object umlaut class field component connections value conl component positions value pos1 component char width number 0 0 The following fonts are supplied with Data Explorer and may be found in this directory usr lpp dx fonts Each one is a Data Explorer format file If you would like to look at the structure of a font file simply Import the data using the Import module and Export it in text format default fonts an area font same as pitman a fixed width font same as roman sfix a variable width font same as roman s cyrilic font a cyrilic double line font Gothic fonts gothiceng t an English gothic triple line font gothicger t a German gothic triple line font gothicit t an Italian gothic triple line font Greek fonts a Greek single line font a Greek double line font italic fonts an italic double line font an italic triple line font font National Language characters 308 IBM Visualization Data Explorer User s Guide roman ext an extended character set Roman single line sans seri
403. osurface or even another data field s computational mesh The Compute module can perform arithmetic or trigonometric operations point by point not only on your data but also on the grid itself Thus warping a grid for example is a simple matter of entering an expression Even standard tools such as Isosurface operate on multiple types of input grids For example if the input field to lsosurface is 2 dimensional the module automatically creates contour lines The Data Explorer renderer can handle opaque or translucent surfaces translucent volumes and opaque or translucent lines or points all in the same image In addition data on different computational or observational grids can be visualized together allowing you to correlate disparate data fields without requiring you to force the data onto the same grid The power and interoperability of the modules is possible because of the underlying data model which is capable of describing a wide variety of types of input data Because the data itself is self describing modules can be flexible in the types of data they accept and can perform their actions appropriately based on their input IBM Visualization Data Explorer User s Guide 1 2 System Structure Data Explorer is designed as a client server model The Data Explorer client server architecture incorporates system components such as TCP IP sockets X Window System and Motif e lt D m lt mall o In this cli
404. ot accurately assess detail at a resolution equal to or less than your sampling rate the Nyquist law states that you cannot derive valid signal from noisy information at less than twice your sample rate For example occasionally you will see peculiar color artifacts that arise when data and therefore interpolated colors change rapidly at the scale of the sampling mesh In those cases the best bet is to zoom out to see only the big picture do not try to read between the lines Related to sampling rate in space is sampling in time Be sure you have collected enough time step detail to ensure you have not completely missed some important transitional state that might have occurred in the middle of an animated sequence It is acceptable to skip through the entire range of time steps during the development of your animation but be sure to fill in the gaps before the final presentation is analyzed As in traditional statistical plotting a computer can all too easily permit the author to scale objects or graphs into wildly distorted aspects In charting there are some simple rules of thumb it is often suggested that the aspect ratio height width be about 0 75 to 1 00 for a 2 dimensional chart This may require rescaling one axis and naturally both axes and their scales must be shown t is also bad form to start an axis at one point then create a break part way along causing a visual foreshortening And it is also inappropriate to start an a
405. our actions Or you can specify precise values for the camera settings as described in Precise Camera Settings on page 82 You control your view of the object by selecting one of the control modes Each mode allows you to control different aspects of your view When you select this option the View Control dialog box appears The basic configuration of this dialog box is illustrated in Figure 35 on page 75 IBM Visualization Data Explorer User s Guide View Control iindo Cine Medo Girib p Mode Mone Set View None cual Projection Orthographic View Angle d 30 000 fm Close Reset Ctrl F Figure 35 View Control Dialog Box Depending on the view mode selected the appearance of the dialog box changes automatically adding controls particular to the current mode Accelerator keys are associated with many of the modes so that it is not even necessary to open the View Control dialog box to access these view control modes Figure 36 lists the modes with their respective accelerator keys Camera Ctrl K Cursors Ctrl X Pick Ctrl l Navigate Pan Zoom Roam Rotate Zoom Figure 36 View Control Modes with Accelerator Keys You can change your view of the image by e Changing your viewing direction e Changing the projection method e Rotating the object Rotate mode e Zooming in or out of the image Zoom mode e Changing the look to point the center of the image Roam mode e Panning and
406. ow to enter and modify text in a text field see Editing Text Fields on page 64 It enables you to enter strings by typing directly into the text field then pressing the Enter key ee SSS Control Panel Figure 70 String Interactor Value Interactor The value stand in has one style of interactor that cannot be changed This interactor consists of a text field For information on how to enter and modify text in a text field see Editing Text Fields on page 64 This interactor enables you to enter scalars vectors and lists by typing directly into the text field and pressing the Enter key The input into the text field must either begin with a numeric value or be enclosed by brackets for vectors See Vectors Matrices and Tensors on page 195 and Lists on page 196 for more information on the syntax of vectors and lists Vector Interactor The vector stand in has two styles of interactor a stepper style and a text style The Vector interactor works like one two or three Steppers stacked in a column With it you can specify the components of a vector e g x y and z from top to bottom See Stepper on page 142 for detailed information on the operation of a Stepper You can also change the dimensionality of the interactor using the Edit menu Set Dimensionality option The text style vector interactor is similar to that of the value interactor 144 IBM Visualization Data Explorer User s Gu
407. ow you can directly access any topic subtopic subsubtopic or related item that is boxed simply by clicking on the box e f the amount of information exceeds the length of the displayed Help window use the vertical scroll bar on the right side of the window e To return to a topic you have viewed during the current session of visual program move the mouse cursor into the Help window and press the right hand button A list of viewed Help topics appears Keeping the mouse button depressed move the cursor to the desired topic in the list and then release the button e To return to the previous Help topic click on Go Back at the bottom of the Help window e To exit online Help click on Close at the bottom of the Help window 66 IBM Visualization Data Explorer Users Guide User Defined Help Files Visual programmers can create online documentation for their visual programs and Control Panels A user can access the comments for the visual program from any primary window and can access the comments for a Control Panel from the Control Panel with which the comments are associated For information on how to add this documentation to your own visual program see Adding Comments to a Visual Program on page 114 and Customizing a Control Panel on page 133 To access comments for the visual program select the Application Comment option from the Help pull down menu A dialog box opens with the comments Note If there are no comments assoc
408. ows you to select the rendering mode with a toggle button lf you select hardware this means use hardware if available at the time Data Explorer is run If a graphics card which supports hardware rendering is not available software rendering will be used instead You can specify the approximation method that Data Explorer uses for each of two execution states button up execution and button down execution Button down execution is applicable in execute on change mode and in navigation For example you might specify None for the approximation method for button up execution and Dots for the approximation method for button down execution When holding the mouse button down in Rotate mode with Execute on Change enabled these rendering methods display a dot representation of the object giving you quick feedback on your camera position until you release the mouse button at which point the object is rendered normally The following is a brief description of the rendering methods you can specify with this dialog box For detailed information about the rendering options see Display on page 109 in BM Visualization Data Explorer User s Reference None No approximation method is specified so a complete rendering of the image is done Chapter 6 Graphical User Interface Important Windows 91 92 e Rendering Rendering Mode gt Software y Hardware Button Up Approximation None Render Every Bu
409. pace IBM Visualization Data Explorer User s Guide Alternatively you can force Data Explorer to extend the data segment if allowed for the architecture by setting DXSHMEM to 1 Note Regardless of the setting of DXSHMEM the aviion and sun4 architectures always use the data segment DXSHMEMSEGMAX Some architectures have a default configuration which limits the size of shared memory segments see the architecture specific README file in usr lpp dx and the system configuration must be changed as root to increase the maximum allowed size of a shared memory segment If the maximum is not reset or if it is already set to a different limit then you can use DXSHMEMSEGMAX to tell Data Explorer what the current limit is in megabytes e g 128 128 MB Data Explorer will allocate multiple shared memory segments if necessary to get the total amount of space but it must be able to allocate them at contiguous virtual memory addresses DXTRIALKEY can be used in place of the expiration file SDXROOT expiration for a trial license The value of the variable is the string specifying the trial key It takes precedence over DXROOT expiration and DXTRIALKEYFILE DXTRIALKEYFILE specifies the name of the expiration file for a trial license It takes precedence over DXROOT expiration DX USER INTERACTOR FILE Specifies a file containing user interactors for use by the SuperviseState and SuperviseWindow modules see SuperviseState on page 332 and
410. patibilities with previous versions of Data Explorer AutoAxes No longer scales the object to be smaller This means that you may need to zoom out a bit in order to see all of the axes labels DXLink Because of the new startup behavior see New Startup Behavior on page xxviii DXLink programs may need to add edit or image to the startup command string Get and Set Have been replaced by GetGlobal GetLocal SetGlobal and SetLocal See Changes to Get and Set modules on page xxix Plot There is a backward incompatibility with regard to the aspect parameter of Plot This parameter now defaults to 1 0 meaning that the ratio of the y to x axis length will be made equal to one Previously no scaling was automatically done if aspect was not set The previous default behavior can be obtained by specifying aspect as inherent Readlmage The Readlmage module now will store all images read in as three bytes rather than than three floating point numbers This will only affect visual programs in which the colors themselves are expected to be floats This default behavior can be overridden either with an environment variable or an input parameter In addition images which are stored in a format such that the colors are specified as lookups into a table will be read in as delayed colors Some modules may not perform properly on delayed colors images This default behavior may also be overridden with either an envir
411. plicitly partitioning Fields into abutting spatially disjoint primitive Fields Positions on the boundaries must be replicated identically Like Multigrid Groups all members must have the same type of data and the same type of connections Series Groups Series of various types such as time series are stored in a subclass of Group called a Series Object A Series Object is the same as a generic Group in most respects except that it associates a series value such as a time stamp with each member Members are stored in and retrieved from a Series Group by index Members cannot be retrieved by series value Fields in a Series Group must all have the same data type and connection element type Figure 17 shows an example of a Series Group where the three members have series positions of 1 2 2 7 and 8 4 respectively Figure 17 Example of a Series Group Chapter 3 Understanding the Data Model 35 e y ct y o O D 36 IBM Visualization Data Explorer User s Guide Chapter 4 Data Explorer Execution Model d Bata Fo 24 4426 Se dme Gu cd e dE cR de 38 4 2 Iterative Execution and Caching of Intermediate Results 40 4 3 Conditional Execution Route and Switch Ls 41 4 4 Iteration using the Sequencer 2 0 200004 43 4 5 Iteration using Looping llle 44 4 6 Preserving Explicit State llle 45 4 7 Advanced Looping Constructs ll
412. plorer User s Guide DX noConf i rmedQuit Turns off the Are you sure you want to quit Data Explorer message DX noCMapOpenMap Removes the Open menu command from the Colormap Editors File menu DX noCMapSaveMap Removes the Save As menu command from the Colormap Editor s File menu DX noCMapSetNameOpt ion Hemoves the Set Colormap Name menu command from the Colormap Editors Options menu DX noDXHelp Removes the On Context On Manual and On Help menu commands from the Help menu of both the Control Panel and the Image window DX noEditorAccess Removes 1 the Delete Show Selected Interactor Add Selected Interactor Show Selected Tool and Comment menu commands from the Control Panels Edit menu 2 the Open Visual Program Editor menu commands from the Image window s Windows menu DX noEditorOnError Turns off default behavior of popping up the VPE when an error occurs Instead a question dialog box is popped up with the name of the visual program which lets the user choose whether or not to open the VPE on the net file DX noImageLoad Removes the Load Macro and Load Module Definition s menu commands from the Image window s File menu DX noImageMenus Hemoves the bar from all Image and Display windows DX noImagePrinting Removes the Print Image menu command from the Image window s File menu DX noImageRWNetFile Appendix D User Interface Configuration 301 c s Cc o E h mall o Q
413. plorer allows you to choose whether a Control Panel opens automatically when you start the system with the Image window or menu bar as the anchor using the image or menubar option Using this option you can have the appropriate Control Panels be immediately available to a user running your visual program The Startup Control Panel option in the Options pull down menu is a toggle button and is toggled on by default If you do not want a particular Control Panel to open automatically toggle the option off by clicking on it in that Control Panel The automatic startup feature can be suppressed by using the suppress startup flag when you run Data Explorer See C 2 Command Line Options on page 295 for more information Opening Existing Control Panels You can open existing Control Panels associated with a visual program in the following ways e Select the Open All Control Panels option from the Windows menu in the VPE or Image window or from the Panels menu in an already open Control Panel e Select the Open Control Panel by Name option from the Windows menu in the VPE or Image window or from the Panels menu in an already open Control Panel From the list of Control Panel names click on the one you want to open If there are no accessible Control Panels no names are displayed e c A o E cr o m ma o E D l tn e Double click on the interactor stand in in the VPE whose Control Panel you want to open All Con
414. ponds to one of the function s input formal parameters Value is one of the types of values that are valid for that argument to the function If the function is a macro the arguments are named in the definition of the macro in the script If the function is a module the argument names are provided in the description of the module in Chapter 2 Functional Modules on page 15 in BM Visualization Data Explorer User s Reference Notes 1 Positional arguments can be supplied only prior to by name arguments because the positional context is lost once a name has been supplied 2 If an argument is supplied both by position and by name then the value given by name takes precedence 3 If an argument is supplied by name more than once in a given function call then the value associated with the last rightmost instance of the input formal parameter is used 4 A name that does not correspond to one of the function s formal parameters and its associated values is considered a semantic error Missing Arguments Any formal parameter of a module that has not had a value passed to it either by position or by name is initialized to the value NULL If NULL is explicitly passed into the module the module may still use the default value provided it is designed to do so he NULL value allows modules to use internal defaults for those values that are not specified in a function call The default value must be specified in the code of the module see
415. program it causes the execution of all modules in the visual program containing the looping tool ForEachN ForEachMember or Done subject to optimization For this reason it is strongly suggested that looping modules NOT be placed in the top level visual program but rather be used only within macros If used within a macro the macro will not output any values until the loop is complete when the ForEachN or ForEachMember list is exhausted or when the Done module causes an exit If a loop occurs inside a macro and you reexecute a visual program calling this macro the loop will not be reexecuted as long as the result of the macro remains in the cache However the presence of a side effect module such as Writelmage or Print inside of a loop will cause the loop to be reexecuted regardless of whether the output of the macro remains in the cache If this is not the desired behavior Route can be used to turn off the entire macro rm X D ie cr mall o le gt o O D For efficiency you might find it desirable to set the caching option to Last Result for modules within the loop In this way multiple intermediate values within a loop will not use up valuable cache space Note that the full execution of a loop is considered to occur within a single execution of the graph as would occur if you select Execute Once from the Execute menu Thus if you change any interactor values DURING the execution of the loop those inte
416. pt g Import FacesLoopsEdges dx c AutoCamera g colored AutoColor g Display colored c The data file is given below and the resulting connections are illustrated in Figure 92 on page 263 The data file can be found in usr Tpp dx samples data FacesLoopsEdges dx Example of faces loops and edges components This example has no holes Positions array These are a list of all the vertices of the object no particular order is required here object position list class array type float rank 1 shape 2 items 11 data follows 0 133985 0 812452 point number 0 0 375019 0 896258 point number 1 0 532733 0 76484 point number 2 0 523806 0 404777 point number 3 0 300626 0 327407 point number 4 0 145888 0 508927 point number 5 0 68152 0 851137 point number 6 0 815428 0 758889 point number 7 0 94636 0 592248 point number 8 0 729132 0 416679 point number 9 0 535709 0 190524 point number 10 Edges array This is a list of connected points by point number All the edges associated with a particular face need to be listed together If points 10 3 and 7 make a triangle the list is 10 3 7 and the 10 is not repeated Note that below for readability the connected points for each loop are shown together However line breaks are not significant to the importer and all of the following numbers could have been on the same line or one to a line with the same result object edge l
417. pyright IBM Corp 1991 1997 299 Table 7 Page 2 of 2 Resource Configuration Table Resource Name Command Line Option if available DX printimageCommand N A Ipr DX printlmageFormat N A PSCOLOR DX printlmagePageSize N A NULL DX printlmageResolution N A m s DX printlmageSize N A NULL DX restrictionLevel restrictionlevel NULL DX savelmageFormat N A String PSCOLOR DX savelmagePageSize N A DX savelmageResolution N A DX savelmageSize N A DX vpeCanvas line Thickness N A DX warningEnabled N A DX errorEnabl ed Specifies the default value of the Error Messages toggle button in the Message window s Option menu DX errorOpensMessage opecifies whether or not the Message window pops up when an error message is printed in the Message window DX infoEnabled Specifies the default value of the Information Messages toggle button in the Message window s Option menu DX info0pensMessage Specifies whether or not the Message window pops up when an informational message is printed in the Message window DX 1imitImage0ptions Removes the Image Depth Throttle Change Image Name and Panel Access menu commands from the Image window s Options menu DX metric Specifies that Data Explorer use the metric system centimeters when set to true The default is the English system inches The Print Image and Save Image dialog boxes option menus are affected accordingly 300 IBM Visualization Data Ex
418. r instance In any case you must define a set of connections before you can perform interpolation operations between sampled data values This is true both for position dependent data and for connection dependent data Once again positions are discrete points in space and connections are logical paths between those points representing reasonable interpolation paths between the sampled data values f you do not have connection information available you can use the Connect or Regrid modules to create connections for scattered point data If you work with regular grids the connections can be defined in a simple way by Data Explorer regardless of the import format you are using See Chapter 3 Chapter 2 Introduction to Visualization 11 Invalid Data Fields Understanding the Data Model on page 15 in this Guide and Chapter 5 Importing Data on page 61 in BM Visualization Data Explorer QuickStart Guide If your work requires irregular grids you will need to carefully read the section of this manual that describes the format of Data Explorer element types You may need to write a filter program to convert the connection list output from your finite element program to the format required by Data Explorer before you can import and visualize data sampled on arbitrary structures Sometimes in the process of collecting or analyzing data certain regions or positions have no data value associated with them For example an instrument may h
419. r integer is called a scalar If the wind velocity and direction at say the center of each grid square is also measured the botanist would record a vector 8 IBM Visualization Data Explorer Users Guide quantity as a second datum sampled at the same place A vector encodes both direction and magnitude with two or more numeric vector components In this example the locations of the corners of each grid marker are recorded as an array of 2 dimensional coordinates that define the sampling area dimensions and the sampling resolution In computer graphics terms these spatial location points are called vertices singular vertex in Data Explorer they are referred to as positions Loosely everyone calls them points lt mall o tn o mall o N o cr mall o o E Four coordinate positions can be connected by a quadrilateral to define a grid element The quadrilateral itself is called a connection in Data Explorer we will discuss other connection types in a moment Since the botanist collected one set of data per grid element such data are termed connection dependent data This implies that the data value is assumed by Data Explorer to be constant within that element Consider another technique for data sampling on a larger scale remote sensing satellites can resolve various features of the Earth down to some finite level of resolution In this case the grid positions are identified by a latitude longitude coordin
420. r key or click on the Delete option of the Edit menu Specifying Values for a Tool s Inputs To provide the values of a given input for a tool use one of these methods e Connect the output tab of another tool to the desired input tab e or e Use the tool s Configuration dialog box When you specify an input value for a tool the corresponding tab on the tool s icon automatically folds in If you do not specify an input value the input tab remains folded out indicating that the input is unbound and the tool uses its default for that input The default values are given in the Configuration dialog box The tabs that are folded in give you a visual representation of the inputs that have user specified values Some tabs require an input those tabs remain highlighted in a different color until you specify an input with a connection or through a Configuration dialog box Some of the tabs are not displayed termed hidden The hidden tabs can be Chapter 6 Graphical User Interface Important Windows 103 revealed or additional tabs can be hidden see Revealing and Hiding Input Tabs on page 110 Also some tools allow you to add or remove input tabs see Adding and Removing Input and Output Tabs on page 106 Figure 49 on page 104 illustrates tools whose inputs have been specified Visual Program Editor ds File Edit Execute Windows Connection Categories Display Figure 49 How Tabs Work An input tab folds in when its inpu
421. r paths continue Chapter 5 Graphical User Interface Basics 71 12 IBM Visualization Data Explorer User s Guide Chapter 6 Graphical User Interface Important Windows 6 1 Using the Image Window 74 Controlling the Image View Control 74 Undo Redo and Reset 2 a 87 AULOAXGSs ms do ee m EUR ERO RSS pup 3e Ee RR YA eR RRS SE 88 Ser Background Colon x33 do ben E eoe eed eek eee ees 89 Display Rotation Globe 0 0000 00000000008 91 Rendering Options ce 91 mage Depi race of med uero cedros ede demde t ede ke MIR de d 93 Changing the Rate of Frame Display Throttle 93 Changing the Title of an Image Window 93 Control Panel Access 0 00000 a e a a en e d 94 Saving an IMAGE a sa aopa h pa add EE ES 24494 aa ES 94 Prinung an Mage ua e GS des on dod a tod e m oae ard dear d 97 6 2 Using the VPE 4 4 ci5e 24 4 48444059446 8445542446 99 Creating a Visual Program 2er 100 Specifying Values for a Tool s Inputs lll 103 Creating Deleting and Moving Tab Connections 104 Moving and Copying Tools a 105 Using Transmitters and Receivers 106 Adding and Removing Input and Output Tabs 106 Entering Values in a Configuration Dialog Box 107 Revealing and Hiding Input Tabs
422. r perspective rendering 77 animation 68 217 237 arithmetic expressions in scripting language 197 Array items category 28 rank 28 shape 28 type 28 Array Objects in Data Explorer file format 272 Array types 28 Arrays compact constant 33 in Data Explorer file format 244 mesh 31 path 31 product 29 regular 29 irregular 28 items in 28 assignment statements in scripting language expression assignments 199 function call assignments 199 general description 198 at variables in scripting language 192 206 207 attributes color multiplier 27 dependence dep 26 derived der 27 element type 27 opacity multiplier 27 reference ref 27 attributes function call in scripting language 202 attributes setting interactor See interactor attributes Copyright IBM Corp 1991 1997 AutoAxes 88 axes box 88 B back colors component 22 binormals component 24 box component 24 by name arguments in scripting language 201 C cache attribute 202 cache in memory use 214 cache object 214 cacheability setting output 214 Camera getting precise settings 82 resetting 85 Camera Objects in Data Explorer file format 278 category of an Array item 28 changing the look to point 79 changing the size of interactors 132 changing your view direction 76 Clipped Objects in Data Explorer file format 278 closing windows 65 color map component 23 color mapping 219 color multiplier attribute 27 Colormap Editor adding control points 122 enterin
423. ractor values will not take effect until the loop is complete This is an important way in which looping differs from using the Sequencer if you change the value of an interactor while the Sequencer is running the value will be updated on the next frame of the sequence 4 6 Preserving Explicit State Some visualization applications require the retention of state from one execution to the next which as discussed earlier cannot be supported within the context of pure data flow Consider for example the creation of a plot of data values at a given point while sequencing through a time series The state of the plot from the prior execution is retrieved It is updated by appending the new time step information and the result is then preserved by resaving the state of the plot for the next execution Data Explorer provides two sets of tools for preserving state depending on whether the state needs to be preserved over one execution of the network or over multiple executions of the network The tools for preserving state are GetLocal SetLocal GetGlobal and SetGlobal The Set tools enable you to save an object in Data Explorer s cache for access in a subsequent execution or iteration The Get tools enable you to retrieve the object saved by the Set tools You pair a GetLocal and SetLocal in a visual program by creating an arc from GetLocal s link output parameter to SetLocal s link input parameter In a visual program a GetLocal typically appears l
424. ray types are discussed in the following sections Irregular Arrays The most general way to specify the contents item values of an Array is to list the values this is called irregular data An example of such an Array Object is illustrated in Figure 8 on page 29 28 IBM Visualization Data Explorer User s Guide type float real vector 3 items n float float float e gt o 09 0 0 60 o6 0o 06 06 06 96 o6 o jw Figure 8 Example of an Irregular Array Regular Array A set of n dimensional points lying on a line in n space with a constant n dimensional delta between them represents for example one edge of a grid of regular positions Regular Arrays are frequently combined as the terms of a Product Array An example of a Regular Array is illustrated in Figure 9 This example represents in compact form the same information as the following irregular Array Lx Yo Xo Xa VYot Val LX5 2X Vo Zyl E N 1 Xp Yo n Dyal type float real vector 2 1tems n origin x y delta xy yal Figure 9 Example of a Regular Array Product Array Encodes multidimensional positional regularity lt is the set of points obtained by summing one point from each of the terms of the product in all possible combinations For example the product of a set of Regular Arrays is a regular grid whose basis vectors are the deltas of the Regular Arrays that are the terms of the product and whose origin is the su
425. re none are actually present and this frequently causes colors to appear that are not in the original signal Both of these effects can be very distracting Finally single width vertical lines will not have the same color Because of the way consumer TV color phosphors are aligned a vertical line at one location may be blue but if you move it slightly it will become red A grid with single width vertical lines will appear to change color as you translate the grid in a horizontal direction So what is the solution to all these problems Do not use single width lines ever Data Explorers Tube module is the easiest way to fix most of these problems Tube generates cylinders around any kind of field with line connections If you have created a mesh of lines with ShowConnections for example you can run this IBM Visualization Data Explorer User s Guide visual object through Tube to fatten up the lines Tube permits you to choose a diameter that looks right As long as you make the tubed lines bigger than one TV line width you will have solved the problem Be aware that single width line text or captions will become virtually illegible on TV To get better looking results using the stroke fonts originally designed for plotters you can use Tube Another technique is to use a multiple line font such as the roman d font supplied with Data Explorer The best solution is to use an area font that is made up of characters containing polygo
426. reating Modifying and Deleting Execution Groups 178 By default all tools in a visual program belong to a single unnamed execution group This group is executed on the master workstation New execution groups are created and existing execution groups are modified and deleted using the Execution Group dialog box Figure 79 on page 179 The dialog box consist of three parts IBM Visualization Data Explorer User s Guide Groups Displays the current set of execution groups A group name can be selected by clicking on the name It can be deselected by clicking on the name a second time or by clicking on another name Name A text field for specifying the name of a new execution group the name of an execution group to modify or the name of an execution group to be displayed If an execution group is selected the name of the group is displayed in the Group Name text field Pushbuttons Create causes a new execution group to be created Add To causes a set of selected tools to be added to an existing execution group Remove From causes a set of selected tools to be removed from an execution group Delete causes an existing execution group to be deleted the tools in the group are not deleted from the VPE canvas Show causes all the tools on the canvas that are members of the selected group to be selected Close causes the dialog box to be closed Execution Groups Figure 79 Execution Group Dialog Box Chapter 9 Graphical User
427. rer format 274 in the Data Model 29 remote tab connections 106 removing input tabs 106 render options 91 rendering volume 231 required inputs 103 reserved words in scripting language 192 Reset interactor 147 resetting the camera 85 resetting the server 185 resizing the image 84 restoring a camera setting 84 restoring a visual program file 115 revealing input tabs 110 roaming in the image scene 79 rotating the image 77 RubberSheet 227 runtime modules loading 183 S saving a visual program file 115 saving an image 94 scalar numeric constants in scripting language definition of 194 floating point numbers scientific notation 195 standard representation 195 integers decimal notation 194 hexadecimal numbers 194 octal numbers 194 scientific notation in scripting language 195 Screen Objects in Data Explorer file format 278 script execution model executing macro or module 208 macro expansion 208 top level environment 208 scripting language Data Explorer 188 scrollbars 101 selecting options with an options box 63 Selector interactor 136 SelectorList interactor 146 separate files for Data Explorer header and data 254 for netCDF variables 285 Sequencer frame controls 69 Index 327 Sequencer continued script commands 206 sequence controls 68 using 68 Series for Data Explorer file format 271 for netCDF file format 284 Series in the Data Model 35 server connecting to 183 resetting 185 SetGlobal preserving state 45
428. rer graphics system used to make images of that data space Given such a mapping the next step is to learn how to visualize your data in meaningful ways Data Explorer provides both a visual programming language and a text based scripting language The scripting language is described in Chapter 10 Data Explorer Scripting Language on page 187 The visual programming language uses a graphically oriented editor instead of a traditional text based editor as in C or Pascal You will be using this graphical programming environment to generate graphic images as output this distinction between graphics as program and graphics as output is subtle but we do not want to confuse the two To build a visual program you physically select place and connect functional modules these are represented graphically as labeled rectangular boxes with tabs sticking out of them Each module can be thought of as a subroutine in a text based programming system You can place multiple instances of the same module analogous to calling a subroutine several times in a program Modules have inputs and outputs those little tabs sticking out just like the arguments and return values in a text language The inputs and outputs of modules are connected together into a network which in some ways resembles a flow chart diagram Unlike a flow chart you cannot loop back a wire to an earlier input in a Data Explorer visual program Note that many modules have hidden tabs for les
429. riables c Palit Variables x xosnos Reus dede Eo B 2 46054 a d E odd E ed en Other Environment Variables len C 2 Command Line Options c Appendix D User Interface Configuration Appendix E Data Explorer Fonts Appendix F Data Explorer Colors Appendix G Accelerator Keys GISSA AMPPTTCPPTT IBM Visualization Data Explorer User s Guide Figures ee lupra ou quee eo 45 46 4T 48 49 90 O Copyright IBM Corp 1991 1997 Examples of Data Dependency 10 Example dFa BIelg ODECE vat ase Aue Yeh de o Pee eee Eo a 18 Shared Components among Different Fields 19 Order of Vertices in Triangles and Tetrahedra 21 Order of Vertices in Quads and Cuboids 21 Examples of Grid Types 2 2 rn 22 Use of Faces Loops and Edge Components 26 Example of an Irregular Array 29 Example of a Regular Array sls 29 Example of a Product Array lr 30 Product Array of Two Regular Arrays ls 31 Example of a Path Array oll 31 Example of a Mesh Array lll 32 Mesh Array of Two Path Arrays with Regular Connections 33 Example of a Constant Array
430. rious pull down menus When a visual program is running any information warnings or errors sent by the server to the user interface are shown in the display area See also Error Messages on page 71 The Message window allows users to save the contents of the text window in two different ways The Save As command of the Message window s File menu brings up a File Selection dialog box that allows the user to designate a file to which the current contents of text window are to be saved Alternatively the Log command of the File menu brings up a File Selection dialog box that allows the user to designate a file that will receive all subsequent messages displayed in the text window The Message window provides a number of techniques to help the user locate the source of errors and warnings Before each successful execution of the visual program the string Begin execution is placed in the text window This allows the user to more easily determine whether messages are the result of the most recent execution Also any line in the text window can be highlighted before execution Highlighted lines remain highlighted over executions making it easy to locate a marker indicating the beginning of execution This technique is particularly useful when a large amount of information from Print or Echo is being displayed in the Message window Alternatively the contents of the text window can be removed with the Clear option of the Message window s
431. rmat creates a formatted string of text suitable for Caption or Text modules to display Format takes a template and text strings and or numbers as value inputs and assembles an informative text string as output For example inputting the minimum value of your data to the first value input the second input tab of a Format module you could create a Caption that reads Minimum temperature 0 0 deg 218 IBM Visualization Data Explorer User s Guide To do this the template inside the Format module would read Minimum temperature 1 1f deg In this template the 1 1f serves as a place holder for the first value which must be floating point provided to Format consequently the minimum value argument is substituted into the string when the visual program is executed The 1 1 means that the floating point number should display at least one number to the left of the decimal point but should round off to only one decimal place to the right of the decimal By tying the data Field to Statistics Transformation category you can easily extract the minimum value of the data use this as the second input to Format If you later input a different data set with a different minimum Caption will automatically change to reflect the new minimum value One trick for showing text together with numbers that are changing is to use a fixed width font instead of a variable or proportional font Variable text looks better when making Cap
432. ro input tabs For example you may want the Compute module to contain only an expression with no inputs The output would be the result of the expression Entering Values in a Configuration Dialog Box The Configuration dialog box displays the current state of a tool s inputs You can modify the contents of the box directly The contents are also automatically updated when changes in the visual program or in interactors in a Control Panel affect a tool s inputs In general specifying input values using the Configuration dialog box should be reserved for those values that remain constant during a visualization session Use an interactor set in a Control Panel to specify values that are likely to be changed frequently This section describes a typical Configuration dialog box illustrated in Figure 50 on page 108 The Configuration dialog box for the Compute module which is unlike the other Configuration dialog boxes is described in Using the Compute Module Configuration Dialog Box on page 111 Chapter 6 Graphical User Interface Important Windows 107 Figure 50 Typical Configuration Dialog Box You can open a Configuration dialog box in one of the following ways e Double click on the rectangular portion of a tool s icon e Select the icon and click on the Edit menu Configuration option or use the Ctrl F accelerator key Note If the tool icon is an interactor stand in a colormap editor stand in or an image tool you must
433. rogram is run as a script You can look at the top of the net file to see which macros are referenced by the program Thus if you need to send a collection of visual programs and macros to another person this can help you to make sure you have sent all the necessary tools IBM Visualization Data Explorer User s Guide Appendix A Using Data Explorer Some Useful Hints A 1 Using Data Explorer Effectively 212 Common PrODISMS sa ps aaa ARA 212 What is the Difference Between Image and Display 212 How do get more information css 213 Memory USE 2cs44 4442 44 6408 de Themed ORO d E SEE ed 213 A 2 Visualization Techniques oll ln 217 DNUS tra a Ss a Ara a o dA SO N E EU a a 217 A TEL 218 Color Mapping ess eras SE ds eee ROAD WA SE Oe ws 219 Contours and Isosurfaces ls 221 MAPPING sas of keene e a E A q ff ud 223 Normals and Shading ss 224 J RIOIS and AISIOGFAMS mm tinae e Ime ode AEG BP dg 227 em Rubbersheet s 227 5 Transformations and Structuring aoaaa aa a 228 Vector Fields ls 229 a Volume Rendering 20 0 ee 2 nn 231 A 3 Design for Interactive Use 232 Interactors and Control Panels 232 Transmitters and Receivers ln 234 Docurmientalloh 2 toss Roms e gas ben wv Wd Wow xe 235 A 4 Design for Video Output
434. rp edge transition in your data lt is sometimes useful to place a special contrasting color in the middle of an otherwise continuous color map For example to highlight the value of 12 degrees C in our temperature data we could insert a sharply defined red notch or band into the middle of our smooth rainbow color map This would highlight that particular value or range for someone examining the scene You can automatically generate a number of control point patterns by choosing Generate Waveforms from the Edit menu in the Colormap window To make a notch IBM Visualization Data Explorer User s Guide choose one of the S shaped curves from the pop up menu in the Generate Waveforms dialog box Set the number of Steps to 4 to make a single notch or 3 to make a single step Click Apply to place control points on the currently chosen curve Hue Saturation Value or Opacity You can then drag the new control points where you like If you use a red color notch in the middle of your data range you probably will not want to use red elsewhere in your color map or it will be difficult for a viewer to tell the 12 degree specially highlighted red area from the 20 degree red maximum values assuming 20 is the maximum In fact it might be safer to use a white or gray color to mark the special value of 12 degrees Do this by creating a notch on the Saturation or Value curves instead of on the Hue curve Similarly you can change the opacity of objec
435. rrent file selection When the dialog box first appears Selection displays the current directory To change the current selection either click on the desired file in the File area or click on the Selection area and type the desired file name The next time you open the dialog box the Selection field displays the directory you most recently specified Pushbuttons 0K approves the file name in the Selection area and proceeds with the Open Save As or Load Macro operation Filter applies the filter string specified in the File Filter area Cancel closes the dialog box In the Open and Load Macro file selection dialog boxes the Comments button lets you view any comments associated with the selected visual program file You can use the scroll bars provided on the right side and the bottom of the directories and file listings to view file and path names that are either too long or too numerous to fit in the available space Saving a Visual Program When saving a visual program Data Explorer saves the following files e The visual program with a net extension e The configuration settings with a cfg extension Data Explorer automatically appends net cfg to the name you enter in the Save As dialog box However if you enter your file name with a net extension Data Explorer does not add another net If you end the file name with any other extension Data Explorer appends the net extension to the extension you have specified For e
436. rther away from the object AutoGlyph Glyph cube and square glyphs have been added ColorBar Has new inputs which allow you to specify precise tick locations and labels for the ticks see AutoAxes Compute Compute2 Now perform string operations such as strcmp strlen strstr etc Compute also provides a random function Display Now has output called where This is the identifier for the window into which the image was displayed See ReadlmageWindow on page xxxii Export Now exports VRML 2 0 data Get Set Are replaced by GetLocal SetLocal and GetGlobal SetGlobal See Changes to Get and Set modules on page xxix Histogram Now will create 2 and 3 dimensional histograms for vector data Image Now has new output called where This is the identifier for the window into which the image was displayed See ReadlmageWindow on page xxxil Also if you choose the Rerender Image option to render the image at a higher or lower resolution screen objects such as captions and color bars will now be WYSIWYG See ScaleScreen on page xxxii Include Has a new input called pointwise If this input is set then Include will remove the connections of the input before removing points Thus only those positions with data values outside the specified range will be removed The default behavior and previous behavior is to also remove all connections and positions referenced by those connections containing at
437. ry mydata usr group groupdata e To set DXDATA for the C shell csh setenv DXDATA usr mydirectory mydata usr group groupdata Other Environment Variables DX8BITCMAP sets the level at which the change to using a private color map is made The allowed values are 1 and the range from O zero to 1 one and represent the Euclidean distance in RGB color space normalized to 1 one for the maximum allowed discrepancy The default value is 0 1 If this variable is set to 1 a private color map will never be used conversely if it is set to 1 a private color map will always be used See Display in BM Visualization Data Explorer User s Reference DXARGS specifies the default set of arguments for Data Explorer start up An option specified on the command line will override the corresponding setting in the variable 292 IBM Visualization Data Explorer User s Guide DXAXESMAXWIDTH sets the number of digits in axes tick labels at which a switch to scientific notation is made The default is 7 DXNO BACKING STORE if set to anything disables framebuffer readbacks Setting this environment variable will improve performance of interaction with hardware rendered images especially for machines for which readback is slow However some of the interactions in the image window such as zoom will result in a black image while interaction is taking place If you are not planning on using the Image tool then it is strongly recommended that this en
438. s 1 0 0 0 we denote a line connection between these two points by O 1 indicating that a line joins point O first point in the positions list to point 1 the second point in the list As mentioned above a triangle connection must reference three positions and a quad references four positions For complete examples of position and connection lists see Chapter 3 Understanding the Data Model on page 15 As a direct extension of this concept when we define volumetric elements like cubes and tetrahedra we can perform 3 dimensional interpolation and derive a reasonable data value for any point in a sample volume The good news about all of this interpolation is that Data Explorer already knows how to do the necessary calculations As a researcher your job is to define your data space to Data Explorer its positions connections and data dependency but you do not have to worry about the details of how the interpolation is actually performed The connections list is optional if it makes no sense to connect your sample points for example if you are studying gas molecules there may be no meaningful interconnecting lines between separate molecules Nevertheless you may wish to define line connections linking the atoms within each molecule in order to visualize interatomic bonds or protein backbones or you may define cubic volumetric elements in the space around the nucleus if you wish to visualize electronic potential fields fo
439. s float locations naxes ndeltas float temperature lat lon temperature field temperature scalar temperature positions locations regular data locations 89 5 1 compact specification origin and 179 1 spacing for lat and lon temperature Data for temperature Partially Regular Grids and Time Series This example describes an ocean circulation model that consists of a time series of four three dimensional scalars temp sali wata and conv and one three dimensional 3 vector vel netCDF typically requires seven variables all scalars the vector counting as three scalars The coordinate system for the velocity vectors corresponds to that of the grid that is u implies north v implies east and w implies down These grids are partially regular in that the time tlat and tlon portions three out of the four dimensions are all regularly soaced time is to be mapped to members of a series group The fourth dimension tlvl is irregularly spaced The compact notation can be used for the regular notation while the all values along the irregular dimension must be specified a product is formed from the dimensions Here is the specification in netCDL notation 286 IBM Visualization Data Explorer User s Guide dimensions time UNLIMITED tlat 30 tlon 50 tlvl 30 vsize 3 At each grid cell for variable vel there are three floats for the u v and w components of the ve
440. s commonly used parameters You can expose hidden parameters by using the Expand button in the module s Configuration dialog box Generally speaking you use Data Explorer to visualize your data in the following way First bring in the data from a disk file as a Field the Import module can read in a Data Explorer format file a General Array Importer file or netCDF CDF or HDF files Next run the imported data Field through one or more modules found in the Realization category Each of these produces a visual object You may also want to process these Realizations through Transformation modules to modify the Chapter 2 Introduction to Visualization 13 14 visual or other characteristics of an object Either one or a collection of visual objects is then displayed in an Image window The Image window provides a number of convenient tools for interactively rotating your visual objects zooming in for a closer look at them and so on There are many different variations of the above scheme for example modules like Construct allow you to create simple Fields without having to import data Structuring category modules permit you to modify Field components in many ways other types of output are provided so you can write image files to disk and so on But the concept of Import Realize Transform Image is the basic and most common approach to using Data Explorer So what happens inside a visual program The Field with its components flows throug
441. s the following irregular Array y is the fastest varying dimension Regular rray type float real Vectort2 f ms origin 0 0 delta 1 0 E Regular Array type float real vector 2 tems E origin 0 0 delta 0 1 X This represents in compact form the same information as the following irregular Array apow e3eg 0 0 0 0 1 0 O 1 2 0 0 2 3 0 1 0 O 1 1 1 1 1 1 2 2 1 2 0 Figure 11 Product Array of Two Regular Arrays Path Array Encodes linear regularity of connections It is a set of n 7 line segments joining n points where the ith line segment joins points and 7 Path Arrays are frequently combined as the terms of a Mesh Array An example of a Path Array is illustrated in Figure 12 int real vector 2 n Figure 12 Example of a Path Array This example represents in compact form the same information as the following irregular Array Chapter 3 Understanding the Data Model 31 32 O 1 1 2 2 3 n 2 n 1 Mesh Array Encodes multidimensional regularity of connections lt is a product of connection Arrays The product is a set of interpolation elements where the product has one interpolation element for each pair of interpolation elements in the two multiplicands and the number of sample points in each interpolation element is the product of the number of sample points in each of the multiplicands interpolation elements An exa
442. s RGB Red Green Blue As in the HSV model just described you specify a color as a triplet a 3 vector Each component can have a value from 0 0 to 1 0 If all three are 0 0 the resulting color is black if all three are 1 0 you get white Given Red 1 0 Green 0 0 Blue 0 0 the color is fully saturated bright red You can observe a graph of RGB lines at the far left of the Colormap tool as you manipulate the colors using the Hue Saturation Value HSV controls You can specify an RGB vector in the Color module in place of connecting a Colormap if you want the output object to have a single color or you can specify one of the X Window System color names And you can convert from RGB to HSV or back using the Convert module See Color on page 75 and Colormap on page 84 in IBM Visualization Data Explorer User s Reference for more details about these different specification schemes Let us assume that we have set the Colormap minimum and maximum to equal the minimum and maximum of the temperature data we collected in the atmosphere this is done automatically if you connect the data Field to the input on Colormap Recall that we collected position dependent data one temperature value at each grid position For this example assume the minimum temperature measured was 0 degrees Centigrade and the maximum 20 What color is 10 That depends entirely on the color map used If we have a standard spectral rainbow map with blue at O and red
443. s for Developers For more detailed descriptions of functions see Appendix D User Interface Configuration on page 299 Option syntax Function encode key 16 digit hex Encode a net file The Visual Program Editor will not numbers lt file gt display an encoded net file and such a file cannot be saved However cfg configuration files can be saved key 16 digit hex number Decodes an encoded net file lt file gt limitlmageOptions Remove options from Image window s Options menu noAnchorAtStartup Start Data Explorer but do not put up any windows by default noCMapOpenMap Remove Open option from Colormap Editor s File menu noCMapSaveMap Remove Save As option from Colormap Editor s File menu noCMapSetNameOption Remove Set Colormap Name option from Colormap Editor s Options menu noConnectionMenus Remove Connection menu from all Windows intended for use with DXLink applications noConfirmedQuit Turn off the Are you sure you want to quit Data Explorer message noDXHelp Remove three options from the Help menu of the control panel and the Image window noEditorAccess Remove options from the Edit menu of the control panel and the Open Visual Program Editor option from the Image window s Windows menu Appendix C Environment Variables and Command Line Options 297 suo L1d0 sa GeLJCA Table 6 Page 2 of 2 Command Line Options for Developers For more detaile
444. s of grids formed with different kinds of positions and connections components Chapter 3 Understanding the Data Model 21 U y cr y o O D mal 22 File Execute Windows Connection Options Figure 6 Examples of Grid Types The three grids in the top row represent surfaces those in the bottom row volumes Reading from left to right the three grid types are irregular irregular positions irregular connections deformed regular irregular positions regular connections and regular regular positions regular connections Data Component The data component stores the user s data values The data values can be position or connection dependent as specified by the value of the dep attribute described in Standard Attributes on page 25 of the data component If the values are position dependent then the connections component supplies a means of interpolating data values between the samples lf the values are connection dependent the data value is constant for each interpolation element Data can also be dependent on faces or polylines see Edges and Polylines on page 25 in which case the data is constant for either the face or the polyline The data are in one to one correspondence with the component upon which they are dependent This means that they are specified in the same order as the items in the corresponding component If that component is specified in a compact form its
445. s ot do SG ed Ge os a SG oe ee e 28 GNOUDS 225 estad ai eee 2h eee eae oe det dor he 34 Chapter 4 Data Explorer Execution Model 37 dott DARE A cad re ae a ee eer ta ae eta cat deg ag AE yt ee 38 4 2 Iterative Execution and Caching of Intermediate Results 40 4 3 Conditional Execution Route and Switch 41 4 4 Iteration using the Sequencer 2020004 43 4 5 Iteration using Looping 0 000000 0 ee eee 44 4 6 Preserving Explicit State 45 4 7 Advanced Looping Constructs 0 200084 50 4 8 External Asynchronous Data Sources 54 4 9 Parallelism using Distributed Processing 55 4 10 Parallelism for Data Explorer SMP 56 Chapter 5 Graphical User Interface Basics 57 5 1 Starting Data Explorer 20 0200 00 2000000200200 00 58 Using Environment Variables 59 5 2 Understanding Data Explorer Windows 60 Looking at Window Structure s 61 Using theiMOuse 4 404406 aed y BARS SESSA weg BEG AS E Ss 62 Moving and Resizing Windows 62 Selecting Pull Down Menus and Pull Down Menu Options 62 Selecting and Deselecting Items with the Mouse 63 Selecting a Choice in an Option Box lll ln 63 Editing Text Fields xu
446. s possible for a local version of a variable to come into existence and obscure a more global version of a variable midway through a macro s execution Variables as Right Side Values The values of variables used in a macro in expressions and as function arguments are found according to standard dynamic scoping rules If the variable exists in the macro s local environment then its value is used Otherwise the enclosing environments all the way to the top level environment are searched to locate the variable The value used is the value associated with the first instance of the variable If the variable is not found in any environment then the value NULL is used 10 n m mall o O cr mall o E Q r o E Q e y e D Example The following is a sample script that illustrates how variables are treated in macros This is a complete sample script macro add a b gt sum c a b c is created and given the value a b C atx x is found in the top level and used in this expression c a z z does not exist anywhere NULL is used sum a b sum is created local to the macro separate from the version of sum in the top level Xx ms sum 10 total add 4 4 total 8 sum stays at 10 Assignment and Function Call Semantics As stated earlier all assignment statements and function calls initiated at the top level environment are executed n a macro the process is slightly different Whe
447. s the macro s name its formal parameters and the names of values that it returns The syntax of a macro header is macro MacroName inputs gt outputs where e The keyword macro indicates that a new macro definition has started e MacroName is an identifier of the name that is being associated with the macro definition The inputs portion of a macro header is a list of identifiers separated by commas The list may be empty These identifiers act as place holders for the arguments passed to the macro when it is called If the macro does not require any arguments then you can omit the list but not the enclosing parentheses The right arrow symbol is needed only for macros with outputs The following are examples of valid headers for macros without outputs macro MyMacro x y macro MyMacro You can also specify default values for the inputs Consider the following example macro X a no input b 4 Echo a b j The values of the arguments a and b vary depending how the macro is invoked For example 204 IBM Visualization Data Explorer User s Guide Macro Body X a and b are set to the defaults no input and 4 X new value 3 a is set to new value b is set to 3 X NULL a and b are set to the defaults no input and 4 X b 6 a gets default of no input b is set to 6 See 10 5 Invoking Data Explorer Macros and Modules on page 200 for further explanation of the function
448. s you to set the layout of the selected interactors in the layout area You can specify horizontal or vertical See Changing the Interactor Layout on page 134 Set Attributes for integer scalar and vector values allows you to specify e The minimum and maximum limits for the interactor values e The number of decimal places displayed for scalar values e he increment of change in value when using stepper slider dial or text style interactors e Whether the specified increment applies to all instances of the interactor or is local to the current interactor Vector interactors allow you to modify these attributes for each component of the vector Specify that component to modify by changing the Component field at the top of the vector interactor s Set Attributes dialog box You can also open the Set Attributes window by double clicking on the border area of the interactor inside the Control Panel See Setting Interactor Attributes on page 134 for detailed information Set Label Allows you to change the title of the interactor See Changing the Label on the Interactor on page 137 Delete Deletes selected interactors Add Element Brings up a cascade menu with the choices Label and Separator These can then be added to the control panel See Control Panels as Dialog Boxes on page 138 Chapter 8 Graphical User Interface Menus Options and the Message Window 163 164 Add Selected Interactor s Adds an i
449. sachusetts 1990 Friedhoff Richard M and Benzon William Visualization The Second Computer Revolution New York Harry N Abrams Inc 1989 Glassner Andrew ed Graphics Gems Academic Press Inc Boston Massachusetts 1990 Hill F S Jr Computer Graphics Macmillan Publishing Company New York 1990 Kirk David ed Graphics Gems lll Academic Press Inc Boston Massachusetts 1992 Robin Harry The Scientific Image from cave to computer Harry N Abrams Inc New York 1992 Rogers David F Procedural Elements for Computer Graphics McGraw Hill Book Company New York 1985 Rogers David F and Adams J Alan Mathematical Elements for Computer Graphics 2nd Ed New York McGraw Hill Book Company 1990 SIGGRAPH Conference Proceedings Association for Computing Machinery Inc A Publication of ACM SIGGRAPH New York various years Tufte Edward The Visual Display of Quantitative Information Graphics Press Cheshire Connecticut 1983 Other sources of information XXIV For additional ideas consult the DX Repository available through anonymous FTP ftp tc cornell edu in directory pub Data Explorer and gopher ftp tc cornell edu port 70 This public software resource includes information and visual programs contributed by Data Explorer users from around the world We encourage you to contribute your innovations and ideas to the Repository in the form of new modules macros visual pro
450. scalars vectors matrices rank n tensors or string constants in braces The elements of a list can be separated by commas although they need not be In Data Explorer a list is the same as an Array see Arrays on page 28 The following are examples of valid lists IBM Visualization Data Explorer User s Guide 1 0 2 0 3 0 3 scalar values for isovalues 3 4 vector values for use as streamline seed points do St of string constants Lists of scalars can also be defined with a convenient shorthand notation that specifies the following e The list s starting value e The list s ending value e A stepping increment optional c n m mall o O cr mall o E Q r o E e e y Q D If you do not specify a stepping increment then the default is 1 If any of the values in the list constructor including the stepping increment are specified as floating point numbers then the generated list contains floating point numbers otherwise it contains integers If the starting value is smaller than the ending value the list elements are generated in increasing order otherwise they are generated in decreasing order Also only the magnitude of the stepping increment is important not the sign A negative stepping increment produces the same results as a positive one The values included in the list are generated by continually adding the value of the stepping increment to the st
451. se in the header section msb most significant byte first and 1sb least significant byte first specify the byte order text and binary specify the data format On all current platforms ieee is a synonym for binary and ascii for text data mode msb text Isb ieee binary ascii 2 8 IBM Visualization Data Explorer User s Guide Default Clause End Clause B 3 CDF Files You can specify the default Object to be imported using the default clause When a Data Explorer data file contains more than one Object which is the usual case the Import module see Import on page 165 in BM Visualization Data Explorer Users Reference decides which Object to import based on the value of the variable parameter Object name or names of the Import module and the default clause if specified If variable is specified to Import then those Objects specified are imported If variable is not specified but a default Object is specified with the default clause then the default Object is imported If variable is not specified and no Object has been defined as the default then the last Object in the file is imported default number name The end of the header section is indicated by an end clause The data section begins with the byte immediately following the first newline after the end clause end CDF is a data abstraction for self describing multidimensional Arrays It represents a simpler data model than that of Data Explorer
452. se indicated by the metric option The default value is determined by saveImageResolution option DX vpeCanvas lineThickness Specifies the thickness of the lines that connect module outputs to module inputs in the VPE DX warningEnabled Specifies the default value of the Warning Messages toggle button in the Message window s Option menu DX warningOpensMessage opecifies whether or not the Message window pops up when a warning message is printed in the Message window Appendix D User Interface Configuration 305 c s Cc o E h mall o Q e o cr mall o e E 306 IBM Visualization Data Explorer User s Guide Appendix E Data Explorer Fonts All fonts used by Data Explorer are stored as files in the usr lpp dx fonts directory Users can add their own fonts by creating a file in the correct format and using the DXFONTS environment variable to list the directory or directories where the additional font files are stored Fonts are stored in the standard Data Explorer file format A font file must contain the following information for more information on the Data Explorer file format see Appendix B Importing Data File Formats on page 241 The font is a group that contains 256 fields one for each ASCII character value and two attributes describing the height of the font For example object myfont class group member 0 value empty member 1 value control a member 65 value A
453. sing the Mode option box or the Ctrl W accelerator key 2 A wire frame box appears around the image The current look to point is marked by a small square box To move the look to point select the point by pressing the eft mouse button and holding the mouse pointer on it You can then move the cursor by dragging the selected point inside the box When the left mouse button is depressed on the point the mouse cursor disappears the look to point remains and the three projections one for each axis appear inside the wire framed box as dots similar to the 3 D cursor function illustrated in Figure 40 on page 86 When you release the mouse button the location of the point becomes the new look to point and the image view is updated Alternatively double clicking on a point in the Image window changes the look to point to the position on which you double click You can set the look to point to a location outside the current boundary box of the object using this method Note You can also enable Roam mode by using the intrctnMode parameter to the Image tool see Image in BM Visualization Data Explorer User s Reference The directions of the axes are indicated by a wire frame 3 D axes diagram in the lower right hand corner of the Image window To move the look to point the movement of the mouse must be along the same direction as one of the axes If you move the mouse in a direction that does not correspond to any of the axes directions the p
454. sitions connections and so on An Array consists of some number of items numbered consecutively starting at O Each item has a type category rank and shape defined as follows Type Types include double float int uint short ushort byte ubyte and string For example byte is signed byte and ubyte is unsigned byte Category A category can be real or complex Rank Rank 0 corresponds to scalars rank 1 to vectors rank 2 to matrices or rank 2 tensors higher ranks correspond to higher order tensors Shape The shape is defined as the list of dimensions of the structure For rank O items scalars there is no shape For rank 1 structures vectors the shape is a single number corresponding to the number of dimensions For rank 2 structures shape is two numbers and so on The following are examples of these classifications e Three dimensional points have type float or double category real rank 1 and shape 3 e Two veciors typically have type float They are category real rank 1 and shape 2 Three vectors are shape 3 e Tetrahedra have type int category real rank 1 and shape 4 e Scalar values typically have type int or float They are category real and rank O with no shape e Strain tensors typically have type float or double They are category real rank 2 and shape 3x3 Data Explorer uses six types of Array Irregular Arrays and five types of compact Array Regular Product Path Mesh and Constant The Ar
455. so useful in helping you determine the inside and outside of an object In addition to a colors component which holds the color mapped information for each data point in a Field you can specify a front colors and a back colors component Which is front and which is back is determined by the direction of the normal for that vertex position normals or polygon connection normals By setting different colors for the inside and outside of a complicated object you may be able to understand its shape better This technique can also be helpful when you are trying to convert a connection list like a finite element mesh into Data Explorer form If you accidentally describe the winding rhymes with binding of a polygonal face in the wrong order the normal for that face will point in the wrong direction Setting back colors to red and front colors to white will clearly indicate which faces are pointing the wrong way The Shade module employs the normals component it will make a normals component if it does not already exist Shade allows you to set up the lighting of your objects to make them more realistic in appearance That is to say when we observe a 3 dimensional object the way light falls on the object is an important cue to our eyes that helps us understand the shape of the object We expect the surfaces of the object that are generally facing a light source to be brighter than Appendix A Using Data Explorer S
456. some important terms and concepts that may be new to you if you have not used a scientific visualization application before So we suggest the following e Read this section first concentrating on topics that are unfamiliar e Follow the tutorials in BM Visualization Data Explorer QuickStart Guide e Start using Data Explorer A good place to begin is the set of example networks or visual programs in the directory usr Tpp dx samples programs You can open up any visual program file and study how the different modules are interconnected and then run the visual programs to observe the visual output e Use the online Help system to get more information about these example visual programs and Data Explorer tools This system also contains hypertext references to additional information The printed documentation contains detailed information including graphics sample code and data examples 2 1 Terminology Rendering Many of the terms used in Data Explorer are borrowed from traditional scientific disciplines others come from computer graphics and a few have been coined by the Data Explorer software developers for lack of any widely accepted term Important Data Explorer terms are defined in the Glossary The process of rendering an image involves a computer calculation of the amount of light falling on each visible surface of the objects in the scene as seen from the point of view of the computer camera the viewer s eye poin
457. ss memory DXPROCESSORS sets the number of processors for Data Explorer SMP DXROOT specifies the top level directory for all the files and directories needed by Data Explorer The default is usr lpp dx DXSHMEM specifies whether or not shared memory should be used The amount of memory allocated by Data Explorer for its data and object management can be set at runtime with the memory command line option At startup Data Explorer either allocates a shared memory segment or expands the existing data segment to create this space SMP multiprocessor systems are required to use shared memory so each processor can share a common data space SGI systems also use shared memory for space IBM systems use shared memory if the size to be allocated is larger than 256 MB In all other cases Data Explorer extends the existing data segment using the brk system call Each architecture SGI IBM HP has a different way of configuring the maximum user data segment size and a different way of setting the limit on the maximum size of a single shared memory segment Consult your system administrator or system documentation if you have problems getting Data Explorer to use the amount of memory which should be available to you If you have problems using a large data segment you can force Data Explorer to use shared memory by setting the DXSHMEM environment variable to any value other than 1 This will override the defaults and use shared memory for s
458. stant Array defines an Array whose elements all have the same value object number class constantarray name type unsigned byte signed byte unsigned short signed short unsigned int signed int hyper float double string category real complex rank number shape number items number msb text data mode offset Isb ieee file file offset binary follows Appendix B Importing Data File Formats 273 ascii If byte short or int are not prefixed with either signed or unsigned by default bytes are unsigned shorts are signed and ints are signed For compatibility with earlier versions char is accepted as a synonym for byte Note For string type data the Array rank should be 1 and the Array shape should be the length of the string plus 1 The only difference between the specification of a Constant Array and the specification of an Array is that for a Constant Array only one value is listed in the data section gridpositions Keyword The gridpositions keyword is used to represent an n dimensional grid of geometrically regular points in a compact form It is a kind of Array Object and can be used in any context where an Array Object would be used It is typically used as a regular positions component The shape of the grid number of points in each dimension is specified by a list of n numbers following the optional counts keyword in the object clause The number n of items in this list deter
459. step between values is 1 1754 x 10 38 Like integers floating point numbers can be prefixed by a minus sign to represent a negative number Floating point numbers can be expressed in two ways IBM Visualization Data Explorer User s Guide Standard representation The standard representation of a floating point number consists of a decimal number followed by a decimal point followed by another decimal number The first decimal number represents the whole part of the floating point number The second represents the fractional part Either the first or the second of the numbers surrounding the decimal point can be omitted but not both If the first is omitted then the number is purely fractional If the second is omitted then the number does not contain a fractional part This second alternative is useful for representing integer values that lie outside of the range representable by the integer format Scientific notation Scientific notation is an alternative means of representing floating point numbers A number in scientific notation has the form xey or xEy The number x can be either a standard floating point number or a decimal integer The number y must be a decimal integer It can be prefixed by a minus sign This scientific notation is simply shorthand for writing xx 10v The effect of the decimal value y is to specify the number of places the decimal point should be shifted to the right or if y is negative to the left T
460. stitute of Technology XIV IBM Visualization Data Explorer User s Guide Copyright notices IBM Visualization Data Explorer contains software copyrighted as follows E du Pont de Nemours and Company Copyright 1997 E du Pont de Nemours and Company Permission to use copy modify distribute and sell this software and its documentation for any purpose is hereby granted without fee provided that the above copyright notice appear in all copies and that both that copyright notice and this permission notice appear in supporting documentation and that the name of E I du Pont de Nemours and Company not be used in advertising or publicity pertaining to distribution of the software without specific written prior permission E du Pont de Nemours and Company makes no representations about the suitability of this software for any purpose It is provided as is without express or implied warranty E du Pont de Nemours and Company disclaims all warranties with regard to this software including all implied warranties of merchantability and fitness in no event shall E du Pont de Nemours and Company be liable for any special indirect or consequential damages or any damages whatsoever resulting from loss of use data or profits whether in an action of contract negligence or other tortious action arising out of or in connection with the use or performance of this software National Space Science Data Center Copyright 199
461. stogram bins option Changing the name of the Colormap Editor Every Colormap Editor is given the default name of Colormap Editor in the box across the top of the window If you want to customize the name of the Colormap Editor you can do so by clicking on the Options menu Change Colormap Name option and entering a new name in the dialog box that appears Note You can also change the name of the Colormap Editor by using the title parameter in the Colormap tool IBM Visualization Data Explorer User s Guide Generate Wave Forms Waveform Range Full Steps 47 gt Apply Close Figure 59 Generate Waveforms Dialog Box Saving and Loading Color Maps You can save a color map by using the Save As command from the File pull down menu You can then make the new color map part of any visual program To access it use the Open command from the File pull down menu of the Colormap Editor menu bar Note that saved color maps may also be imported see Import in BM Visualization Data Explorer User s Reference and passed directly to the Color module Using Data Driven Colormap Editors The Colormap Editor may be data driven meaning that its attributes e g minimum and maximum can be set by connecting the output of a tool to the input of the Colormap tool in the VPE or by typing a value into the Colormap configuration dialog box instead of into the Colormap Editor itself If the Colormap Editor is data
462. sualization on page 7 should get you started However the more detailed information here is useful when you have specific questions about the data model Introduction to the Data Model The Data Explorer data model supports various types of simulation and observational data Data structures that can be represented include e Data defined on a regular orthogonal grid e Data defined on a deformed regular or curvilinear grid e Data defined on various irregular grids such as triangular quadrilateral and tetrahedral meshes e Unstructured data with no connections between the data samples The data samples can be defined over spaces of any dimensionality and independently can also be connected by primitives of various dimensionalities allowing for example triangular and quadrilateral meshes defined over 2 or 3 dimensional points The data values can be associated either with the sample points or with the connections between the sample points Available data types include e Real and complex data e Scalar vector and tensor data e Byte short integer signed and unsigned and floating point data Data are stored in the form of Objects for use by Data Explorer modules An Object is a data structure stored in memory that contains an indication of the Object s type along with additional type dependent information The bulk of the data is encapsulated in Array Objects The data model centers on the notion of a sampled field The nex
463. sualization process called a visual program by connecting a network of Data Explorers modules An expert programmer can create new modules using C or FORTRAN for use with the system modules Besides the user interface Data Explorer also provides a scripting language interface for users who want to build their own visualization functions in a more traditional programming style Data Explorers graphical user interface provides an integrated online help facility This facility provides users with online access to the Data Explorer user manuals as well as with context sensitive help information In addition to the help information provided with Data Explorer the online help facility allows users to document various aspects of their particular visual programs Other users of these visual programs then have online access to this program specific documentation Data Explorer provides an extensive set of modules that you can use to visualize your data For example the lsosurface Streamline and AutoColor modules perform the standard visualization functions of creating constant value surfaces tracing particle paths through velocity fields and coloring objects based on a data value respectively In addition to these expected functions Data Explorer also provides tools to perform more sophisticated manipulation of data The Map module is a general purpose module that can map a data field onto an arbitrary object whether it is a streamline an is
464. t For both integer and scalar stand ins the stepper is the default You can change the style at any time by using the Set Style option from the Edit pull down menu on the Control Panel Stepper The Stepper Figure 66 enables you to enter a value by typing it into the text field or by using the arrow buttons to increase right arrow or decrease left arrow a displayed value The arrow buttons have a built in acceleration function so that the longer you depress a button the faster the value changes Isosurface controls 4 El File Edit Execute Panels Options Help Scalar 4 4500000 Jb Figure 66 Stepper Style Dial The Dial Figure 67 on page 143 has circular shape You can specify a value by manipulating the dial indicator or you can directly enter a value in the field at the bottom of the interactor To manipulate the dial indicator press and hold the mouse button in the circular part of the interactor Turning the dial clockwise increases the interactor value while turning it counterclockwise decreases the value f you move the cursor within the dial shading occurs in intervals around the dial indicator The shading indicates whether the value change is positive or negative The shading is light if you move in a clockwise direction positive it is dark negative if the movement is 142 IBM Visualization Data Explorer User s Guide counterclockwise If you click the pointer within the shaded area the dial indic
465. t During the rendering process surface properties of objects are taken into account as are the colors of both the objects and the lights shining on them In other words a computer graphics renderer samples the scene in front of the camera at the resolution of the computer monitor on which the scene is to be displayed lts sample space is the 3 dimensional world containing the objects But the image renderer does not create a 3 dimensional picture it only calculates the colors of the dots that can be seen on the 2 dimensional monitor screen from the chosen point of view Any parts of objects that cannot be seen from that point of view are neither sampled nor rendered nor are they stored in the image file or displayed on the monitor This 2 dimensional image may appear 3 dimensional to our eyes because of shading occlusion of distant objects by closer ones and other visual cues that in the real world indicate dimensionality Like any image it is a representation however real it may appear Positions and Connections Dependence The concept of sampling should be familiar to anyone who has ever collected data on some kind of grid For example a botanist may lay down a series of square grid markers over an area of interest then count the numbers of species of grasses growing inside each grid square The number so collected becomes a sample value or datum associated with that grid marker A single number like this whether floating point o
466. t component data data end IBM Visualization Data Explorer User s Guide mmmmmumuusm Mmmm m mmm See eee wee oe as TELCEL mmmmmumm ELE nana on e Figure 92 Example of Faces Loops and Edges Example 10 Faces Loops and Edges with a Hole nanan nnn n nia r Oe el om ci a oe mum mua nann n E mm ELLE E 25nn mm mum mm mmm mm mm EEEE enama Figure 93 Example of Faces Loops and Edges with a Hole The following data file is identical to the previous data file except that the third polygon has a square hole in it The resulting connections are illustrated in Figure 93 Appendix B Importing Data File Formats 263 m n mall o D T1 o ms 3 y cr tn 264 Example of faces loops and edges components The third face has a square hole in it Positions array These are a list of all the vertices of the object no particular order is required here object position list class array type float rank 1 shape 2 items 15 data follows 0 133985 0 812452 point number 0 0 375019 0 896258 point number 1 0 532733 0 76484 point number 2 0 523806 0 404777 point number 3 0 300626 0 327407 point number 4 0 145888 0 508927 point number 5 0 68152 0 851137 point number 6 0 815428 0 758889 point number 7 0 94636 0 592248 point number 8 0 729132 0 416679 point number 9 0 535709 0 190524 point number 10 0 600000 0 700000 point number 11 0 7
467. t x20 2 y20 7 With ine connections between adjacent pairs of grid points we can only reasonably perform interpolations along those linear boundaries but not into the middle of our grid elements By defining areas bounded by three or more points we can perform interpolation across the area the polygon surface using weighting functions that take into account the data values at all points surrounding the area In fact this is the same process used by an image rendering program it interpolates from known values at the vertices across the faces of polygons and computes the appropriate color at all visible points on the surface at the resolution allowed by the output device digital file computer monitor etc lt mall o tn o mall o N o cr mall o o E Identifying Connections In Data Explorer we identify connections in the following way List the sample point location vertices in any order that list is called the positions as we discussed above Consider each point in the positions list to have an ordinal number starting at O for the first point in the list these ordinal numbers are not explicitly listed in a Data Explorer file A connection is denoted by a list of lists of numbers in which each entry represents the ordinal values of the points that are to be connected listed in the order they are to be connected So for example if the first point in the positions list is 0 0 0 0 and the second point i
468. t by using the Executive module See Executive on page 126 in BM Visualization Data Explorer User s Reference Data Explorer provides the following commands that allow you to control the Sequencer You can use these commands in a script or by typing them to the executive sequence The sequence command defines the frames that you specify in the Sequencer variables using the images supplied by a function call or expression The following table defines the Sequencer variables Read Read Description Only Write P deltaframe The number of steps between frames Gendframe y The index of the last frame frame v The index of the current frame Gnextframe v The index of the next frame Qstartframe V The index of the first frame In the following example the sequence command defines eleven frames for the Sequencer These frames can be displayed using other Sequencer commands startframe 0 endframe 10 nextframe startframe sequence displayobject 20 frame 206 IBM Visualization Data Explorer User s Guide File Inclusion Prompts play This command begins execution on the frames that have been defined with the sequence command pause This command stops the sequence at the current frame step This command displays the next frame in the current sequence direction stop This command stops the sequence display and returns to the first frame in the sequence forward This command sets the forward direction of t
469. t have established connection to the server When you start Data Explorer the program automatically starts the server connection unless you specified that only the user interface was to be started However if for some reason your workstation becomes disconnected between the time you start Data Explorer and the time you are ready to run a program you must reestablish connection with the server Chapter 9 Graphical User Interface For Advanced Users 183 To start the server connection select the Start Server option from the Connection pull down menus in the VPE or Image window A dialog box appears Figure 81 on page 184 I start Server Figure 81 Start Server Dialog Box The Hostname field by default contains the name localhost If the DXHOST environment variable or the host argument was specified this field contains the setting of that variable You can change the Hostname field by clicking on it and typing in the new name When it displays the desired name connect to the server by clicking on the Connect button To change the options associated with starting the server click on the Options button This opens the Options dialog box Figure 82 Most of the time it is not necessary to use these options Options Figure 82 Start Server Options Dialog Box The fields of this dialog box are as follows 184 IBM Visualization Data Explorer Users Guide I9 Executive opecifies the name of th
470. t is supplied through a connecting arc or is defined in the module s configuration dialog box When the default input is used the tab remains up An output tab folds in when it is connected to another module by an arc A tab that is folded in but has no connecting line leading to it indicates that its input was specified using the tool s Configuration dialog box Creating Deleting and Moving Tab Connections To connect tabs 1 Click and hold the mouse button on the output tab This causes the cursor to change to a downward pointing arrow When the cursor is placed over the output tab the name of the tab is displayed in the tool icon 2 While pressing the mouse button drag the cursor to the desired input tab While you are dragging the cursor from the output tab a white line appears indicating that a connection is being created 3 When you enter the area encompassing a tool icon the tabs that are compatible with the output tab you are trying to connect will change color When the cursor is placed over an input tab the name of the tab is displayed in the tool icon Note You can also connect tabs by starting at the input tab Simply press and hold the mouse button on the desired input tab this causes the cursor to change to an upward pointing arrow Drag the cursor to the 104 IBM Visualization Data Explorer User s Guide desired output tab When the cursor enters the area encompassing a tool icon the output tabs that ar
471. t iteration Unfortunately the visual program illustrated in Figure 26 on page 52 has a minor problem If x equals N the Route will cause the Sum and SetLocal not to execute during the last iteration therefore the output of the macro will be a NULL Chapter 4 Data Explorer Execution Model 51 m gt lt D ie S ct mall o le gt o x D Figure 26 Example 9 Gell acal Illustrated in Figure 27 on page 53 is the fix to the problem A Switch is included to choose the correct input for the output of the macro If x equals N the output of the GetLocal is chosen otherwise the output of Sum is chosen If you want to create a loop containing an early exit in the middle of the loop a break you need to use a Route in combination with Done Illustrated in Figure 28 on page 54 is a macro that performs the equivalent function as the C language statements sum 0 for i 1 i lt n i if i x break sum sumti Data Explorer allows you to have multiple Done tools in a single loop enabling you to have more than one break or continue or combinations of the two ForEachN or ForEachMember simplify the use of loops but they are not necessary for creating them In fact Done itself is sufficient if it is included inside a macro The macro will execute repeatedly as long as the done parameter is equal to O 52 IBM Visualization Data Explorer User s Guide Figure 27 Example 10 Visual Program
472. t of modules completely disconnected from modules on other pages Receivers and transmitters are used to connect modules on different pages To use pages select the Pages option in the Edit menu of the VPE A cascade menu allows you to create an empty page create a page containing the currently selected tools delete the currently displayed page or configure the page that is change its name or position Saving and Restoring a Visual Program The Save As and Open options of the File pull down menu use similar dialog boxes A sample Save As dialog box is illustrated in Figure 54 on page 116 Chapter 6 Graphical User Interface Important Windows 115 Figure 54 Save As Dialog Box File Selection Dialog Boxes The components of the dialog box are Filter Specifies the current search argument for files You can broaden or narrow the scope of the files displayed in the Files area by changing the filter string You can also use the filter to specify a directory in which to search for the files For example a filter of abc net displays all of the visual programs in the abc directory Change the filter string by clicking on it and typing the new string Because Data Explorer appends the net extension to visual programs when it saves them be sure to specify net at the end of the filter string To request smaller groups of files in the current directory 1 Type standard file regular expression notation into the File Fil
473. t section describes the Field Array and Group Objects that implement sampled fields in Data Explorer In addition to these basic Object types other types are used to construct models for rendering e g Transforms Clipped Objects Lights and Cameras These are described in B 2 Data Explorer Native Files on page 244 and in IBM Visualization Data Explorer Programmer s Reference Data are also stored in permanent file storage in the form of the same Objects Although Data Explorer supports the creation of Objects from data stored in other file formats such as netCDF the Data Explorer file format offers significant additional functionality and flexibility Note that the Data Explorer file format is versatile allowing for future expansion of the capabilities of the system without requiring changes to the file format It is possible to represent data types in a Data Explorer file that cannot be processed by the current version of Data Explorer For example in the current release of Data Explorer only single precision floating point positions are universally supported Also most modules support only 1 2 or 3 dimensional positions IBM Visualization Data Explorer User s Guide 3 2 Object Types Fields Field Array and Group Objects implement sampled fields in Data Explorer Additional Object types used to construct models for rendering are described in Appendix B Importing Data File Formats on page 241 Field Objects
474. t the National Center for Supercomputing Applications at the University of Illinois at Urbana Champaign in collaboration with the Information Technology Institute of Singapore THE UNIVERSITY OF ILLINOIS GIVES NO WARRANTY EXPRESSED OR IMPLIED FOR THE SOFTWARE AND OR DOCUMENTATION PROVIDED INCLUDING WITHOUT LIMITATION WARRANTY OF MERCHANTABILITY AND WARRANTY OF FITNESS FOR A PARTICULAR PURPOSE Gradient Technologies Inc and Hewlett Packard Co Copyright Gradient Technologies Inc 1991 1992 1993 Copyright Hewlett Packard Co 1988 1990 June 1993 UNIX is a registered trademark of UNIX Systems Laboratories Inc Gradient is a registered trademark of Gradient Technologies Inc NetLS and Network Licensing System are trademarks of Apollo Computer Inc a subsidiary of Hewlett Packard Co sam Leffler and Silicon Graphics Copyright 1988 1996 Sam Leffler Copyright 1991 1996 Silicon Graphics Inc Permission to use copy modify distribute and sell this software and its documentation for any purpose is hereby granted without fee provided that i the above copyright notices and this permission notice appear in all copies of the software and related documentation and ii the names of Sam Leffler and Silicon Graphics may not be used in any advertising or publicity relating to the software without the specific prior written permission of Sam Leffler and Silicon Graphics THE SOFTWARE IS PROVIDED AS IS AND WITHOUT
475. ter field For example type ab net to select all net files whose names begin with ab 2 Click on the Filter button at the bottom of the dialog box or press Enter to update the information shown To request files located in a different directory 1 Use standard file regular expression notation to specify the directory to search For example to select all the net files in the u xyz directory you would change the filter string to u xyz net 2 Click on the Filter button at the bottom of the dialog box to update the information shown 116 IBM Visualization Data Explorer Users Guide Directories Displays the directories in the current filter path When you click on a directory its name is displayed in the filter field pressing the Enter key then applies that filter You can traverse through the available paths by double clicking on the paths displayed in this portion of the dialog box The parent directory of the filter path can be reached by selecting and applying the directory name that ends with two periods as a filter As you change directories this way the Selection box and Files section are updated accordingly Files Displays the files specified by the File Filter and the directory shown in the Selection area Clicking on a file name once will change the current selection Double clicking on a file name will select that file and proceed with the Open Save As or Load Macro operation Selection Displays the cu
476. th it a minimum and a maximum scalar value You can either specify the minimum and maximum or connect the data Field to the Colormap module and have these values automatically extracted We can describe color to a computer in a number of ways One of the more intuitive is the hue saturation value model used by Data Explorer s Colormap tool Hue is the colors name like blue red and so on Hue is considered to form a circle from red through yellow green cyan blue magenta and back to red think of Hue as an angle around this color wheel scaled from 0 0 to 1 0 Saturation is the richness of a color Decreasing the Saturation of a color from 1 0 to 0 0 makes the color progressively more pastel so for example bright red becomes light red then pink finally turning white You can think of decreasing the Saturation as adding white paint to paint of a pure hue At Saturation 0 0 any color becomes white assuming Value is held at 1 0 Similarly Value is a measure of the amount of black paint mixed with a color As you decrease the color s Value from 1 0 to 0 0 you add more black so bright red becomes progressively darker red and finally black Any color becomes black at a Value of 0 0 All three of Appendix A Using Data Explorer Some Useful Hints 219 220 these parameters interact so you can adjust Hue and decrease Saturation and Value to get a dark pastel blue Another scheme for describing color i
477. the corners of a bounding box that contains the positions of this Field Data Statistics Component The data statistics component contains statistics of the data component The information in this component should be accessed using the Statistics module or the DXStatistics function as the exact contents are undefined If DXStatistics is called on other components e g positions an analogous component in this case positions statistics will be created Faces Loops and Edges Components The faces loops and edges components are used for special purpose applications such as fonts or geometric models The faces component represents a set of faces each described as a set of loops Each entry in the face Array is a single integer index into the loops Array identifying the first of a consecutive set of loops for this face The loops are listed in order of the faces they are associated with so that the list of loops for face i ends in the loops Array just before the first loop for face i 7 Each entry in the loops Array is a single integer index into the edges Array identifying the first of IBM Visualization Data Explorer User s Guide a consecutive set of edges for this loop The edges are listed in order of the loops they are associated with so that the list of edges for loop in the edges Array ends just before the first edge for loop i 7 Each entry in the edges Array is a single integer index into th
478. the exact order in which modules will be executed cannot be controlled by the user for example modules in two parallel branches may execute in any order with respect to one another it is only guaranteed that a module that depends on the results of one or more modules will wait for them to be complete before it is executed 4 2 Iterative Execution and Caching of Intermediate Results 40 Unlike the simple example in Figure 18 on page 39 most real visualization problems involve some form of iteration This may either be direct interaction where the user is adjusting parameters of the visualization and observing their effect on the resulting images or animation in which one or more inputs to the network may vary from frame to frame In iterative applications there are often major parts of the network that are unaffected when input parameters are modified In Figure 18 on page 39 if the isovalue input to the Isosurface module is changed only the affected module and its descendents need to be executed The output of Import is not affected by the change Hence it can be reused which avoids a superfluous access of data on disk The MapToPlane module also does not need to be executed since its inputs did not change One way to implement this capability is via a caching mechanism for partial results Instead of immediately reexecuting when its inputs arrive a module may first determine whether its inputs have changed If they have not changed
479. the interface to a user written module The Module Builder creates the necessary makefiles and a template c file for the module See BM Visualization Data Explorer Programmer s Reference The executive is the component of the system that manages the execution of the modules specified in the scripting language This scripting language is generated by the graphical user interface to invoke visualization functions for visual programs Users can also use the scripting language to write their own programs as described in Chapter 10 Data Explorer Scripting Language on page 187 Data Explorer provides an extensive powerful set of highly interoperable visualization modules The modules used for visualization functions are available e As nodes through the use of their icons in a visual programming network e As function calls available in the scripting language interface provided by the executive layer e For integrated applications as part of the visualization library programming interface See 12 10 Module Access on page 127 in IBM Visualization Data Explorer Programmer s Reference for information on this use of modules Data Management The data management layer is the portion of the programming interface that provides modules with access to the data model which is discussed in Chapter 3 Understanding the Data Model on page 15 This layer includes general system services as well as routines for creating and managing
480. the set of data objects The data management layer also provides an application programming interface API for adding new modules to Data Explorer and for accessing the power and flexibility of the data model Detailed information on this API can be found in BM Visualization Data Explorer Programmer s Reference How the Data Model Facilitates Interoperability The Data Explorer data model is not simply a convenient way to represent data objects It also allows Data Explorer tools to be more powerful than they would be otherwise Tools can be used in multiple ways because the components of the data set are described using a common structure There is no distinction between data oositions and colors in how they are represented within a Data Explorer field object For more information on Data Explorer fields see Chapter 3 Understanding the Data Model on page 15 For example you can use the Compute module to operate on the data to extract the magnitude or x component of a vector e g operate on the positions of a grid to warp the grid or on the colors 4 IBM Visualization Data Explorer User s Guide of a field to negate an image This also means that the user has the capability of modifying or inspecting all aspects of a data object Tools can be used on any object in Data Explorer there is no distinction between data objects and geometry objects An isosurface or an image is represented in the same way
481. the value 1 indicates that the corresponding position is invalid and O that the corresponding position is valid Alternatively the invalid positions component can be an Array of signed or unsigned integers where the component references the positions i e has a ref attribute of positions In that case the component contains a list of the indices of the invalid positions The first method is more space conserving Chapter 3 Understanding the Data Model 23 O y cr y o O D m 24 when there are a large number of invalid elements the second when there are a relatively small number See Compute on page 86 in BM Visualization Data Explorer User s Reference for a way to convert from the ref type to the dep type The invalid connections invalid faces and invalid polylines components can be defined in an analogous way Tangents Normals and Binormals Components The normals component is used to specify a local surface normal for rendering purposes The tangents normals and binormals components specify a local reference frame on a path this is useful for example for twisted ribbon representations of streamlines Normals are used for among other things surface shading By convention the normals are expected to point out from the front of a surface as defined in Colors Front Colors and Back Colors Components on page 22 Normals are expected to have unit length Neighbors Component
482. the values of Object attributes are frequently string Objects However String Objects as such generally do not appear in Data Explorer files because a string valued Object attribute can be specified by using the string keyword as described in Objects on page 269 object number class string string name A Light Object is used to place a light in a scene for the renderer Lights can be either local or distant Local lights have a position and a color Distant lights are at infinity and have a direction and a color It is often not necessary to specify a light in a scene because the renderer has a default built in light that is sufficient for most purposes For ambient lights only color can be specified not direction or position For distant lights the direction can be absolute or it can be relative to the current location of the camera as specified in a from camera clause object number class light type distant name local ambient direction number number number from camera position number number number color number number number color position number number number Note In the current release of the Data Explorer local lights are not supported Appendix B Importing Data File Formats 2 7 ms mall o D ms o ms 3 y cr tn Camera Objects A Camera Object specifies a camera for rendering Camera Objects are not generally found in Data Explorer files but rather are generated as p
483. ther green or 0 1 0 is sufficient to specify the color green 3 It is also possible to set the background color using the bkgrdColor parameter to the Image tool see Image in BM Visualization Data Explorer User s Reference Display Rotation Globe The rotation globe can be displayed only in the Roam and Rotate modes of the View Control dialog box see Controlling the Image View Control on page 74 In either mode activation depression of the Display Rotation Globe toggle button generates a globe in the lower left hand corner of the Image window The orientation of this globe changes in parallel with that of the axes in the lower right hand corner of the window or vice versa depending on which object you manipulate Hold down the left mouse button to rotate the objects in two dimensions Rotate mode and the middle button to orient them in three Roam mode Rendering Options You can choose between software and hardware rendering if you are running Data Explorer on a workstation with a graphics card that supports hardware rendering Approximations in both types of rendering help the user to see the effect of rotation roam or navigation interactions before rendering and display are complete To set the rendering options select Rendering Options in the Options pull down menu in the Image window This causes the Rendering dialog box to appear as illustrated in Figure 43 on page 92 The Rendering dialog box all
484. those interactors If you have not selected anything on the canvas the panel is empty Open Selected Control Panel s Opens all Control Panels containing selected highlighted interactor stand ins Control Panels that are already open are unaffected Open All Control Panels Opens all the Control Panels for the current visual program Open Control Panel by Name Opens a cascade menu with the names of the existing control panels Using this you can open a particular control panel Open Selected Macro s Opens a VPE window containing the expanded representation of the selected macro icon From this newly opened window you can open the macros contained in the currently opened macro You can repeat this operation until only modules are contained in the window See Using Macros in a Visual Program on page 153 for more information This options is grayed out if no macro is selected Open Selected Image Window s Opens an Image window for each selected Display or Image tool icon in the current visual program This option is grayed out if no Display or Image icons are selected Open Selected Colormap Editor s Opens a window where you can map colors and opacities to data values the results of which are displayed in the visual image This option is grayed out if a Colormap icon is not selected Features of the Colormap Editor allow you to e Control the range of data values over which the mapping occurs e Select the colors and opacities
485. tializes the VPE for a new program and clears the canvas If you have opened Control Panels and Image windows from the VPE they are closed If a program you changed but did not save currently exists on the canvas a dialog box appears so you can save changes If you opened the VPE using Open Macro or Open Visual Program Editor this option is grayed out Open Program Opens an existing visual program A dialog box appears for you to specify the desired program name If a program you changed but did not save currently exists on the canvas a dialog box appears asking if you want to save changes If you opened the VPE using Open Macro this option is grayed out See File Selection Dialog Boxes on page 116 for more information IBM Visualization Data Explorer User s Guide Save Program Saves the current visual program and associated Control Panels This option saves the following files filename net for network that is a Data Explorer visual program filename cfg for configuration Save Program As Saves the current visual program and all associated Control Panels under a name you type into the dialog box This option saves the following files filename net for network that is a Data Explorer visual program filename cfg for configuration Program Settings Brings up a cascade menu with two choices e Save As saves the current settings for the visual program e g window placement interaction mode camera viewpoint
486. time an image is displayed in the Image window it will be appended to the file specified in the Selection text field To disable the continuous saving mode 1 Open the Save Image dialog box using the File menu Save Image option 2 Release the Continuous Saving toggle button by clicking on it 3 Click on the Apply button Save Image Options Allow Rerendering allows you to specify whether or not the currently displayed image should be rerendered at a new resolution or aspect ratio If Allow Rerendering is toggled off then the Image Size is completely determined by the resolution of the currently displayed image Image Size and Output PPI cannot be independently controlled and you can not change the aspect ratio of the image from that of the currently displayed image If you attempt to change the aspect ratio of the image size e g by specifying a size of 8x8 when the original image is not at an aspect ratio of 1 1 the new image size will not be accepted by the Image Size text field If you change only one component of the image size e g by specifying 8 x then the other component of the image size will be computed by comparing it to the current aspect ratio and Output PPI will be adjusted such that the number of pixels of the image remains that of the currently displayed image Chapter 6 Graphical User Interface Important Windows 95 96 Gamma Correction Delayed Colors Format Output file name Select File
487. ting a Color and Colormap pair in place of AutoColor then connecting the original temperature Field to the input of the Colormap This would automatically lock the minimum and maximum to the entire range of temperature not just to the range of values that happened to fall on the isosurface But there are other cases in which commutative ordering of modules will yield a quite different visual output For example suppose we have a volumetric Field containing both vector data and a scalar data set We can generate a series of Streamlines through the vector Field Map the scalar data from the volume through which the Streamlines pass onto these lines then AutoColor the lines according to the scalar data To make the lines easier to see we employ the Tube module to create cylinders along the path of each streamline The radius of the Tubes can be adjusted until we get the look we like By performing the operations in that order the original colors are carried from the lines out to the outside of the cylinders resulting in distinct circumferential bands of color on the Tube surfaces Now change the order create Streamlines then Tube the lines This yields uncolored cylinders At this point we Map the scalar data values from the volumetric Field in which the cylinders are embedded onto the surfaces of the cylinders then AutoColor This time we will have patches of color on the cylinders since it is highly unlikely that the volumetric data would l
488. tions variable3 cubes e variablel connections variable3 quads where variable3 is the name of an array containing a vector of point numbers defining each connection element item The length of this vector depends on the choice of connections If the shape is not explicitly specified tetrahedra are assumed Additional Components If additional component information is present in the file the following attributes are valid variablel component variable4 componentname scalar variable5 componentname vector variable6 componentname matrix and variable4 attributes ref componentname dep componentname There are three ways to specify the import of datasets that should be treated as series They are e Single variable e Separate variables e Separate files Single Variable When all data values are defined as a single netCDF variable and the unlimited dimension of the variable is to be interpreted as the series dimension then use one of the following forms of the field attribute e variablel field fieldname scalar series e variablel field fieldname vector series e variablel field fieldname matrix series All other specifications are the same as for simple fields The position and connection information is assumed to be constant for all members of the series If the positions or connections change for each step of the series then the variables used for those arrays must also have a
489. tions that do not include changing values but fixed width text maintains the same width regardless of the numeric characters currently being displayed Try both ways and you will see that the variable text has an annoying shrinking expanding effect as your clock or time step meter changes value To get the fixed text clock to behave correctly you must use a Format template like 03 2f that allows for enough numbers to the left of the decimal point In this example we have predetermined that we will never create a number greater than 999 99 note that if we do go over 1000 the text will expand to show the whole number causing the Caption string to expand the very thing we are trying to avoid The 9603 2f format makes floating point numbers with 3 numerals before the decimal including left side zero padding and 2 numerals after the decimal c tn D m mi mall o gt cr tn Color Mapping Data Explorer provides an automatically generated color map AutoColor an automatically generated grayscale AutoGrayScale and a user definable color map the Colormap module that attaches to the Color module A color map represents a relationship between a continuous range of floating point numeric data values and a set of color values Frequently you will encounter color maps with continuous spectral color tones like a rainbow but there is no requirement that color maps appear continuous Each color map has associated wi
490. tivated whenever one or more of the AutoAxes options are changed Releasing deactivating the button prevents the appearances of an axes box The second part of the dialog box displays six 6 of the available configuration options shown below Depressing enabling any of these option buttons automatically expands the window appropriately to reveal the relevant options Releasing disabling any of these option buttons removes the relevant options Allows you to individually specify a label for each of the three axes XY Contains the following specifications Frame allows you to turn on or off a frame for the axes that is lines which complete the cube in addition to the back three faces which are drawn by default Grid allows you to turn on or off grid lines along major ticks Font allows you to choose a font for the labels The ellipses button allows you to choose from the set of predefined fonts Label Scale allows you to change the size of the labels from the default size For example specifying a labels scale of 2 will make the labels twice as large allows you to specify a color for each part of the axes the grid if drawn ticks labels and background The colors can be any of the defined colors see Color on page 75 in IBM Visualization Data Explorer Users Heference and in addition the background can be drawn as clear invisible The Corners section allows you to explicitly set the range of th
491. to the deltas of the Regular Arrays and origin equal to the sum of the origins of the terms A product of a Regular Array with an irregular Array is a semi regular grid whose unit cells are prisms A Product Array is specified by a list of term clauses naming the Arrays that form the product The last term varies fastest in the resulting list of positions object number class productarray name term number name file file file file number file file name gridconnections Keyword The gridconnections keyword is used to represent the n dimensional cuboidal connections of a regular grid in a compact form It is a kind of Array Object and can be used as the connections component of a Field The shape of the grid number of points in each dimension are specified by a list of n numbers following the optional counts keyword in the object clause The last number corresponds to the fastest varying component of the positions The number n of items in this list determines the dimensionality of the grid The last item in this list corresponds to the fastest varying dimension Appendix B Importing Data File Formats 275 If this grid is part of a Composite Field Object then meshoffsets must be specified to define where this grid is positioned relative to the entire Composite Field The meshoffsets one number for each dimension and specified in the same order as counts are the accumulated count of connections between the origi
492. trol Panel names or Control Panel groups names from appearing in the Open Control Panel by Name option in the Windows window A Control Panel Access dialog box appears in Figure 65 o Control Panel Access Visual Program F Color controls F sosurface controls o F Opacity controls F Color and Opacity F Realization Figure 65 Control Panel Access Dialog Box 140 IBM Visualization Data Explorer User s Guide Each Control Panel and Control Panel group is listed To the left of each is a toggle button This toggle button is used to select which Control Panels or groups can be accessed from the window in which the dialog box was opened To the right of the Control Panel names is an ellipsis toggle Note that Control Panel groups do not have the ellipsis The ellipsis toggle is used to open or raise the corresponding Control Panel when the button is activated Once activated selecting the button again closes the Control Panel and pops up the button To restrict Control Panel access 1 Click on each Control Panel access toggle button that you wish to exclude so that those toggle buttons are deactivated Initially all the toggle buttons are activated 2 Once you have indicated which Control Panels and Control Panel groups you wish to exclude click on OK Selecting the Cancel pushbutton causes the dialog box to be closed and any changes to be canceled Specifying a Startup Control Panel Data Ex
493. trol Panels that contain that interactor are opened If the selected interactor does not currently have a Control Panel Data Explorer creates one for it Alternatively you can select one or more interactor stand ins in the VPE then choose Open Control Panel from the Windows menu in the VPE All Control Panels associated with the selected interactors are opened When Data Explorer is started with the Image window or menu bar as the anchor window some Control Panels may be opened automatically as a visual program is Chapter 7 Graphical User Interface Control Panels Interactors and Macros 141 loaded For visual programs you create you can decide whether a Control Panel should open automatically see Specifying a Startup Control Panel Using Interactors You use interactors to dynamically change the inputs of a tool without making modifications in the VPE window Interactors reside in Control Panel windows As a visual program is built in the Editor window the user selects the interactor stand ins from the Tool Palettes and places them on the canvas Then the corresponding interactors are placed into existing Control Panels or into a new Control Panel as described in Building Control Panels on page 129 Different interactor stand ins can be represented by different interactor styles Integer and Scalar Interactors Integer and scalar interactor stand ins can be represented by four styles e Stepper e Dial e Slider e Tex
494. ts Opacity is the inverse of transparency that is the more opaque the object the less transparent You can set opacity to a value between 0 0 and 1 0 Opacities less than 1 0 allow you to see through an object to reveal objects inside or behind the transparent object For all objects except volumes an Opacity of 0 0 will make the object disappear completely Since Data Explorer uses an emissive volume rendering technique you must set the color of a volume to black RGB of 0 0 0 as well as setting the Opacity to 0 0 to make the volume disappear You will notice that when you view slightly transparent objects through each other the colors of each object combine making it very difficult to accurately assess the color of any one object Used sparingly opacity is a very powerful tool for examining the insides of objects or volumes and gauging the physical relationships between intersecting objects c tn D m mi mall o gt cr tn You can create a variable opacity on an object by manipulating the opacity curve in Colormap This can make paris of an object trail off to transparency useful if some data values are not of interest Be aware that hiding data in this way may mislead someone viewing your results But in some data sets there may be a large number of noisy data values that you would like to exclude in order to see the signal data values of interest In that case setting an Opacity notch to hide t
495. tton Down Approximation None Render Every Close Figure 43 Rendering Options Dialog Box Wireframe available only with hardware rendering Renders the object as a wireframe at the specified density Surfaces are rendered as wireframe meshes while points and volumes are rendered as dots Wireframes are produced at full or fractional density Dots For hardware rendering this approximation renders all points surfaces and volumes as dots at the specified density Lines are rendered as wireframe Dots are produced at full or fractional density For software rendering all points surfaces and volumes are rendered as dots You cannot specify the density for software rendering Box Draws the bounding box of each field in the object to be rendered While the Dots or Wireframe hardware rendering approximation methods are specified the integer for Render every controls the density of the rendering approximation For the Dots approximation it means that every nth vertex is rendered where n is the integer specified For Wireframe approximation the rendering depends on the type of connections For example if the connections are triangles it means that every nth triangle is rendered You can use the Render every value to control the speed of your rendering the higher the value the faster an object can be rendered The default value is 1 meaning every dot and every wireframe is rendered The Render every box is gr
496. turation and Value each work independently of one another As you change their values the RGB boxed area at the left of the window changes automatically to correspond The Opacity area located on the far right hand side of the Colormap Editor window works in a similar way As you make changes in the opacity area the background bar located to the right of the RGB bar reflects your work It shows your adjustments to the opacity of the image in relation to the background colors By default the background bar appears as two vertical stripes However if it is Chapter 6 Graphical User Interface Important Windows 121 122 easier for you to judge the colors of the image and background with a checkerboard style bar select the Set Background Style to Checkboard option on the Options menu see Colormap Options Menu on page 170 In order to perform certain operations on an area it must be selected To select an area either click on the area s label or click in the area itself Only one area can be selected at a time When an area is selected its label is depressed The range of data values onto which HSV and opacity values are mapped is controlled by the min and max fields located near the bottom and top of the Colormap Editor window By default min is set to 0 and max is set to 100 You can change this range to values more appropriate for your data by clicking on either field typing the new value and pressing the Enter key Contr
497. u perform rotation actions and while you place probes in Cursors mode Changing Your Viewing Direction Data Explorer allows you to choose from several defined viewing directions To change the view 1 Select the Set View option box in the View Control dialog box While the mouse button is pressed down an option box listing different view options appears These choices are illustrated in Figure 37 None Top Bottom Front Back Left Right Diagonal Off Top Off Bottom Off Front Off Back Off Left Off Right Off Diagonal Figure 37 Set View Option Box Choose to view the object from the top bottom front back left right or diagonal view Because a head on view of an object tends to detract from the 3 D quality Off options are provided to skew the image slightly To select an option move the mouse so that the desired option is highlighted then release the mouse button The image is redisplayed with the new view Changing the Projection Method Data Explorer provides two methods of image projection These methods make it possible to map a three dimensional image onto a 2 dimensional screen The two methods are IBM Visualization Data Explorer User s Guide Perspective Perspective projection simulates normal camera and human visual systems thereby providing realistic rendering of objects While it is realistic it does not preserve the exact shape and measurements of the object and parallel lines usually do not proje
498. uide to using IBM Visualization Data Explorer for e manipulating and controlling data visualizations e importing various kinds of data for visualization e creating and customizing visual programs with the Visual Program Editor e using the Data Explorer scripting language to create visual programs Who Should Use It How To Use It This Guide is intended for users of different degrees of knowledge and experience with graphical programs Non programmers The non programmer can learn how to use previously created visual programs to examine data sets e g modifying one or more inputs to a visual program and saving and restoring the results Programmers The programmer can learn how to use e the visual programming interface to create visual programs and applications e the scripting language to create visualizations This Guide assumes that you have some knowledge of the operating system and the X Window System being used as well as of OSF Motif For more information see IBM AlXwindows User s Guide or the appropriate window system documentation In this Guide any reference to the X Window System means any window server that supports the X11 protocol including Sun s OpenWindows The Motif window manager mwm has been used in many figures and examples in this Guide Please use the appropriate window manager for your system such as vuewm Hewlett Packard 4dwm SGI or olwm Sun Since title bars and window borders ar
499. ular surface that of the classic teapot It has precomputed normals which are imported as the normals component in addition to positions and connections netcdf teapot8 name of datafile is teapot8 ncdf name of field is surface dimensions pointnums 2268 trinums 3584 axes 3 sides 3 variables float locations pointnums axes float normalvect pointnums axes long tris trinums sides float surfacedata pointnums global attributes source Classic Teapot data from Turner Whitted specific attributes surfacedata field surface surfacedata connections tris triangles surfacedata positions locations surfacedata component normalvect normals vector normalvect attributes dep positions This is the start of a large data section data HDF is a multiobject file structure that is designed to facilitate the transfer of data between machines HDF was created at the National Center for Supercomputing Applications NCSA Data Explorer provides support for importing HDF files that contain a Scientific DataSet SDS A Scientific DataSet is an HDF set that stores rectangular gridded Arrays of data together with the information about the data Note Scientific Data Sets should be created using the DFSD API and not the SD API To import HDF files specify the filename as the name parameter By default all the datasets will be imported and collected into
500. ure 83 Data Imbedded in a Header Section E ee Figure 84 Header Referring to Data in Another File Appendix B Importing Data File Formats 245 Examples data Figure 85 Header and Data in the Same File These configurations can be used in conjunction with each other For example a file can contain both a header and data and can refer to data both in the same file and in another file A file can also have only a header and refer to data in either a data only file or in a file that contains both a header and data This flexibility allows you to construct a header that points to data in existing files and lets you view and edit the header information if necessary using standard tools The following examples illustrate some of the ways you can import data using the Data Explorer native file format You may wish to refer to the full specification of the syntax see Syntax of the Native File Format on page 268 The basic way to create a data file is to first define the Arrays or components contained in a Field and to then describe how to collect the components together To define a higher level structure such as a series first define the components then the Fields and then how to collect the Fields to make a series The examples in this section illustrate the process In the first six examples the data Objects can be viewed by the script shown here Other scripts are shown with the later examples data Import filename d
501. ute name value The left side portion of an assignment statement is a sequence of one or more identifiers separated by commas The attribute name value value pair lists and the brackets are optional and are discussed in Function Call Attributes on page 202 The equal sign is the assignment operator It stores the values specified in the right side portion of the statement in the variables named by the identifiers specified in the eft side portion of the statement You can specify the values in the right side portion of the statement as a sequence of expressions or as the result of a single function call 198 IBM Visualization Data Explorer Users Guide You can also use either of two additional symbols lt or as the assignment operator An assignment statement is terminated with a semicolon indicating the end of the right side portion of the statement The values specified to the right of the assignment operator are assigned to the identifiers to the left of the assignment operator If the number of values equals the number of identifiers the first value is stored in the first identifier the second in the second the third in the third and so on If the number of values is greater than the number of identifiers the extra rightmost values are ignored f the number of values is less than the number of identifiers the values are assigned in order to the leftmost identifiers Those identifiers not receiving a value from
502. uts to create one or more outputs for example an image You derive program inputs from the output of tools in the program or by setting the input values to constants Tools that provide output values as input to other tools are in alphabetical order e Colormap Editors see 6 3 Using the Colormap Editor on page 119 e Interactors see Using Interactors on page 142 e Macros see 7 2 Creating and Using Macros on page 149 e Modules see Chapter 1 Data Explorer Tools on page 1 in IBM Visualization Data Explorer User s Reference e Picks see Using Pick on page 87 e Probes see Using Probes Cursors on page 85 e Sequencers see Using the Sequencer on page 68 e Transmitters and Receivers see Using Transmitters and Receivers on page 106 Chapter 6 Graphical User Interface Important Windows 99 Before building a visual program you should be familiar with the information presented in this chapter as well as the information on Data Explorer modules presented in Chapter 1 Data Explorer Tools on page 1 in BM Visualization Data Explorer Programmer s Reference Chapter 2 Tutorial Using Data Explorer on page 3 in IBM Visualization Data Explorer QuickStart Guide introduces the Data Explorer graphical user interface Chapter 3 Tutorial Il Editing and Creating Visual Programs on page 21 in IBM Visualization Data Explorer QuickStart Guide introduces the basic aspects of working with visual pro
503. ven the grid size or number of connections and positions may be different for each Series member The Series Field is described in detail in Series Groups on page 35 Series values do not have to be continuous but may represent useful information like the actual voltage setting for that Series entry 0 04 2 3 13 4 Series members are accessed by their ordinal position starting at 0 regardless of their value Another way to organize a collection of associated data files is to create individual files for each time step or voltage measurement etc Give each file a filename containing an ordinal number so you can access them easily with a computer program e g myfield 001 dx myfield 002 dx and so on Each file will contain the Field to be imported at each time step In either case Series Field or separately numbered files you can control when a particular time step is visualized in a visual program using the Sequencer tool This tool emits a series of integers You set the minimum maximum and increment as well as choosing to start at a specific number so you can jump ahead in the series if you like The Sequencer can be connected to the Import module to specify which Series member to read in from the specified input file at the next iteration Appendix A Using Data Explorer Some Useful Hints 217 c tn D m mi mall o gt cr tn Annotation Alternately you could Import the Series Group file with I
504. ver ada e ie a a 2 eee eee 185 Copyright IBM Corp 1991 1997 177 9 1 Using Distributed Computation Data Explorer provides you with the capability to distribute your visual program across a network of heterogeneous workstations Distributing your visual program provides you with parallelism and enhanced resource utilization Parallelism is achieved by the simultaneous execution of different portions of the visual program on each of the workstations The amount of parallelism that you can achieve is dependent on the organization of your visual program and the number of available workstations Enhanced resource utilization can be achieved for example by assigning computationally intensive portions of the visual program to the more powerful workstations If the data you are visualizing is located on one or more workstations then performing some of the data realization and transformation on the workstations containing the data can reduce data transfer overheads Distributed processing in Data Explorer is achieved in two ways by using outboard modules user supplied or by placing groups of tools to execution groups These two methods can be used independently or in combination For a discussion of outboard modules see 10 3 Inboard Outboard and Runtime loadable Modules on page 85 in BM Visualization Data Explorer Programmer s Reference Execution groups can be created and modified using the Visual Program Editor or
505. view The larger the width the smaller the object appears Specify the width by clicking on the Camera Width field typing a new value in world coordinates and pressing the Enter key While you are using perspective projection the Width field is grayed out Resizing the Image To resize the image simply resize the image window by dragging its borders to shrink or expand the window The image displayed inside the window is resized accordingly Note that the size of the object in the Image window is controlled only by the width of the window You can specify an exact Image window size by using Camera mode as described in Precise Camera Settings on page 82 For more information on resizing windows see Moving and Resizing Windows on page 62 Restoring Images Data Explorer remembers the 10 most recent camera configurations You can undo the most recent actions in the View Control dialog box by selecting the Undo option box or by using its accelerator key Ctr1 U You can continue to revert to previous configurations until you have reached the first configuration in memory after that the Undo option is disabled grayed out As you revert to previous camera configurations by Undoing actions you can still restore them by using the Redo button providing that you have not performed any other actions since the last Undo The accelerator key for Redo is Ctr1 D Note The Redo button is disabled as soon as you change the camera
506. vironment variable be set The default is that framebuffer readbacks are enabled DXCOLORS specifies a file name containing string and RGB value pairs as an alternate for usr lpp dx lib colors txt The string name can be used by any Data Explorer tool where a color can be specified by name for example Color The HGB value specifies the specific numeric value for the color DXDELAYEDCOLORS enables Readlmage to create delayed color images if the image is a tiff format image saved in a byte with colormap format or a GIF format This feature is enabled if this variable is set to any value Delayed colors use less memory DXEXEC specifies an executive to be run at start up You should set this variable only for a customized version of Data Explorer DXFLING f DXFLING is set to 1 then for hardware rendered images in rotation mode and execute on change mode if you drag the mouse across the image and release the mouse button outside the image the object in the image will begin to rotate and will continue to rotate until you click inside the image The direction and speed of the mouse motion before release will affect the rotation direction and rotation speed of the object in the window DXGAMMA sets the gamma correction for software rendered images displayed to the screen by a Display or Image tool On many display devices a given change in the digital brightness of the image is not reflected in a corresponding change in screen brightness A
507. want any given frame to be displayed 3 Click on the Close button The new rate takes effect You can also set the throttle value by using the throttle parameter to the Image tool see Image in BM Visualization Data Explorer User s Reference Changing the Title of an Image Window By default the title of the Image window is the name of the visual program that produced the image f your visual program requires multiple image windows it may be difficult to distinguish the windows since all of the Image windows by default have the same title In this case you can change the title of each Image window to help you organize them To change the name of the Image 1 Select the Change Image Name option from the Options menu in the Image window A dialog box opens 2 Enter a new name for the image in the text field of the dialog box and click on OK The title bar of the Image window is updated to reflect the change Notes 1 If you start Data Explorer with the Image window as the anchor without specifying a visual program in the command line the title of the Image window defaults to Image However when you load a visual program the Image window assumes either the name of the visual program or if the visual program contains any named images the name of one of the Image windows 2 It is also possible to specify the title of an Image window by using the title parameter to the Image tool see Image in BM Visualization Data E
508. wing ways e Double click on the file name under the Files heading e Click on the file name under the Files heading The file name appears in the Selection text box Click on OK e Click in the Selection text box and type the file name then press Enter or click on OK Note that a complete file name must be specified in the Selection field to read in a file A file name may be highlighted under the Files heading without appearing in the Selection field To select the file click on its name under the Files heading IBM Visualization Data Explorer User s Guide To see any comments that might be associated with a visual program before you load it select a file by clicking on its name once or by entering its name in the Selection text box then click on the Comments button If the visual program has comments associated with it they are displayed otherwise a message appears telling you that there are no comments To see a different list of files change either the file filter or the file directory File Selection Dialog Boxes on page 116 When you open a file its name is displayed in the title bar of the VPE 6 3 Using the Colormap Editor The Colormap Editor is a window that enables you to map colors to specified data values the results of which are displayed in the visual image In addition to color the Colormap Editor also controls the mapping of opacity to data which is the degree of the image s transparency in relation t
509. wm has been used in many figures and examples in this chapter Please use the appropriate window manager for your system such as vuewm for Hewlett Packard 4dwm for SGI and olwm for Sun Since title bars and IBM Visualization Data Explorer User s Guide window borders are features of a window manager the appearance of your windows may differ slightly from those in the figures and examples Looking at Window Structure Figure 30 points out the major parts of a Data Explorer window Definitions of the parts follow the figure Visual Program Editor usr ipp dx samgles tutorial example inet Partion Sequencer Compute Isosartace Map ToPlane Gradient Auto olor Integer Colorssag Isosurtace Selector Switeh Image Figure 30 Visual Program Editor Window The following are features of Data Explorer windows 1 The title bar contains the following items from left to right e The menu button which when pulled down offers various window control options e The window name e The minimize button which reduces the window and all of its secondary windows to a single icon e The maximize button which enlarges the window to full screen size 2 The menu bar displays the titles of pull down menus from which can choose options When you choose a title a pull down menu appears 3 A pull down provides you with options you can select Chapter 5 Graphical User Interface Basics 61 4 A dialog box or in
510. wn module considering how powerful the stock Data Explorer tool set is The next section addresses those who want to create new visual programs So here are a few tips on design for interactive use Interactors and Control Panels 232 Interactors are special two part modules To incorporate an interactor into your visual program you select the preferred type of interactor from the Interactor category place it on the VPE canvas just like any other module and connect it to the appropriate input tab or tabs on other modules The interactor module that appears on the canvas is called a stand in To use the interactor interactively you also place an instance of the interactor in a Control Panel window The interactor in the control panel represents the actual manipulator used by the user exploring the data When a value is set by a user it becomes the new output of the interactor stand in and is thereby fed to the modules connected to the stand in s output Interactors have different appearances depending on its type numeric integer or scalar interactors can be made to look like dials or sliders while string interactors give you a place to type in a string List interactors let you keep a list of items there are lists of strings vectors values integers and scalars It is good programming practice to set interactor minima maxima and increments to reasonable values For example a Scale module will accept a value of 0 0 but the ef
511. x format dx connections ShowConnections data connections AutoColor connections tubes Tube connections 0 08 camera AutoCamera tubes off diagonal image Render tubes camera Display image Note For Figure 86 on page 248 and Figure 87 on page 249 the argument off front is used instead of off diagonal 246 IBM Visualization Data Explorer User s Guide Simply substitute the file name of the data file for filename in the Import statement For information about how to use the Data Explorer script language see Chapter 10 Data Explorer Scripting Language on page 187 Example 1 A Regular Grid The following example illustrates the basic Objects of the data model and shows how to imbed data as text in the header section The Objects and data describe a regular grid This file is found in usr lpp dx samples data regular dx Figure 86 on page 248 shows the resulting structure The axes diagram in the lower right corner of the figure indicates the orientation of the axes This orientation applies to all subsequent examples as well Note that the positions are considered to increment in the order last index varies fastest when matching data to positions For example for this simple 4 x 2 x 3 grid the order of the positions is XpVoZo XgYoZ4 XoYoZol Xoy1Zo and so on This is because the deltas are specified in the order x y Z so z is the last index If the data was stored in the order xgy
512. xample a file named abc xyz would be renamed abc xyz net An existing file can be saved in the following ways e Under the same name replacing the previous version of the file e Under a new name or directory thus creating a new file and preserving the previous version Replacing a Previously Saved File To save a program that has been named and saved previously press Ctrl S or select the File menu Save option This replaces the previous version of the file A named visual program has its name displayed in the title bar of the VPE window Chapter 6 Graphical User Interface Important Windows 117 118 Saving a Visual Program as a New File To save program as a new file 1 Select the Save As option from the File pull down menu The Save As dialog box appears see Figure 54 on page 116 The Selection field displays the current file path 2 Click on the Selection field and add the new file name If you want to save the file to a different directory change the file path in the field as well 3 Press the Enter key or click on OK The file is saved and the Save As dialog box disappears Restoring a Previously Created Program To restore a previously created visual program select the File menu Open option The Open dialog box appears Figure 55 Figure 55 Open Dialog Box It lists all file names in the current directory that are found through the specified file filter A file can be selected in one of the follo
513. xample above the red colored rain forming areas seen through a yellow cloud will in fact be perceived as orange areas We can temporarily hide the yellow cloud by changing its opacity to 0 0 and its color to black and entrain ourselves to see the red regions by themselves This is a fine point of perception but it is important to be aware of Perception of natural objects is greatly modified by psychological memories and judgements about their correctness in size color mass and relationship to each other Once we move into the abstract world of visualization we have no firm psychological constructs on which to base our perceptions While this may imply that we are working with a clean slate no preconceptions and an unbiased scientific viewpoint just the opposite happens we seek to impose interpretation on the scene and may ascribe invalid attributes to objects as we try to derive meaning from the scene On one hand this is precisely why we imaged the volume in the first place We want to derive patterns or shape and then figure out why they exist On the other hand we can be fooled by our own eyes if we are not very careful to comprehend and explain to others exactly the assumptions we make as we convert our sample numbers into colored images By the way you wont find a specific module named VolumeRendering As it happens any volumetric Field can be directly rendered by the Image module or the Render or Display modules So if
514. xis at a point other than the origin if the intent of the chart is to represent absolute amounts of quantities being compared side by side All of these rules of thumb are employed to make good charts nevertheless these rules are too often violated even in the mainstream media Unfortunately these traditional rules of scale do not help us much when we create 3 dimensional objects of arbitrary shape So it becomes incumbent upon you to make sensible decisions in depicting objects never before seen by any viewer It will be very easy to exaggerate a 3 D height field by changing the scale factor in Rubbersheet You can make the one high point in the data leap as high as Mt Everest If that point is in fact a special value in your data this may be an appropriate thing to do If not you may wish to choose a scale better suited to depicting the entire surface On the other hand if there are peaks you must avoid crushing the entire surface to lessen the high points Doing so could lead to potential misinterpretation of your results For many researchers Data Explorer will be the first program they have used that permits them to create and view animation or motion playback of their data This new temporal dimension is often a source of problems until the author gets the hang of things Here are a few tips as you develop your own moving pictures First remember that your viewers have never seen this phenomenon before Give them a chanc
515. xplorer Otherwise the first n variables categorized as positions where n is the dimensionality of the CDF dimensions are used to form the positions component Any additional such variables are treated as data variables If there are no positions type variables the positions component will be a regular grid with origin of O and increments of 1 in each axis where the number of axes corresponds to the dimensionality of the imported CDF r variable If there are records in the CDF each record is imported as a series member In many cases there is a variable with the mnemonic EPOCH which corresponds to a time stamp for each record in the CDF If so the double representing msec since Appendix B Importing Data File Formats 279 ms mall o D ms fo 3 y cr tn 280 O AD in each value of EPOCH is stored as the series position attribute If not the first variable that is record variant and nondimensional variant is considered the series variable This variable is imported as the series position attribute If there is no time variable the series position starts at 1 and increments by 1 per series member so that there is one member for each record in the CDF The series position attribute containing the time stamp may be accessed with the Attribute module You can specify the name or names of the data variable in the variable parameter of the Import tool and the corresponding variable s will be imported In the same way
516. xplorer User s Reference Chapter 6 Graphical User Interface Important Windows 93 Throttle Seconds per Frame 0 000 Figure 44 Throttle Dialog Box Control Panel Access Clicking on this option in the Options pull down menu generates a dialog box with two toggle buttons e The button on the left determines whether the specified control panel will be accessible from the Image window using the Open Control Panel by Name option of the Windows pull down menu when Data Explorer is invoked with the image or menubar option e The button on the right when activated depressed will display the control panel s Saving an Image 94 Data Explorer provides you with the capability to save single images and image series to disk files You save images using the File menu Save Image option of the Image window Selecting this option causes a Save Image dialog box to appear see Figure 45 on page 95 To save an image 1 Open the Save Image dialog box using the File menu Save Image option Select the name of the file into which the image will be written or enter a file name into the Output File Name text field Select the image format Specify any image format options e g Gamma Correction Click on Save Current 6 Click on Apply NO oR OO You can also save an image by using the recordEnable recordFile recordFormat recordRes recordAspect parameters to the Image tool Portions of the S
517. xplorer session by specifying dx as the value of the format parameter for the Import module For more information see Import on page 165 in BM Visualization Data Explorer User s Reference Overview of the Native File Format 244 A Data Explorer file consists of a header section followed by an optional data section The header section consists of a textual description of a collection of Objects The data section contains the Array Object data either as text or in binary and is referred to by the header section A header section can refer to Objects and data either in the current file or in other files Figure 83 on page 245 shows data imbedded in its header Another file cannot refer to data in this file because there is no specified data section However header sections in this file can refer to data sections in other files This method is sometimes more convenient when creating data files with simple programs IBM Visualization Data Explorer User s Guide Figure 84 on page 245 shows a header section referring to a data section in another file The header refers to the data using the data file name and an offset location in bytes from the beginning of the data section in the file Figure 85 on page 246 shows a header section and data section in the same file The header refers to the data section using a byte offset relative to the start of the data section header T1 mall o D m s o g 3 y ct un Fig
518. y given only an image simply displays it to the screen Image given an object renders it and displays it to the screen The camera information is provided via direct interactors rotate zoom etc or through the camera mode option in the View Control dialog box Image has two outputs the object to be rendered including any AutoAxes that may have been added via menu choices and the camera used You would use Render if you needed the image itself for example for the Arrange or Filter modules or if you wanted to use Writelmage For the Image tool the Writelmage function is available through the Save Image and Print Image commands in the Image window or through the hidden recordEnable recordFormat and recordFile parameters to the Image tool You would use Display without a camera if your object is already an image and you simply want to display it You do not need or want to render it You would also use Display without a camera to display a set of Arranged images You would use Display with a camera if you wanted to directly control the camera for example for a computed fly through path You would also use Display if you wanted to define your own direct interaction modes see SuperviseWindow on page 336 and SuperviseState on page 332 in BM Visualization Data Explorer User s Reference rather than using the predefined direct interaction modes of the Image tool c tn D m mi mall o gt cr tn How d
519. y to show a list of visual programs in that directory To select a program click on the name See File Selection Dialog Boxes on page 116 for more information Save Program Saves the current visual program and associated Control Panels This option saves the following files filename net for network that is a Data Explorer visual program and filename cfg for configuration This option is grayed out unless Data Explorer was started in image mode Save Program As Saves the current visual program and all associated Control Panels under a name you type in the dialog box This option saves the following files filename net for network that is a Data Explorer visual program and filename cfg for configuration This option is grayed out unless Data Explorer was started in image mode Program Settings Brings up a cascade menu with two choices e Save As saves the current settings for the visual program e g window placement interaction mode camera viewpoint interactor setup etc The settings are saved in a cfg file e Load loads previously saved settings from a cfg file Chapter 8 Graphical User Interface Menus Options and the Message Window 165 166 Load Macro Loads a macro for use making it available in the tool palette A file selection dialog box appears for you to specify the desired macro file name See Loading Macros on page 152 Load Module Definition s Loads a module definition for use m
520. y describes an interpolation element such as a line triangle tetrahedron or cube The vertices of each such interpolation element are specified by one Array item consisting of a list of indices into the positions Array one index per vertex of the interpolation element Position index numbers begin at O The type of the interpolation elements is specified by the element type attribute of the connections component Two open ended series of element types are currently defined the n dimensional simplexes and the n dimensional cuboids The n dimensional simplexes are represented by connections components with element type attributes of triangles 2 D or tetrahedra 3 D Each item of such a connections component is a list of n 7 integer indices referring to items in the positions component representing the n 1 vertices of an n dimensional simplex These vertices are ordered as illustrated in Figure 4 on page 21 For tetrahedra the parity of all tetrahedra in a given Field must be consistent Figure 4 on page 21 illustrates the two possible parities for tetrahedra In addition for triangles there is a convention for which face is the front using the right hand rule 20 IBM Visualization Data Explorer User s Guide r r r DA LIN A triangles tetrahedra Figure 4 Order of Vertices in Triangles and Tetrahedra In the tetrahedron at right s is the point nearest the viewer at center the point furthest from the v
521. y number of named components specified by component clauses The value of the component is specified as an object name or number in the current file or as an Object name or number in another file object number class field name component component name value number name file file file file number file file name An Array Object specifies the type default float category default real rank default 0 shape and number of items The types are defined as follows signed byte unsigned byte signed 2 byte integer unsigned 2 byte integer signed 4 byte integer unsigned 4 byte integer signed 8 byte integer 4 byte floating point 8 byte floating point character string Note Lists are simply Arrays Thus a list of integers is an Array of type int a list of strings an Array of type string The categories are real A number complex Two numbers representing the real and imaginary components The data is specified by an offset in bytes in the data section of the current file an offset within the data section of another Data Explorer file or by the keyword follows indicating that the data begins immediately following the newline after the follows keyword The offset is specified in bytes for both binary and text files Optional keywords before the data keyword specify the format and byte order of the data The mode keyword before a data location specification sets the default data encodi
522. you are in Navigate mode the camera position is adjusted so that the size of the object in the image area remains unchanged While in Navigate mode changing the view angle does not change the camera position While you are using orthographic projection the View Angle stepper is disabled In orthographic projection you can specify the camera width This is discussed in Precise Camera Settings on page 82 Note Changing the projection method or view angle does not automatically initiate reexecution of the visual program To see the effects of your changes you must select Execute Once or Execute on Change Rotating the Object To rotate the object you are viewing 1 Select Rotate from the Mode pull down box or use the Ctr1 R accelerator key 2 A set of 3 D axes appears in the lower right corner of the Image window Also if you have enabled the Display Rotation Globe option in the Options pull down menu or you do so now a wire frame globe appears in the lower left corner If you press the right mouse button you can drag the mouse to rotate the object clockwise CW and counter clockwise CCW with the image center as the point of rotation If you press the eft or center mouse button you can use the mouse as a track ball and rotate the object in all three dimensions The mode of rotation is determined by the mouse button you use Chapter 6 Graphical User Interface Important Windows 77 78 As you rotate the object the set o
523. you can start Data Explorer with the following command dx edit uionly Once the user interface is started you can connect to the executive portion of Data Explorer by following the procedures described in 9 3 Connecting to the Server on page 183 All of the command line options for Data Explorer are described in C 2 Command Line Options on page 295 Using Environment Variables There are several environment variables that you may find useful to customize Data Explorer These can be set in your login profile or set as required DXMACROS The DXMACROS environment variable is a list of the directories in which Data Explorer will look for macros If you do not specify DXMACROS you will need to load macros individually using the process described in 7 2 Creating and Using Macros on page 149 The directories are searched in the order in which they are specified in the environment variable If multiple macros with the same name are encountered the first macro found is used An example of the statement setting the DXMACROS environment variable in the C shell environment is the following setenv DXMACROS usr mydirectory projectAmacros usr mydirectory projectBmacros where usr mydirectory projectAmacros and usr mydirectory projectBmacros are two directories in which macros will be sought Multiple directories can be listed with directory names separated by a colon Chapter 5 Graphical User Interface Basics 59 DXDATA
524. you can use start end and delta to import a subset of CDF records Variable and global attributes present in the CDF are imported as Object attributes These attributes may be accessed through the Attribute and Inquire modules e g to build metadata driven applications Variables that vary in all dimensions and are record variant are considered data variables Any variable that is not a position or time variable is also considered a data variable allowing every variable to be imported If you want the positions to be a variable other than the one chosen by Data Explorer you can use Replace or Rename to switch the components e g two or more sets of positions information are stored for different coordinate systems Each data variable becomes a data component in a Field Object Hence there is one Field for each data variable in the Group imported Since Data Explorer can handle data more flexibly than CDF some assumptions are imposed upon certain classes of data that may be imported e Since data stored in CDF are not distinguished as cell centered or node based all data components are treated as the latter i e data dep positions The Post module may be used to transform a Field to cell centered i e data dep connections e Since CDF does not natively support Fields other than rank 0 all data variables are treated as scalars The Compute module can be used to construct the appropriate vector representation from multiple scal
525. zooming in or out of the image Pan Zoom mode e Moving the camera within the scene Navigate mode e Specifying precise values for the camera settings Camera mode e Setting probe points in the image Cursors mode e Picking objects in the image Pick mode e Resizing the image e Resetting previous views Undo and Redo buttons To select a mode use its accelerator key or do the following 1 Click on the Mode option box A menu of the mode options is displayed Chapter 6 Graphical User Interface Important Windows 75 76 2 Click on the desired option The option box displays the name of the new mode The dialog box also displays any additional controls for the new mode The different modes are discussed in more detail in subsequent sections Most of the modes use two or three mouse buttons to manipulate the view A diagram is provided in the margin to the left of each section to illustrate the mouse button functions the mode and the accelerator key Some of the modes use an overlay which provides visual feedback before any action is taken to change the image This temporary overlay typically an axes diagram rectangle or brick is laid over the image As you drag with the mouse the overlay changes accordingly The image does not change until you release the mouse button at which time it is updated according to the action you selected Note If Execute on Change is enabled Data Explorer does update the image while yo

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