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1. Figura 19 28 Airports of Alaska X 7 Click on OK to create and load the new raster map see Figure Heatmap 3 Input Point Vector airports E Output Raster ata raster heatmap airports wee Output Format GeoTIFF El Radius 1000000 Decay Ratio 0 1 C Advanced Row Column Cell Size X Cell Size Y C Use Radius from field meters Use Weight from field Sd Ca 4 Figura 19 29 The Heatmap Dialog X The result after loading the heatmap is probably not the result which was expected It is still a grey even surface not showing any variation First some additional configuration of this layer needs to be done to make the heatmap present itself 1 Open the properties dialog of layer heatmap airports select the layer heatmap airports open context menu with right mouse button and select Properties 2 Select the Symbology tab 3 Change Color map E from Grayscale to Pseudocolor 4 Press the Apply button 5 Switch to the Transparency tab and set Global transparency A to 40 6 Select OK The final result is shown in Figure_Heatmap_4 234 Cap tulo 19 Plugins QGIS User Guide Release 1 8 CBP 9 OA Vw QM Gye Sm OR Sy Mm Control rendering order 7094654 56 135924 Y5 Coordinate 5432571 5612755 Scale 1 50660422 1 Y M Render EPSG 2964 E Figura 19 30 The heatmap after loadi
2. C Program Files QGIS python plugins C Documents and Settings SUSERNAME qgis python plugins 19 1 QGIS Plugins 197 QGIS User Guide Release 1 8 If the installation is successful a confirmation message will appear Tf the installation fails the reason for the failure will be displayed in a warning dialog Most often errors are the result of connection problems and or missing Python modules In the former case you will likely need to wait before trying the install again in the latter case you should install the missing modules relevant to your operating system prior to using the plugin For Linux most required modules should be available via a package manager For install instructions in Windows visit the module home page If you are using a proxy you may need to configure it under Edit Options Gnome OSX or Settings Options KDE Windows on the Proxy tab The Uninstall plugin button is enabled only if the selected plugin is installed and is not a core plugin Note that if you have installed an update to a core plugin you can uninstall this update with the Uninstall plugin and revert to the version shipped with Quantum GIS This default version however cannot be uninstalled Repositories tab The second tab Repositories contains a list of plugin repositories available for the Plugin Installer By default only the QGIS Official Repository is enabled You can add several user contrib
3. Figura 15 5 GRASS Digitizing Settings Tab Symbology Tab The Symbology tab allows you to view and set symbology and color settings for various geometry types and their topological status e g closed opened boundary GRASS Edit e A a FETO ER HO Category Settings Symbology Table Line width 1 1 Marker size 9 Lx Type Line Boundary no area Boundary 1 area Boundary 2 areas Centroid in area Figura 15 6 GRASS Digitizing Symbolog Tab Table Tab The Table tab provides information about the database table for a given layer Here you can add new columns to an existing attribute table or create a new database table for a new GRASS vector layer see Section Creating a new GRASS vector layer Tip GRASS Edit Permissions You must be the owner of the GRASS MAP SET you want to edit It is impossible to edit data layers in a MAP SET that is not yours even if you have write permissions 128 Cap tulo 15 GRASS GIS Integration QGIS User Guide Release 1 8 f GRASS Edit TESTES a e2otNQeoetReaavrwRr EO Category Settings Symbology Table Layer MI Com Type Length cat int 11 stri string 30 Add Column Create Alter Table Figura 15 7 GRASS Digitizing Table Tab 15 8 The GRASS region tool The region definition setting a spatial working window in GRA
4. Make lines appear less jagged at the expense of some drawing performance Fix problems with incorrectly filled polygons 7 4 Measuring Measuring works within projected coordinate systems e g UTM and unprojected data If the loaded map is defined with a geographic coordinate system latitude longitude the results from line or area measurements will be incorrect To fix this you need to set an appropriate map coordinate system See Section Working with Projections All measuring modules also use the snapping settings from the digitizing module This is useful if you want to measure along lines or areas in vector layers ty To select a measure tool click on and select the tool you want to use 7 4 1 Measure length areas and angles QGIS is able to measure real distances between given points according to a defined ellipsoid To configure this choose menu option Settings Options click on the Map tools tab and choose the appropriate ellipsoid There you can also define a rubberband color and your preferred measurement units meters or feet and angle units degrees radians and gon The tools then allows you to click points on the map Each segment length as well as the total shows up in the measure window To stop measuring click your right mouse button g Measure v Ellipsoidal Segments in meters 12 741 519 Total 12 742 km Help New Close Figura 7 2 Measure Distance A KDE a Areas can also be
5. Figura 8 3 The Customization dialog QGIS Customization is divided into five groups In Docks you find the dock windows Dock windows are applications that can be started and used as a floating top level window or embedded to the QGIS main window 46 Cap tulo 8 QGIS Configuration QGIS User Guide Release 1 8 as a docked widget see also Panels and Toolbars In Menus you can hide entries in the Menu bar In the Status Bar features like the coordinate information can be daectivated In Toolbars you can de activate the toolbar icons of QGIS and in Widgets you can de activate dialogs as well as their buttons With R Switch to catching widgets in main application you can click on elements in QGIS you want to be hidden and find the corresponding entry in Customization see figure_customization You can also save your various different setups for different use cases as well Before your changes are applied you need to restart QGIS 8 4 Customization 47 QGIS User Guide Release 1 8 48 Cap tulo 8 QGIS Configuration CAP TULO 9 Working with Projections QGIS allows users to define a global and project wide CRS Coordinate Reference System for layers without a pre defined CRS It also allows the user to define custom coordinate reference systems and supports on the fly OTF projection of vector and raster layers All these features allow the user to display layers with different CRS and have them overlay
6. 1 Load the Shapefile railroads shp in QGIS and press Open Amb Sade 10 33 Field Calculator dialog 2 Click on A Toggle editing mode and open the y 3 Select the Create a new field checkbox to safe the calculations into a new field 4 Add length as Output field name real as Output field type and define Output field width 10 and a Precision of 3 5 Now click on function length in the Geometry group to add it as length into the Field calculator expression box and click Ok 6 You can now find a new column length in the attribute table The available functions are listed below column name column name value of the field column name string a string value NULL null value 96 Capitulo 11 Working with Vector Data QGIS User Guide Release 1 8 a IS NULL a has no value a IS NOT NULL a has a value a IN value value a is below the values listed a NOT IN value value a is not below the values listed a OR b a or xb is true a AND b a and b is true NOT a inverted truth value of a sqrt a square root of a sin a sinus of a cos a cosinus of b tan a tangens of a asin a arcussinus of a acos a arcuscosinus of a atan a arcustangens of a to int a convert string a to integer to real a convert string a to real to string a convert number a to string lower a convert string a to lower Case upper a convert string a to upper Case length a length of string a arc
7. 9 Select the Parks layer in the list 10 Click Apply to add the layer to the map Note that proxy settings you have set in your preferences are also recognized Add WFS Layer from a Server Server connections DM Solutions v Connect New Edit Delete Load Save Cache Title A Name Abstract ER Filter Parks park Cities popplace C O Coordinate reference system EPSG 42304 Change Help 2 Apply Close Figura 13 3 Adding a WFS layer A You ll notice the download progress is visualized in the left bottom of the QGIS main window Once the layer is loaded you can identify and select a province or two and view the attribute table Only WES 1 0 0 is supported At this point there have not been many tests against WFS versions implemented in other WFS servers If you encounter problems with any other WFS server please do not hesitate to contact the development team Please refer to Section Mailing lists for further information about the mailinglists Tip Finding WFS Servers You can find additional WFS servers by using Google or your favorite search engine There are a number of lists with public URLs some of them maintained and some not 13 2 QGIS Server QGIS Server is an open source WMS 1 3 and WES 1 0 0 implementation which in addition implements advanced cartographic features for thematic mapping The QGIS Server is a FastCGI CGI Common Gateway Interface application wr
8. Define the projection by clicking on the radio button Projection to enable the projection list We are using Albers Equal Area Alaska feet projection Since we happen to know that it is represented by the EPSG ID 2964 we enter it in the search box Note If you want to repeat this process for another LOCATION and projection and haven t memorized the EPSG ID click on the Projector con in the lower right hand corner of the status bar see Section Working with Projections 9 In Filter insert 2964 to select the projection 10 Click Next 11 To define the default region we have to enter the LOCATION bounds in north south east and west direc tion Here we simply click on the button Set current QGIS extent to apply the extend of the loaded layer alaska shp as the GRASS default region extend 12 Click Next 13 We also need to define a MAPSET within our new LOCATION You can name it whatever you like we used demo When creating a new LOCATION GRASS automatically creates a special MAPSET called PERMANENT designed to store the core data for the project its default spatial extend and coordinate system definitions Neteler amp Mitasova 2008 Literature and Web References 14 Check out the summary to make sure it s correct and click Finish 15 3 GRASS LOCATION and MAPSET 123 QGIS User Guide Release 1 8 15 The new LOCATION alaska and two MAPSETs demo and PERMANENT are created The cur
9. alaska Output column prefix Y OK Cancel Figura 19 36 Zonal statistics dialog KDE 19 21 SQL Anywhere Plugin 239 QGIS User Guide Release 1 8 240 Cap tulo 19 Plugins CAPITULO 20 Help and Support 20 1 Mailing lists QGIS is under active development and as such it won t always work like you expect it to The preferred way to get help is by joining the qgis users mailing list Your questions will reach a broader audience and answers will benefit others 20 1 1 qgis users This mailing list is used for discussion of QGIS in general as well as specific questions regarding its installation and use You can subscribe to the qgis users mailing list by visiting the following URL http lists osgeo org mailman listinfo qgis user 20 1 2 fossgis talk liste For the german speaking audience the german FOSSGIS e V provides the fossgis talk liste mailing list This mailing list is used for discussion of open source GIS in general including QGIS You can subscribe to the fossgis talk liste mailing list by visiting the following URL https lists fossgis de mailman listinfo fossgis talk liste 20 1 3 qgis developer If you are a developer facing problems of a more technical nature you may want to join the qgis developer mailing list here http lists osgeo org mailman listinfo qgis developer 20 1 4 qgis commit Each time a commit is made to the QGIS code repository an email is posted to this list
10. Properties Rename Copy Style Add New Group Expand all Collapse all Update Drawing Order Additionally according to layer position and selection e Make to toplevel item e Group Selected Right mouse button menu for vector layers Zoom to layer extent Show in overview Remove Set Layer CRS Set Project CRS from Layer Open attribute table Toggle editing not available for GRASS layers Save as Save selection as Query Show Feature Count Properties 28 Cap tulo 6 QGIS GUI QGIS User Guide Release 1 8 e Rename e Copy Style e Add New Group e Expand all e Collapse all e Update Drawing Order Additionally according to layer position and selection e Make to toplevel item e Group Selected Right mouse button menu for layer groups Zoom to group e Remove e Set group CRS e Rename e Add New Group e Expand all e Collapse all e Update Drawing Order It is possible to select more than one layer or group at the same time by holding down the Ct r1 key while selecting the layers with the left mouse button You can then move all selected layers to a new group at the same time You are also able to delete more than one Layer or Group at once by selecting several Layers with the Ct rl key and pressing Ctrl D afterwards This way all selected Layers or groups will be removed from the layerlist 6 3 1 Working with the Legend independent layer order Since QGIS 1 8 there is a widget that allows to d
11. QGIS User Guide Release 1 8 g New Vector Layer Y Y Og Type e Point Line Polygon CRS ID EPSG 2964 Specify CRS New attribute Name Name Type Width 80 Precision Attributes list gt Add to attributes list Name Type width Precision id Integer 10 Name String 80 KI MOD Remove selected attribute Help o Cancel Figura 11 31 Creating a new Shapefile layer Dialog Note that QGIS does not yet support creation of 2 5D features i e features with X Y Z coordinates To complete the creation of the new Shapefile layer add the desired attributes by clicking on the Add button and specifying a name and type for the attribute A first id column is added as default but can be removed if not wanted Only Type real hd Type integer h and Type string h attributes are supported Additionally and according to the attribute type you can also define the width and precision of the new attribute column Once you are happy with the attributes click OK and provide a name for the shapefile QGIS will automatically add a shp extension to the name you specify Once the layer has been created it will be added to the map and you can edit it in the same way as described in Section Digitizing an existing layer above Creating a new SpatiaLite layer To create a new SpatiaLite layer for editing choose New a New SpatiaLite Layer from the Layer menu The
12. QGIS User Guide Release 1 8 18 1 Open a new Print Composer Template Before you start to work with the print composer you need to load some raster and vector layers in the QGIS map canvas and adapt their properties to suite your own convenience After everything is rendered and symbolized to your liking you click the e New Print Composer icon in the toolbar or choose File New Print Composer 18 2 Using Print Composer Opening the print composer provides you with a blank canvas to which you can add the current QGIS map canvas legend scalebar images basic shapes arrows and text Figure_composer_1 shows the initial view of the print composer with an activated Snap to grid mode but before any elements are added nr Composer 1 STATE ad 3D gt YADZOnaRadEERNENRNOSA a E Command history Composition Item Properties Composition x Paper and quality Size A4 210x297 mm Width 297 00 O Height 210 00 mm Orientation Landscape ol je lt lt _ Print as raster Quality 300 dpi Snapping V Snap to grid Spacing X offset 0 00 SJ Y offset 0 00 ooo Pen width 0 50 Grid style Dots Selection tolerance mm 0 00 ETE Figura 18 1 Print Composer A The print composer provides three tabs The Composition tab allows you to set paper size orientation the print quality for the output file in dpi and to activate snapping to a grid of a define
13. Tip Accessing secured OGC layers If you need to access secured layers with other secured methods than basic authentication you could use InteProxy as a transparent proxy which does support several authentication methods More information can be found at the InteProxy manual found on the website http inteproxy wald intevation org Tip QGIS WMS Mapserver From Version 1 7 0 QGIS has its own implementation of a WMS 1 3 0 Mapserver Read more about this at chapter QGIS Server 13 1 3 WFS and WFS T Client In QGIS a WFS layer behaves pretty much like any other vector layer You can identify and select features and view the attribute table Since QGIS 1 6 editing WFS T is also supported In general adding a WFS layer is very similar to the procedure used with WMS The difference is there are no default servers defined so we have to add our own Loading a WFS Layer As an example we use the DM Solutions WFS server and display a layer The URL is http www2 dmsolutions ca cgi bin mswfs_gmap 1 Click on the Add WES Layer tool on the Layers toolbar the dialog Add WFS Layer from a Server appears Click on New Enter DM Solutions as name Enter the URL see above Click OK RN AeA U N MAS Choose DM Solutions from the Server Connections combobox 7 Click Connect O 8 Wait for the list of layers to be populated 110 Cap tulo 13 Working with OGC Data QGIS User Guide Release 1 8
14. reprojection by default If you have already loaded a layer and want to enable OTF projection the best practice is to open the Coordinate Reference System tab of the Project Properties dialog select a CRS and activate the Enable on the fly CRS CRS status transformation checkbox The icon will no longer be greyed out and all layers will be OTF projected to the CRS shown next to the icon 50 Capitulo 9 Working with Projections QGIS User Guide Release 1 8 General Coordinate Reference System CRS Identifiable layers lt gt v Enable on the fly CRS transformation Filter Recently used coordinate reference systems Coordinate Reference System Authority ID A WGS 84 Pseudo Mercator EPSG 3857 ETRS89 UTM zone 32N EPSG 25832 CH1903 LVO3 EPSG 21781 DHDN Gauss Kruger zone 3 EPSG 31467 INAD27 Alaska Albers EPSG 2964 WGS 84 UTM zone 31N EPSG 32631 R WGS 84 EPSG 4326 V eR Coordinate reference systems of the world Hide deprecated CRSs Coordinate Reference System Authority ID GDA94 Australian Albers EPSG 3577 NAD27 Alaska Albers EPSG 2964 NAD27 California Albers EPSG 3309 NAD83 Alaska Albers EPSG 3338 NAD83 BC Albers EPSG 3005 NAD83 California Albers EPSG 3310 proj aea lat_1 55 lat_2 65 lat_0 50 lon_0 154 x_0 0 y_0 0 ES ellps clrk66 towgs84 10 158 187 0 0 0 0 units us ft no_defs v o Help Y OK 2 Apply Cancel rn Figu
15. Just open the right mouse menu of the layer and click on Save selection as to define the name of the output file its format and CRS see Section Map Legend It is also possible to specify OGR creation options within the dialog 11 3 Editing 93 QGIS User Guide Release 1 8 Working with non spatial attribute tables QGIS allows also to load non spatial tables This includes currently tables supported by OGR delimited text and the PostgreSQL provider The tables can be used for field lookups or just generally browsed and edited using the table view When you load the table you will see it in the legend field It can be opened e g with the Open Attribute Table tOo and is then editable like any other layer attribute table As an example you can use columns of the non spatial table to define attribute values or a range of values that are allowed to be added to a specific vector layer during digitizing Have a closer look at the edit widget in section Fields Tab to find out more 11 4 Query Builder The Query Builder allows you to define a subset of a table using a SQL like WHERE clause and display the result in the main window The query result then can be saved as a new vector layer 11 4 1 Query Open the attribute table choosing Open Attribute Table from the menu bar Click on the Advanced Search but ton to open the Query builder For example if you have a towns layer with a population field you could select only larger to
16. MMC Site means any World Wide Web server that publishes copyrightable works and also provides prominent facilities for anybody to edit those works A public wiki that anybody can edit is an example of such a server A Massive Multiauthor Collaboration or MMC contained in the site means any set of copyrightable works thus published on the MMC site CC BY SA means the Creative Commons Attribution Share Alike 3 0 license published by Creative Commons Corporation a not for profit corporation with a principal place of business in San Francisco California as well as future copyleft versions of that license published by that same organization Incorporate means to publish or republish a Document in whole or in part as part of another Document An MMC is eligible for relicensing if it is licensed under this License and if all works that were first published under this License somewhere other than this MMC and subsequently incorporated in whole or in part into the MMC 1 had no cover texts or invariant sections and 2 were thus incorporated prior to November 1 2008 The operator of an MMC Site may republish an MMC contained in the site under CC BY SA on the same site at any time before August 1 2009 provided the MMC is eligible for relicensing ADDENDUM How to use this License for your documents To use this License in a document you have written include a copy of the License in the document and put the fo
17. QGIS User Guide Release 1 8 194 Cap tulo 18 Print Composer CAPITULO 19 Plugins 19 1 QGIS Plugins QGIS has been designed with a plugin architecture This allows many new features functions to be easily added to the application Many of the features in QGIS are actually implemented as either core or external plugins e Core Plugins are maintained by the QGIS Development Team and are automatically part of every QGIS distribution They are written in one of two languages C or Python More information about core plugins are provided in Section Using QGIS Core Plugins External Plugins are currently all written in Python They are stored in external repositories and maintained by the individual authors They can be added to QGIS using the Python Plugin Installer More information about external plugins is provided in Section Loading an external QGIS Plugin 19 1 1 Managing Plugins Managing plugins in general means loading or unloading them using the Plugin Manager External plugins can be installed and directly activated or uninstalled using the Python Plugin Installer To deactivate and reactivate external plugins the Plugin Manager is used again Loading a QGIS Core Plugin Loading a QGIS Core Plugin is done from the main menu Plugins Manage Plugins The Plugin Manager lists all the available plugins and their status loaded or unloaded including all core plugins and all external plugins that have been install
18. SRS 108 ST_Shift_Longitude 61 Style_Manager 70 SVG_fill 64 SVG_Marker 64 Symbol_Properties 68 Symbology 100 Symbology_New 63 Symbology_Old 69 Three_Band_Color_Raster 100 Tiger_Format 57 Toggle Editing 84 toolbar 27 Topological_Editing 84 Transparency 101 Transparency_Vector 70 UK_National_Transfer_Format 57 US_Census_Bureau 57 Vector_Transparency 70 Vertex 86 Vertices 86 WCS 105 WES 105 110 WFS T 110 WFS_ Transactional 110 WKT 49 86 WMS 105 WMS C 109 WMS 1 3 0 110 WMS client 105 WMS identify 109 WMS layer transparency 108 WMS metadata 109 WMS properties 109 WMS tiles 109 Work with Attribute Table 91 zoom mouse wheel 29 Zoom In Zoom Out 83 Index 259
19. Street Tram Line Bus Stop etc are defined by these primitives Map features are well known in the OSM community and are stored as tags based on a key and a value OSM is usually distributed in XML format XML payload is used for the communication with the OSM server as well 139 QGIS User Guide Release 1 8 OpenStreetMap Mozilla Firefox Datei Bearbeiten Ansicht Chronik Lesezeichen Extras Hilfe gt E http www openstreetmap org y GH BAusschreibungen F Dateny ESoftware Dictionary FAFOSSGIS FAGBD lernen 2 SIS Handball x E OpenStreetMap x Karte Bearbeiten Chronik Export GPS Tracks Blogs Anmelden Registrieren AS El Grundkarte Mapnik O Osmarender Radfahrerkarte StraBen ohne Name Die freie Wiki Weltkarte OpenStreetMap ist eine freie editierbare Karte der gesamten Welt die von Menschen wie dir erstel wird OpenStreetMap erm glicht es geographische Daten gemeinschaftlich von berall auf der Welt anzuschauen und zu bearbeiten Das Hosting der OpenStreetMap Server wird freundlicherweise von UCL VR Centre und bytemark unterst tzt www openstreetmap org gelesen Figura 16 1 OpenStreetMap data in the web 16 2 QGIS OSM Connection The first part of this section describes how OSM data primitives are displayed in QGIS vector layers As previously mentioned OSM data consists of Nodes Ways and Relations In QGIS
20. This is different from Shapefile creation with QGIS because Shapefiles use the Simple Feature vector model see Section Creating a new Vector layer Tip Creating an attribute table for a new GRASS vector layer If you want to assign attributes to your digitized geometry features make sure to create an attribute table with columns before you start digitizing see figure_grass_digitizing_5 15 7 Digitizing and editing a GRASS vector layer The digitizing tools for GRASS vector layers are accessed using the A Edit GRASS vector layer con on the toolbar Make sure you have loaded a GRASS vector and it is the selected layer in the legend before clicking on the edit tool Figure figure_grass_digitizing_2 shows the GRASS edit dialog that is displayed when you click on the edit tool The tools and settings are discussed in the following sections Tip Digitizing polygons in GRASS If you want to create a polygon in GRASS you first digitize the boundary of the polygon setting the mode to No category Then you add a centroid label point into the closed boundary setting the mode to Next not used The reason is that a topological vector model links attribute information of a polygon always to the centroid and not to the boundary Toolbar In figure grass digitizing you see the GRASS digitizing toolbar icons provided by the GRASS plugin Table table grass digitizing explains the available functionalities e2etw
21. Use default CRS displayed below EPSG 4326 WGS 84 ZI Help Y OK Cancel Figura 9 1 CRS tab in the QGIS Options Dialog X e 14 Use project CRS e 12 Use default CRS displayed below If you want to define the coordinate reference system for a certain layer without CRS information you can also do that in the General tab of the raster see General Tab and vector see General Tab properties dialog If your layer already has a CRS defined it will be displayed as shown in Vector Layer Properties Dialog Tip CRS in the Map Legend Right clicking on a layer in the Map Legend Section Map Legend provides two CRS short cuts Set layer CRS takes you directly to the Coordinate Reference System Selector dialog see figure_projection_2 Set project CRS from Layer redefines the project CRS using the layer s CRS 9 3 Define On The Fly OTF Reprojection QGIS supports OTF reprojection for both raster and vector data However OTF is not activated by default To use OTF projection you must activate the Enable on the fly CRS transformation checkbox in the CRS tab of the A Project Properties dialog There are three ways to achieve this end 1 Select Project Properties from the Edit Gnome OSX or Settings KDE Windows menu 2 Click on the CRS status con in the lower right hand corner of the statusbar 3 Turn OTF on by default by selecting the CRS tab of the Options dialog and selecting Enable on the fly
22. o o oo Adding other elements to the PrintComposer e Navigation tooli ss eee hee ed E ee o e re ee Ped Bo Revert and Restore tools ho ghd ks A A A a je Bis Add Basic ships and Arrow passas gr rar E E padre AA Add attribute table values s smera i do do eras h 24Gb ba Pathe Pee A SR St Raise lower and alien elements oos e s sroda e AN E A RUE SH ew AS 18 10 Creating Output 2 i wae 2 Eee Swe E RA E EEE SE AD ELE SS E RL A aa 18 11 Saving and loading a print composer layout o ee ee ee 19 Plugins 19 1 19 2 19 3 19 4 19 5 19 6 1917 19 8 19 9 OGIS PUSIS Paik er cri E RE RR a eI RRE A Using QGIS Core Pinos as tr ss ya Es te ds e E o woe Coordinate Capture Plugin sp ceros be pe tae be ato e Br DB Manager Plusi n emita EA e A Delimited Text Plugin as o e RA E GE Diagram Overlay P O a cd e a A e a BS Dxt2Shp Converter PluBiM e lt tas sia a dog 8 Bo Se a a a RR Sg a eVas PUSI ess te RAR AS ede PEER EE ee Ee Ee E FLools PIUSID ia a ey a BO A e da boa amp Ges ro ee E 19 10 GDAL Tools Plugin Jams ce See ale a EEE we Eee ee E ee E 19 11 Georeterencer PUSI isos eg a a ae RG Shoe ae RS 19 12 Interpolation Plugin ssp eR ee ee eee ee ea ee pe ee be eas 19 13 MapServer Export Blue lt 34 22854350 56 64 5235 654 6654 56054 645 19 14 Offline Editine Plugin as us e Bp ee ee e RA Sl ee E E 19 15 Oracle GeoRaster Plain 4 apar pru A A cg 4 a Bid 19 16 Raster Terrain
23. 3 832379 99 187 6402 Calculate Is Help V OK Rn Figura 9 3 Custom CRS Dialog A Defining a custom CRS in QGIS requires a good understanding of the Proj 4 projection library To begin refer to the Cartographic Projection Procedures for the UNIX Environment A User s Manual by Gerald I Evenden U S Geological Survey Open File Report 90 284 1990 available at ftp ftp remotesensing org proj OF90 284 pdf This manual describes the use of the proj 4 and related command line utilities The cartographic parameters used with proj 4 are described in the user manual and are the same as those used by QGIS The Custom Coordinate Reference System Definition dialog requires only two parameters to define a user CRS 1 a descriptive name and 2 the cartographic parameters in PROJ 4 format To create a new CRS click the X New button and enter a descriptive name and the CRS parameters After that you can save your CRS by clicking the Save button Note that the Parameters must begin with a proj block to represent the new coordinate reference system You can test your CRS parameters to see if they give sane results by clicking on the Calculate button inside the Test block and pasting your CRS parameters into the Parameters field Then enter known WGS 84 latitude and longitude values in North and East fields respectively Click on Calculate and compare the results with the known values in your coordinate reference system 52 Cap
24. For each data type points lines and polygons vector symbol layer types are available see vector symbol types Depending on the chosen renderer the symbology Depending on the chosen renderer the Style tab provides different following sections The new generation symbology dialog also provides a Style Manager button which gives access to the Style Manager see Section Style Manager The Style Manager allows you to edit and remove existing symbols and add new ones Tip Select and change multiple symbols The New Generation Symbology allows to select multiple symbols and right click to change color transparency size or width of selected entries Single Symbol Renderer The Single Symbol Renderer is used to render all features of the layer using a single user defined symbol The properties that can be adjusted in the Style tab depend partially on the type of the layer but all types share the following structure In the top left part of the tab there is a preview of the current symbol to be rendered In the bottom part of the tab there is a list of symbols already defined for the current style prepared to be used via selecting them from the list The current symbol can be modified using the Change button below the preview which opens a Symbol Properties dialog or the Change button right of the preview which opens an ordinary Color dialog Change Advanci Saved styles o res gt Construction r
25. Image Formats The list of MIME types the server can respond with when drawing the map QGIS supports whatever formats the underlying Qt libraries were built with which is typically at least image png and image jpeg Identity Formats The list of MIME types the server can respond with when you use the Identify tool Currently QGIS supports the text plain type Layer Properties Selected Whether or not this layer was selected when its server was added to this project Visible Whether or not this layer is selected as visible in the legend Not yet used in this version of QGIS Can Identify Whether or not this layer will return any results when the Identify tool is used on it Can be Transparent Whether or not this layer can be rendered with transparency This version of QGIS will always use transparency 1f this is Yes and the image encoding supports transparency Can Zoom In Whether or not this layer can be zoomed in by the server This version of QGIS assumes all WMS layers have this setto Yes Deficient layers may be rendered strangely Cascade Count WMS servers can act as a proxy to other WMS servers to get the raster data for a layer This entry shows how many times the request for this layer is forwarded to peer WMS servers for a result Fixed Width Fixed Height Whether or not this layer has fixed source pixel dimensions This version of QGIS assumes all WMS layers ha
26. Merge attr of selected Features see Advanced digitizing Advanced Digitizing ne E one Sages ed Node Tool see Digitizing an existing layer Digitizing C Rotate Point Symbols see Advanced digitizing Advanced Digitizing After activating A Toggle editing mode for a layer you will find the Add Feature icon in the Edit menu depend ing on the layer type point line or polygon 6 1 3 Edit extra Menu Option Shortcut Reference Toolbar e Add Feature see Digitizing an existing layer Digitizing Es Add Feature see Digitizing an existing layer Digitizing rm Add Feature see Digitizing an existing layer Digitizing 6 1 Menu Bar 23 QGIS User Guide Release 1 8 6 1 4 View Menu Option Shortcut Reference Toolbar Y Pan Map Map Navigation gt Pan Map to Selection Map Navigation a Zoom In Ctrl Map Navigation Q Zoom Out Ctrl Map Navigation Select see Select and deselect features Attributes N9 Identify Features Ctrl Shift I Attributes Measure gt see Measuring Attributes Da Zoom Full Ctrl Shift F Map Navigation a Zoom To Layer Map Navigation Q Zoom To Selection Ctrl J Map Navigation e Zoom Last Map Navigation SP Zoom Next Map Navigation fre Zoom Actual Size Map Navigation Decorations see Decorations Map Tips Attributes New Bookmark Ctrl B see Spatial Bookmarks Attributes E Show Bookmarks Ctrl Shift B see Spatial Bookmarks At
27. New device button enter a name a download command and an upload command for your device and click the Update device button The name will be listed in the device menus in the upload and download windows and can be any string The download command is the command that is used to download data from the device to a GPX file This will probably be a GPSBabel command but you can use any other command line program that can create a GPX file QGIS will replace the keywords Zt ype Sin and Sout when it runs the command Stype will be replaced by w if you are downloading waypoints r if you are downloading routes and t if you are downloading tracks These are command line options that tell GPSBabel which feature type to download in will be replaced by the port name that you choose in the download window and out will be replaced by the name you choose for the GPX file that the downloaded data should be stored in So if you create a device type with the download command gpsbabel type i garmin o gpx in Sout this is actually the download command for the predefined device type Garmin serial and then use it to download waypoints from port dev ttyS0 to the file output gpx QGIS will replace the keywords and run the command gpsbabel w i garmin o gpx dev ttyS0 output gpx The upload command is the command that is used to upload data to the device The same keywords are used but in is now replaced by the name of the GPX file for the laye
28. The QGIS test suite now passes all tests on major platforms and nightly tests You can set tile size for WMS layers 4 7 What s new in the version 1 8 13 QGIS User Guide Release 1 8 14 Cap tulo 4 Features CAP TULO 5 Getting Started This chapter gives a quick overview of installing QGIS some sample data from the QGIS web page and running a first and simple session visualizing raster and vector layers 5 1 Installation Installation of QGIS is very simple Standard installer packages are available for MS Windows and Mac OS X For many flavors of GNU Linux binary packages rpm and deb or software repositories to add to your installation manager are provided Get the latest information on binary packages at the QGIS website at http download qgis org 5 1 1 Installation from source If you need to build QGIS from source please refer to the installation instructions They are distributed with the QGIS source code in a file called INSTALL You can also find it online at https github com qgis Quantum GIS blob master INSTALL 5 1 2 Installation on external media QGIS allows to define a configpath option that overrides the default path e g qgis under Linux for user configuration and forces QSettings to use this directory too This allows users to e g carry a QGIS installation on a flash drive together with all plugins and settings 5 2 Sample Data The user guide contains examples based on th
29. button at the bottom of the module tab 15 9 2 GRASS module examples The following examples will demonstrate the power of some of the GRASS modules 130 Cap tulo 15 GRASS GIS Integration QGIS User Guide Release 1 8 GRASSAS alaska Module v buffer Name der Vektoreingabekarte rivers rivers demo 1 line 7 Pufferdistanz in Karteneinheiten E Name der Vektorausgabekarte l rivers200 Module v buffer v buffer input rivers demo type line layer 1 buffer 200 output rivers200 Toleranz in Karteneinheiten 2 Lines buffers Figura 15 10 GRASS Toolbox Module Output 15 9 The GRASS toolbox 131 QGIS User Guide Release 1 8 Modules Tree Modules List Browser Module v buffer Options Output Manual S 2 v buffer Creates a buffer around features of given type areas must contain centroid KEYWORDS Figura 15 11 GRASS Toolbox Module Manual 4 Creating contour lines The first example creates a vector contour map from an elevation raster DEM Assuming you have the Alaska LOCATION set up as explained in Section Importing data into a GRASS LOCATION e First open the location by clicking the Y Open mapset button and choosing the Alaska location e Now load the gtopo30 elevation raster by clickin Ry Add GRASS raster layer and selecting the gtopo30 y g 8 raster from the demo location Now open
30. echo taxon_name lat long gt gt tmp species_localities txt After selecting a few localities and running the action on each one opening the output file will show something like this Acacia mearnsii 34 0800000000 150 0800000000 Acacia mearnsii 34 9000000000 150 1200000000 Acacia mearnsii 35 2200000000 149 9300000000 Acacia mearnsii 32 2700000000 150 4100000000 As an exercise we create an action that does a Google search on the lakes layer First we need to determine the URL needed to perform a search on a keyword This is easily done by just going to Google and doing a simple search then grabbing the URL from the address bar in your browser From this little effort we see that the format is http google com search q qgis where QGIS is the search term Armed with this information we can proceed 1 Make sure the lakes layer is loaded 2 Open the Layer Properties dialog by double clicking on the layer in the legend or right click and choose Properties from the popup menu 3 Click on the Actions tab 4 Enter a name for the action for example Google Search 5 For the action we need to provide the name of the external program to run In this case we can use Firefox If the program is not in your path you need to provide the full path 6 Following the name of the external application add the URL used for doing a Google search up to but not included the search term http google com search q 7 The text in the A
31. parameters you may end up creating a non functional map file depending on your intended use Although QGIS is good at creating a map file from your project file it may require some tweaking to get the results you want For this example we will create a map file using the project file mapserverproject qgs we just created see Figure_mapserver_export_2 EJ Click the MapServer Export icon in the toolbar menu to start the MapServer dialog see Fig ure_mapserver_export_2 p Enter the name e g qyisproject map for your new map file Browse and find the QGIS project file e g mapserverpro ject qgs you previously saved Enter a name e g MyMap for the map Enter the width and height e g 600 for the width and 400 for the height for your output image D nn A N For this example the layers are in meters so we change the units to meters 226 Cap tulo 19 Plugins QGIS User Guide Release 1 8 7 Choose png for the image type 8 Click OK to generate the new map file qgisproject map QGIS displays the success of your efforts MapServer Export Results Starting O Wrote map section Wrote projection section Wrote output format section Wrote legend section Wrote web section MapServer url still default value http localhost cgi bin mapserv Be sure there is a valid mapserverurl in the ows_onlineresource Wrote map layers Map file completed for tmp aa qgs Map file saved as usr
32. take a look at Christopher Schmidt s 5 minute flash video He used an older version of QGIS version 0 8 but the demo applies equally well to newer versions 19 14 Offline Editing Plugin For data collection it is a common situation to work with a laptop or a cell phone offline in the field Upon returning to the network the changes need to be synchronized with the master data source e g a PostGIS database If several persons are working simultaneously on the same datasets it is difficult to merge the edits by hand even if people don t change the same features The Y Offine Editing Plugin automates the synchronisation by copying the content of a datasource usually PostGIS or WFS T to a SpatiaLite database and storing the offline edits to dedicated tables After being connected to the network again it is possible to apply the offline edits to the master dataset 228 Capitulo 19 Plugins QGIS User Guide Release 1 8 19 14 1 Using the plugin Open some vector layers e g from a PostGIS or WFS T datasource e Save it as a project e Press the Convert to offline project con and select the layers to save The content of the layers is saved to SpatiaLite tables e Edit the layers offline 4 After being connected again upload the changes with the 852 Synchronize button A Quantum GIS 1 7 0 Wroclaw offline editing project File Edit View Layer Setings Plugins Database Vector Paster Help sadias REP KC KRE P
33. then T F JUL and finally T F MEAN 5 Diagram size is based on linear scaling of a classification attribute We choose T F JUL click on Find maximum value and set size to 20 and Size unit ET to Millimeter 6 Now click Apply to display the diagram in the QGIS main window 7 You can now adapt the chart size or change the attribute colors double clicking on the color values in the attribute field Figure_overlay_2 gives an impression 8 Finally click Ok fo Quantum GIS 1 8 0 Lisboa Yow File Edit View Layer Settings Plugins Database Vector Raster Help Dada Reeeeesue ios O7 B8ODGBLADKROOC Hidro CPE EIA a AA 1554328 5541962 17020993 v Of v Figura 19 7 Pie chart diagram from temperature data overlayed on a map Additionally in the Settings Options dialog there is a Overlay tab where it is possible to select the placement 19 6 Diagram Overlay Plugin 203 QGIS User Guide Release 1 8 algorithm of the diagrams The Central point method is a generic one the others use algorithms of the PAL library They also consider diagram objects and labels in different layers 19 7 Dxf2Shp Converter Plugin The dxf2shape converter plugin can be used to convert vector data from DXF to Shapefile format It requires the following parameters to be specified before running g we Dxf Importer y YY Input and output Input Dxf file 1qgis_sample_data gps geodata dxf lcal Output file lqgis_sample_data
34. which start with a double Python comment sign tell SEXTANTE the inputs of the algorithm described in the file and the outputs that it will generate They work exactly with the same syntax as the SEX TANTE scripts that we have already seen so they will not be described here again Check the corresponding section for more information When you declare an input parameter SEXTANTE uses that information for two things creating the user interface to ask the user for the value of that parameter and creating a corresponding R variable that can be later used as input for R commands In the above example we are declaring an input of type vector named polyg When executing the algorithm SEXTANTE will open in R the layer selected by the user and store it in a variable also named polyg So the name of a parameter is also the name of the variable that we can use in R for accesing the value of that parameter thus you should avoid using reserved R words as parameter names Spatial elements such as vector and raster layers are read using the readOGR and readGDAL commands you do not have to worry about adding those commands to your description file SEXTANTE will do it and stored as Spatial DataFrame objects Table fields are stored as strings containing the name of the selected field Tables are opened using the read csv command If a table entered by the user is not in CSV format it will be converted prior to importing it in R Knowing
35. 0 251123 6 964526 13 5 126354 15 1 18393 14 EEE 34 0 E E E tootctor in ly Show selected only Search selected only x Case sensitive Advanced search 2 Figura 11 33 Attribute Table for Alaska layer 4b e Unselectall also with Ctr1 U EN Move selected to top also with Ctr1 T RE Invert selection also with Ctr1 S Abe Copy selected rows to clipboard also with Ctr1 C Q Zoom map to the selected rows also with Ctr1 J es Pan map to the selected rows also with Ctr1 P Gl A Toggle editing mode to edit single values and to enable functionalities described below also with Ctr1 E o Delete selected features also with Ctr1 D E New Column for PostGIS layers and for OGR layers with GDAL version gt 1 6 also with Ctr1 W Delete Column for PostGIS layers and for OGR layers with GDAL version gt 1 9 also with Ctr1 L E a oe Open field calculator also with Ctrl I ul Tip Skip WKT geometry If you want to use attribute data in external programs such as Excel use the Copy selected rows to clipboard button You can copy the information without vector geometries if you deactivate Settings Options General tab Copy geometry in WKT representation from attribute table Save selected features as new layer The selected features can be saved as any OGR supported vector format and also transformed into another Coor dinate Reference System CRS
36. 41471585 West 1365575 11220648 3D no History COMMAND v in ogr 0 dsn C Downloads qgis_cata vmapO airports sh p output airports min area 0 0001 w Help Close Figura 15 15 GRASS LOCATION browser The toolbar inside the Browser tab offers following tools to manage the selected LOCATION Oy Add selected map to canvas Copy selected map Rename selected map e 3 Delete selected map O Set current region to selected map O Refresh browser window The Rename selected map and O Delete selected map only work with maps inside your currently selected MAPSET All other tools also work with raster and vector layers in another MAP SET 15 9 4 Customizing the GRASS Toolbox Nearly all GRASS modules can be added to the GRASS toolbox A XML interface is provided to parse the pretty simple XML files which configures the modules appearance and parameters inside the toolbox A sample XML file for generating the module v buffer v buffer qgm looks like this lt xml version 1 0 encoding UTF 8 gt lt DOCTYPE qgisgrassmodule SYSTEM http mrcc com qgisgrassmodule dtd gt lt qgisgrassmodule label Vector buffer module v buffer gt 136 Cap tulo 15 GRASS GIS Integration QGIS User Guide Release 1 8 lt option key input typeoption type layeroption layer gt lt option key buffer gt lt option key output gt lt qgisgrassmodule gt The parser reads th
37. 4924878 69 11 00 7 57 13 35 Transform Linear Translation 62 968 4384 45 Scale 0 999902 1 00089 Rotation O Mean error 15 4583 599685 4027892 Figura 19 16 Georeferencer Plugin Dialog e 2 Using the e Add Point button add points to the main working area and enter their coordinates see Figure figure_georeferencer_2 For this procedure you have three options e Click on a point in the raster image and enter the X and Y coordinates manually e Click on a point in the raster image and choose the button L from map canvas t add the X and Y coordi nates with the help of a georeferenced map already loaded in the QGIS map canvas With the v button you can move the GCPs in both windows if they are at the wrong place 3 Continue entering points You should have at least 4 points and the more coordinates you can provide the better the result will be There are additional tools on the plugin dialog to zoom and pan the working area in order to locate a relevant set of GCP points TES Enter map coordinates DO O amp Enter X and Y coordinates DMS dd mm ss ss DD dd dd or projected coordinates mmmm mm which correspond with the selected point on the image Alternatively click the button with icon of a pencil and then click a corresponding point on map canvas of QGIS to fill in coordinates of that point a CG dl Snap to background layers From map canvas Y Ol Cancel Lo Figura 19 17 Add
38. 8 2 Relation creation There are 2 ways to create a relation os 1 You can use the ee Create relation button on OSM Feature widget Qe 2 You can create it from the Relation tab of OSM Feature widget using the 444 relation button In both cases a dialog will appear For the second case the feature that is currently identified is automatically considered to be the first relation member so the dialog is prefilled a little When creating a relation please select its type first You can select one of predefined relation types or write your own type After that fill the relation tags and choose its members kzv If you have already selected a relation type try using the Generate tags button It will generate typical tags to your relation type Then you are expected to enter values to the keys Choosing relation members can be done either by writing member identifiers types and roles or using the Identity too and clicking on map Finally when type tags and members are chosen the dialog can be submitted In such case the plugin creates a new relation for you 16 8 3 Changing relation If you want to change an esmo relation identify it first follow steps written above in Section Examining relation After that click on the E Edit relation button You will find it on the OSM Feature widget A new dialog appears nearly the same as for the create relation action The dialog is pre filled with information on given relations Yo
39. Add Delimited Text Loads text files containing x y Delimited Text Plugin Layer coordinates SS LE E Y E p Rus lt M 9 Coordinate Capture DB Manager Diagram Overlay DXF2Shape Converter eVis fTools GPS Tools GRASS GDAL Tools Georeferencer GDAL Heatmap Interpolation plugin MapServer Export Plugin Offline Editing OpenStreetMap Oracle Spatial Georaster Plugin Installer Raster Terrain Analysis Road graph Plugin SPIT SQL Anywhere plugin Spatial Query Zonal Statistics Capture mouse coordinate in different CRS Manage your databases within QGIS Add Diagrams for vectors Converts from DXF to SHP file format Event Visualization Tool A suite of vector tools Tools for loading and importing GPS data GRASS functionality GDAL raster functionality Georeference Raster with GDAL Create heatmap raster from input vector points Interpolation on base of vertices of a vector layer Export a QGIS project file to a MapServer map file Offline editing and synchronizing with database Access OpenStreetMap Access Oracle Spatial GeoRasters Download and install python plugins Compute geomorphological features from DEMs Shortest path analysis Shapefile to PostGIS Import Tool Access SQL anywhere DB Spatial queries on vectors Calculate raster statistics for vector polygons Coordinate Capture Plugin DB Manager Plugin Diagram Overlay Plugin Dxf2Shp Conver
40. Another possibility is to make a selection by right clicking on a layer in the legend and choosing Query If you perform a SQL query here only the selected features are displayed in the map view Features that don t match the SQL query are not visualised in the map view The same function is available from the General tab in the vector Layer Properties dialog You can find a Query builder button right below The selection described above can be used with all vector data providers 11 4 3 Save selected features as new layer The selected features can be saved as any OGR supported vector format and also transformed into another Coor dinate Reference System CRS Just open the right mouse menu of the layer and click on Save selection as gt to define the name of the output file its format and CRS see Section Map Legend It is also possible to specify OGR creation options within the dialog 11 5 Field Calculator 20 en The Field Calculator button in the attribute table allows to perform calculations on basis of existing attribute values or defined functions e g to calculate length or area of geometry features The results can be written to a new attribute column or it can be used to update values in an already existing column You have to bring the vector layer in editing mode before you can click on the field calculator icon to open the dialog see figure_attributes_3 In the dialog you first have to select whether you want to o
41. Browse to the folder qgis_sample_data raster select the ERDAS Img file landcover img and click Open 3 If the file is not listed check if the Filetype combobox at the bottom of the dialog is set on the right type in this case Erdas Imagine Images x img x IMG 4 Now click on the KR Load Vector icon 5 M File should be selected as Source Type in the new Add Vector Layer dialog Now click Browse to select the vector layer 16 Cap tulo 5 Getting Started QGIS User Guide Release 1 8 6 Browse to the folder qgis sample data gml select GML from the filetype combobox then select the GML file Lakes gm1 and click Open then in Add Vector dialog click OK 7 Zoom in a bit to your favorite area with some lakes 8 Double click the lakes layer in the map legend to open the Properties dialog 9 Click on the Style tab and select a blue as fill color 10 Click on the Labels tab and check the Display lables checkbox to enable labeling Choose NAMES field as field containing label 11 To improve readability of labels you can add a white buffer around them by clicking Buffer in the list on the left checking Buffer labels and choosing 3 as buffer size 12 Click Apply check if the result looks good and finally click OK You can see how easy it is to visualize raster and vector layers in QGIS Let s move on to the sections that follow to learn more about the available functionality
42. Calculator The Raster Calculator in the Raster menu see figure_raster_2 allows to perform calculations on basis of existing raster pixel values The results are written to a new raster layer with a GDAL supported format The Raster bands list contains all loaded raster layers that can be used To add a raster to the raster calculator expression field double click its name in the Fields list You can then use the operators to construct calculation expressions or you can just type it into the box In the Result layer section you have to define an output layer You can then define the extent of the calculation area based on an input raster layer or based on X Y coordinates and on Columns and Rows to set the resolution of the output layer If the input layer has a different resolution the values will be resampled with nearest neighbor algorithm 12 3 Raster Calculator 103 QGIS User Guide Release 1 8 f amp Raster bands Raster calculator Result layer Ampllandcover2x Output layer X min 7117600 00000 XMax 4897040 00000 Y min 1367760 00000 Y max 7809680 00000 Columns 3663 Rows 1964 Output format GeoTIFF iz x Add result to project Operators sqrt sin la acos I cos asin tan atan lt gt lt gt AND OR Raster calculator expression landcover 1 landcover 1 Expression valid Y OK o Cancel Figura 12 2 Raster Calculator A The Operators section contains all usable
43. Color of bar black or use the default black color 7 Optionally choose to automatically snap to a round number when the canvas is resized Automatically snap to round number on resize 8 Click OK Tip Settings of Decorations When you save a qgs project any changes you have made to NorthArrow ScaleBar and Copyright will be saved in the project and restored the next time you load the project 7 6 Annotation Tools The L Text Annotation tools in the attribute toolbar provides the possibility to place formatted text in a balloon on the QGIS map canvas Use the Text Annotation tool and click into the map canvas Annotation text y E 9 SleBjli QGIS rocks Background color Y Map position fixed Map marker o Frame width Frame color Y OK Cancel Figura 7 8 Annotation text dialog Delete Double click on the item opens a dialog with various options There is the text editor to enter the formatted text and other item settings E g there is the choice of having the item placed on a map position displayed by a marker 38 Cap tulo 7 General Tools QGIS User Guide Release 1 8 symbol or to have the item on a screen position not related to the map The item can be moved by map position drag the map marker or by moving only the balloon The icons are part of GIS theme and are used by default in the other themes too The Move Annotation tool allows to move the annotation on
44. Currently there are over 150 external plugins available from the Official QGIS Repository Some of these plugins offer functionality that will be required by many users for example providing the user with the ability to view and edit OpenStreetMap data or to add GoogleMap layers while others offer very specialized functions for example Calculate economic pipe diameters for water supply networks It is however quite straightforward to search through all the available external plugins by providing keywords choosing a named repository and or filtering on the status of plugins currently installed or uninstalled in your system Searching and filtering is done from the QGIS Python Plugin Installer see figure_plugins_2 Tip Add more repositories To add external author repositories open the Plugin Installer Plugins gt Fetch Python Plugins go to the tab Repositories and click Add If you do not want one or more of the added repositories they can be disabled via the Edit button or completely removed with the Delete button There is only one step required to integrate external plugins into QGIS e Download an external plugin from a repository using the Python Plugin Installer see Using the QGIS Python Plugin Installer The new external plugin will be added to the list of available plugins in the Plugin 196 Cap tulo 19 Plugins QGIS User Guide Release 1 8 Manager and is automatically loaded Using the
45. ER RARE AS 16 5 Loading OSM data y 0 00005 a BAe a EA ee Be wa de bee nok ale 166 Viewing OSM data gt cs noes aes Ge a A A A RR ee T 16 7 Editing basic OSM data se cose bee ee wa ee ee ee 16 8 Editing relations lt s sos opa rk hoe e da big SOA we iy Beek Sd eB le pe we 16 9 Downloading OSM data cum 28444 e eee Ee e ee Ee ee ale eas 16 10 Uploading OSM data ss a aac he SO OR he a RE CELA Se Bs a 16 11 Savins OSMidalda 2 00 Sond pe me SR O A dra be Ss aoe do a A ee ee ee S R 16 12 Import OSM data psp nda sd e eb bee dw DA ADE bee bee ewe eed SEXTANTE Vel Introduction ii o a wh eH O di RD alk He RD AL a oe Ee aes le BS 100 103 105 105 111 115 115 117 121 121 122 122 124 125 126 126 129 129 139 139 140 141 141 142 143 143 145 146 147 148 149 151 172 17 3 17 4 17 5 17 6 17 7 The SEXTANTE toolboX sa ii a a A O aoe Gl Be goal a E The SEXTANTE graphical model t sussa a re a The SEXTANTE batch processing Inter ace e Using SEXTANTE from the console ums pausa RR AA The SEXTANTE history Manager atu as Se et be eA A ee eS See Ae Configuring external applications ssa ge prado ee beep ee Rae ea be eee ee oes 18 Print Composer 18 1 18 2 18 3 18 4 18 5 18 6 18 7 18 8 18 9 Open a new Print Composer Template 05 24445 ba ee ee ew ee ee eG Using Primt Composer sia a OR Bag a Ba Be a me ee Adding a current QGIS map canvas to the Print Composer
46. Examples of suitable formats for Transparent copies include plain ASCII without markup Texinfo input format LaTeX input format SGML or XML using a publicly available DTD and standard conforming simple HTML PostScript or PDF designed for human modification Examples of transparent image formats include PNG XCF and JPG Opaque formats include proprietary formats that can be read and edited only by proprietary word pro cessors SGML or XML for which the DTD and or processing tools are not generally available and the machine generated HTML PostScript or PDF produced by some word processors for output purposes only The Title Page means for a printed book the title page itself plus such following pages as are needed to hold legibly the material this License requires to appear in the title page For works in formats which do not have any title page as such Title Page means the text near the most prominent appearance of the work s title preceding the beginning of the body of the text The publisher means any person or entity that distributes copies of the Document to the public A section Entitled XYZ means a named subunit of the Document whose title either is precisely XYZ or contains XYZ in parentheses following text that translates XYZ in another language Here XYZ stands for a specific section name mentioned below such as Acknowledgements Dedications Endorsements or History 21 2
47. New SpatiaLite Layer dialog will be displayed as shown in Figure_edit_6 First step is to select an existing SpatiaLite database or to create a new SpatiaLite database This can be done with the browse button to the right of the database field Then add a name for the new layer and define the layer type and the EPSG SRID If desired you can select to Create an autoincrementing primary key To define an attribute table for the new SpatiaLite layer add the names of the attribute columns you want to create with the according column type and click on the Add to attribute list button Once you are happy with the attributes click OK QGIS will automatically add the new layer to the legend and you can edit it in the same way as described in Section Digitizing an existing layer above Further management of SpatiaLite Layers can be done with the DB Manager see DB Manager Plugin 11 3 7 Working with the Attribute Table The attribute table displays features of a selected layer Each row in the table represents one map feature and each column contains a particular piece of information about the feature Features in the table can be searched selected moved or even edited To open the attribute table for a vector layer make the layer active by clicking on it in the map legend area Then from the main menu Layer choose Open Attribute Table It is also possible to rightclick on the layer and 11 3 Editing 91 QGIS User Guide Release 1 8
48. Redo and Undo digitizing steps When Undo is hit the state of all features and attributes are reverted to the state before the reverted operation happened Changes other than normal vector editing operations for example changes done by a plugin may or may not be reverted depending on how the changes were performed To use the undo redo history widget simply click to select an operation in the history list all features will be reverted to the state they were in after the selected operation Simplify Feature 3 The Simplify Feature too allows to reduce the number of vertices of a feature as long as the geometry doesn t change You need to select a feature it will be highlighted by a red rubber band and a slider appears Moving the slider the red rubber band is changing its shape to show how the feature is being simplified Clicking OK the new simplified geometry will be stored If a feature cannot be simplified e g MultiPolygons a message shows up 88 Cap tulo 11 Working with Vector Data QGIS User Guide Release 1 8 Add Ring You can create ring polygons using the O Add Ring con in the toolbar This means inside an existing area it is possible to digitize further polygons that will occur as a hole so only the area in between the boundaries of the outer and inner polygons remain as a ring polygon Add Part You can D add part Polygons to a selected multipolygon The new part polygon has to be digiti
49. RorteavAnr GD Figura 15 3 GRASS Digitizing Toolbar 126 Capitulo 15 GRASS GIS Integration QGIS User Guide Release 1 8 Icon Tool Purpose o e New Point Digitize new point Ls New Line Digitize new line vy 44 New Digitize new boundary finish by selecting new tool Boundary z New Digitize new centroid label existing area Centroid lt gt Move vertex Move one vertex of existing line or boundary and identify new position Add vertex Add a new vertex to existing line B Delete vertex Delete vertex from existing line confirm selected vertex by another click A Move Move selected boundary line point or centroid and click on new position element A a Ene A Split line Split an existing line to 2 parts Delete Delete existing boundary line point or centroid confirm selected element by another element click Edit Edit attributes of selected element note that one element can represent more features attributes see above 0 Close Close session and save current status rebuilds topology afterwards Table GRASS Digitizing 1 GRASS Digitizing Tools Category Tab The Category tab allows you to define the way in which the category values will be assigned to a new geometry element Rotra chvm Settings Symbology Table Mode Next not used N Category 77 Layer 1 Figura 15 4 GRASS Digitizing Category Tab e Mode what cat
50. SEXTANTE Please check them to see real examples of how to create algo rithms using this feature of SEXTANTE You can right click on any script algorithm and select Edit script to edit its code or just to see it 17 5 4 Documenting your scripts As in the case of models you can create additional documentation for your script to explain what they do and how to use them In the script editing dialog you will find a Edit script help button Click on it and it will take you to the help editing dialog Check the chapter about the graphical modeler to know more about this dialog and how to use it Help files are saved in the same folder as the script itself adding the he 1p extension to the filename Notice that you can edit your script s help before saving it for the first time If you later close the script editing dialog without saving the script i e you discard it the help content you wrote will be lost If your script was already saved and is associated to a filename saving is done automatically 17 6 The SEXTANTE history manager 17 6 1 The SEXTANTE history Every time you execute a SEXTANTE algorithm information about the process is stored in the SEXTANTE history manager Along with the parameters used the date and time of the execution are also saved This way it is easy to track the and control all the work that has been developed using SEXTANTE and easily reproduce it The SEXTANTE history manager is a set of registry en
51. SpatiaLite vector layers Note The procedure for editing GRASS layers is different see Section Digitizing and editing a GRASS vector layer for details Tip Concurrent Edits This version of QGIS does not track if somebody else is editing a feature at the same time as you The last person to save their edits wins 11 3 1 Setting the Snapping Tolerance and Search Radius Before we can edit vertices we must set the snapping tolerance and search radius to a value that allows us an optimal editing of the vector layer geometries Snapping tolerance Snapping tolerance is the distance QGIS uses to search for the closest vertex and or segment you are trying to connect when you set a new vertex or move an existing vertex If you aren t within the snapping tolerance QGIS will leave the vertex where you release the mouse button instead of snapping it to an existing vertex and or segment The snapping tolerance setting affects all tools which work with tolerance 1 A general project wide snapping tolerance can be defined choosing Settings gt Options On Mac go to QIS gt Preferences on Linux Edit Options In the Digitizing tab you can select between to vertex to segment or to vertex and segment as default snap mode You can also define a default snapping tolerance and a search radius for vertex edits The tolerance an be set either in map units or in pixels The advantage of choosing pixels is that
52. TABLE set the_geom ST_Shift_Longitude the_geom e If everything went right you should receive a confirmation about the number of features that were updated then you ll be able to load the map and see the difference Figure vector 5 11 1 7 SpatiaLite Layers The first time you load data from a SpatiaLite database begin by clicking on the Add SpatiaLite Layer toolbar button or by selecting the Add SpatiaLite Layer option from the Layer menu or by typing Ctrl Shift L This will bring up a window which will allow you to either connect to a SpatiaLite database already known to QGIS which you can choose from the dropdown menu or to define a new connection to a new database To define a new connection click on New and use the file brow a sqlite extension ser to point to your SpatiaLite database which is a file with If you want to save a vector layer to SpatiaLite format you can do this by right clicking the layer in the legend Then click on Save as define the name of the output file select SpatiaLite as format and the CRS Also you can select SQLite as format and then add SPATIALIT E YES in the OGR data source creation option field This tells OGR to create a SpatiaLite database See also http www gdal org ogr drv_sqlite html QGIS also supports editable views in SpatiaLite Creating a new SpatiaLite layer If you want to create a new SpatiaLite layer please refer to section Creating a n
53. Table allows to create and edit tables and to delete tables and views It 1s also possible to empty tables and to move tables from one to another schema Finally you can also run Vacuum Analyze and add Versioning Support to a table The Tree window lists all existing databases supported by QGIS With a double click you can connect to the database With the right mouse button you can rename and delete existing schemas and tables Tables can also be added to the QGIS canvas with the context menu 200 Cap tulo 19 Plugins QGIS User Guide Release 1 8 o DB Manage Database Schema Table Help e a Refresh SQL window Tree Info Table Preview E v PostGIS 4 A a v Alaska public O public m airports alaska Schema details builtups E geography_colu Owner postgres E geometry_columns Comment standard public schema amp grassland lakes Pe landice Privileges h W majrivers WE pipelines User has privileges s popp e create new objects Ye railroads access objects E spatial ref sys v topology A layer a od Figura 19 4 DB Manager dialog KDE If connected to a database the main window of the DB Manager offers three tabs The Info tab provides informa tion about the table and its geometry as well as about existing Fields Constraints and Indexes It also allows to run Vacuum Analyze and to create a spatial index on a selected table if not already done The Table tab shows all
54. The models folder can be set from the SEXTANTE configuration dialog under the Modeler group Models loaded from the models folder appear not only in the toolbox but also in the algorithms tree in the Algorithms tab of the modeler window That means that you can incorporate a model as a part of a bigger model just as you add any other algorithm In some cases SEXTANTE might not be able to load a model because it cannot find all the algorithms included in its workflow If you have used a given algorithm as part of your model it should be available that is it should appear on the toolbox in order to load that model Deactivating an algorithm provider in the SEXTANTE configuration window renders all the algorithms in that provider unusable by the modeler which might cause problems when loading models Keep that in mind when you have trouble loading or executing models 17 3 5 Editing a model You can edit the model you are currently creating redefining the workflow and the relationships between the algorithms and inputs that define the model itself If you right click on an algorithm in the canvas representing the model you will see a context menu like the one shown next Selecting the Remove option will cause the selected algorithm to be removed An algorithm can be removed only if there are no other algorithms dependind on it That is if no output from the algorithm is used in a different one as input If you try to remove an algorithm th
55. accumulation layer We do not have these ones but since we have the DEM we can calculate them calling the corresponding SAGA algorithms The part of the code where this processing takes place is not difficult to understand if you have read the previous sections in this chapter The first lines however need some additional explanation They provide SEXTANTE the information it needs to turn your code into an algorithm that can be run from any of its components like the toolbox or the graphical modeler These lines start with a double Python comment symbol and have the following structure parameter name parameter type optional values Here is a list of all the parameter types that SEXTANTE supports in its scripts their syntax and some examples 170 Cap tulo 17 SEXTANTE QGIS User Guide Release 1 8 e raster A raster layer e vector A vector layer e table A table number A numerical value A default value must be provided For instance depth number 2 4 e string A text string As in the case of numerical values a default value must be added For instance name string Victor e boolean A boolean value Add True or False after it to set the default value For example verbose boolean True e multiple raster A set of input raster layers e multiple vector A set of input vector layers e field A field in the attributes table of a vector layer The name of the layer has to be added after the field tag
56. all the layers in the project The checkbox in each legend entry can be used to show or hide the layer A layer can be selected and dragged up or down in the legend to change the z ordering Z ordering means that layers listed nearer the top of the legend are drawn over layers listed lower down in the legend Layers in the legend window can be organised into groups There are two ways to do so 6 2 Toolbar 27 QGIS User Guide Release 1 8 1 Right click in the legend window and choose Add Group Type in a name for the group and press Enter Now click on an existing layer and drag it onto the group 2 Select some layers right click in the legend window and choose Group Selected The selected layers will automatically be placed in a new group To bring a layer out of a group you can drag it out or right click on it and choose Make to toplevel item Groups can be nested inside other groups The checkbox for a group will show or hide all the layers in the group with one click The content of the right mouse button context menu depends on whether the selected legend item is a raster or a vector layer For GRASS vector layers oa Toggle editing is not available See section Digitizing and editing a GRASS vector layer for information on editing GRASS vector layers Right mouse button menu for raster layers Zoom to layer extent Zoom to best scale 100 Show in overview Remove Set Layer CRS Set Project CRS from Layer
57. also load an individual layer passing its filepath to the load method 17 5 3 Creating scripts and running them from the toolbox You can create your own algorithms by writing the corresponding Python code and adding a few extra lines to supply additional information needed by SEXTANTE You can find a Create new script under the tools group in the script algorithms block of the toolbox Double click on it to open the script edition dialog That s where you should type your code Saving the script from there in the scripts folder the default one when you open the save file dialog with py extension will automatically create the corresponding algorithm The name of the algorithm the one you will see in the toolbox is created from the filename removing its extension and replacing low hyphens with blank spaces Let s have the following code which calculates the Topographic Wetness Index TWT directly from a DEM dem raster twi output ret_slope sextante runalg saga slopeaspectcurvature dem 0 None None None None None ret area sextante runalg saga catchmentarea mass fluxmethod dem 0 False False False False None None None None None sextante runalg saga topographicwetnessindex twi ret_slope SLOPE ret_area AREA None 1 0 twi As you can see it involves 3 algorithms all of them coming from SAGA The last one of them calculates de TWI but it needs a slope layer and a flow
58. also possible to supress labeling of features and wrap lables on characters Use Data defined settings for attribute based or database connection based settings Labeling polygon layers First step is to activate the Y Label this layer checkbox and select an attribute column to use for labeling Here you can also define labels based on expressions In Label settings define the text style and the scale based visibility see Figure_labels_3 Use the Advanced tab for label placement label distance and labeling priority Define if every part of a multipart feature is to be labeled suppress labeling of features and wrap labels on characters here Use Data defined settings for attribute based or database connection based settings Change engine settings Additionally you can click the Engine settings button and select the search method used to find the best label placement Available is Chain Popmusic Tabu Popmusic Chain Popmusic Tabu Chain and FALP Furthermore the number of candidates can be defined for point line and polygon features and you can define whether to show all labels including colliding labels and label candidates for debugging 72 Cap tulo 11 Working with Vector Data QGIS User Guide Release 1 8 Quantum GIS 1 8 0 Lisboa airports project fle Wg o Layer labeling settings Baster Help LELLA 98 Y be tnis layer win DECUFTION v P Oio wis ay eee Quantum GIS 18 Lisboa airports project fie fo L
59. and optionally the compass direction the camera was pointed when the image was acquired Your vector layer must be loaded into QGIS before running the Event Browser Launch the Event Browser module To launch the Event browser module either click on the em eVis Event Browser con or click on Database eVis eVis Event Browser This will open the Generic Event Browser window The Generic Event Browser window has three tabs displayed at the top of the window The Display tab is used to view the photograph and its associated attribute data The Options tab provides a number of settings that can be adjusted to control the behavior of the eVis plugin Lastly the Configure External Applications tab is used to maintain a table of file extensions and their associated application to allow eVis to display documents other than images Understanding the Display window To see the Display window click on the Display tab in the Generic Event Browser window The Display window is used to view geocoded photographs and their associated attribute data 1 Display window A window where the photograph will appear 2 Zoom in button Zoom in to see more detail If the entire image cannot be displayed in the display window scroll bars will appear on the left and bottom sides of the window to allow you to pan around the image 3 Zoom out button Zoom out to see more area 4 Zoom to full extent button Displays the full extent of the photograph 5
60. and expect to have it ready soon 17 7 Configuring external applications 173 QGIS User Guide Release 1 8 You should however find no problems at all with vector layers since SEXTANTE automatically converts from the original file format to one accepted by the external application before passing the layer to it This adds an extra processing time which might be significant if the layer has a large size so do not be surprised if it takes more to process a layer from a DB connection that one of a similar size stored in a shapefile Providers not using external applications can process any layer that you can open in QGIS since they open it for analysis trough QGIS Regarding output formats raster layers can be saved as TIFF tif files while vector layers are saved as shapefiles shp These have been chosen as the lingua franca between supported third party applications and QGIS If the output filename that you select is not one of the above it will be modified adding the corresponding suffix and the default file format will be used In the case of GDAL the number of supported output formats is larger When you open the file selection dialog you will see that you have more formats and their corresponding extensions available For more information about which formats are supported check the GDAL documentation A note on vector layer selections By default when an external algorithm takes a vector layer it will us
61. and from Diagram type combobox select Text diagram 4 As Background color we choose a light blue and set a fixed size to 18 mm 5 Placement could be set to AroundPoint 6 In the diagram we want to display the values of the three columns T_F_JAN T_F_JUL and T_F_MEAN First select T_F_ JAN as Attributes and click the green button then T F JUL and finally T F MEAN E 7 Now click Apply to display the diagram in the QGIS main window 8 You can now adapt the chart size or change the attribute colors by double clicking on the color values in the attribute field Figure_diagrams_2 gives an impression 9 Finally click Ok Additionally in the Settings Options dialog there is a Overlay tab where it is possible to select the placement algorithm of the diagrams The central point method is a generic one the others use algorithms of the PAL library 11 2 The Vector Properties Dialog 81 QGIS User Guide Release 1 8 de Quantum GIS 1 8 0 Lisboa Yow Hle Edit View Layer Settings Plugins Database Vector Raster Help 148825 BRP CPP EER iP gt COVODBREANDDO Fuso ARET EEIT ETA ge gt Figura 11 26 Diagram from temperature data overlayed on a map They also consider diagram objects and labels in different layers Also see section Diagram Overlay Plugin for additional diagram features 11 3 Editing QGIS supports various capabilities for editing OGR PostGIS and
62. assigned a random color When adding more than one layer at a time different colors are assigned to each layer Once loaded you can zoom around the shapefile using the map navigation tools To change the style of a layer open the Layer Properties dialog by double clicking on the layer name or by right clicking on the name in the legend and choosing Properties from the popup menu See Section Style Tab for more information on setting symbology of vector layers Tip Load layer and project from mounted external drives on OS X On OS X portable drives that are mounted besides the primary hard drive do not show up under File gt Open Project as expected We are working on a more OSX native open save dialog to fix this As a workaround you can type Volumes in the File name box and press return Then you can navigate to external drives and network mounts 56 Capitulo 11 Working with Vector Data QGIS User Guide Release 1 8 File Edit View Layer Settings Plugins Raster Help J 88 a65 URBE eo Oo VBODODBADADOOZ ve 2 o QQ ty XK QM Ro Layers ie 653 Y Control rendering order 5 oordinat 1660167 7902409 sal 1 20608676 v Y W Render gt 5G 2 6 A Figura 11 3 QGIS with Shapefile of Alaska loaded Improving Performance Shape To improve the performance of drawing a shapefile you can create a spatial index A spatial index will improve the speed of both zooming and panning Spatial
63. clause field double click its name in the Values list The Operators section contains all usable operators To add an operator to the SQL where clause field click the appropriate button Relational operators gt string comparison operator LIKE logical operators AND OR are available The Test button shows a message box with the number of features satisfying the current query which is usable in the process of query construction The Clear button clears the text in the SQL where clause text field The Save and Load button allow to save and load SQL queries The OK button closes the window and selects the features satisfying the query The Cancel button closes the window without changing the current selection Tip Changing the Layer Definition You can change the layer definition after it is loaded by altering the SQL query used to define the layer To do this open the vector Layer Properties dialog by double clicking on the layer in the legend and click on the Query Builder button on the General tab See Section The Vector Properties Dialog for more information 11 4 2 Selection With QGIS it is possible also to select features for visualisation using a similar query builder interface to that used in Query Builder In the above section the purpose of the query builder is to highlight all selected features meeting the filter criteria in yellow The rest of the features do not change their appearance
64. common boundaries and at tributes without merging their boundaries Rotate Point Symbols The C Rotate Point Symbols too is currently only supported by the old symbology engine It allows to change the rotation of point symbols in the map canvas if you have defined a rotation column from the attribute table of the point layer in the Style tab of the Layer Properties Otherwise the tool is inactive Figura 11 30 Rotate Point Symbols amp To change the rotation select a point feature in the map canvas and rotate it holding the left mouse button pressed A red arrow with the rotation value will be visualized see Figure_edit_4 When you release the left mouse button again the value will be updated in the attribute table Note If you hold the Ct r 1 key pressed the rotation will be done in 15 degree steps 11 3 6 Creating a new Vector layer QGIS allows to create new Shapefile layers and new SpatiaLite layers Creation of a new GRASS layer is sup ported within the GRASS plugin Please refer to section Creating a new GRASS vector layer for more information on creating GRASS vector layers Creating a new Shapefile layer To create a new Shape layer for editing choose New New Shapefile Layer from the Layer menu The New Vector Layer dialog will be displayed as shown in Figure edit 5 Choose the type of layer point line or polygon and the CRS Coordinate Reference System 90 Cap tulo 11 Working with Vector Data
65. crossing the 180 degrees longitude line 61 CRS 49 108 CSV 86 Custom_Color_Ramp 66 Custom_CRS 52 data providers 198 DB_Manager 62 Debian_Squeeze 112 default_CRS 49 define an action 77 Derived_Fields 95 Digitizing 84 Discrete 102 Displacement_plugin 67 documentation 5 editing 82 EPSG 49 Equal_Interval 66 Erdas Imagine 99 ESRI 55 European_Petroleom_Search_Group 49 example actions 77 Export_as_image 192 Export_as_PDF 192 Export_as_SVG 192 FALP 72 FastCGI 111 Field_Calculator 95 Field_Calculator_Functions 96 Fill_Color 70 Fill_Style 70 Font_Marker 64 Freak_out 100 FWTools 227 GDAL 99 Georeferencer tools 220 GeoTIFF 99 GeoTiff 99 GiST Generalized Search Tree index 61 GML 105 Gradient_Color_Ramp 66 Graduated_Renderer 66 GRASS 120 ver Creating new vectors editing creating a new layer 257 QGIS User Guide Release 1 8 attribute linkage 126 attribute storage 126 category settings 127 digitizing 125 digitizing tools 126 display results 130 133 loading data 122 region 129 region display 129 region editing 129 snapping tolerance 128 Start Plugin 121 symbology settings 128 table editing 128 toolbox 133 topology 125 vector data model 125 GRASS toolbox 129 Browser 136 customize 136 Grayscale 100 Grid Map_Grid 184 Histogram 103 IGNF 49 Import_Maps 52 Institut_Geographique_National_de_France 49 InteP
66. field the weight factor set from an attribute field When the output raster is given the OK button can be used to create a heatmap The first result is a grey surface that still needs to be given additional treatment to make it a heatmap Warning Changing the raster size properties When changing the raster size properties this also changes the resulting output The hotspot areas will become bigger 19 17 3 Creating a Heatmap For the following example we will use the airports vector point layer from the QGIS sample dataset see Sam ple Data Another exellent QGIS tutorial on making heatmaps can be found on http qgis spatialthoughts com In Figure Heatmap 1 the airports of Alaska are shown o 1 Select the Hema toolbutton The heatmap dialog starts see Figure Heatmap 2 gd id f 2 In field Input Point Vector selectairpoirt from the list of point layers loaded in current project 3 In field Output Raster give the name and location using the button of the output raster Give the output raster file the name heatmap airports to give an file extension is not necessary 4 In field Output Format choose GeoTIFF 5 In the field Radius give 1000000 meters 6 The original Decay Ratio of 0 1 is fine 19 17 Heatmap Plugin 233 QGIS User Guide Release 1 8 mM Control rendering order Coordinate 4647165 7614405 Scale 1 50660422 Y M Render EPSG 2964 8 A
67. file alaska qgs and a copy of the qgis_mapserv fcgi file that s all Now we test our project WMS and WES add the WMS and WES as described in Loading WMS Layers and WFS and WFS T Client to QGIS and load the WMS The URL is 112 Cap tulo 13 Working with OGC Data QGIS User Guide Release 1 8 fo Project Properties vosso A ear Cort tere tm ters te ers sen Alaska Boundai QGIS Project This layer shows the boundary of Alaskalfrom the qgis sample dataset B383052 75742545 EPSG 2964 1706565 04847097 6163419 58509934 10880135 87788824 alaska K Figura 13 5 Definitions for a qgis project WMS WFS server KDE http localhost cgi bin project qgis_mapserv fcgi 13 2 QGIS Server 113 QGIS User Guide Release 1 8 114 Cap tulo 13 Working with OGC Data CAP TULO 14 Working with GPS Data 14 1 GPS Plugin 14 1 1 What is GPS GPS the Global Positioning System is a satellite based system that allows anyone with a GPS receiver to find their exact position anywhere in the world It is used as an aid in navigation for example in airplanes in boats and by hikers The GPS receiver uses the signals from the satellites to calculate its latitude longitude and sometimes elevation Most receivers also have the capability to store locations known as waypoints sequences of locations that make up a planned route and a tracklog or track of the receivers movement over time Waypoints route
68. g About ES OGIS Sponsors Please not that for Linux A the Menu Bar items listed above are the default ones in KDE window manager In GNOME Settings menu is missing and its items are to be found here A Project Properties File gt Options Edit gt Configure Shortcuts Edit Style Manager Edit Custom CRS Edit Panels View Toolbars gt View Toggle Full Screen Mode View Tile scale slider View Live GPS tracking View 6 2 Toolbar The toolbar provides access to most of the same functions as the menus plus additional tools for interacting with the map Each toolbar item has popup help available Hold your mouse over the item and a short description of the tool s purpose will be displayed Every menubar can be moved around according to your needs Additionally every menubar can be switched off using your right mouse button context menu holding the mouse over the toolbars read also Panels and Toolbars Tip Restoring toolbars If you have accidentally hidden all your toolbars you can get them back by choosing menu option Settings Toolbars If a toolbar disappears under Windows which seems to be a problem in QGIS from time to time you have to remove HKEY_CURRENT_USER Software QuantumGIS qgis UI state in the registry When you restart QGIS the key is written again with the default state and all toolbars are visible again 6 3 Map Legend The map legend area lists
69. gps geodata shp ia x Export text labels r Output file type Polyline e iP Point f Help OK Cancel Figura 19 8 Dxf2Shape Converter Plugin Input DXF file Enter path to the DXF file to be converted Output Shp file Enter desired name of the Shapefile to be created Output file type Specify the geometry type of the output Shapefile Currently supported types are polyline polygon and point Export text labels When this checkbox is enabled an additional Shapefile point layer will be created and the associated dbf table will contain information about the TEXT fields found in the dxf file and the text strings themselves 19 7 1 Using the Plugin 1 Start QGIS load the Dxf2Shape plugin in the Plugin Manager see Section Loading a QGIS Core Plugin and click on the Dxf2Shape Converter icon which appears in the QGIS toolbar menu The Dxf2Shape plugin dialog appears as shown in Figure_dxf2shape_1 2 Enter input DXF file a name for the output Shapefile and the Shapefile type 3 Enable the Export text labels checkbox if you want to create an extra point layer with labels 4 Click OK 19 8 eVis Plugin The Biodiversity Informatics Facility at the American Museum of Natural History s AMNH Center for Biodi versity and Conservation CBC this section is derived from Horning N K Koy P Ersts 2009 eVis v1 1 0 User s Guide American Museum of Natural History Center for Biodiversity an
70. gt Figura 18 10 General Dialog A Here you can adapt the legend title You can change the font of the legend title layer and item name You can change width and height of the legend symbol and you can add layer symbol icon label and box space Since QGIS 1 8 you can wrap the text of the legend title to a given character 18 4 Adding other elements to the Print Composer 187 QGIS User Guide Release 1 8 Legend items dialog The Legend items dialog of the legend Item Properties tab provides following functionalities see fig ure_composer_11 Legend items v Auto Update gt landcover gt majrivers gt trails gt airports F a Update AN Add group Figura 18 11 Legend Items Dialog e The legend items window lists all legend items and allows to change item order edit layer names remove and restore items of the list After changing the symbology in the QGIS main window you can click on Update to adapt the changes in the legend element of the print composer The item order can be changed using the Up and Down buttons or with drag and drop functionality General options dialog The General options dialog of the legend Item Properties tab provides following functionalities see fig ure_composer_12 General Options Frame color Background color Opacity Outline width 0 30 Position and size V Show frame Item ID Figura 18 12 General Op
71. gt Some basic options for QGIS can be selected using the Options dialog Select the menu option Settings gt Options The tabs where you can optimize your options are 8 3 1 General Tab Prompt to save project changes when required Warn when opening a project file saved with an older version of OGIS Change Selection and Background color Change the QGIS Style Change the icon theme choose between default classic and gis Change icon size between 16 24 and 32 pixel Change the menu size Define double click action in legend choose between open layer properties and open attribute table Capitalize layer names in legend Display classification attribute names in legend Create raster icons in legend Hide splash screen at startup Show tips at startup Open identify results in a dock window QGIS restart required P q Open snapping options in a dock window QGIS restart required Open attribute table in a dock window Add PostGIS layers with double click and select in extended mode Add new layers to selected or current group 42 Cap tulo 8 QGIS Configuration QGIS User Guide Release 1 8 Copy geometry in WKT representation from attribute table e Attribute table behavior choose between Show all features default Show selected features Show features in current canvas Attribute table row cache Define Representation for NULL values Promp
72. import from it where you want to store the converted GPX file and what the name of the new layer should be Note that not all GPS data formats will support all three feature types so for many formats you will only be able to choose between one or two types 14 1 5 Downloading GPS data from a device QGIS can use GPSBabel to download data from a GPS device directly as new vector layers For this we use the Download from GPS tab of the GPS Tools dialog see Figure_GPS_2 Here we select the type of GPS device the port that it is connected to or usb if your GPS supports this the feature type that you want to download the GPX file where the data should be stored and the name of the new layer g GPS Tools VDYoOS Load GPxtile Importotherfile Download rom GPS Uploadto GPS GPX Conver gt GPS device Garmin serial 7 Edit devices Port local gpsd aly Refresh Feature type Waypoints NA Layer name downloaded points Output file lhomeidassau ggis sample data gps downloaded gpx SaveAs Help T Figura 14 2 The download tool The device type you select in the GPS device menu determines how GPSBabel tries to communicate with your GPS device If none of the available types work with your GPS device you can create a new type see section Defining new device types 116 Cap tulo 14 Working with GPS Data QGIS User Guide Release 1 8 The port may be a file name or some other name th
73. integration 8 GDALTools Integrate GDAL Tools into QGIS 9 Georeferencer GDAL Adding projection information to raster using GDAL 10 Heatmap tool Generating raster heatmaps from point data 11 Interpolation plugin interpolate based on vertices of a vector layer 12 Mapserver Export Export QGIS project file to a MapServer map file 13 Offline Editing Allow offline editing and synchronizing with database 14 OpenStreetMap plugin Viewer and editor for openstreetmap data 15 Oracle Spatial GeoRaster support 16 Plugin Installer Download and install QGIS python plugins 17 Raster terrain analysis Raster based terrain analysis 18 Road graph plugin Shortest Path network analysis 19 SPIT Import Shapefile to PostgreSQL PostGIS 20 SQL Anywhere Plugin Store vector layers within a SQL Anywhere database 21 Zonal statictics plugin Calculate count sum mean of raster for each polygon of a vector layer 22 Spatial Query plugin Makes spatial queries on vector layers 23 eVIS Event Visualization Tool 24 fTools Tools for vector data analysis and management 4 6 2 External Python Plugins QGIS offers a growing number of external python plugins that are provided by the community These plugins reside in the official plugins repository and can be easily installed using the Python Plugin Installer See Section Loading an external QGIS Plugin 4 7 What s new in the version 1 8 Please note that this is a release in our cutt
74. lang Based on your locale QGIS selects the correct localization If you would like to change your language you can specify a language code For example lang it starts QGIS in italian localization A list of currently supported languages with language code and status is provided at http hub qgis org wiki quantum gis GUI_Translation_Progress Command line option project Starting QGIS with an existing project file is also possible Just add the command line option project followed by your project name and QGIS will open with all layers loaded described in the given file Command line option extent To start with a specific map extent use this option You need to add the bounding box of your extent in the following order separated by a comma extent xmin ymin xmax ymax Command line option nologo This command line argument hides the splash screen when you start QGIS Command line option noplugins If you have trouble at startup with plugins you can avoid loading them at startup They will still be available in Plugins Manager after wards Command line option nocustomization Using this command line argument existing GUI customization will not be applied at startup Command line option optionspath You can have multiple configurations and decide which one to use when starting QGIS using this option See Options to check where does the operating system save the settings files Presently there is no way to specify i
75. left mouse button To cancel a move click another mouse button If you are moving a feature that is connected to another features these connections won t be damaged Other features will just adapt themselves to a new position of a moved feature Snapping is also supported in this operation this means e When moving a standalone not part of any line polygon point snapping to all map segments and vertices 1s performed e When moving a point that is a member of some lines polygons snapping to all map segments and vertices 1s performed except for vertices of point parents e When moving a line polygon snapping to all map vertices is performed Note that the OSM Plugin tries to snap only to the 3 closest to cursor vertices of a moved line polygon otherwise the operation would by very slow Snapping can be disabled by holding Ct r1 key during the operation 16 7 6 Map feature removing If you want to remove a feature you must identify it first To remove an identified feature use the X Remove this feature button on the OSM Feature widget When removing a line polygon the line polygon itself is deleted so are all its member points that doesn t belong to any other line polygon When removing a point that is member of some lines polygons the point is deleted and the geometries of parent lines polygons are changed The new parent geometry has less vertices than the old one If the parent feature was a polygon with three vertexes i
76. map Item Properties tab e Rectangle is the default setting It only displays an empty box with a message Map will be printed here e Cache renders the map in the current screen resolution If case you zoom in or out the composer window the map is not rendered again but the image will be scaled e Render means that if you zoom in or out the composer window the map will be rendered again but for space reasons only up to a maximum resolution Cache is default preview mode for newly added print composer maps You can resize the map element by clicking on the W Select Move item button selecting the element and dragging one of the blue handles in the corner of the map With the map selected you can now adapt more properties in the map Item Properties tab To move layers within the map element select the map element click the Y Move item content icon and move the layers within the map element frame with the left mouse button After you found the right place for an element you can lock the element position within the print composer canvas Select the map element and click on the right mouse button to Ej Lock the element position and again to unlock the element You can lock the map element also activating the Lock layers for map item checkbox in the Map dialog of the Item Properties tab Note QGIS is now able to show labels from the new labeling plugin also in the map composer but it is not yet scaled correctly So it might be
77. may want to use different transformation algorithms Choice of transformation algorithm is also dependent on the type and quality of input data and the amount of geometric distortion that you are willing to introduce to final result Currently following algorithms are available The Linear algorithm is used to create a world file and is different from the other algorithms as it does not actually transform the raster This algorithm likely won t be sufficient 1f you are dealing with scanned material The Helmert transformation performs simple scaling and rotation transformations The Polynomial algorithms 1 3 are among the most widely used algorithms for georeferencing and each one differs by the degree of distortion introduced to match source and destination ground control points The most widely used polynomial algorithm is the second order polynomial transformation which allows some curvature First order polynomial transformation affine preserves colliniarity and allows scaling translation and rotation only The Thin plate spline TPS algorithm is a more modern georeferencing method which is able to intro duce local deformations in the data This algorithm is useful when very low quality originals are being georeferenced The Projective transformation is a linear rotation and translation of coordinates Define the Resampling method The type of resampling you choose will likely depending on your input data and the ultimate objec
78. measured In the measure window the accumulated area size appears In addition the measuring tool will snap to the currently selected layer provided that layer has its snapping tolerance set See Section Setting the Snapping Tolerance and Search Radius So if you want to measure exactly along a line feature or around a polygon feature first set its snapping tolerance then select the layer Now when using the measuring tools each mouse click within the tolerance setting will snap to that layer 7 4 Measuring 35 QGIS User Guide Release 1 8 g Measure v Ellipsoidal Total 13 082 km Help New Close Figura 7 3 Measure Area A KDE lt i You can also measure angles selecting Measure Angle tool The cursor becomes cross shaped Click to draw the first segment of the angle you wish to measure then move the the cursor to draw the desired angle The measure is displayed in a popup dialog g Ss Angle y Ellipsoidal 70 6921 degrees Close Figura 7 4 Measure Angle a KDE 7 4 2 Select and deselect features The QGIS toolbar provides several tools to select features in the map canvas To select one or several features just click on BR and select your tool PR Select single feature R Select features by rectangle Q Select features by polygon Q Select features by freehand a Q Select features by radius To deselect all selected features click on ax Deselect features from all layers 7
79. most simple symbols txt file contains the definition of a circle symbol because a circle symbol is used for point layers SYMBOLSET SYMBOL NAME circle TYPE ellipse FILLED true POINTS ry ry 19 13 MapServer Export Plugin 227 QGIS User Guide Release 1 8 19 13 4 Testing the Map File We can now test our work If the map file is accessible for you mapserver cgi you can use the one of the url s from the success dialog Another option is using the shp2img tool to create an image from the map file The shp2img utility is part of MapServer and FWTools To create an image from our map e Open a terminal window If you didn t save your map file in your home directory change to the folder where you saved it e Run shp2img m qgisproject map o mapserver _test png and display the image This creates a PNG with all the layers included in the QGIS project file In addition the extent of the PNG will be the same as when we saved the project As you can see in figure_mapserver_export_4 all information except the airport symbols are included Figura 19 23 Test PNG created by shp2img with all MapServer Export layers A 19 13 5 Using Map File If you plan to use the map file to serve WMS requests you probably don t have to tweak anything If you plan to use it with a mapping template or a custom interface you may have a bit of manual work to do To see how easy it is to go from QGIS to serving maps on the web
80. new CRS the used layer units will automatically be changed in the General tab of the Project Properties dialog under the Edit Gnome OSX or Settings KDE Windows menu 9 2 Specifying a Projection QGIS starts each new project using the global default projection The global default CRS is EPSG 4326 WGS 84 proj longlat ellps WGS84 datum WGS84 no_defs and comes predefined in QGIS This default can be changed using the Select button in the first section used to defining the Default Coordinate Reference System to use when starting new projects as shown in figure_projection_1 This choice will be saved for use in subsequent QGIS sessions When you use layers that do not have a CRS you need to define how QGIS responds to these layers This can be done globally or project wide in the CRS tab under Edit s Options Gnome OSX or Settings s Options KDE Windows The options shown in figure projection 1 are e Prompt for CRS 49 QGIS User Guide Release 1 8 Erl Map tools Overlays 17 Digitizing amp CRS B Locale Network lt gt Default Coordinate Reference System for new projects Always start new projects with this CRS EPSG 4326 WGS 84 Select _ Enable on the fly reprojection by default Coordinate Reference System for new layers When a new layer is created or when a layer is loaded that has no Coordinate Reference System CRS e Prompt for CRS __ Use project CRS
81. operators To add an operator to the raster calculator expression box click the appropriate button Mathematical calculations x and trigonometric functions sin cos tan are available Stay tuned for more operators to come With the Add result to project checkbox the result layer will automatically added to the legend area and can be visualized 12 3 1 Examples Convert elevation values from meter to feet Creating an elevation raster feet from a raster in meter you need to use the conversion factor for meters to feet 3 28 The expression is elevation l 3 28 Using a mask If you want to mask out parts of a raster because you are only interested in elevations above 0 meter you can use following expression to create a mask and apply the result to a raster in one step elevation l gt 0 elevation l For every cell greater than or equal to 0 set its value to 1 otherwise set it to 0 This creates the mask on the fly 104 Capitulo 12 Working with Raster Data CAPITULO 13 Working with OGC Data 13 1 Working with OGC Data QGIS supports WMS and WES as data sources 13 1 1 What is OGC Data The Open Geospatial Consortium OGC is an international organization with more than 300 commercial gov ernmental nonprofit and research organizations worldwide Its members develop and implement standards for geospatial content and services GIS data processing and exchange Describing a basic
82. pg_service conf Host Name of the database host This must be a resolvable host name the same as would be used to open a telnet connection or ping the host If the database is on the same computer as QGIS simply enter localhost here Port Port number the PostgreSQL database server listens on The default port is 5432 Database Name of the database SSL mode How the SSL connection will be negotiated with the server Note that massive speedups in PostGIS layer rendering can be achieved by disabling SSL in the connection editor Following options are available disable only try an unencrypted SSL connection allow try a non SSL connection if that fails try an SSL connection prefer the default try an SSL connection if that fails try a non SSL connection require only try an SSL connection Username User name used to login to the database Password Password used with Username to connect to the database Optional you can activate following checkboxes Save Username Save Password Only look in the geometry_columns table Only look in the public schema 58 Cap tulo 11 Working with Vector Data QGIS User Guide Release 1 8 Also list tables with no geometry Use estimated table metadata Once all parameters and options are set you can test the connection by clicking on the Test Connect button Tip QGIS User Settings and Security Depending on your computing en
83. plugins were updated to place their menus in the new Vector Raster and Web top level menus Offset Curves a new digitising tool for creating offset curves was added New tools in the Vector menu to Densify geometries and Build spatial index Export add geometry column tool can export info using layer CRS project CRS or ellipsoidal measurements Model view based tree for rules in rule based renderer Improvements in Spatial Bookmarks New Plugin metadata in metadata txt Refactored postgres data provider support for arbitrary key including non numeric and multi column support for requesting a certain geometry type and or srid in QgsDataSourceURI Added gdal_fillnodata to GDALTools plugin Support for PostGIS TopoGeometry datatype 12 Capitulo 4 Features QGIS User Guide Release 1 8 Python bindings for vector field symbol layer and general updates to the Python bindings Added a Benchmark program Added Row cache for attribute table UUID generation widget for attribute table Added support of editable views in SpatiaLite databases added expression based widget in field calculator Creation of event layers in analysis lib using linear referencing Load save layer styles in the new symbology renderer from to SLD document QGIS Server can act as WES Server WES Client support is now a core feature in QGIS Option to skip WKT geometry when copying from attribute table Support loading of zipped and gzipped layers
84. points to the raster image A The points that are added to the map will be stored in a separate text file filename points usually together with the raster image This allows us to reopen the Georeferencer plugin at a later date and add new points or delete existing ones to optimize the result The points file contains values of the form mapX mapY pixelX pixelY You can use the 58 Load GCP Points and El save GCP Points buttons to manage the files Within the GCP table you can click on a column header and therewith enable e g numerical sorting The GCP list is automatically updated Defining the transformation settings After you have added your GCPs to the raster image you need to define the transformation settings for the georeferencing process 19 11 Georeferencer Plugin 221 QGIS User Guide Release 1 8 4 Transformation settings gt x e amp Transformation type Linear y Resampling method Nearest neighbour v Compression NONE v _ Create world file Output raster Target SRS EPSG 31467 Generate pdf map Generate pdf report a o UN UN y Set Target Resolution Horizontal 100 00000 Vertical 100 00000 oo __ Use 0 for transparency when needed M Load in QGIS when done ES Help Y OK Cancel Figura 19 18 Defining the georeferencer transformation settings A Available Transformation algorithms Depending on how many ground control point you have captured you
85. properly 9 1 Overview of Projection Support QGIS has support for approximately 2 700 known CRS Definitions for each of these CRS are stored in a SQLite database that is installed with QGIS Normally you do not need to manipulate the database directly In fact doing so may cause projection support to fail Custom CRS are stored in a user database See Section Custom Coordinate Reference System for information on managing your custom coordinate reference systems The CRS available in QGIS are based on those defined by the European Petroleum Search Group EPSG and the Institut Geographique National de France IGNE and are largely abstracted from the spatial reference tables used in GDAL EPSG identifiers are present in the database and can be used to specify a CRS in QGIS In order to use OTF projection your data must contain information about its coordinate reference system or you have to define a global layer or project wide CRS For PostGIS layers QGIS uses the spatial reference identifier that was specified when the layer was created For data supported by OGR QGIS relies on the presence of a recognized means of specifying the CRS In the case of shapefiles this means a file containing the Well Known Text WKT specification of the CRS This projection file has the same base name as the shapefile and a prj extension For example a shapefile named alaska shp would have a corresponding projection file named alaska prj Whenever you select a
86. rows 7 V Show grid Grid stroke width 0 50 gt Margin 1 00 gt Header Font Content Font Figura 18 18 Table Dialog amp The Table dialog allows to select the vector layer and columns of the attribute table Attribute columns can be sorted and you can define to show its values ascending or descending e You can define the maximum number of rows to be displayed and if attributes are only shown for visible features of the current composer canvas e Additionally you can define the grid characteristics of the table and the header and content font General options dialog The General options dialog of the attribute table item tab provides following functionalities see fig ure_composer_21 Here you can define color and outline width for the element frame set a background color and opacity for the table The Position and size button opens the Set item position dialog and allows to set the map 18 8 Add attribute table values 191 QGIS User Guide Release 1 8 Item Properties x Table General options Frame color Background color Opacity A Outline width 0 30 gt Position and size iV Show frame Item ID Figura 18 19 General Options Dialog canvas position using reference points or coordinates Furthermore you can select or unselect to display the element frame with the Show frame checkbox Use the Item ID to create a relationship to the other print composeri
87. search for additional C plugin libraries 8 3 4 Rendering Tab By default new layers added to the map should be displayed e Define Number of features to draw before updating the display Use render caching where possible to speed up redraws Make lines appear less jagged at the expense of some drawing performance Fix problems with incorrectly filled polygons Use new generation symbology for rendering e Define the default Raster settings for visualisation RGB band selection Use standard deviation and Contrast Enhancement 8 3 Options 43 QGIS User Guide Release 1 8 Add remove Path s to search for Scalable Vector Graphics SVG symbols Additionally you can define whether to save the path for svg textures absolute or relative in the General tab of the Settings Project Properties menu 8 3 5 Map tools Tab The Mode setting determines which layers will be shown by the Identify tool By switching to Top down or Top down stop at first instead of Current layer attributes for all identifiable layers see the Project properties section under Projects to set which layers are identifiable will be shown with the Identify tool Open feature form if a single feature is identified Define Search radius for identifying and displaying map tips as a percentage of the map width Define Ellipsoid for distance calculations Define Rubberband color for measure tools Define Decimal places Kee
88. simple to load GRASS raster and vector layers in QGIS See following sections for editing GRASS data and creating a new LOCATION More sample GRASS LOCATIONs are available at the GRASS website at http grass osgeo org download data php Tip GRASS Data Loading If you have problems loading data or QGIS terminates abnormally check to make sure you have loaded the GRASS plugin properly as described in section Starting the GRASS plugin 15 3 GRASS LOCATION and MAPSET GRASS data are stored in a directory referred to as GISDBASE This directory often called grassdata must be created before you start working with the GRASS plugin in QGIS Within this directory the GRASS GIS data are organized by projects stored in subdirectories called LOCATION Each LOCATION is defined by its coordinate system map projection and geographical boundaries Each LOCATION can have several MAPSETs subdirectories of the LOCATION that are used to subdivide the project into different topics subregions or as workspaces for individual team members Neteler amp Mitasova 2008 Literature and Web References In order to analyze vector and raster layers with GRASS modules you must import them into a GRASS LOCATION This is not strictly true with the GRASS modules r external and v external you can create read only links to external GDAL OGR supported data sets without importing them But because this is not the usual way for beginners to work with GRASS this functional
89. subprocess Popen command image we have to just remember that the action is one of type Python and to change the command and imagerelpath variables to fit our needs 11 2 The Vector Properties Dialog 79 QGIS User Guide Release 1 8 But what about if the relative path need to be relative to the saved project file The code of the Python action would be command firefox imagerelpath images test_image jpg projectpath qgis core QgsProject instance fileName import os path path os path dirname str projectpath if projectpath else None image os path join path imagerelpath import subprocess subprocess Popen command image Another Python actions example if the one that allows us to add new layers to the project For instance the following examples will add to the project respectively a vector and a raster The name of files to be added to the project and the name to be given to the layer are data driven filename and layname are column names of the table of attributes of the vector where the action was created agis utils iface addVectorlayer yourpath filename shp layername ogr To add a raster a tif image in this example it becomes qgis utils iface addRasterLayer yourpath filename tif layername 11 2 10 Joins Tab o 4 The Joins tab allows you to join a loaded attribute table to a loaded vector layer As key colum
90. table Executing a batch process is similar to performing a single execution of an algorithm Parameter values have to be defined but in this case we need not just a single value for each parameter but a set of them instead one for each time the algorithm has to be executed Values are introduced using a table like the one shown next Grid pe Standard Deviation Search Mode 10 0 Square gt 13 0 1 0 0 Square Lz 3 1 0 0 Square BE 1 0 0 Square iz 3 0 10 o Square BE 1 0 0 Square M 3 0 Figura 17 25 Batch Processing 7 Each line of this table represents a single execution of the algorithm and each cell contains the value of one of the parameters It is similar to the parameters dialog that you see when executing an algorithm from the toolbox but with a different arrangement By default the table contains just two rows You can add or remove rows using the buttons on the lower part of the window Once the size of the table has been set it has to be filled with the desired values 17 4 3 Filling the parameters table For most parameters setting its value is trivial Just type the value or select it from the list of available options depending on the parameter type The main differences are found for parameters representing layers or tables and for output filepaths Regarding input layers and tables when an algorithm is execute
91. the Event ID module either click on the a Event ID icon or click on Plugins eVis Event ID Tool This will cause the cursor to change to an arrow with an i on top of it signifying that the ID tool is active To view the photographs linked to vector features in the active vector layer displayed in the QGIS map window move the Event ID cursor over the feature and then click the mouse After clicking on the feature the Generic Event Browser window is opened and the photographs on or near the clicked locality are available for display 208 Capitulo 19 Plugins QGIS User Guide Release 1 8 in the browser If more than one photograph is available you can cycle through the different features using the Previous and Next buttons The other controls are described in the ref evis_browser section of this guide 19 8 6 Database connection The Database Connection module provides tools to connect to and query a database or other ODBC resource such as a spreadsheet eVis can directly connect to four types of databases Microsoft Access PostgreSQL MySQL SQLite and can also read from ODBC connections When reading from an ODBC database such as an Excel spreadsheet it is necessary to configure your ODBC driver for the operating system you are using Launch the Database Connection module To launch the Database Connection module either click on the appropriate icon E eVis Database Connection gir click on Plugin
92. the Modules Tree tab This GRASS module allows to import GDAL supported raster files into a GRASS LOCATION The module dialog for r in gdal appears 6 Browse to the folder raster in the QGIS alaska dataset and select the file landcover img 7 As raster output name define landcover_grass and click Run In the Output tab you see the currently running GRASS command r in gdal o input path to landcover img output landcover_grass 8 When it says Succesfully finished click View output The landcover_grass raster layer is now imported into GRASS and will be visualized in the QGIS canvas 9 To import the vector GML file Lakes gm1 click the module v in ogr in the Modules Tree tab This GRASS module allows to import OGR supported vector files intoa GRASS LOCATION The module dialog for v in ogr appears 10 Browse to the folder gm1 in the QGIS alaska dataset and select the file Lakes gml as OGR file 11 As vector output name define lakes_grass and click Run You don t have to care about the other options in this example In the Output tab you see the currently running GRASS command v in ogr o dsn path to lakes gml output lakes_grass 12 When it says Succesfully finished click View output The lakes_grass vector layer is now imported into GRASS and will be visualized in the QGIS canvas 15 5 The GRASS vector data model It is important to understand the GRASS vector data model prior to digitizing In general GRASS uses a topol
93. the operation is ignored 144 Cap tulo 16 OpenStreetMap QGIS User Guide Release 1 8 Snapping is performed to all map vertices points from the Point vector layer and all Line and Polygon members Snapping can be disabled by holding the Ct r1 key 16 7 4 Polygon creation For polygon creation there is a q Create polygon button on the OSM Feature widget To create a polygon just click the button and start left clicking on the map Each of your left clicks is remembered as a member vertex of the new polygon The Polygon creation ends when first right click is performed The new polygon will immediately appear on the map Polygon with less than three members cannot be created In such case operation is ignored Snapping is performed to all map vertexes points from Point vector layer and all Line and Polygon members Snapping can be disabled by holding the Ct r1 key 16 7 5 Map feature moving A If you want to move a feature no matter what type please use the GP Move feature button from the OSM Feature widget menu Then you can browse the map features are identified dynamically when you go over them and click on the feature you want to move If a wrong feature is selected after your click don t move it from the place Repeat right clicking until the correct feature is identified When selection is done and you move the cursor you are no more able to change your decision what to move To confirm the move click on the
94. the snapping tolerance doesn t have to be changed after zoom operations In our small digitizing project working with the Alaska dataset we define the snapping units 82 Cap tulo 11 Working with Vector Data QGIS User Guide Release 1 8 in feet Your results may vary but something on the order of 300ft should be fine at a scale of 1 10 000 should be a reasonable setting 2 A layer based snapping tolerance can be defined by choosing Settings or File gt Snapping options to enable and adjust snapping mode and tolerance on a layer basis see figure_edit_1 Note that this layer based snapping overrides the global snapping option set in the Digitizing tab So if you need to edit one layer and snap its vertices to another layer then enable snapping only on the snap to layer then decrease the global snapping tolerance to a smaller value Furthermore snapping will never occur to a layer which is not checked in the snapping options dialog regardless of the global snapping tolerance So be sure to mark the checkbox for those layers that you need to snap to g S Snapping options y Y Y e X alaska to vertex 1 200 000000 mapunits v x x climate to vertex x 200 000000 map units Figura 11 27 Edit snapping options on a layer basis a Search radius Search radius is the distance QGIS uses to search for the closest vertex you are trying to move when you click on the map If you aren t within the search radi
95. to define a workflow creating a single process that involves several sub processes e The SEXTANTE history manager All actions performed using any of the aforementioned elements are stored in a history file and can be later easily reproduced using the history manager 151 QGIS User Guide Release 1 8 SEXTANTE Modeler Enter model name here Enter group name here Terrain Analysis Channels E Terrain Analysis Hydrology Burn Stream Network into DEM Catchment Area Flow Tracing Catchment Area Mass Flux Method Catchment Area Parallel Catchment Area Recursive Cell Balance Edge Contamination Fil Sinks Planchon Darboux 2001 Fil Sinks Wang amp Liu OS Fil Sinks XXL Wang amp Liu Flat Detection Flow Path Length S Flow Width and Specific Catchment A 1s Factor Lake Flood SAGA Wetness Index ui Simple Filter Sink Drainage Route Detection Sink Removal Slope Length Topographic Wetness Index TWI Stream Power Index Topographic Wetness Index TWI Upslope Area Terrain Analysis Lighting Terrain Analysis Morphometry Figura 17 2 SEXTANTE Models WARNING ALGORITHM Thu Mar 15 2012 09 37 52 Sextante runalg saga gaussianlandscapes 100 0 100 0 100 0 0 0 0 None ae ERROR E Tue Mar 13 2012 00 25 27 Could not load R script K_fu
96. to create a free editable map of the world The maps are created using data from portable GPS devices aerial photography other free sources or simply from local knowledge The project was started because most maps have legal or technical restrictions on their use restricting people from using them in creative productive or unexpected ways Both rendered images and the vector dataset of OSM are available for download under a Creative Commons Attribution ShareAlike 2 0 license OpenStreetMap was inspired by sites such as Wikipedia the map display see Figure_OpenStreetMap_1 features a prominent Edit tab and a full revision history is maintained Registered users can upload GPS track logs and edit the vector data using the given editing tools OSM data primitive is an object class that can be stored via the API in the server The three supported types of data are Node Way and Relation e A node is a latitude longitude pair of coordinates It is used as building a block for other features and as a feature itself Points Of Interest if they are tagged as required e A way is a list of at least two nodes that describe a linear feature such as a street or similar Nodes can be members of multiple ways A relation is a group of zero or more primitives with associated roles It is used to specify relationships between objects and may also model an abstract object Several different logical features in a common map Point Of Interest
97. toolbox and open Vector Vector update by other maps Click on the v rast stats module Enter gtopo30 and forest_areas Only one additional parameter is needed Enter column prefix elev and click run This is a computa tionally heavy operation which will run for a long time probably up to two hours Finally open the forest_areas attribute table and verify that several new columns have been added including elev_min elev_max elev_mean etc for each forest polygon 15 9 The GRASS toolbox 135 QGIS User Guide Release 1 8 15 9 3 Working with the GRASS LOCATION browser Another useful feature inside the GRASS Toolbox is the GRASS LOCATION browser In figure_grass_module_7 you can see the current working LOCATION with its MAPSETs In the left browser windows you can browse through all MAPSETs inside the current LOCATION The right browser window shows some meta information for selected raster or vector layers e g resolution bounding box data source connected attribute table for vector data and a command history y GRASS Wools alasica demo 2 alx Modules Tree Modules List Browser WOBONO cs EEES demo Vector airports El a raster gtopo30 Points 76 o E vector Lines 0 m airports Boundaries O aa Centroids 0 EJ rivers rivers200 Areas 0 PERMANENT Islands O North 1981991 58212934 South 436940 04186938 sd East 1406705
98. two lakes not the 5 000 on our big_lakes layer We can create a new layer and use copy paste to plop the needed lakes into it As an example we are copying some lakes to a new layer 1 Load the layer you want to copy from source layer 2 Load or create the layer you want to copy to target layer 3 Start editing for target layer 4 Make the source layer active by clicking on it in the legend 86 Cap tulo 11 Working with Vector Data QGIS User Guide Release 1 8 5 Use the aR Select Single Feature too to select the feature s on the source layer 6 Click on the x Copy Features too 7 Make the destination layer active by clicking on it in the legend 8 Click on the B Paste Features tog 9 Stop editing and save the changes What happens if the source and target layers have different schemas field names and types are not the same QGIS populates what matches and ignores the rest If you don t care about the attributes being copied to the target layer it doesn t matter how you design the fields and data types If you want to make sure everything feature and its attributes gets copied make sure the schemas match Tip Congruency of Pasted Features If your source and destination layers use the same projection then the pasted features will have geometry identical to the source layer However if the destination layer is a different projection then QGIS cannot guarantee the ge ometry is identical This is simply
99. vector analysis sampling geoprocessing geometry and database manage ment tools You can also use the integrated GRASS tools which include the complete GRASS functionality of more than 400 modules See Section GRASS GIS Integration Or you work with SEXTANTE which provides powerful a geospatial analysis framework to call native and third party algorithms from QGIS such as GDAL SAGA GRASS fTools and more see section SEXTANTE 4 5 Publish maps on the Internet QGIS can be used to export data to a mapfile and to publish them on the Internet using a webserver with UMN MapServer installed QGIS can also be used as a WMS WMS C or WES and WFS T client and as WMS or WES server see section Working with OGC Data 4 6 Extend QGIS functionality through plugins QGIS can be adapted to your special needs with the extensible plugin architecture QGIS provides libraries that can be used to create plugins You can even create new applications with C or Python 4 6 1 Core Plugins 1 Add Delimited Text Layer Loads and displays delimited text files containing x y coordinates 2 Coordinate Capture Capture mouse coordinates in different CRS 3 DB Manager Exchange edit and view layers and tables execute SQL queries 10 Capitulo 4 Features QGIS User Guide Release 1 8 4 Diagram Overlay Placing diagrams on vector layer 5 Dxf2Shp Converter Convert DXF to Shape 6 GPS Tools Loading and importing GPS data 7 GRASS GRASS GIS
100. will not be able to tell which vertex is being edited Tip Vertex Markers The current version of QGIS supports three kinds of vertex markers Semi transparent circle Cross and None To change the marker style choose Options from the Settings menu and click on the Digitizing tab and select the appropriate entry Basic operations e Start by activating the di pb Node Tool and selecting a feature by clicking on it Red boxes will appear at each vertex of this feature Selecting vertices You can select vertices by clicking on them one at a time by clicking on an edge to select the vertices at both ends or by clicking and dragging a rectangle around some vertices When a vertex is selected its color changes to blue To add more vertices to the current selection hold down the Ctrl key while clicking Hold down Ct rl or Shi ft when clicking to toggle the selection state of vertices vertices that are currently unselected will be selected as usual but also vertices that are already selected will become unselected Adding vertices To add a vertex simply double click near an edge and a new vertex will appear on the edge near to the cursor Note that the vertex will appear on the edge not at the cursor position therefore it has to be moved if necessary Deleting vertices After selecting vertices for deletion click the Delete key Note that you cannot use the p gt id e gt Node Tool to delete a complete feature QG
101. you just have to make sure that the R folder is included in the PATH environment variable If you can start R just typing R in a console then you are ready to go To add a new algorithm that calls an R function or a more complex R script that you have developed and you would like to have available from SEXTANTE you have to create a script file that tells SEXTANTE how to perform that operation and the corresponding R commands to do so 17 7 Configuring external applications 175 QGIS User Guide Release 1 8 Script files have the extension rsx and creating them is pretty easy if you just have a basic knowledge of R syntax and R scripting They should be stored in the R scripts folder You can set this folder in the R settings group available from the SEXTANTE settings dialog just like you do with the folder for regular SEXTANTE scripts Let s have a look at a very simple file script file which calls the R method spsample to create a random grid within the boundary of the polygons in a given polygon layer This method belong to the maptools package Since almost all the algorithms that you might like to incorporate into SEXTANTE will use or generate spatial data knowledge of spatial packages like maptools and specially sp is mandatory polyg vector numpoints number 10 output output vector Sp group pts spsample polyg numpoints type random output SpatialPointsDataFrame pts as data frame pts The first lines
102. 18 Print Composer QGIS User Guide Release 1 8 The print composer allows you to create several output formats and it is possible to define the resolution print quality and paper size e The Print icon allows to print the layout to a connected printer or a Postscript file depending on installed printer drivers 1 e The um Export as image con exports the composer canvas in several image formats such as PNG BPM TIF JPG The Ay Exportas PDF saves the defined print composer canvas directly as a PDF e The l Export as SVG icon saves the print composer canvas as a SVG Scalable Vector Graphic Note Currently the SVG output is very basic This is not a QGIS problem but a problem of the underlaying Qt library This will hopefully be sorted out in future versions 18 11 Saving and loading a print composer layout v With the a Save as template and 48 Load from template icons you can save the current state of a print composer session asa qpt template and load the template again in another session The gt Composer Manager button in the QGIS toolbar and in File Composer Manager allows to add a new com poser template or to manage already existing templates o Composer manager 2 x o x Composer 1 Alaska New Version Composer 4 Empty composer v Add Show Remove Rename Close Figura 18 21 The Print Composer Manager A 18 11 Saving and loading a print composer layout 193
103. 5 Decorations The Decorations of QGIS includes the Copyright Label the North Arrow and the Scale Bar They are used to decorate the map by adding cartographic elements Note Before QGIS 1 8 the same functionality was provided by the Decoration Plugin 7 5 1 Copyright Label Copyright label adds a Copyright label using the text you prefer to the map 1 Select from menu View Decorations Copyright Label The dialog starts see figure decorations 1 2 Enter the text you want to place on the map You can use HTML as shown in the example 3 Choose the placement of the label from the Placement Bottom Right drop down box 36 Capitulo 7 General Tools QGIS User Guide Release 1 8 Copyright Label Plugin gt vo a Y Enable copyright label Enter your copyright label here amp copy QGIS 2010 Placement Bottom Right v come o Help OK Cancel Figura 7 5 The copyright Dialog 4 Make sure the Enable Copyright Label checkbox is checked 5 Click OK In the example above default QGIS places a copyright symbol followed by the date in the lower right hand corner of the map canvas 7 5 2 North Arrow A North Arrow places a simple north arrow on the map canvas At present there is only one style available You can adjust the angle of the arrow or let QGIS set the direction automatically If you choose to let QGIS determine the direction it makes its best guess as to how the arrow should be
104. 5 Metadata Tab The Metadata tab displays a wealth of information about the raster layer including statistics about each band in the current raster layer Statistics are gathered on a need to know basis so it may well be that a given layers Statistics have not yet been collected This tab is mainly for information You cannot change any values printed inside this tab 12 2 6 Pyramids Tab Large resolution raster layers can slow navigation in QGIS By creating lower resolution copies of the data pyra mids performance can be considerably improved as QGIS selects the most suitable resolution to use depending on the level of zoom You must have write access in the directory where the original data is stored to build pyramids Several resampling methods can be used to calculate the pyramids e Average e Nearest Neighbour When checking the checkbox Build pyramids internally if possible QGIS tries to build pyramids internally Please note that building pyramids may alter the original data file and once created they cannot be removed If you wish to preserve a non pyramided version of your raster make a backup copy prior to building pyramids 12 2 7 Histogram Tab The Histogram tab allows you to view the distribution of the bands or colors in your raster It is generated automaticaly when you open Histogram tab All existing bands will be displayed together You can save the histogram as an image with the button 12 3 Raster
105. 6 45722 5314 45722 5314 45722 5314 60963 3752 60963 3752 60963 3752 76204 2190 Classify Add class Delete class Advanced v Restore Default Style Save As Default Load Style Save Style B Heip Y oK X Apply Cancel Figura 11 10 Graduated Symbolizing options The attribute using the Column listbox e The symbol using the Symbol Properties button e The colors using the Color Ramp list Additionally you can specify the number of classes and also the mode how to classify features inside the classes using the Mode list The available modes are e Equal Interval e Quantile e Natural Breaks Jenks e Standard Deviation e Pretty Breaks The listbox in the bottom part of the Style tab lists the classes together with their ranges labels and symbols that will be rendered The example in figure_symbology_4 shows the graduated rendering dialog for the rivers layer of the QGIS sample dataset Rule based rendering The rule based renderer is used to render all the features from a layer using rule based symbols whose color reflects the classification of a selected feature s attribute to a class The rules are based on SQL statements The dialog allows rule grouping by filter or scale and you can decide if you want to enable symbol levels or use only first matched rule The example in figure_symbology_5 shows the rule based rendering dialog for the rivers layer of the QGIS sample da
106. A Rae hs A A DR de ds Working with Raster Data 12 1 Working with Raster Data a usura E A ae A e AE 12 2 Raster Properties Didot 22 pos a A e ed ee Ae 12 3 Raster Calculator s e e sanepa ts par re a aa bbe es Working with OGC Data 13 1 Working with OGG Datas s s ce 64 604 20 pa db oe a a lA 13 2 OGIS Server sous sra Sah hoe He Bice a A Aw Hae ew E a ae RS we BS Working with GPS Data TAL GPS Plupit 265 54 cae eee ERA GS DAH EA SA Ee ERR ee ee AR 14 2 Live GPS tracking s seola sp ee ee ae A ew e Da ee ae GRASS GIS Integration 15 1 Starting the GRASS plugin gas bho he Be See ee ee ee a 15 2 Loading GRASS raster and vector layers us ums 66 Ba eee e Re EO 15 3 GRASS LOCATION and MAPBSET us e Ta Gee ew eh Ea He AA Ee ad ee da 15 4 Importing data into a GRASS LOCATION 2 00220004 15 The GRASS vector data model 2 22 25 5 450 44 5 56 80 eRh4 54546844 15 6 Creating new GRASS vectorlayer su ums fhe eR Mp eee A Re OG Bo 15 7 Digitizing and editing a GRASS vector layer o e 15 8 The GRASS region tool so irc a o oh a a a AA a a e AG 15 9 Th GRASS toolbox ss kee ds a a ee eS OpenStreetMap 16 1 The OpenStreetMap project ans 2 86 vou we e He HA ee he Bee ey eis aa 162 OGIS OSM Connection ss 64840 eh rs RE a ee ba ee Re E ete 16 3 Installation 24 2444 255962 206 2654 Se 6554 254 e554 5 625 be eee wes 16 4 Basic user interface y sms 4 ER AEE ERE ER RE SOR DES
107. ANTE layers that is layers generated by using algorithms from any of the SEXTANTE components Just create the style you want using QGIS save it to a file and then enter the path to that file in the settings so SEXTANTE can use it Whenever a layer is loaded by SEXTANTE and added to the QGIS canvas it will be rendered with that style Rendering stlyes can be configured individually for each algorithm and each one of its outputs Just right click on the name of the algorithm in the toolbox and select Edit rendering styles You will see a dialog like the one shown next Comvergenceindex A Convergence Index lt OutputRaster gt Figura 17 13 Rendering Styles 7 Select the style file qm1 that you want for each output and press OK Other configuration parameters in the General group are explained below Use filename as layer name The name of each resulting layer created by SEXTANTE is defined by the algorithm generating it In some cases a fixed name might be used that meaning that the same name will be used no matter which input layer is used In other cases the name might depend on the name of the input layer or some of the parameters used to run the algorithm If this checkbox is checked the name will be taken from the output filename instead Notice that if the output is saved to a temporary file the filename of this temporary file is usually long and meaningless one intended to avoid collision with other alrea
108. AUTHORITY EPSG 8901 UNIT degree 0 0174532925199433 AUTHORITY EPSG 9108 AUTHORITY EPSG 4267 PROJECTION Albers_Conic_Equal_Area PARAMETER standard_parallel_1 55 PARAME R standard parallel 2 65 PARAMETER latitude of center 50 PARAME R longitude of center 154 PARAMETER false easting 0 PARAMETER false_northing 0 UNIT us survey feet 0 3048006096012192 If you intend to use QGIS as graphical frontend for GRASS you can find a selection of sample locations e g Spearfish or South Dakota at the official GRASS GIS website http grass osgeo org download data php 5 3 Sample Session Now that you have QGIS installed and a sample dataset available we would like to demonstrate a short and simple QGIS sample session We will visualize a raster and a vector layer We will use the landcover raster layer qgis_sample_data raster landcover img and the lakes vector layer agis_sample_data gml lakes gml 5 3 1 Start QGIS 4 Start QGIS by typing QGIS at a command prompt or if using precompiled binary using the Appli cations menu Start QGIS using the Start menu or desktop shortcut or double click on a QGIS project file X Double click the icon in your Applications folder 5 3 2 Load raster and vector layers from the sample dataset 1 Click on the amp Load Raster icon 2
109. Analysis P O sos sta s gs bo ee PO GP em a ee Sh O RD O E ORS 19 17 Heatmap Plugin 22 iw the a be ee EA EA wee ee eae eA 19 18 Road Graph Plugin ss is ig aoa oe A aa a bho amp Gm O Boe ea A 19 19 Spatial Query Plugins ms ha Bek eA DR A EE ee Gee ae E a eS 1920 SPLITI Plugi ia dj A Ge ae aS RA ee ae a 19 21 SQL Anywhere Plugin o ua RA a ee ee ee 19 22 Zonal Statistics Plugin ss ke eS ee oe a 20 Help and Support 20 1 20 2 20 3 20 4 20 5 20 6 Matlingilists us 45 54 ees ch bee POG AP he EE a ee ee aoe IR a as ees Bhd E EA SE E ew St PEPE SE Ee ASS CSE GU e Bug Tracker sas ra Bok Se ee eS A wm Gy SS gba ad ee wd we ee i Blot arta Eo ee Ba ae ha ee ee A Gh at Ge ae PIS US ss area a a ht Ue eae eds he eae BS a ee aed ee ag doe BD Baca Ge ae WIRI co awi is be Pade ee ESA eA bea wa eae Be be ees 21 Appendix 21 1 21 2 GNU General Public License ga ss rr e GE RR a ts e GNU Free Documentation License sala ee ee ka eS ee ek a ee AS a RAD do E ASS 22 Literature and Web References Index 181 182 182 183 185 189 190 190 190 192 192 193 195 195 199 200 200 201 202 204 204 214 217 220 223 224 228 229 231 232 236 237 237 239 239 241 241 242 242 243 243 243 245 245 248 255 257 CAP TULO 1 Preamble This document is the original user guide of the described software Quantum GIS The software and hardware described in this document are in most cases r
110. Attribute information window All of the attribute information for the point associated with the photo graph being viewed is displayed here If the file type being referenced in the displayed record is not an image but is of a file type defined in the Configure External Applications tab then when you double click on the value of the field containing the path to the file the application to open the file will be launched to view or hear the contents of the file If the file extension is recognized the attribute data will be displayed in green 6 Navigation buttons Use the Previous and Next buttons to load the previous or next feature when more than one feature is selected 7 Feature indicator This heading indicates which feature is being displayed and how many features are available for display Understanding the Options window 1 File path A dropdown list to specify the attribute field that contains the directory path or URL for the photographs or other documents being displayed If the location is a relative path then the checkbox must be clicked The base path for a relative path can be entered in the Base Path text box below Information 19 8 eVis Plugin 205 QGIS User Guide Release 1 8 Generic Event Browser Displaying records 06 of 56 ax Display Options Configure External Applications About so Secondary shrub C Workshop eVis_Data groundphotos DSC_0173 JPG so Figura 19 9 The eVis displa
111. Crosses Intersects Is disjoint Touches Within 19 19 1 Using the plugin As an example we want to find regions in the Alaska dataset that contain airports Following steps are necessary 1 Start QGIS and load the vector layers regions shp and airports shp 2 Load the Spatial Query plugin in the Plugin Manager see Section Loading a QGIS Core Plugin and click on the Va Spatial Query icon which appears in the QGIS toolbar menu The plugin dialog appears 3 Select layer regions as source layer and airports as reference feature layer 4 Select Contains as operator and click Apply Now you get a list of feature IDs from the query and you have several options as shown in figure spatial query 1 ivi e Click on the 9 Create layer with list of items e Select an ID from the list and click on w Create layer with selected A IV e Select the Remove from current selection in the field And use the result to e Additionally you can Zoom to item or display Log messages 19 20 SPIT Plugin QGIS comes with a plugin named SPIT Shapefile to PostGIS Import Tool SPIT can be used to load multiple shapefiles at one time and includes support for schemas To use SPIT open the Plugin Manager from the Plugins menu check the box next to the SPIT plugin and click OK The SPIT icon will be added to the plugin toolbar To import a shapefile click on the hed SPIT tool in the toolbar to open the SPIT Shapefile to PostGI
112. E Ne SC ar hor B n 4090 RD Gra Es ORR T UD ay gt Ea Layers IES 3 eaa A uA 14 i Ce ATA km y Ea si Ms dio a E 3 6 regions_denmark H ne a q j i 5 Create offline project y UQE E ns Offline data dassau Dokumente offline sqlite Browse Select remote layers lake regions denmark E DN Show only editable layers O Cancel gp UR a 1 OQUIS2011 Coordinate 3518111 6237760 Scale 1 161188 9 e Render EPsG 31467 A Figura 19 24 Create an offline project from PostGIS or WFS layers 19 15 Oracle GeoRaster Plugin In Oracle databases raster data can be stored in SDO_GEORASTER objects available with the Oracle Spatial extension In QGIS the OracleGeoRasterPlugin ig supported by GDAL and depends on Oracle s database product being installed and working on your machine While Oracle is proprietary software they provide their software free for development and testing purposes Here is one simple example of how to load raster images to GeoRaster gdal translat of georaster input file tif geor scott tiger orcl This will load the raster into the default GDAL IMPORT table as a column named RASTER 19 15 1 Managing connections Firstly the Oracle GeoRaster Plugin must be enabled using the Plugin Manager see Section Loading a OGIS Core Plugin The first time you load a GeoRaster in QGIS you must create a connect
113. EC TIVE YOU ASSUME THE COST OF ALL NECESSARY SERVICING REPAIR OR CORRECTION IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING WILL ANY COPYRIGHT HOLDER OR ANY OTHER PARTY WHO MAY MODIFY AND OR REDIS TRIBUTE THE PROGRAM AS PERMITTED ABOVE BE LIABLE TO YOU FOR DAMAGES IN CLUDING ANY GENERAL SPECIAL INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE PROGRAM INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PRO GRAMS EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBIL ITY OF SUCH DAMAGES Quantum GIS Qt exception for GPL In addition as a special exception the QGIS Development Team gives permission to link the code of this program with the Qt library including but not limited to the following versions both free and commercial Qt Non commerical Windows Qt Windows Qt X11 Qt Mac and Qt Embedded or with modified versions of Qt that use the same license as Qt and distribute linked combinations including the two You must obey the GNU General Public License in all respects for all of the code used other than Qt If you modify this file you may extend this exception to your version of the file but you are not obligated to do so If you do not wish to do so delete this exception statement from your version 21 2 GNU Free Documentation Li
114. For instance if you have declared a vector input with mylayer vector you could use myfield field mylayer to add a field from that layer as parameter e folder A folder e file A filename The parameter name is the name that will be shown to the user when executing the algorithm and also the variable name to use in the script code The value entered by the user for that parameter will be assigned to a variable with that name When showing the name of the parameter to the user SEXTANTE will edit it to improve its appearance replacing low hyphens with blankspaces So for instance if you want the user to see a parameter named A numerical value you can use the variable name A numerical value Layers and tables values are strings containing the filepath of the corresponding object To tum them into a QGIS object you can use the sextante getObjectFromUri function Multiple inputs also have a string value which contains the filepaths to all selected object separated by semicolons Outputs are defined in a similar manner using the following tags e output raster e output vector output table e output html output file e output number output string The value assigned to the output variables is always a string with a filepath It will correspond to a temporary filepath in case the use has not entered any output filename When you declare an output SEXTANTE will try to add it to QGIS once the algorith
115. GIS menu option first then Quit from the dropdown menu Larger amounts of text may be formatted as a list A do this e do that X do something else or as paragraphs A X Do this and this and this Then do this and this and this and this and this and this and this and this and this Do that Then do that and that and that and that and that and that and that and that and that and that and that and that and that and that and that Screenshots that appear throughout the user guide have been created on different platforms the platform is indi cated by the platform specific icon at the end of the figure caption 4 Capitulo 2 Conventions CAP TULO 3 Foreword Welcome to the wonderful world of Geographical Information Systems GIS Quantum GIS QGIS is an Open Source Geographic Information System The project was born in May of 2002 and was established as a project on SourceForge in June of the same year We ve worked hard to make GIS software which is traditionally expensive proprietary software a viable prospect for anyone with basic access to a Personal Computer QGIS currently runs on most Unix platforms Windows and OS X QGIS is developed using the Qt toolkit http qt digia com and C This means that QGIS feels snappy to use and has a pleasing easy to use graphical user interface GUN QGIS aims to be an easy to use GIS providing common functions and features The initial goal was to provide a GIS
116. GNU Free Documentation License 249 QGIS User Guide Release 1 8 To Preserve the Title of such a section when you modify the Document means that it remains a section Entitled XYZ according to this definition The Document may include Warranty Disclaimers next to the notice which states that this License applies to the Document These Warranty Disclaimers are considered to be included by reference in this License but only as regards disclaiming warranties any other implication that these Warranty Disclaimers may have is void and has no effect on the meaning of this License 2 VERBATIM COPYING You may copy and distribute the Document in any medium either commercially or noncommercially provided that this License the copyright notices and the license notice saying this License applies to the Document are reproduced in all copies and that you add no other conditions whatsoever to those of this License You may not use technical measures to obstruct or control the reading or further copying of the copies you make or distribute However you may accept compensation in exchange for copies If you distribute a large enough number of copies you must also follow the conditions in section 3 You may also lend copies under the same conditions stated above and you may publicly display copies 3 COPYING IN QUANTITY If you publish printed copies or copies in media that commonly have printed covers of the Document numbering more tha
117. IS User Guide Release 1 8 Input vector layer Specify the input point vector layer s from a list of loaded point layers If several layers are specified then data from all layers is used for interpolation Note It is possible to insert lines or 66 polygons as constraints for the triangulation by specifying either points structure lines or break lines Tv in the Type combobox Interpolation attribute Select attribute column to be used for interpolation or enable the Use Z Coordinate checkbox to use the layers stored Z values Interpolation Method Select interpolation method This can be either Triangulated Irregular Network TINY or Inverse Distance Weighted IDW Number of columns rows Specify the number row and colums for the output raster file Output file Specify a name for the output raster file Interpolation plugin Input Output Vector layers elevp Interpolation method Triangular interpolation TIN Interpolation attribute ELEV Number of columns 998 Number of rows 812 Use z Coordinate for interpolati Cellsize X 5000 00000 Cellsize Y 5000 00000 Add Remove xmin 2 84614e 06 X max 2 14422e 06 Vector layer Attribute Type Y min 4 35368e 06 Y max 8 41536e 06 Set to current extent Output file elevation_tin i Cancel Figura 19 19 Interpolation Plugin 19 12 1 Using the plugin Start QGIS and load a point vector layer e g elevp csv Loa
118. IS for that matter you are also asked if you want to save your changes or discard them If the changes cannot be saved e g disk full or the attributes have values that are out of range the QGIS in memory state is preserved This allows you to adjust your edits and try again Tip Data Integrity It is always a good idea to back up your data source before you start editing While the authors of QGIS have made every effort to preserve the integrity of your data we offer no warranty in this regard 11 3 Editing 87 QGIS User Guide Release 1 8 11 3 5 Advanced digitizing Purpose Icon Purpose Undo Redo Simplify Feature Add Ring gt Delete Part Reshape Features e Add Part a Delete Ring A EN Offset Curve ek Split Features Merge Selected Features O Rotate Point Symbols H Merge Attributes of Selected Features Table Advanced Editing Vector layer advanced editing toolbar Undo and Redo The Undo and 7N Redo tools allow the user to undo or redo vector editing operations There is also a dockable widget which shows all operations in the undo redo history see Figure_edit_3 This widget is not displayed by default it can be displayed by right clicking on the toolbar and activating the Undo Redo check box Undo Redo is however active even if the widget is not displayed Undo Redo o x lt empty gt Feature moved Feature added Ring added amp Undo om F Figura 11 29
119. IS will ensure it retains the minimum number of vertices for the feature type you are working on To delete a complete feature use the o Delete Selected too Moving vertices Select all the vertices you want to move Click on a selected vertex or edge and drag in the direction you wish to move All the selected vertices will move together If snapping is enabled the whole selection can jump to the nearest vertex or line Each change made with the node tool is stored as a separate entry in the undo dialog Remember that all operations support topological editing when this is turned on On the fly projection is also supported and the node tool provides tooltips to identify a vertex by hovering the pointer over it Cutting Copying and Pasting Features Selected features can be cut copied and pasted between layers in the same QGIS project as long as destination layers are set to A Toggle editing beforehand Features can also be pasted to external applications as text That is the features are represented in CSV format with the geometry data appearing in the OGC Well Known Text WKT format However in this version of QGIS text features from outside QGIS cannot be pasted to a layer within QGIS When would the copy and paste function come in handy Well it turns out that you can edit more than one layer at a time and copy paste features between layers Why would we want to do this Say we need to do some work on a new layer but only need one or
120. If you want to be up to date with every change to the current code base you can subscribe to this list at http lists osgeo org mailman listinfo qgis commit 20 1 5 qgis trac This list provides email notification related to project management including bug reports tasks and feature requests You can subscribe to this list at http lists osgeo org mailman listinfo qgis trac 241 QGIS User Guide Release 1 8 20 1 6 qgis community team This list deals with topics like documentation context help user guide online experience including web sites blog mailing lists forums and translation efforts If you like to work on the user guide as well this list is a good starting point to ask your questions You can subscribe to this list at http lists osgeo org mailman listinfo qgis community team 20 1 7 qgis release team This list deals with topics like the release process packaging binaries for various OS and announcing new releases to the world at large You can subscribe to this list at http lists osgeo org mailman listinfo qgis release team 20 1 8 qgis tr This list deals with the translation efforts If you like to work on the translation of the manuals or the graphical user interface GUD this list is a good starting point to ask your questions You can subscribe to this list at http lists osgeo org mailman listinfo qgis tr 20 1 9 qgis edu This list deals with QGIS education efforts If you like to work on
121. It is possible to add basic shapes Ellipse Rectangle Triangle and arrows to the print composer canvas The Shape dialog allows to draw an ellipse rectangle or triangle in the print composer canvas You can define its outline and fill color the outline width and a clockwise rotation The Arrow dialog allows to draw an arrow in the print composer canvas You can define color outline and arrow width and it is possible to use a default marker and no marker and a SVG marker For the SVG marker you can additionally add a SVG start and end marker from a directory on your computer 18 8 Add attribute table values It is possible to add parts of a vector attribute table to the print composer canvas Table dialog 190 Cap tulo 18 Print Composer QGIS User Guide Release 1 8 Item Properties x Shape Rectangle v Shape outline color Outline width 1 00 V Transparent fill Rotation 0 Figura 18 16 Shape Dialog 4 Item Properties x Arrow Arrow color Line width 1 00 lt gt lt gt Arrow head width 4 00 Arrow markers e Default marker _ No marker _ SVG markers Start marker End marker Figura 18 17 Arrow Dialog A The Table dialog of the attribute table item tab provides following functionalities see figure_composer_20 Item Properties x Table Layer airports v Attributes vV Show only visible features Composer map Map 0 lt gt lt Maximum
122. Map file Map file mapfile map Save As LAYER information only Map Name QGIS MAP Image type agg v Rendering y Width 100 Height 100 Units meters v MapServer url http localhost cgi bin mapserv Paths Inline Symbolset symbols symbols bt Fontset fonts fonts tt e templates Template Header Browse Footer Browse Layer label options v Force v Anti alias y Partials v Dump Help OK Cancel Figura 19 21 Export to MapServer Dialog A Map file Enter the name for the map file to be created You can use the button at the right to browse for the directory where you want the map file created Qgis Enter the full path to the QGIS project file qgs you want to export You can use the button at project the right to browse for the QGIS project file file Map A name for the map This name is prefixed to all images generated by the mapserver Name Map Width of the output image in pixels Width Map Height of the output image in pixels Height Map Units of measure used for output Units Image Format for the output image generated by MapServer type Web Full path to the MapServer template file to be used with the map file Template Web Full path to the MapServer header file to be used with the map file Header Web Full path to the MapServer footer file to be used with the map file Footer Only the inputs Map file and QGIS project file are required to create a map file however by omitting the other
123. New Spatialite Layer Database home junek test sqlite Layer name alaska Geometry column geometry Type Point Line Polygon MultiPoint Multiline e Multipolygon EPSG 4326 WGS 84 Specify CRS __ Create an autoincrementing primary key New attribute Text data Attributes list I Remove attribute Y OK Cancel Figura 11 32 Creating a New SpatiaLite layer Dialog 4S choose Open Attribute Table from the dropdown menu This will open a new window which displays the feature attributes in the layer figure attributes 1 The number of features and the number of selected features are shown in the attribute table title Selecting features in an attribute table Each selected row in the attribute table displays the attributes of a selected feature in the layer If the set of features selected in the main window is changed the selection is also updated in the attribute table Likewise if the set of rows selected in the attribute table is changed the set of features selected in the main window will be updated Rows can be selected by clicking on the row number on the left side of the row Multiple rows can be marked by holding the Ctr1 key A continuous selection can be made by holding the Shift key and clicking on several row headers on the left side of the rows All rows between the current cursor position and the clicked row are selected Moving the cursor position in the attribute table by clicking a cell in the tabl
124. P TULO 8 QGIS Configuration QGIS is highly configurable through the Settings menu Choose between Panels Toolbars Project properties Options and Customization 8 1 Panels and Toolbars In the Panels gt menu you can switch on and off QGIS widgets The Toolbars menu provides the possibility to switch on and off icon groups in the QGIS toolbar see figure_panels_toolbars Layer Settings Plugins Vector Raster Analysis Help F N Panels gt ES 9 D 9 Toolbars 2 Y Advanced Digitizing 5 Toggle Full Screen Mode Ctrl F Attributes t J Project Properties Ctrl Shift P Database J Custom CRS vV Digitizing Style Manager v File Configure shortcuts Y Help Customization Y Label Options Y Manage Layers Snapping Options Y Map Navigation Y Plugins Y Raster Y Vector Y Web Y GRASS Figura 8 1 The Panels and Toolbars menu A Tip Activating the QGIS Overview In QGIS you can use an overview panel that provides a full extent view of layers added to it It can be selected under the menu Settings Panels Within the view is a rectangle showing the current map extent This allows you to quickly determine which area of the map you are currently viewing Note that labels are not rendered to the map overview even if the layers in the map overview have been set up for labeling If you click and drag the red rectangle in the overview that shows your current extent the main map view will updat
125. PostgreSQL 58 Pretty_Breaks 66 print composer quick print 19 print_composer tools 181 Printing Export_Map 192 Proj 4 52 Proj4 50 Proj4_text 50 258 Index QGIS User Guide Release 1 8 Projections 49 Proxy 106 proxy server 106 Pseudocolor 100 Publish_to_Web_plugin 111 Pyramids 103 QGIS_mapserver 110 QGIS Server 111 QSpatiaLite 62 Quantile 66 Query Builder 94 Raster 99 Raster Calculator 103 Renderer Categorized 65 Renderer Graduated 66 Renderer Point Displacement 67 Renderer Single Symbol 65 Renderers 64 Renderers Old Symbology 70 Rendering 33 Rendering halting 34 rendering quality 35 Rendering scale dependent 34 rendering update during drawing 35 Rendering Rule based 67 Research tools 214 Revert Layout Actions 190 ring polygons 89 Rotate Point symbols 90 Rotated North Arrow 186 Rule based Rendering 67 Scale 34 scale calculate 30 Scalebar Map Scalebar 188 Search Radius 83 Secured OGC Authentication 110 Select using Query 95 SFS 105 Shapefile 55 Shapefile to Postgis Import Tool 237 Shared Polygon Boundaries 84 shp2img 227 shp2pgsql 60 Simple_fill 64 Simple_line 64 Simple_Marker 64 Single_Band_Raster 100 Single_Symbol_Renderer 65 SLD 111 SLD SE 111 Smart_Labeling 71 Snapping 82 Snapping_Tolerance 82 spatial bookmarks see bookmarks 39 Spatialite 62 Spatialite_Manager 62 SPIT 237 Split_Features 89 SQLite 62
126. QGIS Python Plugin Installer In order to download and install an external Python plugin go to Plugins E Fetch Python Plugins The Plugin Installer window will appear figure_plugins_2 with the tab Plugins containing a list of all locally installed Python plugins as well as plugin available in remote repositories 46 QGIS Python Plugin Installer 175 plugins available YU Plugins Repositories Options Filter all repositories v anystatus v Status Name Description not installed SEXTANTE 0 SEXTANTE Geoprocessing Platform for QGIS not installed RT QSpider h Convert the selected table to an event layer bas not installed NumericalDigitize 1 Digitize with just the keyboard Display of stratigraphy from surveys Developing 1 Start Python remote debugger from QGIS plugin not installed Photo2Shape ay Create a point shapefile from a set of geotagged not installed Home range estimation with R abi Kernel NNCH and MCP calculation with R function not installed DumpLoadField 0 Dumps or loads text from to a selected field from not installed Quickly save default qml ik Save default QML with one click not installed OpenLayers Plugin 0 OpenStreetMap Google Maps Bing Maps layers not installed Group Stats 6 Calculates stats for group of features not installed MaxWidth a Calculates the maximum width of a polygon not installed VectorFieldCalc a Calculates vector field parameters given two rast not installed Load Postgis Raster t
127. QGIS User Guide Release 1 8 QGIS Project November 10 2013 Conte do 1 Preamble 1 2 Conventions 3 3 Foreword 5 3 1 Introduction To GIS 24 54 4244 666 Ad Peto ea ee ee ee ee Pee eA 5 4 Features 9 dl Jaw data a A A IS aie eG A Ea EA E VE 9 4 2 Explore data and compose maps ss 255 444 4 book ina e 9 4 3 Create edit manage and exportdata e 10 44 Amalyse data culos e c beee Sag Se Be Be gS LE Gk ce Ge ea a ew gs 10 45 Publish maps on the Internet os cs coa 4 mca oe e ee ee Be E E 10 4 6 Extend QGIS functionality through plugins o e e 10 4 7 What s new im the Version 1 8 ss ss sp mir Rew we ee Bea eS 11 5 Getting Started 15 Dil INSTallatiOM sa os AA is Ee Het eh ae See oh Be ce la te amp Be 15 2 SAMPE DAA sus a pasa Akon be E Se Re ta e Ba ee RO amp Bo 15 5 3 Sample Session 5 55 5 be ee bee ee A 16 54 Starting and Stopping QGIS ss sm e aosa moe el ee BO ea 17 5 3 Command Line Options ss css ee e600 de bee de baa q Gee 17 5G BOO us ges a gos Gein gee ee A De a Re a hs doe os 19 Dil OUP wank ee heehee baw ewe bb bee a eh e ae Ghee eee bee 19 6 QGIS GUI 21 61 Menu Bars eree o a Rs ahead os a Ha Beye ag ee NS thd eee wee da 22 6 2 Toolbar p as hao eee See ed be oe be Ee ee fi poa ae ee be eee eek 27 63 MapLegend casa ss a musa cb bee eee bebe ea ee a EEA eS 27 64 Map VIEW ie goo sy Sk e Bd ego Be hy Seek BER Ge el a ae we 29 6 3 Status Bar sega aoe a ae Ga el ae Be e
128. QGIS education materials this list is a good starting point to ask your questions You can subscribe to this list at http lists osgeo org mailman listinfo qgis edu 20 1 10 qgis psc This list is used to discuss Steering Committee issues related to overall management and direction of Quantum GIS You can subscribe to this list at http lists os geo org mailman listinfo qgis psc You are welcome to subscribe to any of the lists Please remember to contribute to the list by answering questions and sharing your experiences Note that the qgis commit and qgis trac are designed for notification only and not meant for user postings 20 2 IRC We also maintain a presence on IRC visit us by joining the qgis channel on irc freenode net Please wait around for a response to your question as many folks on the channel are doing other things and it may take a while for them to notice your question Commercial support for QGIS is also available Check the website http qgis org en commercial support html for more information If you missed a discussion on IRC not a problem We log all discussion so you can easily catch up Just go to http logs qgis org and read the IRC logs 20 3 BugTracker While the qgis users mailing list is useful for general how do I do XYZ in QGIS type questions you may wish to notify us about bugs in QGIS You can submit bug reports using the QGIS bug tracker at http hub qgis org projects quantum gis issues When
129. RMAT 1 FILE C Users Volaya sextante tempdata 1331800672 151 tif Figura 17 28 History 7 172 Capitulo 17 SEXTANTE QGIS User Guide Release 1 8 Process information is kept as a command line expression even if the algorithm was launched from the toolbox This makes it also useful for those learning how to use the command line interface since they can call an algorithm using the toolbox and then check the history manager to see how that same algorithm could be called from the command line Apart from browsing the entries in the registry processes can be re executed simply double clicking on the corresponding entry Along with algorithm executions SEXTANTE communicates with the user using the other groups of the registry namely Errors Warnings and Information In case something is not working properly having a look at the Errors might help you to see what is happening If you get in contact with a SEXTANTE developer to report a bug or error the information in that group will be very useful for him to find out what is going wrong When executing third party algorithms this is usually done calling their command line interfaces which com municate with the user using the console Although that console is not shown a full dump of it is stored in the Information group each time you run one of those algorithms If for instance you are having problems executing a SAGA algorithm look for an entry name SAGA execution consol
130. S Import Tool dialog Select the PostGIS database you want to connect to and click on Connect If you want you can define or change some import options Now you can add one or more files to the queue by clicking on the Add button To process the files click on the OK button The progress of the import as well as any errors warnings will be displayed as each shapefile is processed Tip Importing Shapefiles Containing PostgreSQL Reserved Words 19 19 Spatial Query Plugin 237 QGIS User Guide Release 1 8 fo Quantum GIS 17 0 Wrociaw voy v y Plugins Database CadTools Raster Vector Help 1 7611803 Figura 19 33 Spatial Query analysis regions contain airports a A SPIT Shapefile to PostGIS Import Tool Y ey H PostgreSQL connections Connect 2964 U public Jarbeit grassdata qgis_sample_data shapefiles popp shp POINT popp public Jarbeit grassdata qgis_sample_data shapefiles railroads shp LINESTRING railroads public Jarbeit grassdata qgis_sample_data shapefiles regions shp MULTIPOLYGON regions public Figura 19 34 Using SPIT Plugin to import Shape files to PostGIS 4b 238 Capitulo 19 Plugins QGIS User Guide Release 1 8 If a shapefile is added to the queue containing fields that are reserved words in the PostgreSQL database a dialog will popup showing the status of each field You can edit the field names prior to import and change any that are reserved wo
131. SS is important for working with raster layers Vector analysis is by default not limited to any defined region definitions But all newly created rasters will have the spatial extension and resolution of the currently defined GRASS region regardless of their original extension and resolution The current GRASS region is stored in the SLOCATION SMAPSET WIND file and it defines north south east and west bounds number of columns and rows horizontal and vertical spatial resolution It is possible to switch on off the visualization of the GRASS region in the QGIS canvas using the Y Display current GRASS region button With the Edit current GRASS region con you can open a dialog to change the current region and the symbology of the GRASS region rectangle in the QGIS canvas Type in the new region bounds and resolution and click OK It also allows to select a new region interactively with your mouse on the QGIS canvas Therefore click with the left mouse button in the QGIS canvas open a rectangle close it using the left mouse button again and click OK The GRASS module g region provide a lot more parameters to define an appropriate region extend and reso lution for your raster analysis You can use these parameters with the GRASS Toolbox described in Section The GRASS toolbox 15 9 The GRASS toolbox The A Open GRASS Tools box provides GRASS module functionalities to work with data inside a selected GRASS LOCATION and MAPSET To use t
132. Scale 100 Show in Overview Remove Set Layer CRS Set Project CRS from Layer Properties Rename Copy Style Add New Group Expand all Collapse all Update Drawing Order 12 2 Raster Properties Dialog To view and set the properties for a raster layer double click on the layer name in the map legend or right click on the layer name and choose Properties from the context menu This will open the Raster Layer Properties dialog see figure_raster_1 There are several tabs on the dialog e Style e Transparency e Colormap e General e Metadata e Pyramids e Histogram 12 2 1 Style Tab QGIS can render raster layers in two different ways 1 Single band one band of the image will be rendered as gray or in pseudocolor or a freak out 2 Three band color three bands from the image will be rendered each band representing the red green or blue component that will be used to create a color image Within both render types you can invert the color output using the Invert color map checkbox Single Band Rendering This selection offers you two possibilites to choose At first you can select which band you like to use for rendering 1f the dataset has more than one band The second option offers a selection of available colortables for rendering v The following settings are available through the dropdownbox Color map 100 Cap tulo 12 Working with Raster Data QGIS User Guide Release 1 8 ay S
133. Title page the name of the publisher of the Modified Version as the publisher Preserve all the copyright notices of the Document Add an appropriate copyright notice for your modifications adjacent to the other copyright notices D nr A W Include immediately after the copyright notices a license notice giving the public permission to use the Modified Version under the terms of this License in the form shown in the Addendum below 250 Capitulo 21 Appendix QGIS User Guide Release 1 8 7 Preserve in that license notice the full lists of Invariant Sections and required Cover Texts given in the Document s license notice 8 Include an unaltered copy of this License 9 Preserve the section Entitled History Preserve its Title and add to it an item stating at least the title year new authors and publisher of the Modified Version as given on the Title Page If there is no section Entitled History in the Document create one stating the title year authors and publisher of the Document as given on its Title Page then add an item describing the Modified Version as stated in the previous sentence 10 Preserve the network location if any given in the Document for public access to a Transparent copy of the Document and likewise the network locations given in the Document for previous versions it was based on These may be placed in the History section You may omit a network location for a work that was p
134. XTANTE algorithm that needs one of them is restricted to tables coming from files in DBase db or Comma Separated Values csv formats e An option to choose from a selection list of possible options e A numerical value to be introduced in a text box You will find a button by its side Clicking on it you will see a dialog that allows you to enter a mathematical expression so you can use it as a handy calculator Some useful variables related to data loaded into QGIS can be added to your expression so you can select a value derived from any of this variables such as the cellsize of a layer or the northern most coordinate of another one tt Enter number or expression ES Enter expression in the text field Double click on elements in the tree to add their values to the expression Min X 262846 525725 Max X 277871 525725 Min Y 4454025 0 Max y 4464275 0 Cellsize 25 0 EF points E lines E 3cuencas E Values from raster layers statistics Figura 17 7 Number Selector 7 e A range with min and max values to be introduced in two text boxes e A text string to be introduced in a text box e A field to choose from the attributes table of a vector layer or a single table selected in another parameter e A Coordinate Reference System CRS You can type the EPSG code directly in the text box or select it from the CRS selection dialog that appear when you click on the button on the right hand size e A extent to be en
135. an select Fill style Texture and click the button for selecting your own texture file Currently the fileformats x jpeg xpm and png are supported Fill color fill color of your features Outline options Outline style Pen style for your outline of your feature You can also set this to no Pen Outline color color of the ouline of your feature Outline width width of your features Once you have styled your layer you also could save your layer style to a separate file ending with qm1 To do this use the button Save Style No need to say that Load Style loads your saved layer style file If you wish to always use a particular style whenever the layer is loaded use the Save As Default button to make your style the default Also if you make changes to the style that you are not happy with use the Restore Default Style button to revert to your default style Vector transparency QGIS allows to set a transparency for every vector layer This can be done with the slider Transparency inside the Style tab This is very useful for overlaying several vector layers 11 2 4 Labels Tab As for the symbology QGIS 1 8 currently provides an old and a new labeling engine in parallel The Labels tab still contains the old labeling The new labeling is implemented as a core application and will replace the features of the old labels tab in one of the next versions We recom
136. anguage de_DE nor String English Geometry If you would like to create it contact the QGIS Record development team Fields and Values cat EXSDESC F_CODE F_CODEDESC FCODESC Expression length Output preview 114703 846113845 Help Y OK Cancel Figura 11 35 Field Calculator A you can use the various fields values and functions to construct the calculation expression or you can just type it into the box To display the values of a field you just right click on the appropriate field You can choose between Load top 10 unique values and Load all unique values On the right side opens the Field Values list with the unique values To add a value to the Field calculator Expression box double click its name in the Field Values list The Operators Math Conversions String Geometry and Record groups provides several functions In Operators you find mathematical operators Find Math for mathematical functions The Conversions group contains func tions that convert one data type to another The String group provides functions for data strings In the Geometry group you find functions for geometry objects With Record group functions you can add a numeration to your data set To add a function to the Field calculator Expression box click on the gt and then doubleclick the function A short example illustrates how the field calculator works We want to calculate the length of the railroads layer from the QGIS sample dataset
137. are nearly black or nearly white Black around the edge to exactly black or white This is often used to fix up lossy compressed aerial photos so that color pixels can be treated as transparent when mosaicing See also http www gdal org nearblack html Fill This utility fills selection raster regions usually nodata areas by interpolation from valid nodata pixels around the edges of the area On http www gdal org gdal_fillnodata html you can find more information z BJ Proximity Grid DEM terrain models This utility generates a raster proximity map indicating the distance from the center of each pixel to the center of the nearest pixel identified as a target pixel Target pixels are those in the source raster for which the raster pixel value is in the set of target pixel values For more information see http www gdal org gdal_proximity html This utility creates regular grid raster from the scattered data read from the OGR datasource Input data will be interpolated to fill grid nodes with values you can choose from various interpolation methods The utility is also described on the GDAL website http www gdal org gdal_grid html Tools to analyze and visualize DEMs It can create a shaded relief a slope an aspect a color relief a Terrain Ruggedness Index a Topographic Position Index and a roughness map from any GDAL supported elevation raster For more information you can read on http www gdal o
138. at has others depending on it SEXTANTE will show you a warning message like the one you can see below Selecting the Edit option or simply double clicking on the algorithm icon will show the parameters dialog of the algorithm so you can change the inputs and parameter values Not all input elements available in the model will 17 3 The SEXTANTE graphical modeler 163 QGIS User Guide Release 1 8 Catchment amp Figura 17 20 Modeler Right Click 7 4 Could not remove element xj Other elements depend on the selected one Remove them before trying to remove it La Figura 17 21 Cannot Delete ALG 7 appear in this case as available inputs Layers or values generated at a more advanced step in the workflow defined by the model will not be available if they cause circular dependencies Select the new values and then click on the OK button as usual The connections between the model elements will change accordingly in the modeler canvas 17 3 6 Activating and deactivating algorithms Algorithms can be deactivated in the modeler so they will not be executed once the model is run This can be used to test just a given part of the model or when you do not need all the outputs it generates To deactivate an algorithm right click on its icon in the model canvas and select the Deactivate option You will see that the algorithm is represented now with a red label under its name indicating that is not active Catchme
139. at your operating system uses as a reference to the physical port in your computer that the GPS device is connected to It may also be simply usb for usb enabled GPS units On Linux this is something like dev ttysS0 or dev ttyS1 e 7 On Windows it is COM1 or COM2 When you click OK the data will be downloaded from the device and appear as a layer in QGIS 14 1 6 Uploading GPS data to a device You can also upload data directly from a vector layer in QGIS to a GPS device using the Upload to GPS tab of the GPS Tools dialog To do this you simply select the layer that you want to upload which must be a GPX layer your GPS device type and the port or usb that it is connected to Just as with the download tool you can specify new device types 1f your device isn t in the list This tool is very useful in combination with the vector editing capabilities of QGIS It allows you to load a map create waypoints and routes and then upload them and use them on your GPS device 14 1 7 Defining new device types There are lots of different types of GPS devices The QGIS developers can t test all of them so if you have one that does not work with any of the device types listed in the Download from GPS and Upload to GPS tools you can define your own device type for it You do this by using the GPS device editor which you start by clicking the Edit devices button in the download or the upload tabs To define a new device you simply click the
140. ataba eVis _Data lt databa lt databa lt sqlsta Poin lt autoco lt query gt lt query gt lt shortd lt descri a va lt databa lt databa lt databa lt databa lt databa lt databa lt sqlsta Poin vall lt autoco lt query gt lt query gt lt shortd lt descri lim lt databa lt databa lt databa ion 1 0 2 gt escription gt Import all photograph points lt shortdescription gt ption gt This command will import all of the data in the SQLite database to OGIS scription gt setype gt SQLITE lt databasetype gt sehost gt seport gt sename gt C textbackslash Workshop textbackslash textbackslash PhotoPoints db lt databasename gt seusername gt sepassword gt tement gt SELECT Attributes Points x Points y FROM Attributes LEFT JOIN ts ON Points rec_id Attributes point_ID lt sqlstatement gt nnect gt false lt autoconnect gt escription gt Import photograph points looking across Valley lt shortdescription gt ption gt This command will import only points that have photographs looking across lley to QGIS lt description gt setype gt SQLITE lt databasetype gt sehost gt seport gt sename gt C Workshop eVis_Data PhotoPoints db lt databasename gt seusername gt sepassword gt tement gt SELECT Attributes Points x Points y FROM Attributes LEFT JOIN ts ON Points rec_id Attributes point_ID where COMMENTS Looking across ey lt sqlstateme
141. atent licenses in effect making the program proprietary To prevent this we have made it clear that any patent must be licensed for everyone s free use or not licensed at all The precise terms and conditions for copying distribution and modification follow TERMS AND CONDITIONS FOR COPYING DISTRIBUTION AND MODIFICATION 0 This License applies to any program or other work which contains a notice placed by the copyright holder saying it may be distributed under the terms of this General Public License The Program below refers to 245 QGIS User Guide Release 1 8 any such program or work and a work based on the Program means either the Program or any derivative work under copyright law that is to say a work containing the Program or a portion of it either verbatim or with modifications and or translated into another language Hereinafter translation is included without limitation in the term modification Each licensee is addressed as you Activities other than copying distribution and modification are not covered by this License they are outside 1ts scope The act of running the Program is not restricted and the output from the Program is covered only 1f its contents constitute a work based on the Program independent of having been made by running the Program Whether that is true depends on what the Program does You may copy and distribute verbatim copies of the Program s source code as you r
142. ats GDAL library gt rout ascii Export raster to ASCII text file gt L routxyz Export raster to text file as xyz values based on cell centers gt o routarc Export raster to ESRIARCGRID gt rout gridatb Export raster to GRIDATB FOR map file TOPMODEL gt o r out mat Export raster to binary MAT File gt e routbin Export raster to binary array gt a routmpeg Export raster series to MPEG movie gt r out png Export raster as non georeferenced PNG image format gt routppm Export raster to PPM image at the resolution of the curr gt 1 routppm3 Export 3 GRASS rasters P G B to PPM image at the r gt routpov Export raster to POVRAY height field file gt routtiff Export raster to 8 24bit TIFF image at the resolution of the ORO OOOO OOO Figura 15 8 GRASS Toolbox and Module Tree a It is also possible to customize the GRASS Toolbox content This procedure is described in Section Customizing the GRASS Toolbox As shown in figure_grass_toolbox_1 you can look for the appropriate GRASS module using the thematically grouped Modules Tree or the searchable Modules List tab Clicking on a graphical module icon a new tab will be added to the toolbox dialog providing three new sub tabs Options Output and Manual Options The Options tab provides a simplified module dialog where you can usually select a raster or vector layer visualized in the QGIS canvas and enter further module spe
143. attributes and the Preview tab renders the geometries as preview 19 5 Delimited Text Plugin The Delimited Text plugin allows you to load a delimited text file as a layer in QGIS 19 5 1 Requirements To view a delimited text file as layer the text file must contain 1 A delimited header row of field names This must be the first line in the text file 2 The header row must contain an X and Y field These fields can have any name 3 The x and y coordinates must be specified as a number The coordinate system is not important As an example of a valid text file we import the elevation point data file elevp csv coming with the QGIS sample dataset See Section Sample Data X Y ELEV 300120 7689960 13 654360 7562040 52 1640 7512840 3 ase Some items of note about the text file are 1 The example text file uses semicolon as delimiter Any character can be used to delimit the fields The first row is the header row It contains the fields X Y and ELEV No quotes are used to delimit text fields The x coordinates are contained in the X field TM OB ee UN The y coordinates are contained in the Y field 19 5 2 Using the Plugin To use the plugin you must first enable it as described in Section Managing Plugins 19 5 Delimited Text Plugin 201 QGIS User Guide Release 1 8 Click the new toolbar icon Ea Add Delimited Text Layer to open the Delimited Text dialog as shown in fig ure_del
144. ayer tabeting settings Settings Plugins Raster Help CE ETTIK EU D AXAAA RO UR Bg Dialog Search method Number of candidates Point 8 Line 8 Polygon 8 Show all labels i e including colliding labels Show label candidates for debugging OK Cancel Figura 11 18 Dialog to change label engine settings 4S 11 2 The Vector Properties Dialog 73 QGIS User Guide Release 1 8 Keywords to use in attribute columns for labeling There is a list of supported key words that can be used for the placement of labels in defined attribute columns For horizontal alignment left center right For vertical alignment bottom base half top Colors can be specified in svg notation e g ff0000 for bold underlined strikeout and italic O false 1 true A combination of key words in one column also works e g base right orbottom left 11 2 6 Fields Tab Within the Fields tab the field attributes of the selected dataset can be manipulated The buttons E ean and Delete Column can be used when the dataset is S Editing mode At the moment only columns from PostGIS layers can be removed and added The OGR library supports to add and remove columns if you have a GDAL version gt 1 9 installed Edit Widget Y Layer Properties lake gt Style Labels Fields General Metadata f Actions Joins Diagr gt amp SEE ld Name Type Length Precision Comment Edit w
145. because there are small rounding off errors involved when converting between projections Deleting Selected Features If we want to delete an entire polygon we can do that by first selecting the polygon using the regular R Select Single Feature too You can select multiple features for deletion Once you have the selection set use the o Delete Selected too to delete the features The ap Cut Features too on the digitizing toolbar can also be used to delete features This effectively deletes the feature but also places it on a spatial clipboard So we cut the feature to delete We could then use the Paste Features too to put it back giving us a one level undo capability Cut copy and paste work on the currently selected features meaning we can operate on more than one at a time Tip Feature Deletion Support When editing ESRI shapefiles the deletion of features only works if QGIS is linked to a GDAL version 1 3 2 or greater The OS X and Windows versions of QGIS available from the download site are built using GDAL 1 3 2 or higher Saving Edited Layers When a layer is in editing mode any changes remain in the memory of QGIS Therefore they are not commit ted saved immediately to the data source or disk If you want to save edits to the current layer but want to continue editing without leaving the editing mode you can click the Save Edits button When you turn editing mode off with the Toggle editing gr quit QG
146. cation by using a set of coordinates Each coordinate refers to a geographic location using a system of x and y values This can be thought of in reference to a Cartesian plane you know the diagrams from school that showed an x and y axis You might have used them to chart declining retirement savings or increasing compound mortgage interest but the concepts are essential to geospatial data analysis and mapping 6 Capitulo 3 Foreword QGIS User Guide Release 1 8 There are various ways of representing these geographic coordinates depending on your purpose This is a whole area of study for another day map projections Vector data takes on three forms each progressively more complex and building on the former 1 Points A single coordinate x y represents a discrete geographic location 2 Lines Multiple coordinates x Y1 X2 Y2 X3 Y3 Xn Yn Strung together in a certain order like drawing a line from Point x y to Point x2 y2 and so on These parts between each point are considered line segments They have a length and the line can be said to have a direction based on the order of the points Technically a line is a single pair of coordinates connected together whereas a line string is multiple lines connected together 3 Polygons When lines are strung together by more than two points with the last point being at the same location as the first we call this a polygon A triangle circle rectangle etc are al
147. cations window in the Generic Event Browser that matches the file extension to an application that can be used to open the file It is also necessary to have the path or URL to the file in the attribute table for the vector layer One additional rule that can be used for URLs that don t contain a file extension for the document you want to open is to specify the file extension before the URL The format is file extension URL The URL is preceded by the file extension and a colon and is particularly useful for accessing documents from Wikis and other web sites that use a database to manage the web pages see Table evis_examples 19 8 4 Using the Generic Event Browser When the Event Browser window opens a photograph will appear in the display window if the document refer enced in the vector file attribute table is an image and if the file location information in the Options window is properly set If a photograph is expected and it does not appear it will be necessary to adjust the parameters in the Options window If a supporting document or an image that does not have a file extension recognized by eVis is referenced in the attribute table the field containing the file path will be highlighted in green in the attribute information window if that file extension is defined in the file reference table located in the Configure External Applications window To open the document double click on the green highlighted line in the attribute information w
148. ce of PostgreSQL layers by ensuring that a PostGIS spatial index exists on each layer in the database PostGIS supports creation of a GiST Generalized Search Tree index to speed up spatial searches of the data GiST index information is taken from the PostGIS documentation available at http postgis refractions net The syntax for creating a GiST index is CREATE INDEX indexname ON tablename USING GIST geometryfield GIST_GEOMETRY_OPS Note that for large tables creating the index can take a long time Once the index is created you should perform a VACUUM ANALYZE See the PostGIS documentation POSTGIS PROJECT Literature and Web References for more information The following is an example of creating a GiST index gsherman madison current psql gis_data Welcome to psql 8 3 0 the PostgreSQL interactive terminal Type copyright for distribution terms h for help with SOL commands for help with psql commands g or terminate with semicolon to execute query q to quit gis_data CREATE INDEX sidx_alaska_lakes ON alaska_lakes gis_data USING GIST the_geom GIST GEOMETRY OPS CREATE INDEX gis_data VACUUM ANALYZE alaska lakes VACUU gis_data q gsherman madison current 11 1 6 Vector layers crossing 180 longitude Many GIS packages don t wrap vector maps with a geographic reference system lat lon crossing the 180 de g
149. ceiving signals from satellites you will see your position in latitude longitude and altitude together with additional attributes GPS Information ss mm e Edi Connect Latitude Longitude Altitude Time of fix Speed Direction HDOP VDOP PDOP H accurancy V accurancy Mode Dimensions Quality Status Satellites Figura 14 3 GPS tracking position and additional attributes a 14 2 2 GPS signal strength thn Here you can see the signal strenght of the satellites you are receiving signals from GPS Information aa L ihi 5 gt Disconnect Figura 14 4 GPS tracking signal strength 118 Cap tulo 14 Working with GPS Data QGIS User Guide Release 1 8 14 2 3 GPS polar window ES If you want to know where in the sky all the connected satellites are you have to switch to the polar screen You can also see the ID numbers of the satellites you are receiving signals from GPS Information 08 4 ia 65 yy conne Figura 14 5 GPS tracking polar window 4S 14 2 4 GPS options In case of connection problems you can switch between e Autodetect e 12 Internal e 12 Serial device e 12 gpsd selecting Host Port and Device your GPS is connected to A click on Connect again initiates the connection to the GPS receiver GPS Information ox Add Poin id track pain e Connect da o Connection _ Autodetect ternal _ Serial device evitt gpsd Ho
150. cense Version 1 3 3 November 2008 Copyright 2000 2001 2002 2007 2008 Free Software Foundation Inc lt http fsf org gt Everyone is permitted to copy and distribute verbatim copies of this license document but changing it is not allowed Preamble The purpose of this License is to make a manual textbook or other functional and useful document free in the sense of freedom to assure everyone the effective freedom to copy and redistribute it with or without modifying 1t either commercially or noncommercially Secondarily this License preserves for the author and publisher a way to get credit for their work while not being considered responsible for modifications made by others 248 Cap tulo 21 Appendix QGIS User Guide Release 1 8 This License is a kind of copyleft which means that derivative works of the document must themselves be free in the same sense It complements the GNU General Public License which is a copyleft license designed for free software We have designed this License in order to use it for manuals for free software because free software needs free documentation a free program should come with manuals providing the same freedoms that the software does But this License is not limited to software manuals it can be used for any textual work regardless of subject matter or whether it is published as a printed book We recommend this License principally for works whose purpose is instru
151. cific parameters to run the module The provided module parameters are often not complete to keep the dialog clear If you want to use further module parameters and flags you need to start the GRASS Shell and run the module in the command line A new feature in QGIS 1 8 0 is the support for a show advanced options button below the simplified module dialog in the Options tab At the moment it is only added to the module v in ascii as an example use but will probably be part of more all modules in the GRASS toolbox in future versions of QGIS This allows to use the complete GRASS module options without the need to switch to the GRASS Shell Output The Output tab provides information about the output status of the module When you click the Run button the module switches to the Output tab and you see information about the analysis process If all works well you will finally see a Successfully finished message Manual The Manual tab shows the HTML help page of the GRASS module You can use it to check further module parameters and flags or to get a deeper knowledge about the purpose of the module At the end of each module manual page you see further links to the Main Help index the Thematic index and the Full index These links provide the same information as if you use the module g manual Tip Display results immediately If you want to display your calculation results immediately in your map canvas you can use the View Output
152. click to continue 95 14 41331 50 12019 Scale kass O Render E Figura 16 4 Changing an OSM feature tag 16 7 2 Point creation For point creation there is a 9 Create point button on the OSM Feature widget To create some points just click on the button and start clicking on the map If your cursor is over some map feature the feature is marked identified immediately If you click on the map when a line or polygon is marked a new point is created directly on such line or polygon as its new member If your cursor is over an existing point a new point cannot be created In such case the OSM plugin will show following message amp OSM point creation ea Point creation failed Two points cannot be at the same place Figura 16 5 OSM point creation message The mechanism of helping a user to hit the line or polygon is called snapping and is enabled by default If you want to create a point very close to some line but not on it you must disable snapping by holding the Ct rl key first 16 7 3 Line creation a For line creation there is a e Create Line button on the OSM Feature widget To create a line just click the button and start left clicking on the map Each of your left clicks is remembered as a vertex of the new line Line creation ends when the first right click is performed The new line will immediately appear on the map Note A Line with less than two members cannot be created In such case
153. creating a new ticket for a bug please provide an email address where we can request additional information Please bear in mind that your bug may not always enjoy the priority you might hope for depending on its severity Some bugs may require significant developer effort to remedy and the manpower is not always available for this 242 Capitulo 20 Help and Support QGIS User Guide Release 1 8 Feature requests can be submitted as well using the same ticket system as for bugs Please make sure to select the type Feature If you have found a bug and fixed it yourself you can submit this patch also Again the lovely redmine ticketsystem at http hub qgis org projects quantum gis issues has this type as well Check Patch supplied checkbox and attach your patch before submitting bug Someone of the developers will review it and apply it to QGIS Please don t be alarmed if your patch is not applied straight away developers may be tied up with other committments 20 4 Blog The QGIS community also runs a weblog at http www qgis org planet which has some interesting articles for users and developers as well provided by other blogs in the community You are invited to contribute your own QGIS blog 20 5 Plugins The website http plugins qgis org provides the official QGIS plugins web portal Here you find a list of all stable and experimental QGIS plugins available via the Official QGIS Plugin Repository 20 6 Wiki Last
154. ction field should now look like this firefox http google com search q 8 Click on the drop down box containing the field names for the lakes layer It s located just to the left of the Insert Field button 78 Cap tulo 11 Working with Vector Data QGIS User Guide Release 1 8 9 From the drop down box The valid attribute names for this layer select NAMES and click Insert Field 10 Your action text now looks like this firefox http google com search q NAM EJ un 11 To finalize the action click the Insert action button This completes the action and it is ready to use The final text of the action should look like this firefox http google com search q SNAMES We can now use the action Close the Layer Properties dialog and zoom in to an area of interest Make sure the lakes layer is active and identify a lake In the result box you 11 now see that our action is visible Identify Results Feature Value E alaska Layer cat 600 Actions 4 View feature form Derived AREA_MI 535693 726324 NAME Alaska cat 600 Figura 11 23 Select feature and choose action a When we click on the action it brings up Firefox and navigates to the URL http www google com search q Tustumena It is also possible to add further attribute fields to the ac tion Therefore you can add a to the end of the action text select another field and click on Insert Field In this examp
155. ction or reference 1 APPLICABILITY AND DEFINITIONS This License applies to any manual or other work in any medium that contains a notice placed by the copyright holder saying it can be distributed under the terms of this License Such a notice grants a world wide royalty free license unlimited in duration to use that work under the conditions stated herein The Document below refers to any such manual or work Any member of the public is a licensee and is addressed as you You accept the license if you copy modify or distribute the work in a way requiring permission under copyright law A Modified Version of the Document means any work containing the Document or a portion of it either copied verbatim or with modifications and or translated into another language A Secondary Section is a named appendix or a front matter section of the Document that deals exclusively with the relationship of the publishers or authors of the Document to the Document s overall subject or to related matters and contains nothing that could fall directly within that overall subject Thus if the Document is in part a textbook of mathematics a Secondary Section may not explain any mathematics The relationship could be a matter of historical connection with the subject or with related matters or of legal commercial philosophical ethical or political position regarding them The Invariant Sections are certain Secondary Sections w
156. ctions eXJjoins 71 Diagrams Action list Type Name Action Capture 1 Generic Echo attribute s value echo MY FIELD Y 2 Generic Run an application ogr2ogr f ESRI Shapefile O Y 3 Python Get feature id QtGui QMessageBox information 4 Python Selected field s value Identif QtGui QMessageBox information 5 Python Clicked coordinates Run fea QtGui QMessageBox information 6 Open Open file PATH 7 Open Search on web based on at http www google it q ATTR _ Move up Remove action Add default actions Action properties Type Open Y _ Capture output Name Search on open web browser based on attribute s value http www google it q NAMES Action Insert expression NAMES Insert field Add to action list Update selected action Restore Default Style Save As Default Load Style Save Style Es Help Y OK Apply Cancel Figura 11 22 Overview action dialog with some sample actions ra Actions are useful when you frequently want to run an external application or view a web page based on one or more values in your vector layer They are devided into 6 types and can be used like this e Generic Mac Windows and Unix actions start an external process e Python actions execute a python expression e Generic and Python actions are visible everywhere e Mac Windows and Unix actions are visible only on the respective platform i e
157. ctor new symbology because the old symbology will be removed in one of the next releases If you want or need to switch back to the old symbology you can click on the Old symbology button in the Style tab of the Layer Properties dialog 11 2 The Vector Properties Dialog 69 QGIS User Guide Release 1 8 You can also make the old symobolgy the default deactivating Use new generation symbology for rendering in the Rendering tab under Settings gt s Options The old QGIS symbology supports the following renderers Single symbol a single style is applied to every object in the layer Graduated symbol objects within the layer are displayed with different symbols classified by the values of a particular field Continuous color objects within the layer are displayed with a spread of colours classified by the numer ical values within a specified field Unique value objects are classified by the unique values within a specified field with each value having a different symbol To change the symbology for a layer simply double click on its legend entry and the vector Layer Properties dialog will be shown Style Options Within this dialog you can style your vector layer Depending on the selected rendering option you have the possibility to also classify your map features At least the following styling options apply for nearly all renderers el Fill style Style for filling Beside the given brushes you c
158. d Conservation Available from http biodiversityinformatics amnh org and released under the GNU FDL has developed the Event Visualiza tion Tool eVis another software tool to add to the suite of conservation monitoring and decision support tools for guiding protected area and landscape planning This plugin enables users to easily link geocoded 1 e referenced with latitude and longitude or X and Y coordinates photographs and other supporting documents to vector data in QGIS 204 Cap tulo 19 Plugins QGIS User Guide Release 1 8 eVis is now automatically installed and enabled in new versions of QGIS and as with all plugins it can be disabled and enabled using the Plugin Manager See Managing Plugins The eVis plugin is made up of three modules the Database Connection tool Event ID tool and the Event Browser These work together to allow viewing of geocoded photographs and other documents that are linked to features stored in vector files databases or spreadsheets 19 8 1 Event Browser The Event Browser module provides the functionality to display geocoded photographs that are linked to vector features displayed in the QGIS map window Point data for example can be from a vector file that can be input using QGIS or it can be from the result of a database query The vector feature must have attribute information associated with it to describe the location and name of the file containing the photograph
159. d Editors Tara Athan Radim Blazek Godofredo Contreras Otto Dassau Martin Dobias Peter Ersts Anne Ghisla Stephan Holl N Horning Magnus Homann Werner Macho Carson J Q Farmer Tyler Mitchell K Koy Lars Luthman Claudia A Engel Brendan Morely David Willis Jiirgen E Fischer Marco Hugentobler Larissa Junek Diethard Jansen Paolo Corti Gavin Macaulay Gary E Sherman Tim Sutton Alex Bruy Raymond Nijssen Richard Duivenvoorde Andreas Neumann Sponsors The update of this user manual was kindly sponsored by Kanton Solothurn Switzerland Copyright c 2004 2013 QGIS Development Team Internet http www qgis org License of this document Permission is granted to copy distribute and or modify this document under the terms of the GNU Free Docu mentation License Version 1 3 or any later version published by the Free Software Foundation with no Invariant Sections no Front Cover Texts and no Back Cover Texts A copy of the license is included in Appendix GNU Free Documentation License QGIS User Guide Release 1 8 2 Cap tulo 1 Preamble CAP TULO 2 Conventions This section describes a collection of uniform styles throughout the manual The conventions used in this manual are as follows GUI Conventions The GUI convention styles are intended to mimic the appearance of the GUI In general the objective is to use the non hover appearance so a user can visually scan the GUI to find somethi
160. d as part of a batch process those input data objects are taken directly from files and not from the set of them already opened in QGIS For this reason any algorithm can be executed as a batch process even if no data objects at all are opened and the algorithm cannot be run from the toolbox 166 Cap tulo 17 SEXTANTE QGIS User Guide Release 1 8 Filenames for input data objects are introduced directly typing or more conveniently clicking on the button on the right hand of the cell which shows a typical file chooser dialog Multiple files can be selected at once If the input parameter represents a single data object and several files are selected each one of them will be put in a separate row adding new ones if needed If it represents a multiple input all the selected files will be added to a single cell separated by semicolons Output data objects are always saved to a file and unlike when executing an algorithm from the toolbox saving to a temporary one is not permitted You can type the name directly or use the file chooser dialog that appears when clicking on the accompanying button Once you select the file a new dialog is shown to allow for autocompletion of other cells in the same column same parameter Figura 17 26 Batch Processing Save If the default value Do not autocomplete is selected SEXTANTE will just put the selected filename in the selected cell from the parameters table If any
161. d in secion Diagrams Tab Before starting the Diagram Overlay Plugin needs to be activated using the Plugin Manager see Section Loading a QGIS Core Plugin It will then appear as Overlay tab in the Layer Properties dialog next to the Diagrams tab The Overlay tab provides support for Pie charts Bar charts and proportional SVG symbols Similar to the Diagrams tab we will demonstrate an example and overlay the alaska boundary layer a piechart diagram showing some temperature data from a climate vector layer Both vector layers are part of the QGIS sample dataset see Section Sample Data 1 First click on the Load Vector icon browse to the QGIS sample dataset folder and load the two vector shape layers alaska shp and climate shp 202 Cap tulo 19 Plugins QGIS User Guide Release 1 8 40 Layer Properties climate VYvLUw tabels E Fields 4 General Metadata e actions e joins E Diagrams Overlay lt gt v Display diagrams Diagram type Pie chart v Attributes T F MEAN v Add Remove Figura 19 6 Vector properties dialog with overlay tab A 2 Double click the climate layer in the map legend to open the Layer Properties dialog 3 Click on the Overlay tab activate Display diagrams and select Pie Chart from Diagram type EM combobox 4 We want to display the values of the three columns T F JAN T F JUL and T F MEAN First select T F JAN as Attributes and click the Add button
162. d resolution Please note the Snap to grid feature only works if you define a grid resolution gt 0 Furthermore you can also activate the Print as raster checkbox This means all elements will be rastered before printing or saving as Postscript of PDF e The Item Properties tab displays the properties for the selected map element Click the Y Select Moye tom icon to select an element e g legend scalebar or label on the canvas Then click the Item Properties tab and customize the settings for the selected element e The Command history tab displays a history of all changes applied to the print composer layout With a mouse click it is possible to undo and redo layout steps back and forth to a certain status You can add multiple elements to the composer It is also possible to have more than one map view or legend or scalebar in the print composer canvas Each element has its own properties and in the case of the map its own extent If you want to remove any elements from the composer canvas you can do that with the Delete or the Backspace key 182 Capitulo 18 Print Composer QGIS User Guide Release 1 8 18 3 Adding a current QGIS map canvas to the Print Composer Click on the amp Add new map toolbar button in the print composer toolbar to add the QGIS map canvas Now drag a rectangle on the composer canvas with the left mouse button to add the map To display the current map you can choose between three different modes in the
163. d the Interpolation plugin in the Plugin Manager see Section Loading a QGIS Core Plugin and click on the 51 Interpolation con which appears in the QGIS toolbar menu The Interpolation plugin dialog appears as shown in Figure_interpolation_1 Select an input layer e g elevp hd and column e g ELEV for interpolation Select an interpolation method e g Triangulated Irregular Network TIN and specify a cellsize of 5000 as well as the raster output filename e g elevation_tin Click OK For the current example double click el evat ion_tin in the layer list to open the raster Layer Properties Tg dialog and select Pseudocolor as Color Map in the Symbology tab Or you can define a new color table as described in section Working with Raster Data 19 13 MapServer Export Plugin You can use QGIS to compose your map by adding and arranging layers symbolizing them customizing the colors and then creating a map file for MapServer Note Currently the plugin only works when you use Old Symbology in QGIS New Symbology is not yet supported 224 Cap tulo 19 Plugins QGIS User Guide Release 1 8 19 13 1 Creating the Project File The MapServer Export Plugin operates on a saved QGIS project file and not on the current contents of the map canvas and legend This has been a source of confusion for a number of users As described below before you start using the MapSer
164. data model for geographic features an increasing number of specifications are developed to serve specific needs for interoperable location and geospatial technology including GIS Further information can be found under http www opengeospatial org Important OGC specifications are e WMS Web Map Service e WES Web Feature Service e WCS Web Coverage Service e CAT Web Catalog Service e SFS Simple Features for SQL e GML Geography Markup Language OGC services are increasingly being used to exchange geospatial data between different GIS implementations and data stores QGIS can now deal with three of the above specifications being SFS through support of the PostgreSQL PostGIS data provider see Section PostGIS Layers WFS and WMS as a client 13 1 2 WMS Client Overview of WMS Support QGIS currently can act as a WMS client that understands WMS 1 1 1 1 1 and 1 3 servers It has particularly been tested against publicly accessible servers such as DEMIS WMS servers act upon requests by the client e g QGIS for a raster map with a given extent set of layers symbolization style and transparency The WMS server then consults its local data sources rasterizes the map and sends it back to the client in a raster format For QGIS this would typically be JPEG or PNG WMS is generically a REST Representational State Transfer service rather than a fully blown Web Service As such you can actually take the URLs generat
165. data viewer QGIS has reached the point in its evolution where it is being used by many for their daily GIS data viewing needs QGIS supports a number of raster and vector data formats with new format support easily added using the plugin architecture QGIS is released under the GNU General Public License GPL Developing QGIS under this license means that you can inspect and modify the source code and guarantees that you our happy user will always have access to a GIS program that is free of cost and can be freely modified You should have received a full copy of the license with your copy of QGIS and you also can find it in Appendix GNU General Public License Tip Up to date Documentation The latest version of this document can always be found in the documentation area of the QGIS website at http documentation qgis org 3 1 Introduction To GIS A Geographical Information System GIS Mitchell 2005 Literature and Web References is a collection of soft ware that allows you to create visualize query and analyze geospatial data Geospatial data refers to information about the geographic location of an entity This often involves the use of a geographic coordinate like a latitude or longitude value Spatial data is another commonly used term as are geographic data GIS data map data location data coordinate data and spatial geometry data Applications using geospatial data perform a variety of functions Map production is the m
166. der is added to the PATH environment variable Just open a console and type saga_cmd to check that the system can found where SAGA binaries are located About SAGA grid system limitations Most of SAGA algorithms that require several input raster layers require them to have the same grid system That is to cover the same geographic area and have the same cellsize so their corresponding grids match When calling SAGA algorithms from SEXTANTE you can use any layer regardless of its cellsize and extent When multiple raster layers are used as input for a SAGA algorithm SEXTANTE resamples them to a common grid system and then passes them to SAGA unless the SAGA algorithm can operate with layers from different grid systems The definition of that common grid system is controlled by the user and you will find several parameters in the SAGA group of the setting window to do so There are two ways of setting the target grid system e Setting it manually You define the extent setting the values of the following parameters Resampling min X Resampling max X Resampling min Y 174 Capitulo 17 SEXTANTE QGIS User Guide Release 1 8 Resampling max Y Resampling cellsize Notice that SEXTANTE will resample input layers to that extent even if they do not overlap with it Setting it automatically from input layers To select this option just check the Use min covering grid system for resampling option All the other set
167. different contents make the title of each such section unique by adding at the end of it in parentheses the name of the original author or publisher of that section if known or else a unique number Make the same adjustment to the section titles in the list of Invariant Sections in the license notice of the combined work In the combination you must combine any sections Entitled History in the various original documents forming one section Entitled History likewise combine any sections Entitled Acknowledgements and any sections Entitled Dedications You must delete all sections Entitled Endorsements 6 COLLECTIONS OF DOCUMENTS 21 2 GNU Free Documentation License 251 QGIS User Guide Release 1 8 You may make a collection consisting of the Document and other documents released under this License and replace the individual copies of this License in the various documents with a single copy that is included in the collection provided that you follow the rules of this License for verbatim copying of each of the documents in all other respects You may extract a single document from such a collection and distribute it individually under this License provided you insert a copy of this License into the extracted document and follow this License in all other respects regarding verbatim copying of that document 7 AGGREGATION WITH INDEPENDENT WORKS A compilation of the Document or its derivatives with
168. doing The file format was updated several times compared to earlier QGIS versions Project files from older QGIS versions may not work properly anymore To be made aware of this in the General tab under Settings Options you can select Prompt to save project changes when required Warn when opening a project file saved with an older version of QGIS 5 7 Output There are several ways to generate output from your QGIS session We have discussed one already in Section Projects saving as a project file Here is a sampling of other ways to produce output files e Menu option File A Save as Image Opens a file dialog where you select the name path and type of image PNG or JPG format A world file with extension PNGW or JPGW saved in the same folder georeferences the image e Menu option File 1 New Print Composer opens a dialog where you can layout and print the current map canvas see Section Print Composer 5 6 Projects 19 QGIS User Guide Release 1 8 20 Cap tulo 5 Getting Started CAP TULO 6 QGIS GUI When QGIS starts you are presented with the GUI as shown below the numbers 1 through 5 in yellow ovals refer to the six major areas of the interface as discussed below Quantum GIS 1 8 0 Lisboa landcover POMAR RM 4 Zane Ro paBivvlegou i nate E 1164108 5030513 Seale 14526540 v Y Render EPSG 2064 4 Figura 6 1 QGIS GUI with Alaska sample data Note Your window d
169. dy existing filenames Use only selected features If this option is selected whenever a vector layer is used as input for an algorithm only its selected features will be used If the layer has no selected features all of them will be used Apart from the General block in the settings dialog you will also find one for each algorithm provider They contain an Activate item that you can use to make algorithms appear or not in the toolbox Also some algo rithm providers have their own configuration items that we will explain later when covering particular algorithm providers 17 2 The SEXTANTE toolbox 159 QGIS User Guide Release 1 8 17 3 The SEXTANTE graphical modeler 17 3 1 Introduction The graphical modeler allows to create complex models using a simple and easy to use interface When working with a GIS most analysis operations are not isolated but part of a chain of operations instead Using the graphical modeler that chain of processes can be wrapped into a single process so it is easier and more convenient to execute than a single process later on a different set on inputs No matter how many steps and different algorithms it involves a model is executed as a single algorithm thus saving time and effort specially for larger models The modeler can be opened from the SEXTANTE menu but also from the toolbox In the Modeler branch of the algorithms tree you will find a group named Tools which contains an entry called C
170. e SQL commands can be entered in this text window A helpful tutorial on SQL commands is available at http www w3schools com sql For example to extract all of the data from a worksheet in an Excel file select x from sheet1 where sheet 1 is the name of the worksheet Click on the Run Query button to execute the command If the query is successful a Database File Selection window will be displayed If the query is not successful an error message will appear in the Output Console window In the Database File Selection window enter the name of the layer that will be created from the results of the query in the Name of New Layer textbox 1 SQL Query Text Window A screen to type SQL queries Run Query Button to execute the query entered in the SOL Query Window Console Window The console window where messages related to processing are displayed Help Displays the on line help na A WwW N OK Closes the main Database Connection window p Use the X Coordinate Y and Y Coordinate V comboboxes to select the field from the database that store the X or longitude and Y or latitude coordinates Clicking on the OK button causes the vector layer created from the SQL query to be displayed in the QGIS map window To save this vector file for future use you can use the QGIS Save as command that is accessed by right clicking on the layer name in the QGIS map legend and then selecting Save as Tip C
171. e does not change the row selection Changing the selection in the main canvas does not move the cursor position in the attribute table The table can be sorted by any column by clicking on the column header A small arrow indicates the sort order downward pointing means descending values from the top row down upward pointing means ascending values from the top row down For a simple search by attributes on only one column the Look for field can be used Select the field column from which the search should be performed from the dropdown menu and hit the Search button The matching rows will be selected and the total number of matching rows will appear in the title bar of the attribute table and in the status bar of the main window For more complex searches use the Advanced search button which will launch the Search Query Builder described in Section Query Builder To show selected records only use the checkbox Show selected only To search selected records only use the checkbox Search selected only The Case sensitive checkbox allows to select case sensitive The other buttons at the bottom left of the attribute table window provide following functionality 92 Capitulo 11 Working with Vector Data QGIS User Guide Release 1 8 g Attribute table alaska O 653 feature s selected wo amp AREA MI 0 168541 0 209257 0 837275 0 322511 1 46241 2 778535 0 359589 0 225724 0 136504 1 272344 0 095759
172. e QGIS sample dataset The Windows installer has an option to download the QGIS sample dataset If checked the data will be down loaded to your My Documents folder and placed in a folder called GIS Database You may use Windows Explorer to move this folder to any convenient location If you did not select the checkbox to install the sample dataset during the initial QGIS installation you can either e use GIS data that you already have download the sample data from the qgis website at http download qgis org or uninstall QGIS and reinstall with the data download option checked only if the above solutions are unsuc cessful X For GNU Linux and Mac OSX there are not yet dataset installation packages available as rpm deb or dmg To use the sample dataset download the file qgis_sample_data as ZIP or TAR archive from http download osgeo org qgis data and unzip or untar the archive on your system The Alaska dataset includes 15 QGIS User Guide Release 1 8 all GIS data that are used as examples and screenshots in the user guide and also includes a small GRASS database The projection for the qgis sample dataset is Alaska Albers Equal Area with unit feet The EPSG code 1s 2964 PROJCS Albers Equal Area GEOGCS NAD27 DATUM North_American_Datum_1927 SPHEROID Clarke 1866 6378206 4 294 978698213898 AUTHORITY EPSG 7008 TOWGS84 3 142 183 0 0 0 0 AUTHORITY EPSG 6267 PRIMEM Greenwich 0
173. e a message at the far right of the status bar On the right side of the status bar is a small checkbox which can be used to temporarily prevent layers being rendered to the map view see Section Rendering below The icon y immediately stops the current map rendering process To the right of the render functions you find the EPSG code of the current project CRS and a projector icon Clicking on this opens the projection properties for the current project Tip Calculating the correct Scale of your Map Canvas When you start QGIS degrees is the default unit and it tells QGIS that any coordinate in your layer is in degrees 30 Cap tulo 6 QGIS GUI QGIS User Guide Release 1 8 To get correct scale values you can either change this to meter manually in the General tab under Settings gt Project Properties or you can select a project Coordinate Reference System CRS clicking on the CRS Sans icon in the lower right hand corner of the statusbar In the last case the units are set to what the project projection specifies e g units m 6 5 Status Bar 31 QGIS User Guide Release 1 8 32 Cap tulo 6 QGIS GUI CAP TULO 7 General Tools 7 1 Keyboard shortcuts QGIS provides default keyboard shortcuts for many features You find them in Section Menu Bar Additionally the menu option Settings gt Configure Shortcuts allows to change the default keyboard shortcuts and to add new keyboard shortcut
174. e accordingly Tip Show Log Messages Since QGIS 1 8 it s possible to track the QGIS messages You can activate rog Messages in the menu Settings Panels and follow the messages in the General and Plugin tab during loading and operation 41 QGIS User Guide Release 1 8 8 2 Project Properties In the properties window for the project under a Settings gt Project Properties or 7 ties you set project specific options These include Settings Project Proper In the General tab the project title selection and background color layer units precision and the option to save relative paths to layers can be defined You can define the layer units only used when CRS transfor mation is disabled and the precision of decimal places to use The CRS Coordinate Reference System tab enables you to choose the CRS for this project and to enable on the fly re projection of raster and vector layers when displaying layers from a different CRS With the third Identifiable layers tab you set or disable which layers will respond to the identify tool See the Map tools paragraph from the Options section to enable identifying of multiple layers The tab OWS Server allows to define information about the QGIS mapserver Service Capabilities the Extent and the CRS Restrictions as well as the WFS Capabilities Activating the Add WKT geometry to feature info response will allow to query the WMS layers 8 3 Options
175. e all its features even if a selection exist in QGIS You can make an external algorithm aware of that selection by checking the Use selected features in external applications item in the General settings group When you do so each time you execute an external algorithm that uses a vector layer the selected features of that layer will be exported to a new layer and the algorithm will work with that new layer instead Notice that if you select this option a layer with no selection will behave like a layer with all its features selected not like an empty layer 17 7 2 SAGA SAGA algorithms can be run from SEXTANTE if you have SAGA installed in your system and you configure SEXTANTE properly so it can find SAGA executables In particular the SAGA command line executable is needed to run SAGA algorithms SAGA binaries are not included with SEXTANTE so you have to download and install the software yourself Please check the SAGA website at for more information SAGA 2 0 8 is needed Once SAGA is installed and if you are running Windows open the SEXTANTE configuration dialog In the SAGA block you will find a setting named SAGA Folder Enter the path to the folder where SAGA is installed Close the configuration dialog and now you are ready to run SAGA algorithms from SEXTANTE In case you are using Linux there is no need to configure that and you will not see those folders Instead you must make sure that SAGA is properly installed and its fol
176. e for this service if you wish that you receive source code or can get it if you want it that you can change the software or use pieces of 1t in new free programs and that you know you can do these things To protect your rights we need to make restrictions that forbid anyone to deny you these rights or to ask you to surrender the rights These restrictions translate to certain responsibilities for you if you distribute copies of the software or if you modify it For example 1f you distribute copies of such a program whether gratis or for a fee you must give the recipients all the rights that you have You must make sure that they too receive or can get the source code And you must show them these terms so they know their rights We protect your rights with two steps 1 copyright the software and 2 offer you this license which gives you legal permission to copy distribute and or modify the software Also for each author s protection and ours we want to make certain that everyone understands that there is no warranty for this free software If the software is modified by someone else and passed on we want its recipients to know that what they have is not the original so that any problems introduced by others will not reflect on the original authors reputations Finally any free program is threatened constantly by software patents We wish to avoid the danger that redis tributors of a free program will individually obtain p
177. e holding down the left mouse button to the Applications folder This will create a link that you can use to start QGIS browser In figure_browser_standalone_metadata you can see the enhanced functionality of Qgis browser The Param tab provides the details of your connection based datasets like PostGIS or MSSQL Spatial The Metadata tab contains general information about the file see Metadata Tab With the Preview tab you can have a look at your files without importing them into your QGIS project It s also possible to preview the attributes of your files in the Attributes tab 54 Capitulo 10 QGIS Browser CAP TULO 1 1 Working with Vector Data 11 1 Supported Data Formats QGIS uses the OGR library to read and write vector data formats GRASS vector and PostgreSQL support is supplied by native QGIS data provider plugins including ESRI Shapefiles MapInfo and Microstation file formats PostGIS SpatiaLite Oracle Spatial databases and many more The vector data can also be loaded in read mode from zip and gzip archives into QGIS At the date of this document 69 vector formats are supported by the OGR library see OGR SOFTWARE SUITE Literature and Web References The complete list is available at http www gdal org ogr ogr_formats html Note Not all of the listed formats may work in QGIS for various reasons For example some require external commercial libraries or the GDAL OGR installation of your OS was not build to supp
178. e output to check all the messages generated by SAGA and try to find out where the problem is Some algorithms even if they can produce a result with the given input data might add comments or additional information to Warning in case they detect potential problems from that data in order to warn you about them Make sure you check those messages in case you are having unexpected results 17 7 Configuring external applications 17 7 1 Introduction SEXTANTE can be extended using additional applications calling them from within SEXTANTE Currently SAGA GRASS OTB Orfeo Toolbox and R are supported along with some other command line applications that provide spatial data analysis functionalities Algorithms relying on an external application are managed by their own algorithm provider This chapter will show you how to configure SEXTANTE to include these additional applications and will explain some particular features of the algorithm based on them Once you have correctly configured the system you will be able to execute external algorithms from any SEXTANTE component like the toolbox or the graphical modeler just like you do with any other SEXTANTE geoalgorithm By default all algorithms that rely on an external appplication not shipped with QGIS are not enabled You can enable them in the SEXTANTE configuration dialog Make sure that the corresponding application is already installed in your system Enabling an algorithm provider wit
179. e strongly compared to the first shaded relief map Quantum GIS 1 2 0 Daphnis SVEN Ble Edit wiew Layer Settings Plugins Jools Help EAS A AS uRERO Dexi ve ZoeKNQO PRD O7BCODABKOE eam AMA 4 ATI Layers ox mm a q Eres ES ae Y o v gtopo30_shade2 x Q a a p Q y a DEST ox a x x a 3 a gt x 1050050 1423981 Scale bt o EP Figura 15 14 Displaying shaded relief created with the GRASS module r shaded relief 4 Raster statistics in a vector map The next example shows how a GRASS module can aggregate raster data and add columns of statistics for each polygon in a vector map Again using the Alaska data refer to Importing data into a GRASS LOCATION to import the trees shapefile from the shapefiles directory into GRASS Now an intermediary step is required centroids must be added to the imported trees map to make it a complete GRASS area vector including both boundaries and centroids From the toolbox choose Vector Manage features and open the module v centroids Enter as the output vector map forest areas and run the module Now load the forest_areas vector and display the types of forests deciduous evergreen mixed in different colors In the layer Properties window Symbology tab choose from Legend type Unique value and set the Classification field to VEGDESC Refer to the explanation of the symbology tab ref sec_symbology in the vector section Next reopen the GRASS
180. e the shape of some line your action affects not only the OSM Way but also the OSM Nodes that are part of it QGIS standard editing tools cannot tell the OSM provider which members of which line has changed and how It can tell only what s the new geometry of which line and that s not enough to propagate changes to the OSM database correctly The Line layer does also not know the identifiers of the line members The same problem occurs when you try to edit the Polygon layer 140 Capitulo 16 OpenStreetMap QGIS User Guide Release 1 8 For this reason the OSM plugin need its own tools for editing OSM data While they are used the OSM layers can be changed correctly The Plugin editing tools consists of tools for Point Line Polygon and Relation creation deletion and moving Note To create a connection between the OSM plugin and standard editing tools changes in QuantumGIS core code would be necessary 16 3 Installation The OpenStreetMap plugin is a core plugin inside QGIS The OpenStreetMap plugin can be selected in the Plugin Manager as described in section Loading a OGIS Core Plugin 16 4 Basic user interface The first time the OSM plugin is started and after the first data are loaded several new OSM plugin icons appear in the QGIS toolbar menu together with new dock windows as shown in figure_OpenStreetMap_2 File Edit View Layer Settings Plugins Help TFALAAALLAILO BEeuuE Layers ox OSM Feat
181. e wa a a ee ae 30 7 General Tools 33 Tel Keyboard shorteuts o i iin ea e o e e See a aH 33 T Comet help ss a e e AE e e BR 33 da Rendenne ss emos je eG Red ee Bate aed ba Baie Aaa hes ed blades we RN 33 7A Measure ge bee rad ene eR eS EY IG eam bee Sa ee EOS 35 T3 DecoratlOnS se waos Pica ee eb be Oh A bea wee eh eae ea 36 T6 Annotation TOONS ss bce bgt Be Re we A aa eich e Gm Boe ee a a E 38 7 7 Spatial Bookmarks s sms a ms 25 ee ENED RA a Ee ae Ee a eS 39 Te Nesting Projects as ma sean De Bie ee Ke Ye Re ee A A Bk Bae 40 8 QGIS Configuration 41 10 11 12 13 14 15 16 17 8 1 Panels andi Toolbars cuisine lo alos ca de a He BO SR ek a a ee a A E 3 2 Project Properties os ob eA ea ee eA e eke wee ee Ee BS o eek has eS SE a GO A a ly Re be Be de 84 Customization cerda a EAD EEE ae GA wee AAA 06 A AU Working with Projections 9 1 Overview of Projection SUpport ap 2 2024 ee 85 805454 444 cf be eeu d bean 0 2 Specifying a Projection su she po a RE Rae ea ee ee ee E 9 3 Define On The Fly OTF Reprojection ocre Be A Ee ae eG 94 Custom Coordinate Reference System lt s co seuri ee a AA QGIS Browser Working with Vector Data 11 1 Supported Data Formats ss pos a a ae a SR ae Bla Be Bee a AS 11 2 The Vector Properties Dial g omic HA EA Re we ew ee BS 11 3 Editing os mm a de A e o aa a de a iia a 114 Query Builder 3 252444 25 a sm a a A ee oS 115 Field Calculator e is ri ake
182. eceive it in any medium provided that you conspicuously and appropriately publish on each copy an appropriate copyright notice and disclaimer of warranty keep intact all the notices that refer to this License and to the absence of any warranty and give any other recipients of the Program a copy of this License along with the Program You may charge a fee for the physical act of transferring a copy and you may at your option offer warranty protection in exchange for a fee You may modify your copy or copies of the Program or any portion of it thus forming a work based on the Program and copy and distribute such modifications or work under the terms of Section 1 above provided that you also meet all of these conditions a You must cause the modified files to carry prominent notices stating that you changed the files and the date of any change b You must cause any work that you distribute or publish that in whole or in part contains or is derived from the Program or any part thereof to be licensed as a whole at no charge to all third parties under the terms of this License c If the modified program normally reads commands interactively when run you must cause it when started running for such interactive use in the most ordinary way to print or display an announcement including an appropriate copyright notice and a notice that there is no warranty or else saying that you provide a warranty and that users may redistribute the pr
183. ecorations title bar etc may appear different depending on your operating system and window manager The QGIS GUI is divided into five areas 1 Menu Bar 2 Tool Bar 3 Map Legend 4 Map View 5 Status Bar These five components of the QGIS interface are described in more detail in the following sections Two more sections present keyboard shortcuts and context help 21 QGIS User Guide Release 1 8 6 1 Menu Bar The menu bar provides access to various QGIS features using a standard hierarchical menu The top level menus and a summary of some of the menu options are listed below together with the icons of the corresponding tools as they appear on the toolbar as well as keyboard shortcuts Keyboard shortcuts can also be configured manually shortcuts presented in this section are the defaults using the Configure Shortcuts tool under Settings Although most menu options have a corresponding tool and vice versa the menus are not organized quite like the toolbars The toolbar containing the tool is listed after each menu option as a checkbox entry Some menu options only appear if the corresponding plugin is loaded For more information about tools and toolbars see Section Toolbar 6 1 1 File Menu Option Shortcut Reference Toolbar E New Project Ctrl N see Projects File E Open Project Ctrl 0 see Projects File Open Recent Projects see Projects Save Project Ctrl s see Projects File a Save Project As Ct
184. ed Usti nad Labem Czech Republic Hlavni trida street data repaired Sumperk Czech Republic OSM account Username Tajro Password 000000000 Show password Save password Upload Close Figura 16 7 OSM upload dialog 16 11 Saving OSM data To save data from a current map extent to an XML file click on the ES Save OSM to file button If there is no such button the OSM toolbar in your QuantumGIS installation is probably disabled You can enable it again in Settings gt Toolbars OpenStreetMap After clicking on the button a new dialog appears m Save OSM Where to save ooo Ji Features to save Points X Relations Lines Tags Figura 16 8 OSM saving dialog Select features you want to save into XML file and the file itself Use the OK button to start the operation The process will create an XML file in which OSM data from your current map extent are represented The OSM version of the output file is 0 6 Elements of OSM data lt node gt lt way gt lt relation gt do not contain information on their changesets and uids This information are not compulsory yet see DTD for OSM XML version 0 6 In the output file OSM elements are not ordered Notice that not only data from the current extent are saved Into the output file the whole polygons and lines are 148 Cap tulo 16 OpenStreetMap QGIS User Guide Release 1 8 saved even if only a small part
185. ed and automatically activated using the Python Plugin Installer see Section Loading an external QGIS Plugin Those plugins that are already loaded have a check mark to the left of their name Figure_plugins_1 shows the Plugin Manager dialog To enable a particular plugin click on the checkbox to the left of the plugin name and click OK When you exit the application a list of loaded plugins is retained and the next time you run QGIS these plugins are automatically loaded Tip Crashing Plugins If you find that QGIS crashes on startup a plugin may be at fault You can stop all plugins from loading by editing your stored settings file see Options for location Locate the plugins settings and change all the plugin values to false to prevent them from loading 4b For example to prevent the Delimited text plugin from loading the entry in SHOME config QuantumGIS qgis conf on Linux should look like this Add Delimited Text Layer false Do this for each plugin in the Plugins section You can then start QGIS and add the plugins one at a time from the Plugin Manager to determine which plugin is causing the problem 195 QGIS User Guide Release 1 8 g QGIS Plugin Manager Y UDS Filter To enable disable a plugin click its checkbox or description Add Delimited TextLayer a Loads and displays delimited text files containing x y coordinates Coordinate Capture gt Capture mouse coordinates in differen
186. ed by QGIS and use them in a web browser to retrieve the same 105 QGIS User Guide Release 1 8 images that QGIS uses internally This can be useful for troubleshooting as there are several brands of WMS servers in the market and they all have their own interpretation of the WMS standard WMS layers can be added quite simply as long as you know the URL to access the WMS server you have a serviceable connection to that server and the server understands HTTP as the data transport mechanism Selecting WMS Servers The first time you use the WMS feature there are no servers defined Begin by clicking the e Add WMS layer button inside the toolbar or through the Layer Add WMS Layer menu The dialog Add Layer s from a Server for adding layers from the WMS server appears You can add some servers to play with by clicking the Add default servers button This will add two WMS demo servers for you to use the WMS servers of the DM Solutions Group and Lizardtech To define a new WMS server in the tab Layers select the New button Then enter the parameters to connect to your desired WMS server as listed in table OGC 1 Name A name for this connection This name will be used in the Server Connections drop down box so that you can distinguish it from other WMS Servers URL URL of the server providing the data This must be a resolvable host name the same format as you would use to open a telnet connection or ping a host Userna
187. efault Load Style Save Style Fl Help Y OK amp Apply Cancel Figura 11 6 Vector Layer Properties Dialog A 11 2 1 Style Tab Sy Since QGIS 1 4 0 a new symbology was integrated in parallel to improve and finally replace the old sym bology QGIS 1 8 now uses the new symbology as default which provides a variety of improvements and new features A description of the old symbology is available in section Old Symbology There are three types of symbols marker symbols for points line symbols for lines and fill and outline symbols for polygons Symbols can consist of one or more symbol layers It is possible to define the color of a symbol and this color is then defined for all symbol layers Some layers may have the color locked for those the color 11 2 The Vector Properties Dialog 63 QGIS User Guide Release 1 8 can not be altered This is useful when you define the color of a multilayer symbol Similarly it is possible to define the width for line symbols as well as size and rotation for marker symbols Available symbol layer types e Point layers Font marker Rendering with a font Simple marker Rendering with a hardcoded marker SVG marker Rendering with a SVG picture Ellipse marker Rendering with ellipse shapes derived from attributes Vector field marker Rendering with vector fields derived from attributes e Line layers Line decoration Add a line decoration e g an ar
188. efine a legend independent drawing order You can activate it in the menu Settings Panels Determine the drawing order of the layers in the map view here Doing so makes it possible to order your layers in order of importance for example but to still display them in the correct order see figure_layer_order Checking the control rendering order box underneath the list of layers will cause a revert to default behavior 6 4 Map View This is the business end of QGIS maps are displayed in this area The map displayed in this window will depend on the vector and raster layers you have chosen to load see sections that follow for more information on how to load layers The map view can be panned shifting the focus of the map display to another region and zoomed in and out Various other operations can be performed on the map as described in the toolbar description above The map view and the legend are tightly bound to each other the maps in view reflect changes you make in the legend area Tip Zooming the Map with the Mouse Wheel You can use the mouse wheel to zoom in and out on the map Place the mouse cursor inside the map area and roll the wheel forward away from you to zoom in and backwards towards you to zoom out The mouse cursor position is the center where the zoom occurs You can customize the behavior of the mouse wheel zoom using the Map tools tab under the Settings Options menu 6 4 Map View 29 QGIS Us
189. egistered trademarks and are therefore subject to the legal require ments Quantum GIS is subject to the GNU General Public License Find more information on the Quantum GIS Homepage http www qgis org The details data results etc in this document have been written and verified to the best of knowledge and responsibility of the authors and editors Nevertheless mistakes concerning the content are possible Therefore all data are not liable to any duties or guarantees The authors editors and publishers do not take any responsibility or liability for failures and their consequences Your are always welcome to indicate possible mistakes This document has been typeset with reStructuredText It is available as reST source code via github and online as HTML and PDF via http documentation qgis org Translated versions of this document can be downloaded in several formats via the documentation area of the QGIS project as well For more information about contributing to this document and about translating it please visit http www qgis org wiki Links in this Document This document contains internal and external links Clicking on an internal link moves within the document while clicking on an external link opens an internet address In PDF form internal and external links are shown in blue and are handled by the system browser In HTML form the browser displays and handles both identically User Installation and Coding Guide Authors an
190. egory value shall be applied to new geometry elements Next not used apply next not yet used category value to geometry element Manual entry manually define the category value for the geometry element in the Category entry field No category Do not apply a category value to the geometry element This is e g used for area boundaries because the category values are connected via the centroid e Category A number ID is attached to each digitized geometry element It is used to connect each geometry element with its attributes Field layer Each geometry element can be connected with several attribute tables using different GRASS geometry layers Default layer number is 1 15 7 Digitizing and editing a GRASS vector layer 127 QGIS User Guide Release 1 8 Tip Creating an additional GRASS layer with QGIS If you would like to add more layers to your dataset just add a new number in the Field layer entry box and press return In the Table tab you can create your new table connected to your new layer Settings Tab The Settings tab allows you to set the snapping in screen pixels The threshold defines at what distance new points or line ends are snapped to existing nodes This helps to prevent gaps or dangles between boundaries The default 1s set to 10 pixels AU ER Lar AVEO ir Category Settings L Symbology Table Snapping in screen pixels fio E
191. ent GRASS version you can change that setting and point to the folder where that other version is kept GRASS 6 4 is needed for algorithms to work correctly If you are running Linux you just have to make sure that GRASS is correctly installed and that it can be run without problem from a console GRASS algorithms use a region for calculations This region can be defined manually using values similar to the ones found in the SAGA configuration or automatically taking the minimum extent that covers all the input layers used to execute the algorithm each time If this is the behaviour you prefer just check the Use min covering region option in the GRASS configuration parameters GRASS includes help files describing each algorithm If you set the GRASS help folder parameter SEXTANTE will open them when you use the Show help button from the parameters window of the algorithm The last parameter that has to be configured is related to the mapset A mapset is needed to run GRASS and SEXTANTE creates a temporary one for each execution You have to tell SEXTANTE if the data you are working with uses geographical lat lon coordinates or projected ones 17 7 5 GDAL No additional configuration is needed to run GDAL algorithms since it is already incorporated to QGIS and SEXTANTE can infere its configuration from it 17 7 6 Orfeo ToolBox Orfeo ToolBox OTB algorithms can be run from SEXTANTE if you have OTB installed in your system and confi
192. ents X min 3729676 978 X max 1819415 094 Y m n 1733650 575 Y max 6758661 729 Set to map canvas extent Figura 18 3 Extents Dialog A The Map extent area allow to specify the map extent using Y and X min max values or clicking the Set to map canvas extent button If you change the view on the QGIS map canvas by zooming or panning or changing vector or raster properties you can update the print composer view selecting the map element in the print composer and clicking the Update preview button in the map Item Properties tab see Figure figure_composer_2 a 18 3 2 Map item properties tab Grid and General options dialog Grid dialog The Grid dialog of the map Item Properties tab provides following functionalities see Figure_composer_4 Grid V Show grid Grid type Solid Interval X 200000 00000 Interval Y 200000 00000 gt O lt gt IX Offset X 0 00000 gt Offset Y 0 00000 Cross width 3 00000 lt gt Line width 0 00000 gt __ Draw annotation Figura 18 4 Grid Dialog amp e The Show grid checkbox allows to overlay a grid to the map element As grid type you can specify to use solid line or cross Furthermore you can define an interval in X and Y direction an X and Y offset and the width used for cross or line grid type e The Draw annotation checkbox allows to add coordinates to the map frame The annotation can be drawn inside or outside the map frame The annotation di
193. epart polygons Extract nodes from line and polygon layers and output them as points Table Ftools 4 fTools Geometry tools Note The Simplify geometry tool can be used to remove duplicate nodes in line and polygon geometries just set the Simplify tolerance parameter to O and this will do the trick 19 9 5 Data management tools Icon Tool Purpose A YA Define Specify the CRS for shapefiles whose CRS has not been defined projection o Join Join additional attributes to vector layer based on spatial relationship Attributes from attributes by one vector layer are appended to the attribute table of another layer and exported as a location shapefile oN Split vector Split input layer into multiple separate layers based on input field layer RE Merge Merge several shapefiles within a folder into a new shapefile based on the layer type shapefiles to point line area one Create Create a spatial index for OGR supported formats spatial index Table Ftools 5 fTools Data management tools 216 Cap tulo 19 Plugins QGIS User Guide Release 1 8 19 10 GDAL Tools Plugin 19 10 1 What is GDALTools The GDAL Tools plugin offers a GUI to the collection of tools in the Geospatial Data Abstraction Library http gdal osgeo org These are raster management tools to query re project warp and merge a wide variety of raster formats Also included are tools to create a contour vector laye
194. er Guide Release 1 8 Subgroup 1 majrivers airports majrivers lakes Figura 6 2 Define a legend independent layer order Tip Panning the Map with the Arrow Keys and Space Bar You can use the arrow keys to pan in the map Place the mouse cursor inside the map area and click on the right arrow key to pan East left arrow key to pan West up arrow key to pan North and down arrow key to pan South You can also pan the map using the space bar just move the mouse while holding down space bar 6 5 Status Bar The status bar shows you your current position in map coordinates e g meters or decimal degrees as the mouse pointer is moved across the map view To the left of the coordinate display in the status bar is a small button that will toggle between showing coordinate position or the view extents of the map view as you pan and zoom in and out Next to the coordinate display you find the scale display It shows the scale of the map view If you zoom in or out QGIS shows you the current scale Since QGIS 1 8 there is a scale selector which allows you to choose between predefined scales from 1 500 until 1 1000000 A progress bar in the status bar shows progress of rendering as each layer is drawn to the map view In some cases such as the gathering of statistics in raster layers the progress bar will be used to show the status of lengthy operations If a new plugin or a plugin update is available you will se
195. eries When the queries are loaded their titles as defined in the XML file will appear in the dropdown menu located just below the L Open File icon the full description of the query is displayed in the text window under the dropdown menu Select the query you want to run from the dropdown menu and then click on the SQL Query tab to see that the query has been loaded into the query window If it is the first time you are running a predefined query or are switching databases you need to be sure to connect to the database Click on the Run Query button in the SQL Query tab to execute the command If the query is successful a Database File Selection window will be displayed If the query is not successful an error message will appear in the Output Console window 1 Open Query File Launches the Open File file browser to search for the XML file holding the predefined queries 2 Predefined Queries A dropdown list with all of the queries defined by the predefined queries XML file 19 8 eVis Plugin 211 QGIS User Guide Release 1 8 Database Connection is command will import only points that have photos that mention limestone to QGIS Figura 19 14 The eVis Predefined queries tab 7 3 Query description A short description of the query This description is from the predefined queries XML file 4 Console Window The console window where messages related to processing are displayed 5 Help Displays t
196. ersion is given a distinguishing version number If the Program specifies a version number of this License which applies to 1t and any later version you have the option of following the terms and conditions either of that version or of any later version published by the Free Software Foundation If the Program does not specify a version number of this License you may choose any version ever published by the Free Software Foundation If you wish to incorporate parts of the Program into other free programs whose distribution conditions are different write to the author to ask for permission For software which is copyrighted by the Free Software Foundation write to the Free Software Foundation we sometimes make exceptions for this Our decision will be guided by the two goals of preserving the free status of all derivatives of our free software and of promoting the sharing and reuse of software generally NO WARRANTY 11 BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE THERE IS NO WARRANTY FOR THE PROGRAM TO THE EXTENT PERMITTED BY APPLICABLE LAW EXCEPT WHEN OTH ERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND OR OTHER PARTIES PROVIDE THE PROGRAM AS IS WITHOUT WARRANTY OF ANY KIND EITHER EXPRESSED OR IM PLIED INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABIL ITY AND FITNESS FOR A PARTICULAR PURPOSE THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU SHOULD THE PROGRAM PROVE DEF
197. esulting files as input to SEXTANTE Also note that the reprojection process can be performed with SEXTANTE which incorporates tools to do so 17 2 3 Data objects generated by SEXTANTE algorithms Data objects generated by SEXTANTE can be of any of the following types e A raster layer e A vector layer e A table e An HTML file used for text and graphical outputs They are all saved to disk there are no in memory results and the parameters table will contain a text box corresponding to each one of these outputs where you can type the output channel to use for saving it An output channel contains the information needed to save the resulting object somewhere In the most usual case you will save it to a file but the architecture of SEXTANTE allows for any other way of storing it For instance a vector layer can be stored in a database or even uploaded to a remote server using a WFS T service Although solutions like these are not yet implemented SEXTANTE is prepared to handle them and we expect to add new kinds of output channels in a near feature To select an output channel just click on the button on the right side of the text box That will open a save file dialog where you can select the desired filepath Supported file extensions are shown in the file format selector of the dialog depending on the kind of output and the algorithm The format of the output is defined by the filename extension The supported formats depend on the one
198. ew SpatiaLite layer 62 Cap tulo 11 Working with Vector Data QGIS User Guide Release 1 8 Tip SpatiaLite data management Plugins For SpatiaLite data management you can also use several Python plugins QSpatiaLite SpatiaLite Manager or DB Manager core plugin recommended They can be downloaded and installed with the Plugin Installer 11 1 8 MSSQL Spatial Layers QGIS also provides native MS SQL 2008 support The Add MSSQL Spatial Layer ig part of the new toolbar button or available in the MS SQL node in the QBrowser tree providing drag and drop import support 11 2 The Vector Properties Dialog The Layer Properties dialog for a vector layer provides information about the layer symbology settings and labeling options If your vector layer has been loaded from a PostgreSQL PostGIS datastore you can also alter the underlying SQL for the layer by invoking the Query Builder dialog on the General tab To access the Layer Properties dialog double click on a layer in the legend or right click on the layer and select Properties from the popup menu L amp Layer Properties alaska Y DDR ay Style Labels Fields General GD Metadata ih Actions ed Joins 7 Die lt gt Options Displayname alaska Display field v Edit UI Create Spatial Index Initfunction Specify CRS EPSG 2964 NAD27 AlaskaAlbers __ Use scale dependent rendering Minimum Maximum Subset Query Builder Restore Default Style Save As D
199. f a vector layer 176 Capitulo 17 SEXTANTE QGIS User Guide Release 1 8 layer vector field field layer nortest group library nortest gt lillie test layer field The output ot the last line is printed but the output of the first is not and neither are the outputs from other command lines added automatically by SEXTANTE If your algorithm creates any kind of graphics using the plot method add the following line showplots This will cause SEXTANTE to redirect all R graphical outputs to a temporary file which will be later opened once R execution has finished Both graphics and console results will be shown in the SEXTANTE results manager For more information please check the script files provided with SEXTANTE Most of them are rather simple and will greatly help you understand how to create your own ones 17 7 4 GRASS Configuring GRASS is not much different from configuring SAGA First the path to the GRASS folder has to be defined but only if you are running Windows Additionaly a shell interpreter usually msys exe which can be found in most GRASS for Windows distributions has to be defined and its path set up as well By default SEXTANTE tries to configure its GRASS connector to use the GRASS distribution that ships along with QGIS This should work without problems in most systems but if you experience problems you might have to do it manually Also if you want to use a differ
200. features and settings and how to use them 5 4 Starting and Stopping QGIS In Section Sample Session you already learned how to start QGIS We will repeat this here and you will see that QGIS also provides further command line options Assuming that QGIS is installed in the PATH you can start QGIS by typing qgis at a command prompt or by double clicking on the QGIS application link or shortcut on the desktop or in the application menu e Start QGIS using the Start menu or desktop shortcut or double click on a QGIS project file X Double click the icon in your Applications folder If you need to start QGIS in a shell run path to installation executable Contents MacOS Qgis To stop QGIS click the menu options a Y File X QGIS gt Quit or use the shortcut Ctr1 0 5 5 Command Line Options a QGIS supports a number of options when started from the command line To get a list of the options enter qgis help on the command line The usage statement for QGIS is agis help Quantum GIS 1 8 0 Lisboa Lisboa exported Quantum GIS QGIS is a viewer for spatial data sets including raster and vector data Usage agis options FILES options snapshot filename emit snapshot of loaded datasets to given file width width width of snapshot to emit height height height of snapshot to emit lang language use language for interface text project projectfile load the given QGIS project extent
201. first geometry problem will be reported 44 Capitulo 8 QGIS Configuration QGIS User Guide Release 1 8 The next 3 options refer to the EN Offset Curve too in Advanced digitizing Through the various settings it is possible to influence the shape of the line offset These options are possible from GEOS 3 3 e Join style for curve offset e Quadrantsegments for curve offset e Miter limit for curve offset 8 3 8 CRS Tab The CRS tab is divided in two areas The first area allows to define the default CRS for new projects e Select a CRS and Always start new projects with this CRS Enable on the fly re projection by default The second area allows to define the action when a new layer is created or when a layer without CRS is loaded e Prompt for Coordinate Reference System CRS e Use project Coordinate Reference System CRS e Use default Coordinate Reference System CRS displayed below 8 3 9 Locale Tab Overwrite system locale and Locale to use instead e Information about active system locale 8 3 10 Network Tab g Options 2 yox X General Rendering i Maptools 12 Overlays Digitizing cRS FB Locale Network Y Use proxy for web access Host localhost Port 64609 User Password Proxy type DefaultProxy v Exclude URLs starting with Add Remove Cache settings Directory homeidassau qgisicachel Size 51200 Clear WMS search address h
202. following functionalities General options Frame color Background color Opacity _ i Outline width 0 30 Position and size V Show frame Item ID Figura 18 9 General Options Dialog Dialog 4S e Here you can define color and outline width for the element frame set a background color and opacity for the picture The Position and size button opens the Set item position dialog and allows to set the map canvas position using reference points or coordinates Furthermore you can select or unselect to display the element frame with the Show frame checkbox With the Item ID you can create a relationship to other print composer items 18 4 3 Legend item properties tab General Legend items and Item option dia log C E To add a map legend click the Add new legend icon place the element with the left mouse button on the print composer canvas and position and customize their appearance in the legend tem Properties tab General dialog The General dialog of the legend item tab provides following functionalities see figure_composer_10 Item Properties x General Title Font Group Font Layer Font Item Font Symbol width 7 00 mm Symbol height 4 00 mm Group Space 2 00 mm Layer space 2 00 mm Symbol space 2 00 mm Icon label space 2 00 mm Box space 2 00 mm Map Map 0 Wrap text on lt lt gt lt gt lt gt lt gt of lt gt Ci A
203. frequently used symbols and can use it without having to recreate it everytime Style items symbols and color ramps have always a name by which they can be queried from the style There is at least one default style in QGIS modifiable and the user can add further styles In the lower part of the Style tab there are four buttons for managing styles Use Restore Default Style to get back to your default settings Save As Default to save your style as default Load Style to get to your own styles and Save Style to save your own styles Layer styles can also be transferred from one layer to another layer Activate a layer and choose Layer E Copy style and switch to another layer Then choose Layer Paste style Renderers 64 Capitulo 11 Working with Vector Data QGIS User Guide Release 1 8 The renderer is responsible for drawing a feature together with the correct symbol There are four types of renderers single symbol categorized called unique color in the old symbology graduated and rule based There is no continuous color renderer because it is in fact only a special case of the graduated renderer The categorized and graduated renderer can be created by specifying a symbol and a color ramp they will set the colors for symbols appropriately Working with the New Generation Symbology In the Style tab you can choose one of the five renderers single symbol categorized graduated rule based and point displacement
204. g c0110 This will prevent the co110 field name being mistaken for the co11 field name with a O on the end The brackets will be removed by QGIS when it substitutes in the value of the field If you want the substituted field to be surrounded by square brackets use a second set like this Sc0110 Using the Identify Features tool you can open Identify Results dialog It includes a Derived item that contains information relevant to the layer type The values in this item can be accessed in a similar way to the other fields by using preceeding the derived field name by Derived For example a point layer has an X and Y field and the value of these can be used in the action with Derived X and Derived Y The derived attributes are only available from the Identify Results dialog box not the Attribute Table dialog box Two example actions are shown below 11 2 The Vector Properties Dialog 77 QGIS User Guide Release 1 8 e konqueror http www google com search q nam e konqueror http www google com search q 3 In the first example the web browser konqueror is invoked and passed a URL to open The URL performs a Google search on the value of the nam field from our vector layer Note that the application or script called by the action must be in the path or you must provide the full path To be sure we could rewrite the first exam ple as opt kde3 bin konqueror http www google com search gq nam This
205. g a new GeoTiff or by adding a world file to the existing image The basic approach to georeferencing a raster is to locate points on the raster for which you can accurately determine their coordinates Features Icon Purpose Icon Purpose amp Open raster gt Start georeferencing a cone Generate GDAL Script E Load GCP Points Save GCP Points As Transformation settings o e Add Point o Delete Point S v Move GCP Point Pan a Zoom In Q Zoom Out Rh Zoom To Layer A Zoom Last SP Zoom Next el Link Georeferencer to QGIS 47 Link QGIS to Georeferencer Table Georeferencer 1 Georeferencer Tools 19 11 1 Usual procedure As X and Y coordinates DMS dd mm ss ss DD dd dd or projected coordinates nmmm mm which corre spond with the selected point on the image two alternative procedures can be used The raster itself sometimes provides crosses with coordinates written on the image In this case you can enter the coordinates manually e Using already georeferenced layers this can be either vector or raster data that contain the same ob jects features that you have on the image that you want to georeference and the projection you want to have your image In this case you can enter the coordinates by clicking on the reference dataset loaded in QGIS map canvas The usual procedure for georeferencing an image involves selecting multiple points on the raster specifying their coordinates and choosing a
206. g a numerical value as it can be seen in the next figure apart from the description of the parameter you have to set a default value and a range of valid values DE S 2 Min Max values Default value 0 Figura 17 15 Model Parameters 7 For each added input a new element is added to the modeler canvas SF P oP Point 4 DEM Landsat Figura 17 16 Model Parameters 7 17 3 3 Definition of the workflow Once the inputs have been defined it is time to define the algorithms to apply on them Algorithms can be found in the Algorithms tab grouped much in the same way as they are in the toolbox EA AA Inputs Algorithms E e here E rel Ld E lg Modeler a S Example models 7 p p IDLH SHS ene cample scripts GA y ntributions oreferencing ostatistics PRO Ba a 3 f A E Imagery Segmentation E Imagery Tools E Kriging Projections and Transformations E Recreations Simulation Ecosystems 5 Simulation Fire Spreading Simulation Hydrology S Table Calculus gt Table Te E Terrain Analysis Channels E Terrain Analysis Hydrology 2 EB Terrain Analysis Lighting E E Terrain Analysis Morphometry El Terrain Analysis Profiles ED E E Figura 17 17 Model Parameters 7 To add an algorithm double click on its name An execution d
207. g new vector layers and analysing GRASS 2D and 3D data with more than 300 GRASS modules In this Section we ll introduce the plugin functionalities and give some examples on managing and working with GRASS data Following main features are provided with the toolbar menu when you start the GRASS plugin as described in section Starting the GRASS plugin E Y Open mapset e iy New mapset Oy Close mapset Py Add GRASS vector layer a E Add GRASS raster layer Y Create new GRASS vector ma A Edit GRASS vector layer SY Open GRASS tools Ly Display current GRASS region Edit current GRASS region 15 1 Starting the GRASS plugin To use GRASS functionalities and or visualize GRASS vector and raster layers in QGIS you must select and load PA the GRASS plugin with the Plugin Manager Therefore click the menu Plugins Manage Plugins select GRASS and click OK You can now start loading raster and vector layers from an existing GRASS LOCATION see section Loading GRASS raster and vector layers Or you create a new GRASS LOCATION with QGIS see section Creating a new GRASS LOCATION and import some raster and vector data see Section Importing data into a GRASS LOCATION for further analysis with the GRASS Toolbox see section The GRASS toolbox 121 QGIS User Guide Release 1 8 15 2 Loading GRASS raster and vector layers With the GRASS plugin you can load vector or raster layers using the appropria
208. ge any patents or other property right claims or to contest validity of any such claims this section has the sole purpose of protecting the integrity of the free software distribution system which is implemented by public license practices Many people have made generous contributions to the wide range of software distributed through that system in reliance on consistent application of that system it is up to the author donor to decide if he or she is willing to distribute software through any other system and a licensee cannot impose that choice This section is intended to make thoroughly clear what is believed to be a consequence of the rest of this License 8 If the distribution and or use of the Program is restricted in certain countries either by patents or by copy righted interfaces the original copyright holder who places the Program under this License may add an explicit geographical distribution limitation excluding those countries so that distribution is permitted only in or among countries not thus excluded In such case this License incorporates the limitation as if written in the body of this License 9 The Free Software Foundation may publish revised and or new versions of the General Public License from time to time Such new versions will be similar in spirit to the present version but may differ in detail to address new problems or concerns 21 1 GNU General Public License 247 QGIS User Guide Release 1 8 Each v
209. generated outside of QGIS using Oracle PL SQL or gdaladdo The following is example using gdaladdo 230 Capitulo 19 Plugins QGIS User Guide Release 1 8 Select Oracle Spatial GeoRaster Server Connections example Connect Ne Delete Subdatasets georaster scotttigerorcl GDAL_RDT 214 georaster scotttigerorcl GDAL_RDT 215 georaster scotttiger orcl GDAL_RDT 216 georaster scotttigerorcl GDAL RDT217 georaster scott tiger orcl GDAL RDT218 Selection georaster scott tiger orcl GDAL_IMPORT RASTER Update E META 5 GeoRaster objects on table GDAL_IMPORT column RASTER Figura 19 26 Select Oracle GeoRaster dialog gdaladdo georaster scott tiger orcl georaster _table georaster georid 6 r nearest 2 4 6 8 16 32 This is an example using PL SQL S sqlplus scott tiger SQL gt DECLARE gr sdo_georaster BEGIN SELECT image INTO gr FROM cities WHERE id 1 FOR UPDATE sdo_geor generatePyramid gr rLevel 5 resampling NN UPDATE cities SET image gr WHERE id 1 COMMIT 19 16 Raster Terrain Analysis Plugin P The Raster Terrain Analysis Plugin can be used to calculate the slope aspect hillshade ruggedness index and relief for digital elevation models DEM It is very simple to handle and provides an intuitive graphical user interface for creating new raster layers See Figure raster terrain 1 Description of the analys
210. gging tool for OpenStreetMap data OSM WMS OpenStreetMap WMS WMS Demo f r OSM Daten Germany by IT Consult Halle GmbH OpenStreetMap WMS Graustufenvariante WMS Demo f r OSM Daten Germany by IT Consult Halle GmbH OSM_Basic OSM_Basic UMN MapServer Landcover UMN MapServer Landcover UMN MapServer Landcover Open Street Map Open Street Map This is the UMN MapServer application for the FlightGear Lande This is the UMN MapServer application for the FlightGear Landc This is the UMN MapServer application for the FlightGear Lande amp Add selected row to WMS list Help Add Q Close A 1 Layer s selected Figura 13 2 Dialog for searching WMS servers after some keywords As you can see it is possible to enter a search string in the text field and hit the Search button After a short while the search result will be populated into the list below the text field Browse the result list and inspect your search results within the table To visualize the results select a table entry press the Add selected row to WMS list button and change back to the tab Layers QGIS automatically has updated your server list and the selected search result is already enabled in the list of saved WMS servers in the Layers tab You only need to request the list of 108 Cap tulo 13 Working with OGC Data QGIS User Guide Release 1 8 layers by clicking the Connect button This option is quite handy when you want to search maps b
211. gured SEXTANTE properly so it can find all necessary files command line tools and libraries Please note that OTB binaries are not included in SEXTANTE so you have to download and install the software yourself Please check the OTB website for more information 17 7 Configuring external applications 177 QGIS User Guide Release 1 8 Once OTB is installed start QGIS open the SEXTANTE configuration dialog and configure OTB algorithm provider In the Orfeo Toolbox image analysis block you will find all settings related to OTB First ensure that algorithms are enabled Then configure path to the folder where OTB command line tools and libraries are installed rs usually OTB applications folder point to usr lib otb applications and OTB command line tools folder is usr bin E if you use OSGeo4W installer than install otb bin package and enter C OSGeo4W apps orfeotoolbox applications as OTB applications folder and C OSGeo4W bin as OTB command line tools folder 17 7 7 TauDEM To use this provider you need to install TauDEM command line tools Windows Please visit TauDEM homepage for installation instructions and precompiled binaries for 32bit and 64bit systems IMPORTANT you need TauDEM 5 0 6 executables version 5 2 currently not supported Linux There are no packages for most Linux distribution so you should compile TauDEM by yourself As TauDEM uses MPICH2 first install it using your favorite package manager A
212. he GRASS toolbox you need to open a LOCATION and MAPSET where you have write permission usually granted if you created the MAP SET This is necessary because new raster or vector layers created during analysis need to be written to the currently selected LOCATION and MAPSET The GRASS Shell inside the GRASS Toolbox provides access to almost all more than 330 GRASS modules through a command line interface To offer a more user friendly working environment about 200 of the available GRASS modules and functionalities are also provided by graphical dialogs within the GRASS plugin Toolbox 15 9 1 Working with GRASS modules The GRASS Shell inside the GRASS Toolbox provides access to almost all more than 300 GRASS modules in a command line interface To offer a more user friendly working environment about 200 of the available GRASS modules and functionalities are also provided by graphical dialogs A complete list of GRASS modules available in the graphical Toolbox in QGIS version 1 8 0 is available in the GRASS wiki http grass osgeo org wiki GRASS QGIS relevant module list 15 8 The GRASS region tool 129 QGIS User Guide Release 1 8 g GRASS Tools ndsgk2 besitzer2 vw O amp Modules Tree Modules List Browser J File management E Import into GRASS E Export from GRASS Export raster from GRASS y gt e r out gdal gtiff Export raster to Geo TIFF gt r outgdal Export raster to various form
213. he geometry is forest or lake For now it can be only a number in the future GRASS will also support names as fields in the user interface 15 5 The GRASS vector data model 125 QGIS User Guide Release 1 8 Attributes can be stored inside the GRASS LOCATION as DBase or SQLITE3 or in external database tables for example PostgreSQL MySQL Oracle etc Attributes in database tables are linked to geometry elements using a category value Category key ID is an integer attached to geometry primitives and it is used as the link to one key column in the database table Tip Learning the GRASS Vector Model The best way to learn the GRASS vector model and its capabilities is to download one of the many GRASS tutorials where the vector model is described more deeply See http grass osgeo org gdp manuals php for more information books and tutorials in several languages 15 6 Creating a new GRASS vector layer To create a new GRASS vector layer with the GRASS plugin click the Y Create new GRASS vector toolbar icon Enter a name in the text box and you can start digitizing point line or polygon geometries following the procedure described in Section Digitizing and editing a GRASS vector layer In GRASS it is possible to organize all sort of geometry types point line and area in one layer because GRASS uses a topological vector model so you don t need to select the geometry type when creating a new GRASS vector
214. he on line help 6 OK Closes the main Database Connection window XML format for eVis predefined queries The XML tags read by eVis 212 Cap tulo 19 Plugins QGIS User Guide Release 1 8 Tag Description query Defines the beginning and end of a query statement shortde A short description of the query that appears in the eVis dropdown menu scription descrip A more detailed description of the query displayed in the Predefined Query text window tion database The database type as defined in the Database Type dropdown menu in the Database Connection type tab database The port as defined in the Port textbox in the Database Connection tab port database The database name as defined in the Database Name textbox in the Database Connection tab name databaseuser The database username as defined in the Username textbox in the Database Connection tab name databasep The database password as defined in the Password textbox in the Database Connection tab assword sqlstate The SQL command ment autocon A flag true or false to specify if the above tags should be used to automatically connect to nect database without running the database connection routine in the Database Connection tab A complete sample XML file with three queries is displayed below lt xml vers lt doc gt lt query gt lt shortd lt descri lt de lt databa lt databa lt databa lt d
215. he resulting vector will load faster This process will be used when you have a highly detailed vector but you are creating a very small scale map so the detail is unnecessary Tip The simplify tool Note that the QGIS fTools plugin has a Simplify geometries tool that works just like the GRASS v generalize Douglas Peuker algorithm However the purpose of this example is different The contour lines created by r contour have sharp angles that should be smoothed Among the v generalize algorithms there is Chaikens which does just that also Hermite splines Be aware that these algorithms can add additional vertices to the vector causing it to load even more slowly e Open the GRASS toolbox and double click the categories Vector gt Develop map Generalization then click on the v generalize module to open its options window e Check that the ctour_100 vector appears as the Name of input vector e From the list of algorithms choose Chaiken s Leave all other options at their default and scroll down to the last row to enter in the field Name for output vector map ctour_100_smooth and click Run e The process takes several moments Once Successfully finished appears in the output windows click View output and then close You may change the color of the vector to display it clearly on the raster background and to contrast with the original contour lines You will notice that the new contour lines have s
216. he terms of Sections 1 and 2 above provided that you also do one of the following a Accompany it with the complete corresponding machine readable source code which must be dis tributed under the terms of Sections 1 and 2 above on a medium customarily used for software inter change or b Accompany it with a written offer valid for at least three years to give any third party for a charge no more than your cost of physically performing source distribution a complete machine readable copy of the corresponding source code to be distributed under the terms of Sections 1 and 2 above on a medium customarily used for software interchange or 246 Cap tulo 21 Appendix QGIS User Guide Release 1 8 c Accompany it with the information you received as to the offer to distribute corresponding source code This alternative is allowed only for noncommercial distribution and only if you received the program in object code or executable form with such an offer in accord with Subsection b above The source code for a work means the preferred form of the work for making modifications to it For an executable work complete source code means all the source code for all modules it contains plus any associated interface definition files plus the scripts used to control compilation and installation of the ex ecutable However as a special exception the source code distributed need not include anything that is normally distributed in ei
217. he vector layer written with the Qt Creator IDE and tools at http qt digia com Product Developer Tools Create a Spatial Index only for OGR supported formats Add an Init function for the layer They will overwrite existing QGIS widget initializations if applied Update Extents information for a layer View or change the projection of the specific vector layer clicking on Specify CRS Furthermore you can activate and set Use scale dependent rendering define provider specific options e g encoding and with the Query Builder button you can create a subset of the features in the layer that will be visualized also refer to section Selection 11 2 8 Metadata Tab 0 The Metadata tab contains general information about the layer including specifics about the type and lo cation number of features feature type and the editing capabilities The Extents section providing layer extent information and the Layer Spatial Reference System section providing information about the CRS of the layer This is a quick way to get information about the layer Additionally you can add edit a title for the layer and some abtract information These information will be saved in the QGIS project file for following sessions and will be used for QGIS server 11 2 9 Actions Tab X QGIS provides the ability to perform an action based on the attributes of a feature This can be used to perform any number of actions for example running a program with argumen
218. hose titles are designated as being those of Invariant Sections in the notice that says that the Document is released under this License If a section does not fit the above definition of Secondary then it is not allowed to be designated as Invariant The Document may contain zero Invariant Sections If the Document does not identify any Invariant Sections then there are none The Cover Texts are certain short passages of text that are listed as Front Cover Texts or Back Cover Texts in the notice that says that the Document is released under this License A Front Cover Text may be at most 5 words and a Back Cover Text may be at most 25 words A Transparent copy of the Document means a machine readable copy represented in a format whose specifi cation is available to the general public that is suitable for revising the document straightforwardly with generic text editors or for images composed of pixels generic paint programs or for drawings some widely available drawing editor and that is suitable for input to text formatters or for automatic translation to a variety of formats suitable for input to text formatters A copy made in an otherwise Transparent file format whose markup or ab sence of markup has been arranged to thwart or discourage subsequent modification by readers is not Transparent An image format is not Transparent if used for any substantial amount of text A copy that is not Transparent is called Opaque
219. hout installing the application it needs will cause the algorithms to appear in the toolbox but an error will be thrown when you try to execute them This is because the algorithm descriptions needed to create the parameters dialog and give SEXTANTE the information it needs about the algorithm are not included with each appllication but with SEXTANTE instead That is they are part of SEXTANTE so you have them in your installation even if you have not installed any other software Running the algorithm however needs the application binaries to be installed in your system A note on file formats When using an external software opening a file in QGIS does not mean that it can be opened and processed as well on that other software In most cases it can read what you have opened in QGIS but in some cases that might not be the case When using databases or uncommon file formats whether for raster of vector layers problems might arise If that happens try to use well known file formats that you are sure that are understood by both programs and check to console output in the history and log dialog for knowing more about what is going wrong Using GRASS raster layers is for instance one case in which you might have trouble and not be able to complete your work if you call an external algorithm using such a layer as input For this reason these layers will not appear as available to SEXTANTE algorithms we are currently working on solving this
220. ial data is called raster data or simply a raster The most easily recognised form of raster data is digital satellite imagery or air photos Elevation shading or digital elevation models are also typically represented as raster data Any type of map feature can be represented as raster data but there are limitations A raster is a regular grid made up of cells or in the case of imagery pixels They have a fixed number of rows and columns Each cell has a numeric value and has a certain geographic size e g 30x30 meters in size Multiple overlapping rasters are used to represent images using more than one colour value i e one raster for each set of red green and blue values is combined to create a colour image Satellite imagery also represents data in multiple bands Each band is essentially a separate spatially overlapping raster where each band holds values of certain wavelengths of light As you can imagine a large raster takes up more file space A raster with smaller cells can provide more detail but takes up more file space The trick is finding the right balance between cell size for storage purposes and cell size for analytical or mapping purposes 3 1 3 Vector Data Vector data is also used in geospatial applications If you stayed awake during trigonometry and coordinate geometry classes you will already be familiar with some of the qualities of vector data In its simplest sense vectors are a way of describing a lo
221. ialog will appear with a content similar to the one found in the execution panel that SEXTANTE shows when executing the algorithm from the toolbox the one 17 3 The SEXTANTE graphical modeler 161 QGIS User Guide Release 1 8 shown next correspond to the SAGA Convergence index algorithm the same one we saw in the section dedicated to the SEXTANTE toolbox Convergencendex Convergence Index lt OutputRaster gt Figura 17 18 Model Parameters 7 As you can see some differences exist Instead of the file output box that was used to set the filepath for output layers and tables a simple text box is If the layer generated by the algorithm is just a temporary result that will be used as the input of another algorithm and should not be kept as a final result just do not edit that textbox Typing anything on it means that the result is a final one and the text that you supply will be the description for the output which will be the one the user will see when executing the model Selecting the value of each parameter is also a bit different since there are importante differences between the context of the modeler and the toolbox one Let s see how to introduce the values for each type of parameter e Layers raster and vector and tables They are selected from a list but in this case the possible values are not the layers or tables currently loaded in QGIS but the list of model inputs of the correspo
222. ibute the Program or any work based on the Program the recipient automatically receives a license from the original licensor to copy distribute or modify the Program subject to these terms and conditions You may not impose any further restrictions on the recipients exercise of the rights granted herein You are not responsible for enforcing compliance by third parties to this License 7 If as a consequence of a court judgment or allegation of patent infringement or for any other reason not limited to patent issues conditions are imposed on you whether by court order agreement or otherwise that contradict the conditions of this License they do not excuse you from the conditions of this License If you cannot distribute so as to satisfy simultaneously your obligations under this License and any other pertinent obligations then as a consequence you may not distribute the Program at all For example if a patent license would not permit royalty free redistribution of the Program by all those who receive copies directly or indirectly through you then the only way you could satisfy both it and this License would be to refrain entirely from distribution of the Program If any portion of this section is held invalid or unenforceable under any particular circumstance the balance of the section is intended to apply and the section as a whole is intended to apply in other circumstances It is not the purpose of this section to induce you to infrin
223. ication of geospatial technology it is essentially doing geospatial data analysis and listing the results for you 3 1 1 Why is all this so new Well it s not There are many new hardware devices that are enabling mobile geospatial services Many open source geospatial applications are also available but the existence of geospatially focused hardware and software is nothing new Global positioning system GPS receivers are becoming commonplace but have been used in various industries for more than a decade Likewise desktop mapping and analysis tools have also been a major commercial market primarily focused on industries such as natural resource management What is new is how the latest hardware and software is being applied and who is applying it Traditional users of mapping and analysis tools were highly trained GIS Analysts or digital mapping technicians trained to use CAD like tools Now the processing capabilities of home PCs and open source software OSS packages have enabled an army of hobbyists professionals web developers etc to interact with geospatial data The learning curve has come down The costs have come down The amount of geospatial technology saturation has increased How is geospatial data stored In a nutshell there are two types of geospatial data in widespread use today This is in addition to traditional tabular data that is also widely used by geospatial applications 3 1 2 Raster Data One type of geospat
224. ick in the inner area of the polygon The tool will automatically add a node where the new line crosses the border It is also possible to remove part of the area from the polygon starting the new line outside the polygon adding vertices inside and ending the line outside the polygon with a right click Note The reshape tool may alter the starting position of a polygon ring or a closed line So the point that is represented twice will not be the same any more This may not be a problem for most applications but it is something to consider Offset Curves The EN Offset Curve tool is a new editing tool It creates parallel shifts of lines and polygon rings The tool can be applied to the edited layer the geometries are modified or also to background layers creates copies of the lines rings and adds it to the the edited layer It is thus ideally suited for the creation of distance line layers The displacement is shown at the bottom left of the taskbar 11 3 Editing 89 QGIS User Guide Release 1 8 Split Features You can split features using the amp y Split Features split icon on the toolbar Just draw a line across the feature you want to Merge selected features The Merge Selected Features too allows to merge features that have common boundaries and the same attributes Merge attributes of selected features The Merge Attributes of Selected Features too allows to merge attributes of features with
225. ick on the Add Vector Layer toolbar button or press Ctr1 Shift V to open the Add Vector Layer dialog Select 22 Directory Change to Filter m to Arc Info Binary Coverage Navigate to the directory that contains the coverage files and select it Similarly you can load directory based vector files in the UK National Transfer Format as well as the raw TIGER Format of the US Census Bureau 11 1 4 PostGIS Layers PostGIS layers are stored in a PostgreSQL database The advantages of PostGIS are the spatial indexing filter ing and query capabilities it provides Using PostGIS vector functions such as select and identify work more accurately than with OGR layers in QGIS Creating a stored Connection The first time you use a PostGIS data source you must create a connection to the PostgreSQL database that contains the data Begin by clicking on the Add PostGIS Layer toolbar button selecting the Add PostGIS Layer option from the Layer menu or typing Ctr1 Shift D You can also open the Add Vector Layer dialog and select 24 Database The Add PostGIS Table s dialog will be displayed To access the connection manager click on the New button to display the Create a New PostGIS Connection dialog The parameters required for a connection are e Name A name for this connection Can be the same as Database Service Service parameter to be used alternatively to hostname port and potentially database This can be defined in
226. ide Release 1 8 WMS layers rendered by a server are overlaid in the order listed in the Layers section from top to bottom of the list If you want to change the overlay order you can use the tab Layer Order Transparency In this version of QGIS the Global transparency setting from the Layer Properties is hard coded to be always on where available Tip WMS Layer Transparency The availability of WMS image transparency depends on the image encoding used PNG and GIF support trans parency whilst JPEG leaves it unsupported Coordinate Reference System A Coordinate Reference System CRS is the OGC terminology for a QGIS Projection Each WMS Layer can be presented in multiple CRSs depending on the capability of the WMS server To choose a CRS select Change and a dialog similar to Figure Projection 3 in Working with Projections will appear The main difference with the WMS version of the screen is that only those CRSs supported by the WMS Server will be shown Server Search Within QGIS you can search for WMS servers Figure_OGC_2 shows the tab Server Search with the Add Layer s from a Server dialog fo Add Layer s from a Server Y V OG Layers Layer Order Tilese Server Search K OSM Search Tite Description Live Haiti OSM WMS via Mapnik live osm data via tile2 dbseo com contact dbsgeo gmail com OSM Latvia data OSM Latvia data Geofabrik Tools OSM Inspector Addresses OSM Inspector is a debu
227. idget Alias EE NAMES String 80 0 Line edit 3 2 AREA_MI Real 32 3 Line edit qe Attribute Edit Dialog cat IWS CC i Allows to set numeric values from a specified range The edit widget can be either a slider or a spin box Editable ly Minimum fo D Maximum 0 Step o Lx Current minimum for this value is 2147483648 and current maximum is 2147483647 O cana Restore Default Style Save As Default Load Style Save Style P Help OK Apply Cancel Figura 11 19 Dialog to select an edit widget for an attribute column 4b Within the Fields tab you also find an edit widget column This column can be used to define values or a range of values that are allowed to be added to the specific attribute table column If you click on the edit widget button a dialog opens where you can define different widgets These widgets are e Line edit an edit field which allows to enter simple text or restrict to numbers for numeric attributes e Classification Displays a combo box with the values used for classification if you have chosen unique value as legend type in the Style tab of the properties dialog e Range Allows to set numeric values from a specific range The edit widget can be either a slider or a spin box Unique values The user can select one of the values already used in the attribute table If editable is activated a line edit is shown with autocompletion support otherwise a combo box is
228. igura 11 8 Categorized Symbolizing options You can create a custom color ramp choosing New color ramp from the Color ramp dropdown menu A dialog will prompt for the ramp type Gradient Random ColorBrewer then each one has options for number of steps and or multiple stops in the color ramp See figure_symbology_3 for an example of custom color ramp 4 Gradient color ramp VYOS Color 1 Change Color2 M Change v Multiple stops Color Offset v Add stop 00c0co 30 008080 60 Remove stop Preview 2 OK Cancel Figura 11 9 Example of custom gradient color ramp with multiple stops a Graduated Renderer The Graduated Renderer is used to render all the features from a layer using a single user defined symbol whose color reflects the classification of a selected feature s attribute to a class Like Categorized Renderer it allows to define rotation and size scale from specified columns Analogue to the categorized rendered the Style tab allows you to select 66 Cap tulo 11 Working with Vector Data QGIS User Guide Release 1 8 6 Layer Penais anaes JUDO amp Style Labels 7 Reids 4 General J Metadata Actions e joins Diagrams Graduated Y Old symbology Column LENGTH v Symbol Classes 5 Color ramp ff H RayiGn Mode Equal Interval Symbol Range Label 0 0000 1524 0 0000 15240 8438 15240 8438 15240 8438 30481 6876 30481 6876 30481 687
229. illustrated 2005 NETELER M AND MITASOVA H Open source gis A grass gis approach 2008 OGR SOFTWARE SUITE Geospatial data abstraction library http www gdal org ogr 2012 OPEN GEOSPATIAL CONSORTIUM Web map service 1 1 1 implementation specification http portal opengeospatial org 2002 OPEN GEOSPATIAL CONSORTIUM Web map service 1 3 0 implementation specification http portal opengeospatial org 2004 POSTGIS PROJECT Spatial support for postgresql http postgis refractions net 2012 255 QGIS User Guide Release 1 8 256 Cap tulo 22 Literature and Web References Index o 11 Actions 77 Analysis tools 214 annotation 38 apache 112 apache2 112 Arc Info_ASCII_ Grid 99 Arc Info_Binary_Grid 99 ArcInfo_Binary_Coverage 57 attribute table 91 Attribute_Actions 77 Attribute_Table_Selection 92 Avoid_Intersections_Of_Polygons 84 bookmarks 39 Browse_Maps 52 Calculator_Field 95 CAT 105 Categorized_Renderer 65 Centroid_fill 64 CGI 111 Chain 72 change the symbology 70 Colliding_Labels 72 Color_interpolation 102 Color_Ramp 66 Color_ramps 64 ColorBrewer 66 Colormap 102 command line options 17 Common_Gateway_Interface 111 Compose_Maps 179 Composer_Manager 193 Composer_Template 181 Connection_Manager 58 Context help 33 Contrast_enhancement 101 Coordinate_Reference_System 49 108 crashes 195 Create_Maps 179 Create_New_Layers 90
230. imited_text_1 g en Create a Layer from a Delimited Text File y Y Ye File Name home dassau qgis_sample_data cswelevp csv Layer name elevp _ Tal x Space Selected delimiters f i Comma _ Semicolon _ Colon Plain characters Regular expression Start import at row 0 E e XYfields Xfield X y Y field Y ly WKT field ly Sample text Y 2 300120 7689960 13 654360 7562040 52 3 HA J Help Y OK Cancel Figura 19 5 Delimited Text Dialog A First select the file e g qgis_sample_data csv elevp csv to import by clicking on the Browse button Once the file is selected the plugin attempts to parse the file using the last used delimiter in this case a semicolon To properly parse the file it is important to select the correct delimiter To change the delimiter to tab use t this is a regular expression for the tab character Once the file is parsed choose the X and Y fields from the dropdown lists and if available also the WKT field for the CRS information Finally enter a Layer name e g elevp as shown in figure delimited text 1 To add the layer to the map click OK The delimited text file now behaves as any other map layer in QGIS 19 6 Diagram Overlay Plugin y E The Diagram Overlay Plugin allows you to add a graphic overlay to a vector layer see figure overlay 1 It provides additional and not yet implemented features to the Diagrams tab describe
231. in visible in the Status Bar during your entire QGIS session and may cause a program crash when exiting In this case please disable the checkbox In addition you may specify the type of plugins that are displayed by the Python Plugin Installer Under Allowed plugins you can specify whether you would like to e 12 Only show plugins from the official repository e Show all plugins except those marked as experimental e Show all plugins even those marked as experimental Tip Using experimental plugins Experimental plugins are generally unsuitable for production use These plugins are in the early stages of devel opment and should be considered incomplete or proof of concept tools The QGIS development team does not recommend installing these plugins unless you intend to use them for testing purposes 19 1 2 Data Providers Data Providers are special plugins that provides access to a data store By default QGIS supports PostGIS layers and disk based data stores supported by the GDAL OGR library A Data Provider plugin extends the ability of QGIS to use other data sources Data Provider plugins are registered automatically by QGIS at startup They are not managed by the Plugin Manager but used behind the scenes when a data type is added as a layer in QGIS 198 Capitulo 19 Plugins QGIS User Guide Release 1 8 9 N Using QGIS Core Plugins Icon Plugin Description Manual Reference B
232. indexes used by QGIS have a qix extension Use these steps to create the index e Load a shapefile Open the Layer Properties dialog by double clicking on the shapefile name in the legend or by right clicking and choosing Properties from the popup menu In the tab General click the Create Spatial Index button Problem loading a shape prj file If you load a shapefile with prj file and QGIS is not able to read the coordinate reference system from that file you have to define the proper projection manually within the General tab of the Layer Properties dialog of the layer This is due to the fact that prj files often do not provide the complete projection parameters as used in QGIS and listed in the CRS dialog For that reason if you create a new shapefile with QGIS two different projection files are created A prj file with limited projection parameters compatible with ESRI software and a qpj file providing the complete parameters of the used CRS Whenever QGIS finds a qpj file it will be used instead of the prj 11 1 2 Loading a MapInfo Layer To load a MapInfo layer click on the Add Vector Layer toolbar button or type Ctr1 Shi ft V change the file type filter Filter Iv to Mapinfo File OGR and select the MapInfo layer you want to load 11 1 Supported Data Formats 57 QGIS User Guide Release 1 8 11 1 3 Loading an Arcinfo Binary Coverage amp To load an ArcInfo binary coverage cl
233. indow If a supporting document is referenced in the attribute information window and the file path is not highlighted in green then it will be necessary to add an entry for the file s filename extension in the Configure External Applications window If the file path is highlighted in green but does not open when double clicked it will be necessary to adjust the parameters in the Options window so the file can be located by eVis If no compass bearing is provided in the Options window a red asterisk will be displayed on top of the vector feature that is associated with the photograph being displayed If a compass bearing is provided then an arrow will appear pointing in the direction indicated by the value in the compass bearing display field in the Generic Event Browser window The arrow will be centered over the point that is associated with the photograph or other document To close the Generic Event Browser window click on the Close button from the Display window 19 8 5 Event ID Tool The Event ID module allows you to display a photograph by clicking on a feature displayed in the QGIS map window The vector feature must have attribute information associated with it to describe the location and name of the file containing the photograph and optionally the compass direction the camera was pointed when the image was acquired This layer must be loaded into QGIS before running the Event ID tool Launch the Event ID module To launch
234. ines a connection between OSM and QGIS data Each feature of OSM data has some tags pairs of key and value that define the feature properties Each feature of a QGIS vector layer also has its attributes key and value With this option you can define which properties of OSM objects should be visible when displaying detailed information about QGIS features 142 Cap tulo 16 OpenStreetMap QGIS User Guide Release 1 8 Replace current data Checking this option means that new data should replace current data the user is working with Layers of current data will be removed and new ones will be loaded When loading OSM data for the first time this option is not active because there is nothing to replace Use custom renderer This option determines how many details of the map will be used There are three pre defined OSM styles for map displaying Use Small scale if you want to view OSM data at low level to see all details and to edit something If not you can use Medium scale or Large scale QGIS 1 8 0 doesn t support changing the renderer style dynamically Click OK to load your data If this is the first time the OSM file is loaded the plugin must first parse the database This may take few seconds or minutes it depends on the amount of loaded data 16 6 Viewing OSM data After the OSM data are loaded you can identify map features using the appropriate tool Use the Ro A button on the top left of the OSM Featu
235. ing edge release series As such it contains new features and extends the programmatic interface over QGIS 1 0 x and QGIS 1 7 0 We recommend that you use this version over previous releases This release includes hundreds of bug fixes and many new features and enhancements that will be described in this manual QGIS Browser A stand alone app and a new panel in QGIS The browser lets you easily navigate your file system and connection based PostGIS WFS etc datasets preview them and drag and drop items into the canvas DB Manager The DB manager is now officially part of QGIS core You can drag layers from the QGIS Browser into DB Manager and it will import your layer into your spatial database Drag and drop tables between spatial databases and they will get imported You can use the DB Manager to execute SQL queries against your spatial database 4 7 What s new in the version 1 8 11 QGIS User Guide Release 1 8 and then view the spatial output for queries by adding the results to QGIS as a query layer You can also create edit delete and empty tables and move them to another schema Terrain Analysis Plugin A new core plugin was added for doing terrain analysis slope aspect hillshade relief and ruggedness index New symbol layer types e Line Pattern Fill e Point Pattern Fill e Ellipse renderer render ellipse and also rectangles triangles crosses New plugin repository Note that the old repository is now no
236. ing the layout process it is possible to revert and restore changes This can be done with the revert and restore tools N Revert last changes 3 Restore last changes or by mouse click within the Command history tab see figure_composer_9 Item Properties Command history SQXWAQ9 RsCSZERNAMORBBAL Command history Item deleted L d Legend added egen Change item position Label added maj rivers Change item position Change item position Change item position Change item position E Change item position trails Rotation synchronisation toggled Change item position Change item position change item position E Change item position airports Rotation synchronisation toggled Change item position 8 Legend item removed Change item position Change item position lakes Scalebar map changed Scale bar added E Change item position Change item position Scalebar segment size alaska Scalebar segments left Scalebar n segments Change item position Change item position Change item position Scalebar style changed Scalebar style changed Scalebar segments left Scalebar map units per segment Composition so a Ei Paper and quality Size aq 210x297 mm v width 297 00 Heignt210 00 mm Y Orientation Landscape y Figura 18 15 Command history in the Print Composer A 18 7 Add Basic shape and Arrow
237. ins l Diagrams Point displacement v Old symbology _ Center symbol Renderer Single Symbol Renderer settings Displacement circles Circle pen width 0 40 Circle color Circle radius modification 0 00 Point distance tolerance 0 0000100 Labels Label attribute ELEV Label font Label color Use scale dependent labelling max scale denominator Restore Default Style Save As Default Load Style Save Style P Hep Y OK Cancel Figura 11 12 Point displacement dialog Symbol Properties The symbol properties dialog allows the user to specify different properties of the symbol to be rendered In the bottom left part of the dialog you find a preview of the current symbol as it will be displayed in the map canvas Above the preview is the list of symbol layers To start the Symbol properties dialog click the Change button in the Style tab of the Layer Properties dialog The buttons allow adding or removing layers changing the position of layers or locking layers for color changes In the right part of the dialog there are shown the settings applicable to the single symbol layer selected in the v symbol layer list The most important is the Symbol Layer Type combobox which allows you to choose the layer type The available options depend on the layer type Point Line Polygon The symbol layer type options are described in section vector_symbol_types Y
238. ion Bw yy Connection details Name Alaska URL http Mocalhost cgi bin qgis_mapserv fcgl If the service requires basic authentication enter a user name and optional password User name Password _ Ignore GetMap URI reported in capabilities Ignore GetFeatureinfo URI reported in capabilities E Help Y OK Cancel Scale 1 31797981 v Qf W Render EPSG 2664 Figura 13 4 Standard WMS with USA boundaries included in the qgis server KDE 13 2 2 Creating a WMS WFS from a QGIS project To provide a new qgis wms wfs server we have to create a qgis project file with some data Here we use the alaska shapefile from the qgis_sample_dataset Define the colors and styles of the layers in QGIS and define the project CRS if not already done Then open the OWS Server tab in the menu Settings gt Project Properties and define the general fields under Service Capabilities For WMS Capabilities define Coordinate System Restrictions and Advertised Ex tend Additionally you can enable the checkbox Y Add WKT geometry to feature into response to make the lay ers queryable and add a Maximum width and height that can be requested For WFS Capabilities you only need to select the layers that you want to provide as WFS Now save the session in a project file alaska qgs To provide the project as a WMS WES we create a new folder usr lib cgi bin project with admin privileges and add the project
239. ion View Show Bookmarks The Geospatial Bookmarks dialog allows you to zoom to or delete a bookmark You can not edit the bookmark name or coordinates 7 7 3 Zooming to a Bookmark From the Geospatial Bookmarks dialog select the desired bookmark by clicking on it then click Zoom To You can also zoom to a bookmark by double clicking on it 7 7 4 Deleting a Bookmark To delete a bookmark from the Geospatial Bookmarks dialog click on it then click Delete Confirm your choice by clicking Yes or cancel the delete by clicking No 7 8 Nesting Projects If you want to embed content from other project files into your project you can choose Layer Embed Layers and Groups 7 8 1 Embedding layers The following dialog allows you to embed layers from other projects 1 Press to look for another project from the Alaska dataset 2 Select the project file grassland You can see the content of the project see figure_embed_dialog 3 Press Ctrl and klick on the layers grassland and regions The layers are embedded in the map legend and the map view now Project file 5sau alaska_grassland qgs regions grassland OK Cancel Figura 7 10 Select layers and groups to embed A While the embedded layers are editable you can t change it s properties like Style and Labeling Removing embedded layers Right click on the embedded layer and choose Remove 40 Cap tulo 7 General Tools CA
240. ion to the Oracle database that contains the data To do this begin by clicking on the Select GeoRaster toolbar button it will open the Select Oracle Spatial GeoRaster dialog window Click on New to open the dialog window and specify the connection parameters See Figure oracle raster 1 Name Enter a name for the database connection 19 15 Oracle GeoRaster Plugin 229 QGIS User Guide Release 1 8 e Database instance Enter the name of the database that you will connect to e Username Specify your own username that you will use to access the database e Password The password associated with your username that is required to access the database g Create Oracle Connection 5 x Name example Database instance orcl Username scott Password e Y Save Password O cance Figura 19 25 Create Oracle connection dialog Now back on the main Oracle Spatial GeoRaster dialog window see Figure_oracle_raster_2 use the drop down list to choose one connection and use the Connect button to establish a connection You may also Edit the connection by opening the previous dialog and making changes to the connection information or use the Delete button to remove the connection from the drop down list 19 15 2 Selecting a GeoRaster Once a connection has been established the sub datasets window will show the names of all the tables that contains GeoRaster columns in that database in the format of a GDAL subdataset
241. is Slope Calculates slope angle for each cell in degrees based on first order derivative estimation Aspect Exposition starting with O for north direction in degrees counterclockwise Hillshade Create shaded map using light and shadow to provide a more three dimensional appearance for a shaded relief map Ruggedness Index A quantitative measurement of terrain heterogeneity as described by Riley et al 1999 It is calculated for every location by summarizing the change in elevation within the 3x3 pixel grid e Relief Creating a shaded relief map from digital elevation data Implemented is a method to choose the elevation colors analysing the frequency distribution 19 16 Raster Terrain Analysis Plugin 231 QGIS User Guide Release 1 8 ter View Layer Settings Plugins ac en aX 1448825 88 CPP ERR Paio AN SODOBLANROOC ZEAL ROP ce MPAARAAARL gt de gt gt Layers ox 54 gtopo30 4 Y Slope Elevation layer gtopo30 Output layer 1qgis_sample_data grassdata slope Output format GeoTIFF o Z factor 1 0 TE Add result to project Y OK Cancel 389018 v Qf v Render EPsG 2001 A Figura 19 27 Raster Terrain Modelling Plugin slope calculation 19 16 1 Using the plugin 1 Start QGIS and load the gtopo30 raster layer from the GRASS sample location 2 Load the Raster Terrain Analysis plugin in the Plugin Manager see Section Loading a OGIS Core Plugin 3 Select an analysis meth
242. is definition and creates a new tab inside the toolbox when you select the module A more detailed description for adding new modules changing the modules group etc can be found on the QGIS wiki at http hub ggis org projects quantum gis wiki Adding New Tools to the GRASS Toolbox 15 9 The GRASS toolbox 137 QGIS User Guide Release 1 8 138 Cap tulo 15 GRASS GIS Integration CAPITULO 16 OpenStreetMap In recent years the OpenStreetMap project has gained popularity because in many countries no free geodata such as digital roadmaps are available The objective of the OSM project is to create a free editable map of the world from GPS data aerial photography or from local knowledge To support this objective QGIS provides a plugin that enables its users to work with OSM data The OpenStreetMap plugin a core QGIS plugin provides the basic functionalities for OSM data manipulation this includes data loading importing saving downloading editing and uploading data back to the OpenStreetMap server While implementing the OSM plugin an inspiration was taken from existing OSM data editors The purpose was to combine their functionalities to get the best possible result The following section gives a brief introduction to principles of the OSM project Parts of the following paragraphs are copied from the OpenStreetMap web site at http www openstreetmap org 16 1 The OpenStreetMap project OpenStreetMap is a project
243. it has to be saved and the modeler dialog closed to allow the toolbox to refresh its contents 162 Cap tulo 17 SEXTANTE QGIS User Guide Release 1 8 SEXTANTE Modeler 0 x Inputs Algorithms Enter model name here Enter group name here Design Python code El lg Modeler fa ic E DEM Slope Aspect Curvature Catchment Area Flow Tracing Transformation U Topographic Wetness Index TWI els rology E E in E E phometry a El Jerraio Analvsis Profiles JEL CJ Figura 17 19 Model Parameters 7 17 3 4 Saving and loading models Use the Save button to save the current model and the Open one to open any model previously saved Model are saved with the mode1 extension If the model has been previously saved from the modeler window you will not be prompted for a filename since there is already a file associated with that model and it will be used Before saving a model you have to enter a name and a group for it using the text boxes in the upper part of the window Models saved on the mode1s folder the default folder when you are prompted for a filename to save the model will appear in the toolbox in the corresponding branch When the toolbox is invoked SEXTANTE searches the models folder for files with model extension and loads the models they contain Since a model is itself a SEXTANTE algorithm it can be added to the toolbox just like any other algorithm
244. itive values and west declinations should use negative values 4 Directory base path The base path onto which the relative path defined in Figure_eVis_2 A will be appended 5 Replace path If this checkbox is checked only the file name from the A will be appended to the Base Path 6 Apply rule to all documents If checked the same path rules that are defined for photographs will be used for non image documents such as movies text documents and sound files If not checked the path rules will only apply to photographs and other documents will ignore the Base Path parameter 7 Save settings If the checkbox is checked the values for the associated parameters will be saved for the next session when the window is closed or when the Save button below is pressed 8 Reset values Resets the values on this line to the default setting 9 Restore faults This will reset all of the fields to their default settings It has the same effect as clicking all of the Reset buttons 10 Save This will save the settings without closing the Options pane Understanding the Configure External Applications window Generic Event Browser Displaying records 01 of 01 E 2 x Display Options Configure External Applications About File extension and external application in which to load a document of that type bol IL A A Figura 19 11 The eVis External Applications window 7 1 File reference table A table containing fi
245. itten in C that works together with a webserver e g Apache Lighttpd It is funded by the EU projects Orchestra Sany and the city of Uster in Switzerland It uses QGIS as backend for the GIS logic and for map rendering Furthermore the Qt library is used for graphics and for platform independent C programming In contrast to other WMS software the QGIS Server uses carto graphic rules as a configuration language both for the server configuration and for the user defined cartographic tules Moreover the QGIS Server project provides the Publish to Web plugin a plugin for QGIS desktop which exports the current layers and symbology as a web project for QGIS Server containing cartographic visualization rules expressed in SLD As QGIS desktop and QGIS Server use the same visualization libraries the maps that are published on the web look the same as in desktop GIS The Publish to Web plugin currently supports basic symbolization with more complex cartographic visualization rules introduced manually As the configuration is performed with the SLD standard and its documented extensions there is only one standardised language to learn which greatly simplifies the complexity of creating maps for the Web In one of the following manuals we will provide a sample configuration to set up a QGIS Server But for now we recommend to read one of the following URLs to get more information 13 2 QGIS Server 111 QGIS User Guide Relea
246. ity will not be described here 15 3 1 Creating a new GRASS LOCATION As an example here is how the sample GRASS LOCATION alaska which is projected in Albers Equal Area projection with unit feet was created for the QGIS sample dataset This sample GRASS LOCATION alaska 122 Capitulo 15 GRASS GIS Integration QGIS User Guide Release 1 8 GRASS Database LOCATION MAPSET Geometry and attribute data Raster layers home user grassdata irports aska __ Vector layers Figura 15 1 GRASS data in the alaska LOCATION will be used for all examples and exercises in the following GRASS GIS related chapters It is useful to download and install the dataset on your computer Sample Data l 2 Start QGIS and make sure the GRASS plugin is loaded Visualize the alaska shp Shapefile see Section Loading a Shapefile from the QGIS alaska dataset Sample Data In the GRASS toolbar click on the Moo mapset icon to bring up the MAPSET wizard Select an existing GRASS database GISDBASE folder grassdata or create one for the new LOCATION using a file manager on your computer Then click Next We can use this wizard to create a new MAPSET within an existing LOCATION see section Adding a new MAPSET or to create a new LOCATION altogether Click on the radio button Create new location see figure_grass_location_2 Enter a name for the LOCATION we used alaska and click Next
247. izard 3 Select the GRASS database GISDBASE folder grassdata with the LOCATION alaska where we want to add a further MAP SET called test 4 Click Next 5 We can use this wizard to create a new MAPSET within an existing LOCATION or to create a new LOCATION altogether Click on the radio button Select location see figure_grass_location_2 and click Next 6 Enter the name text for the new MAPSET Below in the wizard you see a list of existing MAPSETs and its Owners 7 Click Next check out the summary to make sure it s all correct and click Finish 15 4 Importing data into a GRASS LOCATION This Section gives an example how to import raster and vector data into the alaska GRASS LOCATION provided by the QGIS alaska dataset Therefore we use a landcover raster map landcover img and a vector GML File 124 Capitulo 15 GRASS GIS Integration QGIS User Guide Release 1 8 lakes gml from the QGIS alaska dataset Sample Data 1 Start QGIS and make sure the GRASS plugin is loaded 2 In the GRASS toolbar click the BYoren MAPSET icon to bring up the MAPSET wizard 3 Select as GRASS database the folder grassdata in the QGIS alaska dataset as LOCATION alaska as MAPSET demo and click OK SM open GRASS tools 4 Now click the pen 20 icon The GRASS Toolbox see section The GRASS toolbox dialog appears 5 To import the raster map landcover img click the module r in gdal in
248. ization as the authoritative definition of a standard You may add a passage of up to five words as a Front Cover Text and a passage of up to 25 words as a Back Cover Text to the end of the list of Cover Texts in the Modified Version Only one passage of Front Cover Text and one of Back Cover Text may be added by or through arrangements made by any one entity If the Document already includes a cover text for the same cover previously added by you or by arrangement made by the same entity you are acting on behalf of you may not add another but you may replace the old one on explicit permission from the previous publisher that added the old one The author s and publisher s of the Document do not by this License give permission to use their names for publicity for or to assert or imply endorsement of any Modified Version 5 COMBINING DOCUMENTS You may combine the Document with other documents released under this License under the terms defined in section 4 above for modified versions provided that you include in the combination all of the Invariant Sections of all of the original documents unmodified and list them all as Invariant Sections of your combined work in its license notice and that you preserve all their Warranty Disclaimers The combined work need only contain one copy of this License and multiple identical Invariant Sections may be replaced with a single copy If there are multiple Invariant Sections with the same name but
249. l on your system You can save the layout as template and load it again in another session See a list of tools in table_composer_1 Icon Purpose Icon Purpose Lis la IE PST HOP SAO Es E EI Load from template Export to an image format Export print composition to SVG Zoom to full extent Zoom out Revert last change Y EE 2021 Save as template Export as PDF Print or export as Postscript Zoom in Refresh view Restore last change Add new map from QGIS map canvas Lea Add image to print composition Add label to print composition Add new legend to print composition Add new scalebar to print composition Add arrow to print composition Select Move item in print composition Group items of print composition Raise selected items Move selected items to top Align selected items left Align selected items center Align selected items top w 3 lil Y PA O Add basic shape to print composition Add attribute table to print composition Move content within an item Ungroup items of print composition Lower selected items Move selected items to bottom Align selected items right Align selected items center vertical Align selected items bottom Table Composer 1 Print Composer Tools All Print Composer tools are available in menus and as icons in a toolbar The toolbar can be switched off and on using the right mouse button holding the mouse over the toolbar 181
250. l polygons The key feature of polygons is that there is a fixed area within them 3 1 Introduction To GIS 7 QGIS User Guide Release 1 8 8 Cap tulo 3 Foreword CAP TULO 4 Features QGIS offers many common GIS functionalities provided by core features and plugins As a short summary they are presented in six categories to gain a first insight 4 1 View data You can view and overlay vector and raster data in different formats and projections without conversion to an internal or common format Supported formats include 4 2 Spatially enabled tables and views using PostGIS SpatiaLite and MSSQL Spatial vector formats supported by the installed OGR library including ESRI shapefiles MapInfo SDTS GML and many more see section Working with Vector Data Raster and imagery formats supported by the installed GDAL Geospatial Data Abstraction Library library such as GeoTiff Erdas Img ArcInfo Ascii Grid JPEG PNG and many more see section Working with Raster Data GRASS raster and vector data from GRASS databases location mapset see section GRASS GIS Integra tion Online spatial data served as OGC compliant Web Map Service WMS or Web Feature Service WFS see section Working with OGC Data OpenStreetMap data see section OpenStreetMap Explore data and compose maps You can compose maps and interactively explore spatial data with a friendly GUI The many helpful tools available in the GUI inc
251. l try to find a column in the view that is derived from a suitable table column It does this by parsing the view definition SQL However there are several aspects of SQL that QGIS ignores these include the use of table aliases and columns that are generated by SQL functions If a suitable column cannot be found QGIS will not load the layer If this occurs the solution is to alter the view so that it does include a suitable column a type of int4 and either a primary key or with a unique constraint preferably indexed 11 1 5 Importing Data into PostgreSQL Data can be imported into PostgreSQL PostGIS using several tools such as the SPIT plugin or the command line tools shp2pgsql or ogr2ogr SPIT Plugin QGIS comes with a core plugin named la SPIT Shapefile to PostGIS Import Tool SPIT can be used to load multiple shapefiles at one time and includes support for schemas See Section SPIT Plugin for more information shp2pgsdl PostGIS includes a utility called shp2pgsql that can be used to import shapefiles into a PostGIS enabled database For example to import a shapefile named lakes shp into a PostgreSQL database named gis data use the following command shp2pgsql s 2964 lakes shp lakes new psql gis data This creates a new layer named lakes newinthe gis data database The new layer will have a spatial ref erence identifier SRID of 2964 See Section Working with Projections for more information on spatial reference systems a
252. labeling so position conflicts between diagrams and labels are detected and solved In addition to chart positions can be fixed by the users hand A Layer Properties climate UD Style Labels Fields 4 General QJ Metadata amp Actions e joins 1 Diagrams lt gt y Display diagrams Diagram type Text diagram _v Priority Low High Appearance _ Scale dependent visibility Minimum 1 Maximum 1 Background color Pen color MN Pen width 0 30000 Font Size v Fixed size 18 00 O Size units mm v inearly between 0 and the following attribute value Position Placement AroundPoint v Line Options Distance 1 00 gt Data defined position x None v y None v Attributes ID y Attribute Color T_F_ JAN TFJUL T_F_MEAN A Restore Default Style Save As Default Load Style Save Style Es Help 2 OK Apply Cancel Figura 11 25 Vector properties dialog with diagram tab We will demonstrate an example and overlay the alaska boundary layer a text diagram showing some temperature data from a climate vector layer Both vector layers are part of the QGIS sample dataset see Section Sample Data 1 First click on the Load Vector icon browse to the QGIS sample dataset folder and load the two vector shape layers alaska shp and climate shp 2 Double click the climate layer in the map legend to open the Layer Properties dialog 9 3 Click on the Diagrams tab activate Display diagrams
253. lat 2 65 lat_0 50 lon_0 154 x_0 0 y_0 0 datum NAD27 units us ft no_defs Figura 10 1 Qgis browser as a standalone application to view metadata preview and attributes 5 Use QGIS Browser to preview your data The drag and drop function makes it easy to get your data into the Map view and the Map legend 1 Activate QGIS Browser Right click on the tool bar and click Browser Klick on the Browser tab YD wR wW HD Projections Drag the panel into the legend window Browse in your database and choose the shapefile folder from qgis_sample_data Press the Shift key and klick on airports shp and alaska shp Press the left mouse button then drag and drop the files into the map canvas Right click on a layer and choose Set project CRS from layer For more information see Working with 53 QGIS User Guide Release 1 8 8 Click on X Zoom Full to make the layers visible It s also possible to run QGIS Browser as a standalone application Start qgis browser A Type in qbrowser at a command prompt 7 Start QGIS browser using the Start menu or desktop shortcut or double click on a QGIS project file X QGIS browser is not available yet from your your Applications folder However it can eas ily be made available In Finder use Go gt Go to map and use it to find the folder Applications QGIS app Contents MacOS bin Use the key combination option command and drag qbrowser app whil
254. le Download Cancel Figura 16 6 OSM download dialog Open data automatically after download Determines if the download process should be followed by loading bh the data process or not If you prefer not to load data now you can do it later by using the Load OSM from fle button Replace current data This option is active only if 8 Open data automatically after download is checked Checking this option means that downloaded data should replace current data we are working with now Layers of the current data will be removed and new ones will be loaded When starting QGIS and downloading OSM data for the first time this option is initially inactive because there is nothing to replace Use custom renderer This option is active only if the Open data automatically after download checkbox 1s checked It determines how many details will be in the map There are three predefined OSM styles for map displaying Use Small scale if you want to view OSM data at low level to see all details and to edit something If not you can use Medium scale or Large scale QGIS 1 8 0 does not support changing the renderer style dynamically Click the Download button to start the download process A progress dialog will continuously inform you about how much of data is already downloaded When an error occurs during the download process a dialog tells you why When action finishes successfully both the progress dialog and d
255. le and batch mode are supported For more information please visit utility page at GDAL site http www gdal org gdalwarp html amp Extract This utility helps you to extract projection information from an input file If you want to projection extract projection from a whole directory you can use the Batch mode It creates both prj and wld files 19 10 GDAL Tools Plugin 217 QGIS User Guide Release 1 8 Conversion gt This program burns vector geometries points lines and polygons into the raster band s of a Rasterize raster image Vectors are read from OGR supported vector formats Note that the vector data must in the same coordinate system as the raster data on the fly reprojection is not provided For more information see http www gdal org gdal rasterize html a Poly This utility creates vector polygons for all connected regions of pixels in the raster sharing a gonize common pixel value Each polygon is created with an attribute indicating the pixel value of that polygon The utility will create the output vector datasource if it does not already exist defaulting to ESRI shapefile format See also http www gdal org gdal_polygonize html 5 This utility can be used to convert raster data between different formats potentially performing Translate some operations like subsettings resampling and rescaling pixels in the process For more information you can read on http www gdal org gdal_translate ht
256. le tab of the Layer properties and the expression based labeling a Sa i o in the SS Labeling core application 11 5 Field Calculator 97 QGIS User Guide Release 1 8 98 Cap tulo 11 Working with Vector Data CAPITULO 12 Working with Raster Data 12 1 Working with Raster Data This Section describes how to visualize and set raster layer properties QGIS uses the GDAL library to read and write raster data formats including Arc Info Binary Grid Arc Info ASCII Grid GeoTIFF Erdas Imagine and many more GRASS raster support is supplied by a native QGIS data provider plugin The raster data can also be loaded in read mode from zip and gzip archives into QGIS At the date of this document more than 100 raster formats are supported by the GDAL library see GDAL SOFTWARE SUITE Literature and Web References A complete list is available at http www gdal org formats_list html Note Not all of the listed formats may work in QGIS for various reasons For example some require external commercial libraries or the GDAL installation of your OS was not built to support the format you want to use Only those formats that have been well tested will appear in the list of file types when loading a raster into QGIS Other untested formats can be loaded by selecting the GDAL All files x filter Working with GRASS raster data is described in Section GRASS GIS Integration 12 1 1 What is raster data Raster data i
257. le there is just no other field available that would make sense to search for You can define multiple actions for a layer and each will show up in the Identify Results dialog You can think of all kinds of uses for actions For example if you have a point layer containing locations of images or photos along with a file name you could create an action to launch a viewer to display the image You could also use actions to launch web based reports for an attribute field or combination of fields specifying them in the same way we did in our Google search example We can also make more complex examples for instance on how to use Python actions Usually when we create an action to open a file with an external application we can use absolute paths or even tually relative paths in the second case the path is relative to the location of the external program executable file But what about we need to use relative paths relative to the selected layer a file based one like a shapefile or spatialite The following code will do the trick command firefox imagerelpath images test test image jpg layer qgis utils iface activeLayer import os path layerpath layer source if layer providerType ogr else qgis core QgsDataSourceURI layer source database if layer providerType spatialite else None path os path dirname str layerpath image os path join path imagerelpath import subprocess
258. le types that can be opened using eVis Each file type needs a file extension and the path to an application that can open that type of file This provides the capability of opening a broad range of files such as movies sound recordings and text documents instead of only images 2 Add new file type Add a new file type with a unique extension and the path for the application that can open the file 3 Delete current row Delete the file type highlighted in the table and defined by a file extension and a path to an associated application 19 8 2 Specifying the location and name of a photograph The location and name of the photograph can be stored using an absolute or relative path or a URL if the pho tograph is available on a web server Examples of the different approaches are listed in Table evis_examples 19 8 eVis Plugin 207 QGIS User Guide Release 1 8 X Y FILE BEARING 780596 1784017 C Workshop eVis_Data groundphotos DSC_0168 JPG 275 780596 1784017 groundphotos DSC_0169 JPG 80 780819 1784015 http biodiversityinform org testdata DSC_0170 JPG 10 780596 1784017 pdf http www test com attach php attachment_id 12 76 19 8 3 Specifying the location and name of other supporting documents Supporting documents such as text documents videos and sound clips can also be displayed or played by eVis To do this it is necessary to add an entry in the file reference table that can be accessed from the Configure External Appli
259. lib cgi bin mytest map gt IF this mapfile is accessible by your mapserver you should be able to see the capabilities by Firing this url http localhost cgi bin mapserv MAP usr lib cgi bin mytest map amp SERVICE WMS amp VERSION 1 1 1 amp REQUEST GetCapabilities gt if this mapfile is accessible by your mapserver you should be able to see a map by firing this url http localhost cgi bin mapserv MAP usr lib cgi bin mytest map amp LAYERS ALL amp MODE MAP Figura 19 22 Export to MapServer Succesfull Dialog 4S You can view the map file in any text editor or visualizer If you take a look you ll notice that the export tool adds the metadata needed to enable our map file for WMS 19 13 3 Troubleshooting If you get error messages from mapserver like loadSymbolSet Unable to access file symbols symbols txt or msLoadFontset Unable to access file Error opening fontset fonts fonts txt This means that that the map file is requesting for fonts or symbol definition files but that Mapserver cannot find those Either comment the lines containing those names in the map file this is possible if you do not have labels or use styles from the symbols txt Or create those files see below The most simple fonts txt file because arial is used in the QGIS generated map files contains the following line either relative to the map file or a full path arial usr share fonts truetype msttcorefonts arial ttf The
260. ll descriptive name Calling the method with saga slopeaspectcurvature as parameter you get the following description gt gt gt sextante alghelp saga slopeaspectcurvature ALGORITHM Slope Aspect Curvature ELEVATION lt ParameterRaster gt ETHOD lt ParameterSelection gt SLOPE lt OutputRaster gt ASPECT lt OutputRaster gt CURV lt OutputRaster gt HCURV lt OutputRaster gt VCURV lt OutputRaster gt Now you have everything you need to run any algorithm As we have already mentioned there is only one single command to execute algorithms runalg Its syntax is as follows gt gt gt sextante runalg name_of_the_algorithm paraml param2 paramN Outputl Output2 OutputN The list of parameters and outputs to add depends on the algorithm you want to run and is exactly the list that the alghelp method gives you in the same order as shown Depending on the type of parameter values are introduced differently The next one is a quick review of how to introduce values for each type of input parameter e Raster Layer Vector Layer or Table Simply use a string with the name that identifies the data object to use the name it has in the QGIS Table of Contents or a filename if the corresponding layer is not opened it will be opened but not added to the map canvas If you have an instance of a QGIS object representing the layer you can also pass it as parameter If the input is optional and
261. llowing copyright and license notices just after the title page Copyright O YEAR YOUR NAME Permission is granted to copy distribute and or modify this document under the terms of the GNU Free Documentation License Version 1 3 or any later version published by the Free Software Foundation with no Invariant Sections no Front Cover Texts and no Back Cover Texts A copy of the license is included in the section entitled GNU Free Documentation License If you have Invariant Sections Front Cover Texts and Back Cover Texts replace the with Texts line with this with the Invariant Sections being LIST THEIR TITLES with the Front Cover Texts being LIST and with the Back Cover Texts being LIST If you have Invariant Sections without Cover Texts or some other combination of the three merge those two alternatives to suit the situation If your document contains nontrivial examples of program code we recommend releasing these examples in parallel under your choice of free software license such as the GNU General Public License to permit their use in free software 21 2 GNU Free Documentation License 253 QGIS User Guide Release 1 8 254 Cap tulo 21 Appendix CAP TULO 22 Literature and Web References GDAL SOFTWARE SUITE Geospatial data abstraction library htt www gdal org 2012 GRASS PROJECT Geographic ressource analysis support system http grass osgeo org 2012 MITCHELL T Web mapping
262. longer supported by default plugin authors are kindly requested to move their plugins to the new repository Get the QGIS Plugins list at http plugins qgis org plugins More new features Support for nesting projects within other projects to embed content from other project files Group Selected Option to group layers to a group Message log Lets you keep an eye on the messages QGIS generates during loading and operation GUI Customization Allows setting up simplified QGIS interface by hiding various components of main window and widgets in dialogs Action Tool is now accessible from the map tools toolbar and allows you to click on a vector feature and execute an action New scale selector select from a list of predefined scales Pan To Selected tool Pans the map to selected feature s does not change the zoom level Copy and paste styles between layers Updated CRS selector dialog Define Legend independent drawing order MSSQL Spatial Support you can now connect to your Microsoft SQL Server spatial databases using QGIS Print Composers allows to have multiple lines on legend items using a specified character Expression based labeling Heatmap Plugin a new core plugin has been added for generating raster heatmaps from point data The GPS live tracking user interface was overhauled and many fixes and improvements were added to it The menu was re organised a little we now have separate menus for Vector Raster Web and many
263. lso TauDEM works fine with OpenMPI so you can use it instead of MPICH2 Download TauDEM 5 0 6 source code and extract files in some folder Open linearpart h file and add after line include mpi h add new line with tinclude lt stdint h gt so you ll get include mpi h tinclude lt stdlib h gt Save changes and close file Now open tiff10 h find line include stdint h and replace quotes with lt gt so you ll get include lt stdint h gt Save changes and close file Create build directory and cd into it mkdir build cd build Configure your build with command CXX mpicxx cmake DCMAKE INSTALL PREFIX usr local and then compile make Finaly to install TauDEM into usr local bin run 178 Cap tulo 17 SEXTANTE QGIS User Guide Release 1 8 sudo make install 17 7 Configuring external applications 179 QGIS User Guide Release 1 8 180 Cap tulo 17 SEXTANTE CAPITULO 18 Print Composer The print composer provides growing layout and printing capabilities It allows you to add elements such as the QGIS map canvas legend scalebar images basic shapes arrows and text labels You can size group align and position each element and adjust the properties to create your layout The layout can be printed or exported to image formats Postscript PDF or to SVG export to SVG is not working properly with some recent Qt4 versions You should try and check individua
264. lude QGIS browser On the fly projection Map composer Overview panel Spatial bookmarks Identify select features Edit view search attributes Feature labeling Change vector and raster symbology Add a graticule layer now via fTools plugin and as decoration QGIS User Guide Release 1 8 e Decorate your map with a north arrow scale bar and copyright label e Save and restore projects 4 3 Create edit manage and export data You can create edit manage and export vector maps in several formats Raster data have to be imported into GRASS to be able to edit and export them into other formats QGIS offers the following Digitizing tools for OGR supported formats and GRASS vector layer Create and edit shapefiles and GRASS vector layers Geocode images with the Georeferencer plugin GPS tools to import and export GPX format and convert other GPS formats to GPX or down upload directly to a GPS unit on Linux usb has been addedto list of GPS devices Visualize and edit OpenStreetMap data Create PostGIS layers from shapefiles with the SPIT plugin Improved handling of PostGIS tables Manage vector attribute tables with the new attribute table see section Working with the Attribute Table or Table Manager plugin Save screenshots as georeferenced images 4 4 Analyse data You can perform spatial data analysis on PostgreSQL PostGIS and other OGR supported formats using the fTools Python plugin QGIS currently offers
265. lue Double clicking on the color column opens the dialog Select color where you can select a color to apply on that value Further you can also add labels for each color but this value won t be displayed when you use the identify feature tool You can also click on the button E Load color map from band which tries to load the table from the band if it has any E x And you can use the buttons 58 Load color map from file gr Export color map to file load an existing color table or to save the defined color table for other sessions The block Generate new color map allows you to create newly categorized colormaps You only need to select 1 00 gt IV the number of entries and press the button Classify Currently only one Classification mode is supported Equal interval 102 Cap tulo 12 Working with Raster Data QGIS User Guide Release 1 8 12 2 4 General Tab The General tab displays basic information about the selected raster including the layer source and display name in the legend which can be modified This tab also shows a thumbnail of the layer its legend symbol and the palette Additionally scale dependent visibility can be set in this tab You need to check the checkbox and set an appropri ate scale where your data will be displayed in the map canvas Also the coordinate reference system CRS is printed here as a PROJ 4 string This can be modified by hitting the Specify button 12 2
266. ly we maintain a WIKI web site at http hub qgis org projects quantum gis wiki where you can find a variety of useful information relating to QGIS development release plans links to download sites message translation hints and so on Check it out there are some goodies inside 20 4 Blog 243 QGIS User Guide Release 1 8 244 Cap tulo 20 Help and Support CAP TULO 21 Appendix 21 1 GNU General Public License Version 2 June 1991 Copyright C 1989 1991 Free Software Foundation Inc 59 Temple Place Suite 330 Boston MA 02111 1307 USA Everyone is permitted to copy and distribute verbatim copies of this license document but changing it is not allowed Preamble The licenses for most software are designed to take away your freedom to share and change it By contrast the GNU General Public License is intended to guarantee your freedom to share and change free software to make sure the software is free for all its users This General Public License applies to most of the Free Software Foundation s software and to any other program whose authors commit to using it Some other Free Software Foundation software is covered by the GNU Library General Public License instead You can apply it to your programs too When we speak of free software we are referring to freedom not price Our General Public Licenses are designed to make sure that you have the freedom to distribute copies of free software and charg
267. m is finished That is the reason why although the runalg method does not load the layers it produces the final TWI layer will be loaded since it is saved to the file entered by the user which is the value of the corresponding output Do not use the load method in your script algorithms but just when working with the console line If a layer is created as output of an algorithm it should be declared as such Otherwise you will not be able to properly use the algorithm in the modeler since its syntax as defined by the tags explained above will not match what the algorithm really creates Hidden outputs numbers and strings do not have a value Instead it is you who has to assign a value to them To do so just set the value of a variable with the name you used to declare that output For instance if you have used this declaration 17 5 Using SEXTANTE from the console 171 QGIS User Guide Release 1 8 average output number the following line will set the value of the output to 5 average 5 In addition to the tags for parameters and outputs you can also define the group under which the algorithm will be shown using the group tag If you algorithm takes a long time to process it is a good idea to inform the user You have a global named progress available with two available methods setText text and setPercentage percent to modify the progress text and the progress bar Several examples are provided with
268. m selection within subsets Random points Regular points Vector grid Select by location Polygon from layer extent Randomly select n number of features or n percentage of features Randomly select features within subsets based on a unique ID field Generate pseudo random points over a given input layer Generate a regular grid of points over a specified region and export them as a point shapefile Generate a line or polygon grid based on user specified grid spacing Select features based on their location relative to another layer to form a new selection or add or subtract from the current selection Create a single rectangular polygon layer from the extent of an input raster or vector layer Table Ftools 2 fTools Research tools 19 9 3 Geoprocessing tools Icon Tool Purpose D Convex hull s Create minimum convex hull s for an input layer or based on an ID field e Buffer s Create buffer s around features based on distance or distance field AS Intersect Overlay layers such that output contains areas where both layers intersect amp Union Overlay layers such that output contains intersecting and non intersecting areas amp Symmetrical Overlay layers such that output contains those areas of the input and difference difference layers that do not intersect if 5 Clip Overlay layers such that output contains areas that intersect the clip layer O Difference Overlay layers such that o
269. me Username to access a secured WMS server This parameter is optional Password Password for a basic authenticated WMS server This parameter is optional Ignore GetMap Ignore GetMap URI reported in capabilities use given URI from URL field above URI Ignore Ignore GetFeatureInfo URI reported in capabilities use given URI from URL field GetFeatureInfo above URI Table OGC 1 WMS Connection Parameters If you need to set up a proxy server to be able to receive WMS services from the internet you can add your proxy server in the options Choose menu Settings Options and click on the tab Network amp Proxy There you can add your proxy settings and enable them by setting the Use proxy for web access Make sure that you Te select the correct proxy type from the Proxy type dropdown menu Once the new WMS Server connection has been created it will be preserved for future QGIS sessions Tip On WMS Server URLs Be sure when entering in the WMS server URL that you have the base URL For example you shouldn t have fragments such as request GetCapabilities or version 1 0 0 in your URL Loading WMS Layers Once you have successfully filled in your parameters you can select the Connect button to retrieve the capabil ities of the selected server This includes the Image encoding Layers Layer Styles and Projections Since this is a network operation the speed of the response depends on the quality of your
270. mend to switch to the new labeling described in section New Labeling The old labeling in the Labels tab allows you to enable labeling features and control a number of options related to fonts placement style alignment and buffering We will illustrate this by labeling the lakes shapefile of the QGIS sample dataset 1 Load the Shapefile alaska shp and GML file lakes gm1 in QGIS 70 Capitulo 11 Working with Vector Data QGIS User Guide Release 1 8 Zoom in a bit to your favorite area with some lake Make the lakes layer active Open the Layer Properties dialog Click on the Labels tab nH NA A ug N Check the Display labels checkbox to enable labeling re Choose the field to label with We will use Field containing label NAMES 8 Enter a default for lakes that have no name The default label will be used each time QGIS encounters a lake with no value in the NAMES field 9 If you have labels extending over several lines check Y Multiline labels QGIS will check for a true line return in your label field and insert the line breaks accordingly A true line return is a single character n not two separate characters like a backlash followed by the character n To insert line returns in an attribute field configure the edit widget to be text edit not line edit 10 Click Apply Now we have labels How do they look They are probably too big and poorly placed in relation to the marker symb
271. ml E RGB This utility will compute an optimal pseudo color table for a given RGB image using a median to PCT cut algorithm on a downsampled RGB histogram Then it converts the image into a pseudo colored image using the color table This conversion utilizes Floyd Steinberg dithering error diffusion to maximize output image visual quality The utility is also desribed at http www gdal org rgb2pct html PCT This utility will convert a pseudocolor band on the input file into an output RGB file of the to RGB desired format For more information see http www gdal org pct2rgb html Extraction A This program generates a vector contour file from the input raster elevation model DEM On Con http www gdal org gdal_contour html you can find more information tour This utility allows to clip extract subset raster using selected extent or based on mask layer Clip bounds More information can be found at http www gdal org gdal_translate html per 218 Cap tulo 19 Plugins QGIS User Guide Release 1 8 Analysis rm bi bi Sieve This utility removes raster polygons smaller than a provided threshold size in pixels and replaces them with the pixel value of the largest neighbor polygon The result can be written back to the existing raster band or copied into a new file For more information see http www gdal org gdal sieve html bI Near This utility will scan an image and try to set all pixels that
272. moother corners than the original while staying faithful to the original overall shape Wy Quantum GIS 1 2 0 Daphnis File Edit View Layer Settings Plugins Tools Help BEEF E S A a UA O D ut ve oo a q oras Layers DE 2 ctour_100_smooth Q Y Ye ctour_100 Q E y gtopo30 Q a a BP Q 9 as pe ud lt a Mal overview 2 x x EN E 1285135504738 Scale 129179536077 4 v Render k 4 Figura 15 12 GRASS module v generalize to smooth a vector map a Tip Other uses for r contour The procedure described above can be used in other equivalent situations If you have a raster map of precipitation data for example then the same method will be used to create a vector map of isohyetal constant rainfall lines 15 9 The GRASS toolbox 133 QGIS User Guide Release 1 8 Creating a Hillshade 3D effect Several methods are used to display elevation layers and give a 3D effect to maps The use of contour lines as shown above is one popular method often chosen to produce topographic maps Another way to display a 3D effect is by hillshading The hillshade effect is created from a DEM elevation raster by first calculating the slope and aspect of each cell then simulating the sun s position in the sky and giving a reflectance value to each cell Thus you get sun facing slopes lighted and the slopes facing away from the sun in shadow are darkened e Begin this example by l
273. mouse button on the print composer canvas and position and customize their appearance in the label Item Properties tab Label dialog The Label dialog of the label item tab provides following functionalities Item Properties x Label Quantum GIS Font Font color Horizontal Alignment O Left O Center O Right Vertical Alignment o Top Middle Bottom _ xs Margin 1 00mm V Figura 18 6 Label Options Dialog A e The Label dialog offers to add text labels to the composer canvas You can define the horizontal and vertical alignment select font and font color for the text and it is possible to define a text margin in mm 18 4 Adding other elements to the Print Composer 185 QGIS User Guide Release 1 8 General options dialog The General options dialog of the label Item Properties tab provides following functionalities General options Frame color Background color Opacity o Outline width 0 30 Position and size V Show frame Item ID Figura 18 7 General Options Dialog A e Here you can define color and outline width for the element frame set a background color and opacity for the label The Position button opens the Set items position dialog and allows to set the map canvas position using reference points or coordinates Furthermore you can select or unselect to display the element frame with the Show frame checkbox Use the Item ID to create a relationship
274. mum scales at which a layer will be visible To set scale dependency rendering open the Properties dialog by double clicking on the layer in the legend On the General tab set the minimum and maximum scale values and then click on the Muse scale dependent rendering checkbox You can determine the scale values by first zooming to the level you want to use and noting the scale value in the QGIS status bar 7 3 2 Controlling Map Rendering Map rendering can be controlled in the following ways Suspending Rendering To suspend rendering click the Render checkbox in the lower right corner of the statusbar When the Render checkbox is not checked QGIS does not redraw the canvas in response to any of the events described in Section Rendering Examples of when you might want to suspend rendering include e Add many layers and symbolize them prior to drawing e Add one or more large layers and set scale dependency before drawing e Add one or more large layers and zoom to a specific view before drawing Any combination of the above Checking the Render checkbox enables rendering and causes an immediate refresh of the map canvas Setting Layer Add Option You can set an option to always load new layers without drawing them This means the layer will be added to the map but its visibility checkbox in the legend will be unchecked by default To set this option choose menu option Settings Options and click on the Rendering tab Uncheck
275. n which file where to write the settings therefore you can create a copy of the original settings file and rename it Command line option configpath This option is similar to the one above but furthermore overrides the default path qgis for user configuration and forces QSettings to use this directory too This allows users to e g carry QGIS installation on a flash drive together with all plugins and settings 18 Cap tulo 5 Getting Started QGIS User Guide Release 1 8 5 6 Projects The state of your QGIS session is considered a Project QGIS works on one project at a time Settings are either considered as being per project or as a default for new projects see Section Options QGIS can save the state of your workspace into a project file using the menu options File gt Save Project or File gt a Save Project As Load saved projects into a QGIS session using File gt a Open Project or File gt Open Recent Project If you wish to clear your session and start fresh choose File gt New Project Either of these menu options will prompt you to save the existing project if changes have been made since it was opened or last saved The kinds of information saved in a project file include e Layers added e Layer properties including symbolization e Projection for the map view e Last viewed extent The project file is saved in XML format so it is possible to edit the file outside QGIS if you know what you are
276. n 100 and the Document s license notice requires Cover Texts you must enclose the copies in covers that carry clearly and legibly all these Cover Texts Front Cover Texts on the front cover and Back Cover Texts on the back cover Both covers must also clearly and legibly identify you as the publisher of these copies The front cover must present the full title with all words of the title equally prominent and visible You may add other material on the covers in addition Copying with changes limited to the covers as long as they preserve the title of the Document and satisfy these conditions can be treated as verbatim copying in other respects If the required texts for either cover are too voluminous to fit legibly you should put the first ones listed as many as fit reasonably on the actual cover and continue the rest onto adjacent pages If you publish or distribute Opaque copies of the Document numbering more than 100 you must either include a machine readable Transparent copy along with each Opaque copy or state in or with each Opaque copy a computer network location from which the general network using public has access to download using public standard network protocols a complete Transparent copy of the Document free of added material If you use the latter option you must take reasonably prudent steps when you begin distribution of Opaque copies in quantity to ensure that this Transparent copy will remain thus accessible at the sta
277. n GIS are matrices of discrete cells that represent features on above or below the earth s surface Each cell in the raster grid is the same size and cells are usually rectangular in QGIS they will always be rectangular Typical raster datasets include remote sensing data such as aerial photography or satellite imagery and modelled data such as an elevation matrix Unlike vector data raster data typically do not have an associated database record for each cell They are geocoded by its pixel resolution and the x y coordinate of a corner pixel of the raster layer This allows QGIS to position the data correctly in the map canvas QGIS makes use of georeference information inside the raster layer e g GeoTiff or in an appropriate world file to properly display the data 12 1 2 Loading raster data in QGIS Raster layers are loaded either by clicking on the Load Raster icon or by selecting the Layer gt q Raster Layer menu option More than one layer can be loaded at the same time by holding down the Control or Shift key and clicking on multiple items in the dialog Open a GDAL Supported Raster Data Source Once a raster layer is loaded in the map legend you can click on the layer name with the right mouse button to select and activate layer specific features or to open a dialog to set raster properties for the layer Right mouse button menu for raster layers 99 QGIS User Guide Release 1 8 Zoom to layer extent Zoom to Best
278. n the radius is choosen too small you will not get a nice heatmap In places where more circles around points overlap eachother the brighter hotspots will occur Decay Ratio is used to show with which ratio the heat dies out from the center When O is given minimum the heat will be concentrated in the centre of given radius and be com pletely extinguished at the edge When 10 is given maximum the heat is concentrated at the edge and in the centre it is completely extinguished Higher given values are allowed but have no effect When is given the heat is spread evenly over the whole circle When a negative Decay Ratio is given you will create a Coolmap instead of a Heatmap When the Advanced checkbox is checked it will give acces to additional advanced options Row and Column can be used to change the pixelsize of the output raster More rows and colums means a smaller pixelsize and the size of the output file will become bigger and processing a bit slower When doubling the number of rows this will automatically double the size of Columns and the cell sizes will also be halved The area of the output raster will remain the same e Cell Size X and Cell Size Y influence the pixelsize of the output raster and will also change the rows and columns The point vector layer may have attribute fields that can be used to create a heatmap Use Radius from Field the radius set from an attribute field Use Weight from
279. name Click on one of the listed subdatasets and then click on Select to choose the table name Now another list of subdatasets will show with the names of GeoRaster columns on that table This is usually a short list since most users will not have more than one or two GeoRaster columns on the same table Click on one of the listed subdatasets and then click on Select to choose one of the the table column combination The dialog will now show all the rows that contains GeoRaster objects Note that the subdataset list will now show the Raster Data Table and Raster Id s pairs At anytime the Selection entry can be edited in order to go directly to a known GeoRaster or to go back to the beginning and select another table name The Selection data entry can also be used to enter a Where clause at the end of the iden tification string e g geor scott tiger orcl gdal_import raster geoid See http www gdal org frmt_georaster html for more information 19 15 3 Displaying GeoRaster Finally by selecting a GeoRaster from the list of Raster Data Table and Raster Id s the raster image will be loaded into QGIS The Select Oracle Spatial GeoRaster dialog can be closed now and next time it opens it will keep the same connection and will show the same previous list of subdataset making it very easy to open up another image from the same context Note GeoRasters that contains pyramids will display much faster but the pyramids need to be
280. nate the licenses of parties who have received copies or rights from you under this License If your rights have been terminated and not permanently reinstated receipt of a copy of some or all of the same material does not give you any rights to use it 10 FUTURE REVISIONS OF THIS LICENSE The Free Software Foundation may publish new revised versions of the GNU Free Documentation License from time to time Such new versions will be similar in spirit to the present version but may differ in detail to address new problems or concerns See http www gnu org copyleft Each version of the License is given a distinguishing version number If the Document specifies that a particular numbered version of this License or any later version applies to it you have the option of following the terms and conditions either of that specified version or of any later version that has been published not as a draft by the Free Software Foundation If the Document does not specify a version number of this License you may choose any version ever published not as a draft by the Free Software Foundation If the Document specifies that a 252 Capitulo 21 Appendix QGIS User Guide Release 1 8 proxy can decide which future versions of this License can be used that proxy s public statement of acceptance of a version permanently authorizes you to choose that version for the Document 11 RELICENSING Massive Multiauthor Collaboration Site or
281. nction_ _Ripley_K rsx E Tue Mar 13 2012 00 25 27 Could not load R script G_function_ _distance to nearest event rsx E Tue Mar 13 2012 00 25 27 Could not load R script F_function_ _distance_from_a_point_to nearest event rsx SAGA execution commands recreations_fractals Gaussian Landscapes NX 100 0 NY 100 0 H 100 0 METHOD 0 M 0 0 GRID C Users Volaya sextante tempdata 1331800672 151 tif sgrd io_gdal 1 GRIDS C Users Volaya sextante tempdata 1331800672 151 tif sgrd FORMAT 1 FILE C Users Volaya sextante tempdata 133 1800672 151 tif Figura 17 3 SEXTANTE History 7 152 Capitulo 17 SEXTANTE QGIS User Guide Release 1 8 e The SEXTANTE batch processing interface manager This interface allows you to execute batch processes and automate the execution of a single algorithm on multiple datasets DE Grid Standard Deviation Search Mode 1 0 0 Square lx 34 1 0 0 Square y 34 1 0 0 Square r 34 1 0 0 Square 7 34 10 0 Square iz 34 1 0 0 Square he 3 4 aJ aJe Figura 17 4 SEXTANTE Batch Processing Along the following sections we will review each one of this elements in detail 17 2 The SEXTANTE toolbox 17 2 1 Introduction The Toolbox is the main element of the SEXTANTE GUL and the one that you are more likely to use in your daily work It shows the list of all available alg
282. nd projections Tip Exporting datasets from PostGIS Like the import tool shp2pgsql there is also a tool to export PostGIS datasets as shapefiles pgsql2shp This is shipped within your PostGIS distribution ogr2ogr Beside shp2pgsql and SPIT there is another tool for feeding geodata in PostGIS ogr2ogr This is part of your GDAL installation To import a shapefile into PostGIS do the following ogr2ogr f PostgreSQL PG dbname postgis host myhost de user postgres N password topsecret alaska shp This will import the shapefile alaska shp into the PostGIS database postgis using the user postgres with the password topsecret on host server myhost de Note that OGR must be built with PostgreSQL to support PostGIS You can see this by typing ogrinfo formats grep i post If you like to use PostgreSQL s COPY command instead of the default INSERT INTO method you can export the following environment variable at least available on A and X 60 Cap tulo 11 Working with Vector Data QGIS User Guide Release 1 8 export PG_USE_COPY YES ogr2ogr does not create spatial indexes like shp2pgsl does You need to create them manually using the nor mal SQL command CREATE INDEX afterwards as an extra step as described in the next section Improving Performance Improving Performance Retrieving features from a PostgreSQL database can be time consuming especially over a network You can improve the drawing performan
283. nding type or other layers or tables generated by algorithms already added to the model Numerical values Literal values can be introduced directly on the textbox But this textbox is also a list that can be used to select any of the numerical value inputs of the model In this case the parameter will take the value introduced by the user when executing the model String Like in the case of numerical values literal strings can be typed or an input string can be selected Table field The fields of the parent table or layer cannot be known at design time since they depend of the selection of the user each time the model is executed To set the value for this parameter type the name of a field directly in the textbox or use the list to select a table field input already added to the model The validity of the selected field will be checked by SEXTANTE at run time Once all the parameter have been assigned valid values click on OK and the algorithm will be added to the canvas It will be linked to all the other elements in the canvas whether algorithms or inputs which provide objects that are used as inputs for that algorithm Elements can be dragged to a different position within the canvas to change the way the module structure is displayed and make it more clear and intuitive Links between elements are update automatically You can run your algorithm anytime clicking on the Run button However in order to use it from the toolbox
284. necessary to switch back to the standard labeling in some cases 18 3 1 Map item properties tab Map and Extents dialog Map dialog The Map dialog of the map Item Properies tab provides following functionalities see figure composer 2 Item Properties x Map Cache v Update preview Width 180 Height 163 Scale 9396463 Rotation 0 00 degrees Y Lock layers for map item v Draw map canvas items Figura 18 2 Map Dialog amp e The Preview area allows to define the preview modes Rectangle Cache and Render as described above Click on the Update preview button to apply changes to the map view The Map area allows to resize the map element specifying the width and height or the scale The field A Rotation 1 00 v allows to rotate the map element content clockwise in degrees Note a coordinate frame can only be added with the default value O Furthermore you can enable the checkboxes Lock layers for map items and Draw map canvas items 18 3 Adding a current QGIS map canvas to the Print Composer 183 QGIS User Guide Release 1 8 If you change the view on the QGIS map canvas by zooming or panning or changing vector or raster properties you can update the print composer view selecting the map element in the print composer and clicking the Update preview button Extents dialog The Extents dialog of the map item tab provides following functionalities see Figure figure_composer_3 Ext
285. need more detailed information about the different proxy settings please refer to the manual of the under lying QT library documentation at http doc trolltech com 4 5 qnetworkproxy html ProxyType enum Tip Using Proxies Using proxies can sometimes be tricky It is useful to trial and error the above proxy types and check if they succeed in your case You can modify the options according to your needs Some of the changes may require a restart of QGIS before they will be effective settings are saved in a texfile HOMF config QuantumGIS qgis conf X you can find your settings in HOME Library Preferences org qgis qgis plist settings are stored in the registry under HKEY CURRENT_USER Software QuantumGIS qgis 8 4 Customization The customization tool is a new development in QGIS 1 8 It lets you de activate almost every element in the QGIS user interface This can get very useful if you have a lot of plug ins installed that you never use and that are filling your screen g Customization YOS Rg f Expandall Collapse All Select All Label Description Ed mactionSaveProject amp Save Project EA mActionSaveProjectAs Save Project MActionShowComposerManager Composer M mPrintComposersMenu Print Compo mRecentProjectsMenu amp Open Rece gt gt Y mHelpMenu amp Help gt 4 mLayerMenu amp Layer v Y mPluginMenu amp Plugins ts Reset Y OK Apply O Cancel
286. network connection to the WMS server While downloading data from the WMS server the download progress is visualized in the left bottom of the WMS dialog Your screen should now look a bit like figure OGR 1 which shows the response provided by the DM Solutions Group WMS server Image Encoding The Image encoding section now lists the formats that are supported by both the client and server Choose one depending on your image accuracy requirements Tip Image Encoding 106 Capitulo 13 Working with OGC Data QGIS User Guide Release 1 8 Add Layer s from a Server Layers y Server Search DM Solutions GMap _Connect _ New Edit Delete Load Save Add default servers Name Title Abstract DEMO GMap WMS De This demonstration server was se bathymetry Elevation Bath land_fn Foreign Lands park Parks drain_fn Water drainage Drainage prov_bound Province fedlimit Federal Limit rail Railroads road Roads popplace Cities Image encoding e PNG PNG24 JPEG GIF TIFF _ a Options 0 coordinate reference systems available Layer name Tile size Feature limit for GetFeaturelnfo Help Select layer s Figura 13 1 Dialog for adding a WMS server showing its available layers You will typically find that a WMS server offers you the choice of JPEG or PNG image encoding JPEG is a lossy compression format whereas PNG faithfully reproduces the raw raster data Use JPEG if you e
287. ng ES Download OSM data ig used to download data from the OpenStreetMap server Upload OSM data s used to upload changes on current data 3 Import data from a layer js used to import data from a vector layer At least one vector layer must be loaded and current OSM data must be selected ES Save OSM to file js used to save OSM data back to an XML file More detailed information on all the widgets buttons and dialogs can be found in appropriate sections of this plugin section according to their functionality editing identification etc 16 5 Loading OSM data The first action that should be done after starting the OSM Plugin is opening data from an OSM file OSM data can be import as shapefile or downloaded directly from the OpenStreetMap server Here we are focusing on the first mentioned method E z To load data from a file use the Load OSM from file icon If there is no such button maybe someone disabled OpenStreetMap toolbar in your QGIS installation You can enable it again selecting Settings Toolbars gt OpenStreetMap Load OSM OpenStreetMap file to load Add columns for tags name place x highway landuse waterway railway amenity Figura 16 3 Load OSM data dialog The purpose of its elements is explained below OpenStreetMap file to load Click on the button to select the file osm file you want to load data from Add columns for tags This option determ
288. ng looks like a grey surface X M Control rendering order 7094654 56 135924 5 Coordinate 6629986 4290237 Scale 1 50660422 Y M Render EPSG 2964 A Figura 19 31 Final result of heatmap created of airports of Alaska X 19 17 Heatmap Plugin 235 QGIS User Guide Release 1 8 19 18 Road Graph Plugin The Road Graph Plugin is a C plugin for QGIS that calculates the shortest path between two points on any polyline layer and plots this path over the road network g Quantum GIS 1 7 0 Wroclaw ye x File Edit View Layer Settings Plugins Database CadTools Raster Vector Help 148825 RP EPC KRY Babe ORR gt v0 gt Z2a KO PAD O gt BONBBLKOOC eS gt y Y AAA AAN PO QQnrAQeaagraoeogwn eo Br Ss ton Shortest path ox Start 507871 6 1818e 06 EJ wi Stop 514042 6 17995e 06 lt E Criterion Length Length 18 55914km Time 8 55914h a es N j 4 lt Calculate J Export Clear a 4 _ x i 2 Help i ee IA A eqcis2o1 Coordinate 508222 6178316 Scale 1 57731 QA ly Render EPSG 25832 A Figura 19 32 Road Graph Plugin amp Main features calculate path it s length and travel time optimize by length or by travel time export path to a vector layer e highlight roads directions this is slow and used mainly for debug purposes and for the settings testing As a roads layer you can use any polyline vector la
289. ng on the legend entry for that layer Alternately you can use the Toggle Editing 4 Toggle editing button from the digitizing toolbar to start or stop the editing mode Once the layer is in edit mode markers will appear at the vertices and additional tool buttons on the editing toolbar will become available 84 Capitulo 11 Working with Vector Data QGIS User Guide Release 1 8 Tip Save Regularly Remember to Save Edits regularly This will also check that your data source can accept all the changes Adding Features s e You can use the e Add Feature eg Add Feature or 4 Add Feature cons on the toolbar to put the QGIS cursor into digitizing mode For each feature you first digitize the geometry then enter its attributes To digitize the geometry left click on the map area to create the first point of your new feature For lines and polygons keep on left clicking for each additional point you wish to capture When you have finished adding points right click anywhere on the map area to confirm you have finished entering the geometry of that feature The attribute window will appear allowing you to enter the information for the new feature Figure_edit_2 shows setting attributes for a fictitious new river in Alaska In the Digitizing tab under the Settings Options menu you can also activate Suppress attributes pop up windows after each created feature Reuse last entered attribute values Enter Att
290. ng that looks like the instruction in the manual Menu Options Layer Add a Raster Layer or Settings Toolbars Digitizing Tool amp Add a Raster Layer Button Save as Default Dialog Box Title Layer Properties Tab General Checkbox Render Radio Button 24 Postgis SRID 4 EPSG ID Select a Number 1 00 Select a String vi Browse for a File 2 Select a Color Border color O Change Slider Input Text Displayname A shadow indicates a clickable GUI component Text or Keyboard Conventions The manual also includes styles related to text keyboard commands and coding to indicate different entities such as classes or methods They don t correspond to any actual appearance Hyperlinks http qgis org Keystroke Combinations press Ct r1 B meaning press and hold the Ctrl key and then press the B key Name of a File lakes shp Name of a Class NewLayer Method classFactory Server myhost de QGIS User Guide Release 1 8 e User Text qgis help Lines of code are indicated by a fixed width font PROJCS NAD_1927_Albers GEOGCS GCS_North_American_1927 Platform specific instructions GUI sequences and small amounts of text can be formatted inline Click a Y File X QGIS gt Quit to close QGIS This indicates that on Linux Unix and Windows platforms click the File menu option first then Quit from the dropdown menu while on Macintosh OSX platforms click the Q
291. nly update selected features create a new attribute field where the results of the calculation will be added or update an existing field If you choose to add a new field you need to enter a field name a field type integer real or string the total field width and the field precision see figure_attributes_3 For example if you choose a field width of 10 and a field precision of 3 it means you have 6 signs before the dot then the dot and another 3 signs for the precision The Function List contains functions as well as fields and values View the help function in the Selected Function Help In Expression you see the calculation expressions you create with the Function List The most commonly used operators see Operators In the Function List click on Fields and Values to view all attributes of the attribute table to be searched To add an attribute to the Field calculator Expression field double click its name in the Fields and Values list Generally 11 5 Field Calculator 95 QGIS User Guide Release 1 8 g Feld calculator JOUR __ Only update selected features y Create a new field Update existing field Output field name length Output field type Decimal number real Output field width 10 Precision 3 Function List Selected Function Help Search Oops QGIS can t find help for this function Operators Math The help file for Slength was not found Conversions It was neither available in your l
292. ns you have to define a join layer a join field and a target field QGIS currently supports to join non spatial table formats supported by OGR delimited text and the PostgreSQL provider see figure joins 1 4 Layer Properties alaska Labels Fields A General 4D Metadata Actions od joins lt gt Join layer Join field Target field popp TYPE NAME g Add vector join 2 x o amp Join layer popp vi Join field TYPE vi Target field v Cache join layer in virtual memory __ Create attribute index on join field Y OK Cancel Restore Default Style Save As Default Load Style Save Style Es Help Y OK Apply Cancel Figura 11 24 Join an attribute table to an existing vector layer a Additionally the add vector join dialog allows to e Cache join layer in virtual memory Create attribute index on the join field 80 Cap tulo 11 Working with Vector Data QGIS User Guide Release 1 8 11 2 11 Diagrams Tab y The Diagrams tab allows you to add a graphic overlay to a vector layer see figure diagrams 1 The current core implementation of diagrams provides support for piecharts and text diagrams Text values of different data columns are displayed one below the other with a circle or a box and dividers Diagram size is based on a fixed size or on linear scaling according to a classification attribute The placement of the diagrams interacts with the new
293. nt Area Parallel deactivated Figura 17 22 Deactivate All algorithms depending directly or undirectly on that algorithm will also appear as inactive since they cannot be executed now To activate an algorithm just right click on its icon and select the Activate option 17 3 7 Editing model help files and meta information You can document your models from SEXTANTE Just click on the Edit model help button and a dialog like the one shown next will appear On the right hand side you will see a simple HTML page created using the description of the input parameters and outputs of the algorithm along with some additional items like a general description of the model or its author The first time you open the help editor all those descriptions are empty but you can edit them using the elements on the left hand side of the dialog Select an element on the upper part and the write its description in the texbox below 164 Capitulo 17 SEXTANTE QGIS User Guide Release 1 8 aixi Algorithm description j E ord pr Algorithm description Outputs Algorithm created by In put parameters Algorithm help written by Elevation Select elements on the tree and fil their description in the textbox below The elevation layer Values must be expressed in meters Clipping layer Clipping layer An optional clipping layer Outputs Figura 17 23 Help Edition 7 Model help is saved in a file in the same folder as the model it
294. nt coordinate systems When downloading a GPX file from your GPS unit or a web site and then loading it in Quantum GIS be sure that the data stored in the GPX file uses WGS84 latitude longitude Quantum GIS expects this and it is the official GPX specification See http www topografix com GPX 1 1 115 QGIS User Guide Release 1 8 fe GPS Tools JODE Load GPXfile Importotherfile Download fromGPS Uploadto GPS GPXConwerl File home dassau qgis_sample_data gps national_monuments_wgs84 gpx Feature types x Waypoints Routes x Tracks Help OK Cancel Figura 14 1 The GPS Tools dialog window A 14 1 3 GPSBabel Since QGIS uses GPX files you need a way to convert other GPS file formats to GPX This can be done for many formats using the free program GPSBabel which is available at http www gpsbabel org This program can also transfer GPS data between your computer and a GPS device QGIS uses GPSBabel to do these things so it is recommended that you install it However if you just want to load GPS data from GPX files you will not need it Version 1 2 3 of GPSBabel is known to work with QGIS but you should be able to use later versions without any problems 14 1 4 Importing GPS data To import GPS data from a file that is not a GPX file you use the tool Import other file in the GPS Tools dialog Here you select the file that you want to import and the file type which feature type you want to
295. nt gt nnect gt false lt autoconnect gt escription gt Import photograph points that mention limestone lt shortdescription gt ption gt This command will import only points that have photographs that mention estone to QGIS lt description gt setype gt SOLITE lt databasetype gt sehost gt seport gt 19 8 eVis Plugin 213 QGIS User Guide Release 1 8 lt databasename gt C Workshop eVis_Data PhotoPoints db lt databasename gt lt databaseusername gt lt databasepassword gt lt sqlstatement gt SELECT Attributes x Points x Points y FROM Attributes LEFT JOIN Points ON Points rec id Attributes point ID where COMMENTS like limestone lt sqlstatement gt lt autoconnect gt false lt autoconnect gt lt query gt lt doc gt 19 9 fTools Plugin The goal of the fTools python plugin is to provide a one stop resource for many common vector based GIS tasks without the need for additional software libraries or complex workarounds It provides a growing suite of spatial data management and analysis functions that are both fast and functional fTools is now automatically installed and enabled in new versions of QGIS and as with all plugins it can be disabled and enabled using the Plugin Manager See Section Loading a QGIS Core Plugin When enabled the fTools plugin adds a Vector menu to QGIS providing functions ranging from Analysis and Research Tools to Geometr
296. o QGIS Upgrade al istall upgrade plugin Uninstall plugin Help The plugins will be installed to qgis python plugins Close Figura 19 2 Installing external python plugins Each plugin can be either e not installed this means the plugin is available in the repository but is not installed yet In order to install it select the plugin from the list and click the button Install plugin e new this means that the plugin is newly available in the repository e installed this indicates that the plugin is already installed If it is also available in any repository the Reinstall plugin button will be enabled If the available version is older than the installed version the Downgrade plugin button will appear instead e upgradeable this means that the plugin is installed but there is an updated version available In this case the Upgrade plugin and Upgrade all buttons will be enabled invalid this means that the plugin is installed but is unavailable or broken The reason will be explained in the plugin description field Plugins tab To install a plugin select it from the list and click the Install plugin button The plugin is then activated and installed in its own directory 4 Linux and other unices share qgis python plugins SHOME qgis python plugins e X Mac OS x Contents MacOS share qgis python plugins Users SUSERNAME qgis python plugins e 7 Windows
297. oad Restore Default Style Save As Default Load Style Save Style Help OK lt Apply O Cancel Figura 11 7 Single symbol line properties A In the Style tab you can apart from a general layer transparency also define to use millimeter or map units for the size scale In the Advanced button next to the Save as style button you can use data defined size scale and rotation Here the Symbol levels menu allows to enable and define the order in which the symbol layers are rendered if the symbol consists of more than one layer After having done any needed changes the symbol can be added to the list of current style symbols using the Save as style button and then easily be used in the future Furthermore you can use the Save Style button to save the symbol as a QGIS layer style file qml or SLD file sld Currently in version 1 8 SLDs can be exported from any type of renderer single symbol categorized graduated or rule based but when importing an SLD either a single symbol or rule based renderer is created That means that categorized or graduated styles are converted to rule based If you want to preserve those renderers you have to stick to the QML format On the other hand it could be very handy sometimes to have this easy way of converting styles to rule based Categorized Renderer 11 2 The Vector Properties Dialog 65 QGIS User Guide Release 1 8 The Categorized Renderer is used to render all feature
298. oading the gtopo30 elevation raster Start the GRASS toolbox and under the Raster category double click to open Spatial analysis gt Terrain analysis Then click r shaded relief to open the module Change the azimuth angle 1 00 270 to 315 e Enter gtopo30_shade for the new hillshade raster and click Run e When the process completes add the hillshade raster to the map You should see it displayed in grayscale e To view both the hill shading and the colors of the gtopo30 together shift the hillshade map below the gtopo30 map in the table of contents then open the Properties window of gtopo30 switch to the transparency tab and set its transparency level to about 25 You should now have the gtopo30 elevation with its colormap and transparency setting displayed above the grayscale hillshade map In order to see the visual effects of the hillshading turn off the gt opo30_shade map then turn it back on Using the GRASS shell The GRASS plugin in QGIS is designed for users who are new to GRASS and not familiar with all the modules and options As such some modules in the toolbox do not show all the options available and some modules do not appear at all The GRASS shell or console gives the user access to those additional GRASS modules that do not appear in the toolbox tree and also to some additional options to the modules that are in the toolbox with the simplest default parameters This example demonstrates the use of an additi
299. od from menu e g Raster Terrain Analysis Slope The Slope dialog appears as shown in Figure raster terrain 1 4 Specify an output file path and an output file type 5 Click OK 19 17 Heatmap Plugin The 0 Heatmap plugin allows to create a heatmap from a point vector map A heatmap is a raster map showing the density or magnitude of point related information From the result hotspots can easily be identified 19 17 1 Activate the Heatmap plugin First this core plugin needs to be activated using the Plugin Manager see Section Loading a OGIS Core Plugin After activation the heatmap icon can be found in the Raster Toolbar Select from menu View Toolbars gt Raster to activate the Raster Toolbar when it is not yet activated 19 17 2 Using the Heatmap plugin The Heatmap toolbutton starts the dialog of the Heatmap plugin see figure_heatmap_2 The dialog has the following options Input Point Vector dialog Provides a selection of loaded point vector maps 232 Capitulo 19 Plugins QGIS User Guide Release 1 8 Output Raster Using the button you select the folder and the name of the output raster the Heatmap plugin will generate It is not necessary to give a file extension Output Format Selection of the output format Although all formats supported by GDAL can be choosen GeoTIFF is most in cases the best format to choose Radius can be used to give the radius in meters or mapunit Whe
300. of returning the full list of algorithm it will only display those that include that string If for instance you are looking for an algorithm to calculate slope from a DEM type alglist slope to get the following result DIM Filter slope based gt saga dtmfilter slope based Downslope Distance Gradient gt saga downslopedistancegradient Relative Heights and Slope Positions gt saga relativeheightsandslopepositions Slope Length gt saga slopelength Slope Aspect Curvatur gt saga slopeaspectcurvature 168 Cap tulo 17 SEXTANTE QGIS User Guide Release 1 8 Upslope Area gt saga upslopearea Vegetation Index slope based gt saga vegetationindex slopebased This result might change depending on the algorithms you have available It is easier now to find the algorithm you are looking for and its command line name in this case saga slopeaspectcurvature Once you know the command line name of the algorithm the next thing to do is to know the right syntax to execute it That means knowing which parameters are needed and the order in which they have to be passed when calling the runalg method SEXTANTE has a method to describe an algorithm in detail which can be used to get a list of the parameters that an algorithms require and the outputs that it will generate To do it you can use the alghelp name_of_the_algorithm method Use the command line name of the algorithm not the fu
301. of the other options is selected all the cells below the selected one will be automatically filled based on a defined criteria This way it is much easier to fill the table and the batch process can be defined with less effort Automatic filling can be done simply adding correlative numbers to the selected filepath or appending the value of another field at the same row This is particularly useful for naming output data object according to input ones Slope C Documents and Settings usuario Mis documentos slope2 tif C Documents and Settings usuario Mis documentos slope3 tif C Documents and Settings usuario Mis documentos slope tif Figura 17 27 Batch Processing File Path 7 17 4 4 Executing the batch process To execute the batch process once you have introduced all the necessary values just click on OK SEXTANTE will show the progress of the global batch process in the progress bar in the lower part of the dialog 17 5 Using SEXTANTE from the console 17 5 1 Introduction The console allows advanced users to increase their productivity and perform complex operations that cannot be performed using any of the other elements of the SEXTANTE GUI Models involving several algorithms can be 17 5 Using SEXTANTE from the console 167 QGIS User Guide Release 1 8 defined using the command line interface and additional operations such as loops and conditional sentences can be added to create more flexible and
302. of them is visible in the current extent For each saved line polygon all its member nodes are saved too 16 12 Import OSM data To import OSM data from an opened non OSM vector layer follow this instructions Choose current OSM data by clicking on one of their layers Click on the ES Import data from a layer button If there is no such button someone has probably disabled the OpenStreetMap toolbar in your QGIS installation You can enable it again in Settings Toolbars OpenStreetMap After clicking on the button following message may show up OSM Import ce There are currently no available vector layers Figura 16 9 OSM import message dialog In such case there is no vector layer currently loaded The import must be done from a loaded layer please load a vector layer from which you want to import data After a layer is opened your second try should give you a better result don t forget to mark the current OSM layer again Import data to OSM In this dialog you can import a layer loaded in QGIS into active OSM data Layer polys 0 m Import only current selection Figura 16 10 Import data to OSM dialog Use the submit dialog to start the process of OSM data importing Reject it if you are not sure you want to import something 16 12 Import OSM data 149 QGIS User Guide Release 1 8 150 Cap tulo 16 OpenStreetMap CAP TULO 17 SEXTANTE 17 1 Introduction This chapter introd
303. of value representing the table e CRS Enter the EPSG code number of the desired CRS e Extent You must use a string with xmin xmax ymin and ymax values separated by commas Boolean file string and numerical parameters do not need any additional explanations Input parameters such as strings booleans or numerical values have default values To use them use None in the corresponding parameter entry For output data objects type the filepath to be used to save it just as it is done from the toolbox If you want to save the result to a temporary file use None The extension of the file determines the file format If you enter a file extension not included in the ones supported by the algorithm the default file format for that output type will be used and its corresponding extension appended to the given filepath Unlike when an algorithm is executed from the toolbox outputs are not added to the map canvas if you execute that same algorithm from the Python console If you want to add an output to it you have to do it yourself after running the algorithm To do so you can use QGIS API commands or even easier use one of the handy methods provided by SEXTANTE for such task The runalg method returns a dictionary with the output names the ones shown in the algorithm description as keys and the filepaths of those outputs as values To add all the outputs generated by an algorithm pass that dictionary to the loadFromAlg method You can
304. og from the Edit Gnome OSX or Settings KDE Windows menu you must click on the Coordinate Reference System tab to view the CRS settings Opening the dialog from the CRS status icon will automatically bring the Coordinate Reference System tab to the front 9 3 Define On The Fly OTF Reprojection 51 QGIS User Guide Release 1 8 9 4 Custom Coordinate Reference System If QGIS does not provide the coordinate reference system you need you can define a custom CRS To define a CRS select Mein CRS from the Edit Gnome OSX or Settings KDE Windows menu Custom CRS are stored in your QGIS user database In addition to your custom CRS this database also contains your spatial bookmarks and other custom data Define You can define your own custom Coordinate Reference System CRS here The definition must conform to the proj4 format for specifying a CRS Name UTM Test Parameters proj utm zone 31 ellps WGS84 datum WGS84 units m no_defs towgs84 0 0 0 4 lofl DID ale Test Use the text boxes below to test the CRS definition you are creating Enter a coordinate where both the lat long and the transformed result are known for example by reading off a map Then press the calculate button to see if the CRS definition you are creating is accurate Parameters proj utm zone 31 ellps WGS84 datum WGS84 units m no_defs towgs84 0 0 0 Geographic WGS84 Destination CRS North 58 232322 6 474 931 1148 East
305. ogical vector model This means that areas are not represented as closed polygons but by one or more boundaries A boundary between two adjacent areas is digitized only once and it is shared by both areas Boundaries must be connected and closed without gaps An area is identified and labeled by the centroid of the area Besides boundaries and centroids a vector map can also contain points and lines All these geometry elements can be mixed in one vector and will be represented in different so called layers inside one GRASS vector map So in GRASS a layer is not a vector or raster map but a level inside a vector layer This is important to distinguish carefully Although it is possible to mix geometry elements it is unusual and even in GRASS only used in special cases such as vector network analysis Normally you should prefere to store different geometry elements in different layers It is possible to store several layers in one vector dataset For example fields forests and lakes can be stored in one vector Adjacent forest and lake can share the same boundary but they have separate attribute tables It is also possible to attach attributes to boundaries For example the boundary between lake and forest is a road so it can have a different attribute table The layer of the feature is defined by layer inside GRASS Layer is the number which defines if there are more than one layer inside the dataset e g if t
306. ogram under these conditions and telling the user how to view a copy of this License Exception if the Program itself is interactive but does not normally print such an announcement your work based on the Program is not required to print an announcement These requirements apply to the modified work as a whole If identifiable sections of that work are not derived from the Program and can be reasonably considered independent and separate works in themselves then this License and its terms do not apply to those sections when you distribute them as separate works But when you distribute the same sections as part of a whole which is a work based on the Program the distribution of the whole must be on the terms of this License whose permissions for other licensees extend to the entire whole and thus to each and every part regardless of who wrote it Thus it is not the intent of this section to claim rights or contest your rights to work written entirely by you rather the intent is to exercise the right to control the distribution of derivative or collective works based on the Program In addition mere aggregation of another work not based on the Program with the Program or with a work based on the Program on a volume of a storage or distribution medium does not bring the other work under the scope of this License You may copy and distribute the Program or a work based on it under Section 2 in object code or exe cutable form under t
307. ol for the lakes Select the Font entry and use the Font and Color buttons to set the font and color You can also change the angle and the placement of the text label To change the position of the text relative to the feature 1 Beneath the Basic label options change the placement by selecting one of the radio buttons in the Placement group To fix our labels choose the Right radio button 2 the Font size units allows you to select between Points or Map units 3 Click Apply to see your changes without closing the dialog Things are looking better but the labels are still too close to the marker To fix this we can use the options on the Offset entry which is on the bottom of the menu Here we can add offsets for the X and Y directions Adding an X offset of 5 will move our labels off the marker and make them more readable Of course if your marker symbol or font is larger more of an offset will be required The last adjustment we ll make is to Buf fer the labels This just means putting a backdrop around them to make them stand out better To buffer the lakes labels 1 Click the Buffer Labels checkbox to enable buffering 2 Choose a size for the buffer using the spin box 3 Choose a color by clicking on Color and choosing your favorite from the color selector You can also set some transparency for the buffer if you prefer 4 Click Apply to see if you like the changes If you aren t happy with the re
308. onal option in the r shaded relief module that was shown above g GRASS Tools alaska demo 2 V O G Modules Tree Modules List Browser E dassau laptop Dokumente gt g list vect r vector Dateien im Mapset lt demo gt vorhanden airports alaska rivers dassau laptop Dokumente gt g region rast gtopo30 ap projection 99 Albers Equal Area zone o datum nad27 ellipsoid clark66 north 7809680 south 1367760 west 7117600 east 4897040 nsres 3280 ewres 3280 rows 1964 cols 3663 cells 7194132 dassau laptop Dokumente gt ff EDI Figura 15 13 The GRASS shell r shaded relief module 4S The module r shaded relief can take a parameter zmult which multiplies the elevation values relative to the X Y coordinate units so that the hillshade effect is even more pronounced e Load the gtopo30 elevation raster as above then start the GRASS toolbox and click on the GRASS shell In the shell window type the command r shaded relief map gtopo30 shade gtopo30_shade2 azimuth 315 zmult 3 and press Enter 134 Cap tulo 15 GRASS GIS Integration QGIS User Guide Release 1 8 After the process finishes shift to the Browse tab and double click on the new gtopo30_shade2 raster to display in QGIS e As explained above shift the shaded relief raster below the gtopo30 raster in the Table of Contents then check transparency of the colored gtopo30 layer You should see that the 3D effect stands out mor
309. oriented For placement of the arrow you have four options corresponding to the four corners of the map canvas Angle Placement Bottom Left Enable North Arrow y Set direction automatically Help OK Cancel Figura 7 6 The North Arrow Dialog 7 5 3 Scale Bar Scale Bar adds a simple scale bar to the map canvas You control the style and placement as well as the labeling of the bar QGIS only supports displaying the scale in the same units as your map frame So if the units of your layers are in meters you can t create a scale bar in feet Likewise if you are using decimal degrees you can t create a scale bar to display distance in meters To add a scale bar 1 Select from menu View Decorations Scale Bar The dialog starts see figure_decorations_3 7 5 Decorations 37 QGIS User Guide Release 1 8 g Scale Bar Decoration 2 xy o amp Placement Top Right v Scale bar style Tick Down v Color of bar ESSE Size of bar 30 metres km Enable scale bar v Automatically snap to round number on resize ES Help Y OK Q Cancel Figura 7 7 The Scale Bar Dialog amp Choose the placement from the Placement Bottom Left drop down list Choose the style from the Scale bar style Tick Down list na A WwW N Set the size of the bar and its label Size of bar 30 degrees Make sure the Enable scale bar checkbox is checked O Select the color for the bar
310. orithms grouped in different blocks and is the access point to run them whether as a single process or as a batch process involving several executions of a same algorithm on different sets of inputs SEXTANTE Toolbox JE 48 Modeler 0 geoalgorithms E R 8 geoalgorithms t SAGA 300 geoalgorithms Scripts 0 geoalgorithms Tools de ftools 23 geoalgorithms 8 mmagis 7 geoalgorithms Figura 17 5 SEXTANTE Toolbox 7 The toolbox contains all the algorithms available divided into groups Each group represents a so called algo rithm provider which is a set of algorithms coming from the same source for instance from a third party ap plication with geoprocessing capabilities Some of this groups represent algorithms from one of such third party applications like SAGA GRASS or R while other contain algorithms directly coded along with SEXTANTE elements not relying on any additional software Currently these providers all reuse code from already exist ing QGIS plugins more specifically from the fTools vector library shiped along with QGIS and the contributed 17 2 The SEXTANTE toolbox 153 QGIS User Guide Release 1 8 mmggis plugin that you can install using the Plugin Manager making them more useful since they can be exe cuted from elements such as the modeler or the batch processing interface which we will soon describe Additionally two more p
311. ort the format you want to use Only those formats that have been well tested will appear in the list of file types when loading a vector into QGIS Other untested formats can be loaded by selecting Working with GRASS vector data is described in Section GRASS GIS Integration This section describes how to work with several common formats ESRI Shapefiles PostGIS layers and SpatiaLite layers Many of the features available in QGIS work the same regardless of the vector data source This is by design and includes the identify select labeling and attributes functions 11 1 1 ESRI Shapefiles The standard vector file format used in QGIS is the ESRI Shapefile Support is provided by the OGR Simple Feature Library http www gdal org ogr A shapefile actually consists of several files The following three are required 1 shp file containing the feature geometries 2 dbf file containing the attributes in dBase format 3 shx index file Shapefiles also can include a file with a prj suffix which contains the projection information While it is very useful to have a projection file it is not mandatory A shapefile dataset can contain additional files For further details see the ESRI technical specification at http www esri com library whitepapers pdfs shapefile pdf Loading a Shapefile To load a shapefile start QGIS and click on the Add Vector Layer toolbar button or simply type Ctr1 Shift V This will bring
312. ost easily understood function of geospatial applications Mapping programs take geospatial data and render it in a form that is viewable usually on a computer screen or printed page Applications can present static maps a simple image or dynamic maps that are customised by the person viewing the map through a desktop program or a web page Many people mistakenly assume that geospatial applications just produce maps but geospatial data analysis is another primary function of geospatial applications Some typical types of analysis include computing 1 distances between geographic locations 2 the amount of area e g square meters within a certain geographic region 3 what geographic features overlap other features QGIS User Guide Release 1 8 4 the amount of overlap between features 5 the number of locations within a certain distance of another 6 and so on These may seem simplistic but can be applied in all sorts of ways across many disciplines The results of analysis may be shown on a map but are often tabulated into a report to support management decisions The recent phenomena of location based services promises to introduce all sorts of other features but many will be based on a combination of maps and analysis For example you have a cell phone that tracks your geographic location If you have the right software your phone can tell you what kind of restaurants are within walking distance While this is a novel appl
313. ostgreSQL database type is selected Database Name The name of the database Connect A button to connect to the database using the parameters defined above Output Console The console window where messages related to processing are displayed Username Username for use when a database is password protected Password Password for use when a database is password protected O ON Hn nr Bb up Predefined Queries Tab to open the Predefined Queries window 10 Database Connection Tab to open the Database Connection window 11 SQL Query Tab to open the SQL Query window 12 Help Displays the on line help 13 OK Close the main Database Connection window 19 8 eVis Plugin 209 QGIS User Guide Release 1 8 Database Connection A Predfined Queries I Database Connection J G Database Type ODBC Ly A Username Database Host localhost B Password Database Name PhotoPoint excel l D E Comet Connection Status connected SQL Query K Output Console New Database connection requested Connection to localhost PhotoPoint_excel established Tables gt PhotoPoints Figura 19 12 The eVis Database connection window 7 Running SQL queries SQL queries are used to extract information from a database or ODBC resource In eVis the output from these queries is a vector layer added to the QGIS map window Click on the SQL Query tab to display the SQL query interfac
314. other separate and independent documents or works in or on a volume of a storage or distribution medium is called an aggregate 1f the copyright resulting from the compilation is not used to limit the legal rights of the compilation s users beyond what the individual works permit When the Document is included in an aggregate this License does not apply to the other works in the aggregate which are not themselves derivative works of the Document If the Cover Text requirement of section 3 is applicable to these copies of the Document then if the Document is less than one half of the entire aggregate the Document s Cover Texts may be placed on covers that bracket the Document within the aggregate or the electronic equivalent of covers if the Document is in electronic form Otherwise they must appear on printed covers that bracket the whole aggregate 8 TRANSLATION Translation is considered a kind of modification so you may distribute translations of the Document under the terms of section 4 Replacing Invariant Sections with translations requires special permission from their copyright holders but you may include translations of some or all Invariant Sections in addition to the original versions of these Invariant Sections You may include a translation of this License and all the license notices in the Document and any Warranty Disclaimers provided that you also include the original English version of this License and the original ver
315. ou can also change the symbol layer properties in the 68 Cap tulo 11 Working with Vector Data QGIS User Guide Release 1 8 right part of the dialog For example 1f you have chosen an SVG marker for a point layer it is now possible to change its color using Color button L6G Symbol properties 2 x e Gs Symbol layers Symbol layer type Simple line Simple line Symbol layer properties Simple line Color change BM Simple line Pen width 0 70000 Offset 0 00000 Pen style Solid Line v _ Use custom dash pattern Symbol preview Join style ABevel y Cap style E Square v OK Cancel Figura 11 13 Line composed from three simple lines 11 2 2 Style Manager The Style Manager is a small helper application that lists symbols and color ramps available in a style It also allows you to add and or remove items To launch the Style Manager click on Settings Style Manager in the main menu Alternatively you can access it via the Style tab g Style Manager 2 Y Y x 1 Marker Z Line amp Fill 6 Color ramp e fs Punkt blue square car green diamond orange star dp Add Edit Export Import Help Q Close Figura 11 14 Style Manager to manage symbols and color ramps a 11 2 3 Old Symbology Note QGIS 1 8 still supports the usage of the old symbology although it is recommended to switch to the new symbology described in section ve
316. ownload dialog will close themselves 16 10 Uploading OSM data Note that the upload is always done on current OSM data Before opening the OSM Upload dialog please be sure that you really have the right active layer with OSM data To upload current data to the OSM server click on the ES Upload OSM data button If there is no such button OSM toolbar in your QGIS installation is disabled You can enable it again in Settings Toolbars OpenStreetMap After clicking the Upload button a new dialog will appear At the top of the dialog you can check if you are uploading the correct data There is a short name of a current database In the table you find information on how many changes will be uploaded Statistics are displayed separately for each feature type In the Comment on your changes box you can write brief information on meaning of your upload operation Just write in brief what data changes you ve done or let the box empty Fill OSM account arrays so that the server could authenticate you If you don t have an account on the OSM server it s the best time to create one at http www openstreetmap org Finally use Upload to start an upload operation 16 10 Uploading OSM data 147 QGIS User Guide Release 1 8 O Upload OSM data Changes in 090902 090857 downloaded osm Trans Junes Jroigonspelevens Added 12 1 0 0 Removed 0 0 0 0 Changed 0 0 L 0 Comment on your changes New streets add
317. p tools tab under the Settings ws Options menu Panning with the arrow keys Panning the map during digitizing is possible with the arrow keys Place the mouse cursor inside the map area and click on the right arrow key to pan east left arrow key to pan west up arrow key to pan north and down arrow key 11 3 Editing 83 QGIS User Guide Release 1 8 to pan south You can also use the spacebar to temporarily cause mouse movements to pan then map The PgUp and PgDown keys on your keyboard will cause the map display to zoom in or out without interrupting your digitizing session 11 3 3 Topological editing Besides layer based snapping options you can also define some topological functionalities in the Snapping op tions dialog in the Settings or File menu Here you can define Enable topological editing and or for polygon layers you can activate the column Avoid Int which avoids intersection of new polygons Enable topological editing The option Enable topological editing is for editing and maintaining common boundaries in polygon mosaics QGIS detects a shared boundary in a polygon mosaic and you only have to move the vertex once and QGIS will take care about updating the other boundary Avoid intersections of new polygons The second topological option in the Avoid Int column called Avoid intersections of new polygons avoids overlaps in polygon mosaics It is for quicker digitizing of adjacent polygon
318. p base unit 2 Define preferred measurement units meters or feet Define preferred angle units Degrees Radians or Gon v Define Mouse wheel action 4 Zoom Zoom and recenter Zoom to mouse cursor Nothing Define Zoom factor for wheel mouse 8 3 6 Overlays Tab v Define Placement algorithm for labels symboly and diagrams choose between Central point standard Chain Popmusic tabu chain Popmusic tabu and Popmusic chain 8 3 7 Digitizing Tab Define Rubberband Line color and Line width Tv Define Default snap mode To vertex To segment To vertex and segment Define Default snapping tolerance in map units or pixel Define search radius for vertex edits in map units or pixel Show markers only for selected features V Define vertex Marker style Cross default Semi transparent circle or None and vertex Marker size Suppress attributes pop up windows after each created feature Reuse last entered attribute values Validate geometries Editing complex lines polygons with many nodes can end up with very slow rendering This is because the default validation procedures in QGIS can use a lot of time To speed up rendering it is possible to select GEOS geometry validation starting from GEOS 3 3 or to switch it off GEOS geometry validation is much faster but the disadvantage is that only the
319. placement and the labeling priority You can define if every part of a multipart feature is to be labeled here With the wrap label on character function you can define a character for a line break in the labels The Data defined settings tab provides you with the attribute based definition of Font properties Buffer properties and Position airports project file JB as RRC CPPS KR Z SAQIRAVAAA LPO v wily w 4 cs Se z SOS Label settings 4 Advanced FS Data defined settings 540 gt Y is airports YM takes LL We majrivers LM casa x Scale based visibility CER Minimum 1 Maximum 10000000 Browser Layers __ Formatted numbers Overview P ox V Apply Cancel Figura 11 15 Smart labeling of vector point layers Labeling line layers First step is to activate the Label this layer checkbox in the Label settings tab and select an attribute column to use for labeling Here you can also define labels based on expressions After that you can define the text style and the scale based visibility Further labeling options are available through the Advanced tab You can define the label placement and label distance a line orientation dependend position and the labeling priority here Furthermore you can define if every part of a multipart line is to be labeled if lines shall be merged to avoid duplicate labels and if a direction symbol is added see Figure_labels_2 It is
320. powerful workflows There is not a SEXTANTE console in QGIS but all SEXTANTE commands are available instead from QGIS built in Python console That means that you can incorporate those command to your console work and connect SEXTANTE algorithms to all the other features including methods from the QGIS APJ available from there The code that you can execute from the Python console even if it does call any SEXTANTE method can be converted into a new SEXTANTE algorithm that you can later call from the toolbox the graphical modeler or any other SEXTANTE component just like you do with any other SEXTANTE algorithm In fact some algorithms that you can find in the toolbox like all the ones in the mmggis group are simple scripts In this chapter we will see how to use SEXTANTE from the QGIS Python console and also how to write your own algorithms using Python 17 5 2 Calling SEXTANTE from the Python console The first thing you have to do is to import the SEXTANTE functions with the following line gt gt gt import sextante Now there is basically just one interesting thing you can do with SEXTANTE from the console to execute an algorithm That is done using the runalg method which takes the name of the algorithm to execute as its first parameter and then a variable number of additional parameter depending on the requirements of the algorithm So the first thing you need to know is the name of the algorithm to execute That is not
321. r or a shaded relief from a raster DEM and to make a vrt Virtual Raster Tile in XML format from a collection of one or more raster files These tools are available when the plugin is installed and activated The GDAL Library The GDAL library consists of a set of command line programs each with a large list of options Users comfortable with running commands from a terminal may prefer the command line with access to the full set of options The GDALTools plugin offers an easy interface to the tools exposing only the most popular options 19 10 2 List of GDAL tools Plugins Vector Raster Help E Raster calculator L RU a F 7 3 Za arojectons Warp Reproject oy Q gt dl amp Assign projection E i Extraction f err ox y Extract projection Analysis Miscellaneous gt GdalTools settings About GdalTools Figura 19 15 The GDALTools menu list Projections Warp This utility is an image mosaicing reprojection and warping utility The program can Reproject reproject to any supported projection and can also apply GCPs stored with the image if the image is raw with control information For more information you can read on the GDAL website http www gdal org gdalwarp html DD Assign This tool allows to assign projection to rasters that already georeferenced but miss projection projection information Also with it help it is possible to alter existing projection definition Both single fi
322. r extension restrictions as output but they do not belong to any of the categories above Those outut files will not be processed by QGIS opened or included into the current QGIS project since most of the times correspond to file formats or elements not supported by QGIS This is for instance the case with LAS files used for LiDAR data The files get created but you won t see anything new in your QGIS working session For all the other types of outputs you will find a check box that you can use to tell SEXTANTE not whether to load the file once it is generated by the algorithm or not By default all files are opened SEXTANTE does not support optional outputs so all outputs are created but you can uncheck the corresponding check box if you are not interested in a given output which virtually makes it behave like an optional output although the layer is created anyway but if you leave the text box empty it will be saved to a temporary file and deleted once you exit QGIS 158 Capitulo 17 SEXTANTE QGIS User Guide Release 1 8 17 2 4 Configuring SEXTANTE As it has been mentioned the configuration menu gives access to a new dialog where you can configure how SEXTANTE works Configuration parameters are structured in separate blocks that you can select on the left hand side of the dialog Along with the aforementioned Output folder entry the General block contains parameters for setting the default rendering style for SEXT
323. r that is being uploaded and Sout is replaced by the port name You can learn more about GPSBabel and it s available command line options at http www gpsbabel org Once you have created a new device type it will appear in the device lists for the download and upload tools 14 2 Live GPS tracking To activate Live GPS tracking in QGIS you need to select Settings GPS information You will get a new docked window on the left side of the canvas There are 4 possible screens in this GPS tracking window AH GPS position coordinates and for manually entering Vertices and Features 14 2 Live GPS tracking 117 QGIS User Guide Release 1 8 thn GPS signal strength of satellite connections e GPS polar screen showing number and polar position of satellites e GPS options screen see figure gps options With a plugged in GPS receiver has to be supported by your operating system a simple click on Connect con nects the GPS to QGIS A second click now on Disconnect disconnects the GPS receiver from your computer For GNU Linux gpsd support is integrated to support connection to most GPS receivers Therefore you first have to configure gpsd properly to connect QGIS to it Warning If you want to record your position to the canvas you have to create a new vector layer first and switch it to editable status to be able to record your track 14 2 1 Position and additional attributes A If the GPS is re
324. ra 9 2 Projection Dialog 7 The Coordinate Reference System tab of the Project Properties dialog contains five important components as shown in Figure_projection_2 and described below 1 Enable on the fly CRS transformation this checkbox is used to enable or disable OTF projection When off each layer is drawn using the coordinates as read from the data source and the components described below are inactive When on the coordinates in each layer are projected to the coordinate reference system defined for the map canvas Coordinate Reference System this is a list of all CRS supported by QGIS including Geographic Pro jected and Custom coordinate reference systems To define a CRS select it from the list by expanding the appropriate node and selecting the CRS The active CRS is preselected Proj4 text this is the CRS string used by the Proj4 projection engine This text is read only and provided for informational purposes Filter if you know the EPSG code the identifier or the name for a Coordinate Reference System you can use the search feature to find it Enter the EPSG code the identifier or the name Recently used CRS if you have certain CRS that you frequently use in your everyday GIS work these will be displayed in the table at the bottom of the Projection Dialog Click on one of these buttons to select the associated CRS Tip Project Properties Dialog If you open the Project Properties dial
325. rameters depend on the characteristics of the algorithm the structure is similar for all of them The parameters found on the table can be of one of the following types e A raster layer to select from a list of all the ones available currently opened in QGIS The selector contains as well a button on its right hand side to let you select filenames that represent layers currently not loaded in QGIS A vector layer to select from a list of all the ones available in the QGIS Layers not loaded in QGIS can be selected as well as in the case of raster layers but only if the algorithm does not require a table field selected from the attributes table of the layer In that case only opened layers can be selected since they need to be open so as to retrieve the list of field names available You will see a button by each vector layer selector If the algorithm contains several of them you will be able to toggle just one of them If the button corresponding to a vector input is toggled the algorithm will 154 Capitulo 17 SEXTANTE QGIS User Guide Release 1 8 be executed iteratively on each one of its features We will see more about this kind of execution at the end of this section e A table to select from a list of all the ones available in QGIS Non spatial tables are loaded into QGIS like vector layers and in fact they are treated as such by the program Currently the list of available tables that you will see when executing a SE
326. rds or change any other field names as desired Attempting to import a shapefile with reserved words as field names will likely fail 19 21 SQL Anywhere Plugin SQL Anywhere is a proprietary relational database management system RDBMS from Sybase SOL Anywhere includes spatial support including OGC shape files etc and built in functions to export to KML GML and SVG formats SQL Anywhere Connections Connection information New Schema a Table Type SRID Line Interpretation Geometry column Sql Server lt C J 3 lt gt Search options Estimate table metadata Search other users tables P Hep TT Build Query Close Help 8 OK Q Cancel ya A Figura 19 35 SQL Anywhere dialog KDE A The P SQL Anywhere allows to connect to spatialy enabled SQL Anywhere databases The Add SQL Anywhere layer dialog is similar in functionality to the dialogs for PostGIS and SpatiaLite 19 22 Zonal Statistics Plugin With the FS Zonal Statistics Plugin yoy can analyze the results of a thematic classification It allows to calculate several values of the pixels of a raster layer with the help of a polygonal vector layer see figure_zonal_statistics You can calculate the sum the mean value and the total count of the pixels that are within a polygon The plugin generates output columns in the vector layer with a user defined prefix qe Dialog yUOe Raster layer landcover v Polygon layer containing the zones
327. re widget Using this tool you can easily explore all map objects When the mouse cursor is placed over an object you can see all information on it directly in the OSM Feature widget There is also a dynamic rubberband displayed on the map so that the user is able to determine which feature is currently identified The Properties tab of the widget contains of all feature tags Clicking on the Relation tab shows you a list of all relations connected with identified feature If you want to hold a feature for a while to be able to read its properties and relations move the mouse cursor at the same time try left clicking while you are over the feature Identification process will stop until next left clicking Sometimes there is more than one feature at a point where left clicking was performed This happens especially when clicking on cross roads or if you did not zoom enough into the map In this situation only one of such features is identified and marked with the rubberband but the plugin remembers all of them Then still in the pause mode you can cycle through the identified features by right clicking 16 7 Editing basic OSM data Basic data in this context means non relational OSM features nodes and ways If you prefer to examine how to perform relational editing skip this section and move on to the next one Basic data editing is a key part of the OSM Plugin You can change the property position or shape of any existing basic fea
328. reate new model The modeler has a working canvas where the structure of the model and the workflow it represents are shown On the left part of the window a panel with two tabs can be used to add new elements to the model Figura 17 14 Modeler 7 Creating a model involves two steps 1 Definition of necessary inputs These inputs will be added to the parameters window so the user can set their values when executing the model The model itself is a SEXTANTE algorithm so the parameters window is generated automatically as it happens with all the algorithms included in SEXTANTE 2 Definition of the workflow Using the input data of the model the workflow is defined adding algorithms and selecting how they use those inputs or the outputs generated by other algorithms already in the model 17 3 2 Definition of inputs The first step to create a model is to define the inputs it needs The following elements are found in the Inputs tabs on the left side of the modeler window e Raster layer e Vector layer e String e Table field Table e Numerical value e Boolean value 160 Capitulo 17 SEXTANTE QGIS User Guide Release 1 8 Double clicking on any of them a dialog is shown to define its characteristics Depending on the parameter itself the dialog will contain just one basic element the description which is what the user will see when executing the model or more of them For instance when addin
329. reating a vector layer from a Microsoft Excel Worksheet 210 Cap tulo 19 Plugins QGIS User Guide Release 1 8 Database Connection A Predfined Queries select FROM PhotoPoints Run Query B Output Console New Database connection requested Connection to localhost PhotoPoint_excel established Tables gt PhotoPoints C Figura 19 13 The eVis SQL query tab 7 When creating a vector layer from a Microsoft Excel Worksheet you might see that unwanted zeros 0 have been inserted in the attribute table rows beneath valid data This can be caused by deleting the values for these cells in Excel using the Backspace key To correct this problem you need to open the Excel file you ll need to close QGIS if there if you are connected to the file to allow you to edit the file and then use Edit Delete to remove the blank rows from the file To avoid this problem you can simply delete several rows in the Excel Worksheet using Edit Delete before saving the file Running predefined queries With predefined queries you can select previously written queries stored in XML format in a file This is partic ularly helpful if you are not familiar with SQL commands Click on the Predefined Queries tab to display the predefined query interface To load a set of predefined queries click on the LA Open File icon This opens the Open File window which is used to locate the file containing the SQL qu
330. rection can be defined as horizontal vertical horizontal and vertical or boundary direction And finally you can define the grid color the annotation font the annotation distance from the map frame and the precision of the drawn coordinates General options dialog 184 Cap tulo 18 Print Composer QGIS User Guide Release 1 8 The General options dialog of the map Item Properties tab provides following functionalities see Fig ure_composer_5 General options Frame color Background color Opacity em Outline width 0 30 Position and size Y Show frame Item ID Figura 18 5 General Options Dialog e Here you can define color and outline width for the element frame set a background color and opacity for the map canvas The Position and size button opens the Set item position dialog and allows to set the map canvas position using reference points or coordinates Furthermore you can select or unselect to display the element frame with the Show frame checkbox With the Item ID you can create a relationship to the other print composer items 18 4 Adding other elements to the Print Composer Besides adding a current QGIS map canvas to the Print Composer it is also possible to add position move and customize legend scalebar images and label elements 18 4 1 Label item properties tab Label and General options dialog To add a label click the SG Add label con place the element with the left
331. rees longitude line http postgis refractions net documentation manual 1 4 ST Shift Longitude html As re sult if we open such map in QGIS we will see two far distinct locations that should show near each other In Figure vector 4 the tiny point on the far left of the map canvas Chatham Islands should be within the grid right of New Zealand main islands JS HAC RRECLPE KREMOMAAXAAAPO KWL AGRORR A pn BB ODEEZROLOLISDO DaCE En GONDOAA DSF Levers am T de nz saeg qua Lt 255455 sae NT O a rece E Figura 11 4 Map in lat lon crossing the 180 longitude line a A workaround is to transform the longitude values using PostGIS and the ST Shift Longitude function This function reads every point vertex in every component of every feature in a geometry and if the longitude coordi 11 1 Supported Data Formats 61 QGIS User Guide Release 1 8 nate is lt 0 adds 360 to it The result would be a 0 360 version of the data to be plotted in a 180 centric map Usage Figura 11 5 Crossing 180 longitude applying the ST_Shift_Longitude function Import data to PostGIS Importing Data into PostgreSQL using for example the PostGIS Manager plugin or the SPIT plugin e Use the PostGIS command line interface to issue the following command this is an example where TA BLE is the actual name of your PostGIS table gis_data update
332. relevant transformation type Based on the input parameters and data the plugin will compute the world file parameters The more coordinates you provide the better the result will be The first step is to start QGIS load the Georeferencer Plugin see Section Loading a OGIS Core Plugin and click eh Georeferencer on the icon which appears in the QGIS toolbar menu The Georeferencer Plugin dialog appears as shown in figure georeferencer 1 For this example we are using a topo sheet of South Dakota from SDGS It can later be visualized to gether with the data from the GRASS spearfish60 location You can download the topo sheet here http grass osgeo org sampledata spearfish toposheet tar gz Entering ground control points GCPs 1 To start georeferencing an unreferenced raster we must load it using the amp button The raster will show up in the main working area of the dialog Once the raster is loaded we can start to enter reference points 220 Cap tulo 19 Plugins QGIS User Guide Release 1 8 Georeferencer spearfish topoz4tif DM File Edit View Settings Help EB PB BAA o NA QUe SP cama GCP table ax on off id srcX srcY dstX dstY dX pixels dY pixels residual pixels Y O 591643 82 4927100 04 591640 54 492710253 8 33 6 24 10 41 Y 1 600148 15 4925581 28 600163 08 4925588 83 10 72 0 17 10 72 Y 2 602545 30 4915570 99 602557 88 4915567 96 8 61 1 49 8 73 Y 3 608459 33 4924864 37 608451 72
333. rently opened working set is MAPSET demo as you defined 16 Notice that some of the tools in the GRASS toolbar that were disabled are now enabled NEWAVapset GRASS Location Location Select location spearfish60 y The GRASS location is a collection of maps for a particular territory or project lt Back Next gt m Cancel Figura 15 2 Creating a new GRASS LOCATION or a new MAPSET in QGIS If that seemed like a lot of steps it s really not all that bad and a very quick way to create a LOCATION The LOCATION alaska is now ready for data import see section Importing data into a GRASS LOCATION You can also use the already existing vector and raster data in the sample GRASS LOCATION alaska included in the QGIS alaska dataset Sample Data and move on to Section The GRASS vector data model 15 3 2 Adding a new MAPSET A user has only write access to a GRASS MAP SET he created This means that besides access to his own MAPSET each user can read maps in other user s MAP SET s but he can modify or remove only the maps in his own MAP SET All MAPSETs include a WIND file that stores the current boundary coordinate values and the currently selected raster resolution Neteler amp Mitasova 2008 Literature and Web References see Section The GRASS region tool 1 Start QGIS and make sure the GRASS plugin is loaded 2 In the GRASS toolbar click on the y New mapset icon to bring up the MAPSET w
334. rg gdaldem html Miscellaneous Fo Build Virtual Raster y ma Merge Information S Y Build Overviews Tile Index This program builds a VRT Virtual Dataset that is a mosaic of the list of input gdal datasets See also http www gdal org gdalbuildvrt html This utility will automatically mosaic a set of images All the images must be in the same coordinate system and have a matching number of bands but they may be overlapping and at different resolutions In areas of overlap the last image will be copied over earlier ones The utility is also described on http www gdal org gdal_merge html This utility lists various information about a GDAL supported raster dataset On http www gdal org gdalinfo html you can find more information The gdaladdo utility can be used to build or rebuild overview images for most supported file formats with one of several downsampling algorithms For more information see http www gdal org gdaladdo html This utility builds a shapefile with a record for each input raster file an attribute containing the filename and a polygon geometry outlining the raster See also http www gdal org gdaltindex html 19 10 GDAL Tools Plugin 219 QGIS User Guide Release 1 8 19 11 Georeferencer Plugin The Georeferencer Plugin is a tool for generating world files for rasters It allows you to reference rasters to geographic or projected coordinate systems by creatin
335. ribute Values cat dbl F_CODEDESC txt NAM txt MyNewRiver F_CODE txt ShinyNewCode here Figura 11 28 Enter Attribute Values Dialog after digitizing a new vector feature A 4 ee With the v Move Features con on the toolbar you can move existing features Tip Attribute Value Types For editing the attribute types are validated during the entry Because of this it is not possible to enter a number into the text column in the dialog Enter Attribute Values or vice versa If you need to do so you should edit the attributes in a second step within the Attribute table dialog Node Tool For both PostgreSQL PostGIS and shapefile based layers the di b Node Tool provides manipulation capabilites of feature vertices similar to CAD programs It is possible to simply select multiple vertices at once and to move add or delete them alltogether The node tool also works with on the fly projection turned on and supports the topological editing feature This tool is unlike other tools in Quantum GIS persistent so when some operation is done selection stays active for this feature and tool If the node tool couldn t find any features a warning will be displayed 11 3 Editing 85 QGIS User Guide Release 1 8 A Important is to set the property Settings gt s Options Digitizing gt Search Radius 1 00 4 to a number greater than zero i e 10 Otherwise QGIS
336. rl Shift S see Projects File i Save as Image see Output 2 1 New Print Composer Ctrl P see Print Composer File Composer manager see Print Composer File Print Composers gt see Print Composer Exit Ctrl Q 22 Cap tulo 6 QGIS GUI QGIS User Guide Release 1 8 6 1 2 Edit Menu Option Shortcut Reference Toolbar cdi Undo Ctrl 2Z see Advanced digitizing Advanced Digitizing fa Redo Ctrl Shift Z see Advanced digitizing Advanced Digitizing 4p Cut Features Ctrl X see Digitizing an existing layer Digitizing E Copy Features Ctrl C see Digitizing an existing layer Digitizing Paste Features Ctrl V see Digitizing an existing layer Digitizing e e e Add Feature Ctrl see Digitizing an existing layer Digitizing A Move Feature s see Digitizing an existing layer Digitizing o Delete Selected see Digitizing an existing layer Digitizing 3 Simplify Feature see Advanced digitizing Advanced Digitizing Add Ring see Advanced digitizing Advanced Digitizing D Add Part see Advanced digitizing Advanced Digitizing 8 Delete Ring see Advanced digitizing Advanced Digitizing W Delete Part see Advanced digitizing Advanced Digitizing A Reshape Features see Advanced digitizing Advanced Digitizing EN Offset Curves see Advanced digitizing Advanced Digitizing A Split Features see Advanced digitizing Advanced Digitizing Merge selected Features see Advanced digitizing Advanced Digitizing
337. roviders can be found namely Models and Scripts This providers include user created algorithms and allow you to define your own workflows and processing tasks We will devote a full section to them a bit later In the upper part of the toolbox you can find a text box To reduce the number of algorithms shown in the toolbox and make it easier to find the one you need you can enter any word or phrase on the text box Notice that as you type the number of algorithms in the toolbox is reduced to just those which contain the text you have entered in their names To execute an algorithm just double click on its name in the toolbox 17 2 2 The algorithm dialog Once you double click on the name of the algorithm that you want to execute a dialog similar to the next one is shown in this case the dialog corresponds to the SAGA Convergence index algorithm KT My Convergence Index lt OutputRaster gt Figura 17 6 Parameters Dialog 7 This dialog is used to set the input values that the algorithm needs to be executed It shows a table where input values and configuration parameters are to be set It of course has a different content depending on the require ments of the algorithm to be executed and is created automatically based on those requirements On the left side the name of the parameter is shown On the right side the value of the parameter can be set Although the number and type of pa
338. row to indicate line direction Marker line A line rendered by repeating a marker symbol Simple line Usual rendering of a line with specified width color and pen style e Polygon layers Centroid fill Fill a polygon centroid with a hardcoded marker SVG fill Fill a polygon with a SVG symbol Simple fill Usual rendering of a polygon with defined fill color fill pattern and outline Line pattern fill Fill a polygon with a line pattern Point pattern fill Fill a polygon with a point pattern Outline Line decoration Add a line decoration e g an arrow to indicate line direction Outline Marker line Use a hardcoded marker as area outline Outline Simple line Define width color and pen style as area outline Color ramps Color ramps are used to define a range of colors that can be used during the creation of renderers The symbol s color will be set from the color ramp There are three types of color ramps e Gradient Linear gradient from one color to some other e Random Randomly generated colors from a specified area of color space ColorBrewer Create color area from a color shema and a defined number of color classes Color ramps can be defined in the Color ramp tab of the Style Manager by clicking the Add button and then choosing a color ramp type see section vector_style_manager Styles A style groups a set of various symbols and color ramps You can define your prefered or
339. roxy 110 join a loaded attribute table to a loaded vector layer 80 join layer 80 Keyboard shortcuts 33 Label_Engine_Settings 72 Labeling_Engine 70 Labeling New 70 Labeling_Old 70 layer visibility 27 layout toolbars 27 Layout_Maps 179 legend 27 license GPL 245 Line_decoration 64 load a shapefile 55 loading_raster 99 Manage_Color_Ramps 70 Manage_Symbols 70 Map overview 41 Map_Legend 187 Map_Navigation 83 Map_Template 181 MapInfo 57 Mapserver_Export_Plugin 224 Marker_line 64 measure 35 angles 35 areas 35 line length 35 menus 22 merge attributes of features 90 Merge_Attributes_of_Selected_Features 90 Merge_Selected_Features 90 Metadata 103 msexport 225 Multi_Band_Raster 100 multipolygon 89 Natural_Breaks_ Jenks 66 nesting projects 40 New_Labeling 71 New_Shapefile_Layer 90 New_Spatialite_Layer 91 New_Symbology 63 Node_Tool 85 Nodes 86 Non_Spatial_Attribute_Tables 93 OGC 105 OGR 55 OGR Simple Feature Library 55 ogr2ogr 60 Old_Symbology 69 Old_Symbology_Renderers 70 Open_Geospatial_Consortium 105 Outline_Options 70 output save as image 19 Pan 83 pan arrow keys 30 pgsql2shp 60 Picture_database 186 plugins 195 installing 197 manager 195 Python Plugin Installer 197 types 195 upgrading 197 Point_Displacement_Renderer 67 Popmusic_Chain 72 Popmusic_Tabu 72 Popmusic_Tabu_Chain 72 PostGIS 58 PostGIS spatial index 61
340. s Q Hide All Layers Save selection as vector file amp Remove All From Overview Ctrl Cir D Shift C Ctrl1 Shift 0 Ctr1 Shift U Ctrl Shift H see Style Tab See Working with the Attribute Table Attributes Digitizing Digitizing Manage Layers Manage Layers Manage Layers 6 1 6 Settings Menu Option Shortcut Reference Toolbar Panels Toolbars gt Toggle Full Screen Mode 2 Project Properties y A Custom CRS Style Manager gt Configure shortcuts gt Customization gt Options Snapping Options CEerL F Ctrl Shift P see Projects see Panels and Toolbars see Panels and Toolbars see Custom Coordinate Reference System see Style Manager see Customization see Options 6 1 7 Plugins Menu Option Shortcut Reference Toolbar E Fetch Python Plugins A Manage Plugins Python Console GRASS see OGIS Plugins see Managing Plugins see GRASS GIS Integration GRASS 6 1 Menu Bar 25 QGIS User Guide Release 1 8 6 1 8 Vector Menu Option Shortcut Reference Toolbar Analysis Tools see fTools Plugin Coordinate Capture see Coordinate Capture Plugin Data Management Tools see fTools Plugin Dxf2Shp gt see Dxf2Shp Converter Plugin Vector Geome
341. s If you already have one polygon it is possible with this option to digitise the second one such that both intersect and QGIS then cuts the second polygon to the common boundary The advantage is that users don t have to digitize all vertices of the common boundary 11 3 4 Digitizing an existing layer By default QGIS loads layers read only This is a safeguard to avoid accidentally editing a layer if there is a slip of the mouse However you can choose to edit any layer as long as the data provider supports it and the underlying data source is writable i e its files are not read only Layer editing is most versatile when used on PostgreSQL PostGIS data sources In general editing vector layers is divided into a digitizing and an advanced digitizing tool bar described in Section Advanced digitizing You can select and unselect both under Settings Toolbars Using the basic digitizing tools you can perform the following functions Icon Purpose Icon Purpose A gt Toggle editing e Adding Features Capture Point y o es Adding Features Capture Line 4 Adding Features Capture Polygon a Move Feature fp Node Tool o Delete Selected dp Cut Features Copy Features Fe Paste Features Save edits and continue Table Editing Vector layer basic editing toolbar All editing sessions start by choosing the L Toggle editing option This can be found in the context menu after right clicki
342. s gt eVis Database Connection This will launch the Database Connection window The window has three tabs Predefined Queries Database Connection and SOL Query The Output Console window at the bottom of the window displays the status of actions initiated by the different sections of this module Connect to a database Click on the Database Connection tab to open the database connection interface Next use the Database Type v combobox to select the type of database that you want to connect to If a password or username is required that information can be entered in the Username and Password textboxes Enter the database host in the Database Host textbox This option is not available if you selected MS Access as the database type If the database resides on your desktop you should enter localhost Enter the name of the database in the Database Name textbox If you selected ODBC as the database type you need to enter the data source name When all of the parameters are filled in click on the Connect button If the connection is successful a message will be written in the Output Console window stating that the connection was established If a connection was not established you will need to check that the correct parameters were entered above 1 Database Type A dropdown list to specify the type of database that will be used Database Host The name of the database host Port The port number if a MySQL or P
343. s and tracks are the three basic feature types in GPS data QGIS displays waypoints in point layers while routes and tracks are displayed in linestring layers 14 1 2 Loading GPS data from a file There are dozens of different file formats for storing GPS data The format that QGIS uses is called GPX GPS eXchange format which is a standard interchange format that can contain any number of waypoints routes and tracks in the same file To load a GPX file you first need to load the plugin Plugins A Plugin Manager opens the Plugin Manager Dialog Activate the GPS Tools checkbox When this plugin is loaded two buttons with a small handheld GPS device will show up in the toolbar e Create new GPX Layer O GPS Tools For working with GPS data we provide an example GPX file available in the QGIS sample dataset qgis sample data gps national monuments gpx See Section Sample Data for more information about the sample data 1 Click on the P GPS Tools con and open the Load GPX file tab see figure_GPS_1 2 Browse to the folder qgis sample data gps select the GPX file national_monuments gpx and click Open Use the Browse button to select the GPX file then use the checkboxes to select the feature types you want to load from that GPX file Each feature type will be loaded in a separate layer when you click OK The file national monuments gpx only includes waypoints Note GPS units allow to store data in differe
344. s from a layer using a single user defined symbol which color reflects the value of a selected feature s attribute The Style tab allows you to select e The attribute using the Column listbox e The symbol using the Symbol dialog The colors using the Color Ramp listbox The Advanced button in the lower right corner of the dialog allows to set the fields containing rotation and size scale information For convenience the list in the bottom part of the tab lists the values of all currently selected attributes together including the symbols that will be rendered The example in figure_symbology_2 shows the category rendering dialog used for the rivers layer of the QGIS sample dataset rae Fe Bet nah JUDE af Style labels Fields 4 General J Metadata Actions o joins Diagrams Categorized v Old symbology Column DECRIPTION Y Symbol change Color ramp Blues Symbol Value Label Aniak River Aniak River Colville River Colville River Copper River Copper River Kobuk River Kobuk River Koyukuk River Koyukuk River Kuskokwim River Kuskokwim River neuer Fluss neuer Fluss Noatak River Noatak River Porcupine River Porcupine River Susitna River Susitna River Tanana River Tanana River Yukon River Yukon River new river new river Classify Add Delete Delete all f Advanced v Restore Default Style Save As Default Load Style Save Style E helo Y OK amp Apply Cancel F
345. s supported by the algorithm itself To select a format just select the corresponding file extension or add it if you are directly typing the filepath instead If the extension of the filepath you entered does not match any of the supported ones a default extension usually dbf for tables t if for raster layers and shp for vector ones will be appended to the filepath and the file format corresponding to that extension will be used to save the layer or table If you do not enter any filename the result will be saved as a temporary file and in the corresponding default file format and will be deleted once you exit QGIS take care with that in case you save your project and it contains temporary layers You can set a default folder for output data objects Go to the configuration dialog you can open it from the SEXTANTE menu and in the General group you will find a parameter named Output folder This output folder is used as the default path in case you type just a filename with no path i e myf ile shp when executing an algorithm Apart from raster layers and tables SEXTANTE also generates graphics and texts as HTML files These results are shown at the end of the algorithm execution in a new dialog This dialog will keep the results produced by SEXTANTE during the current session and can be shown at any time by selecting in menu SEXTANTE gt SEXTANTE results viewer Some external applications might have files with no particula
346. s that do not have an entry in the geometry_columns table This includes both tables and views Defining a spatial view provides a powerful means to visualize your data Refer to your PostgreSQL manual for information on creating views Some details about PostgreSQL layers This section contains some details on how QGIS accesses PostgreSQL layers Most of the time QGIS should simply provide you with a list of database tables that can be loaded and load them on request However if you have trouble loading a PostgreSQL table into QGIS the information below may help you understand any QGIS messages and give you direction on changing the PostgreSQL table or view definition to allow QGIS to load it QGIS requires that PostgreSQL layers contain a column that can be used as a unique key for the layer For tables this usually means that the table needs a primary key or a column with a unique constraint on it In QGIS this column needs to be of type int4 an integer of size 4 bytes Alternatively the ctid column can be used as primary key Ifa table lacks these items the oid column will be used instead Performance will be improved if the column is indexed note that primary keys are automatically indexed in PostgreSQL 11 1 Supported Data Formats 59 QGIS User Guide Release 1 8 If the PostgreSQL layer is a view the same requirement exists but views do not have primary keys or columns with unique constraints on them In this case QGIS wil
347. s to QGIS features Configure shortcuts Action Y About 2 Add All to Overview Add PostGIS Layer Ctrl Shift D Add Raster Layer Ctrl Shift R Add Ring Add SpatiaLite Layer Ctrl Shift L Add Vector Layer Ctrl Shift W 42 Add WMS Layer Ctrl Shift W amp Add to Overview Ctrl Shift O 2 Capture Line Ctrl Capture Point Ctrl Capture Polygon Ctrl Shift Check Qgis Version Change Set none Set default None Figura 7 1 Define shortcut options 4b KDE Configuration is very simple Just select a feature from the list and click on Change Set none or Set default Once you have found your configuration you can save it as XML file and load it to another QGIS installation 7 2 Context help When you need help on a specific topic you can access context help via the Help button available in most dialogs please note that third party plugins can point to dedicated web pages 7 3 Rendering By default QGIS renders all visible layers whenever the map canvas must be refreshed The events that trigger a refresh of the map canvas include e Adding a layer 33 QGIS User Guide Release 1 8 Panning or zooming e Resizing the QGIS window e Changing the visibility of a layer or layers QGIS allows you to control the rendering process in a number of ways 7 3 1 Scale Dependent Rendering Scale dependent rendering allows you to specify the minimum and maxi
348. script we will explain them later in this same manual and modify it to incorporate actions and methods not available in the graphical modeler such as loops or conditional sentences This feature is also a very practical way of learning how to use SEXTANTE from the console and how to create SEXTANTE algorithms using Python code so you can use it as a learning tool when you start creating your own SEXTANTE scripts You will find a button below the text field containing the Python code Click on it to directly create a new script from that code without having to copy and paste it in the SEXTANTE script editor 17 4 The SEXTANTE batch processing interface 17 4 1 Introduction SEXTANTE algorithms including models can be executed as a batch process That is they can be executed using not a single set of inputs but several of them executing the algorithm as many times as needed This is 17 4 The SEXTANTE batch processing interface 165 QGIS User Guide Release 1 8 useful when processing large amounts of data since it is not necessary to launch the algorithm many times from the toolbox To execute an algorithm as a batch process right click on its name in the toolbox and select the Execute as batch process option in the pop up menu that will appear Directional Statistics for Singl Fast Nanrannnt bis a mm ESAS Execute as batch process Figura 17 24 Batch Processing Right Click 7 17 4 2 The parameters
349. se 1 8 e http karlinapp ethz ch qgis_wms e http hub qgis org projects quantum gis wiki QGIS_Server_Tutorial e http linfiniti com 2010 08 qgis mapserver a wms server for the masses 13 2 1 Sample installation on Debian Squeeze At this point we will give a short and simple sample installation howto for Debian Squeeze Many other OS provide packages for QGIS Server too If you have to build it all from source please refer to the URLs above Apart from qgis and qgis mapserver you need a webserver in our case apache2 You can install all pack ages with aptitude or apt get install together with other necessary dependency packages After installation you should test 1f the webserver and qgis server works as expected Make sure the apache server is running with etc init d apache2 start Open a web browser and type URL http localhost If apache is up you should see the message It works Now we test the qgis server installation The aqgis mapserv fcgi is available at usr lib cgi bin qgis_mapserv fcgi and provides a standard wms that shows the state boundaries of Alaska Add the WMS with the URL http localhost cgi bin qgis_mapserv fcgi as described in Selecting WMS Servers Quantum 1 8 0 Lisboa muel File Edit View Layer Settings Plugins Database Vector Raster Help J444 25 Q ke eRe FEF ERP 9 gt S ROBAGRZAADOCZEARS KO Py cia DeAQARAWIAKLS gt P ag gt Layers e de Create a new WMS conneci t
350. self You do not have to worry about saving it since 1t is done automatically 17 3 8 About available algorithms You might notice that some algorithms that can be be executed from the toolbox do not appear in the list of available ones when you are designing a model To be included in a model and algorithm must have a correct semantic so as to be properly linked to other in the workflow If an algorithm does not have such well defined semantic for instance 1f the number of output layers cannot be know in advance then it is not possible to use it within a model and thus does not appear in the list of them that you can find in the modeler dialog Additionaly you will see some algorithms in the modeler that are not found in the toolbox This algorithms are meant to be used exclusively as part of a model and they are of no interest in a different context The Calculator algorithm is an example of that It is just a simple arithmetic calculator that you can use to modify numerical values entered by the user or generated by some other algorithm This tools is really useful within a model but outside of that context it doesn t make too much sense 17 3 9 SEXTANTE models as Python code This feature is temporarily unavailable Along with the tab that contains the graphical design of the model you will find another one containing a Python script which performs the same task as the model itself Using that code you can create a console
351. sions of those notices and disclaimers In case of a disagreement between the translation and the original version of this License or a notice or disclaimer the original version will prevail If a section in the Document is Entitled Acknowledgements Dedications or History the requirement sec tion 4 to Preserve its Title section 1 will typically require changing the actual title 9 TERMINATION You may not copy modify sublicense or distribute the Document except as expressly provided under this License Any attempt otherwise to copy modify sublicense or distribute it is void and will automatically terminate your rights under this License However if you cease all violation of this License then your license from a particular copyright holder is reinstated a provisionally unless and until the copyright holder explicitly and finally terminates your license and b permanently if the copyright holder fails to notify you of the violation by some reasonable means prior to 60 days after the cessation Moreover your license from a particular copyright holder is reinstated permanently if the copyright holder notifies you of the violation by some reasonable means this is the first time you have received notice of violation of this License for any work from that copyright holder and you cure the violation prior to 30 days after your receipt of the notice Termination of your rights under this section does not termi
352. st localhost Port 2947 Device Digitizing __ Automatically save added feature Track Y Automatically add points 2 width o Color Y Cursor Y Large Small Map centering always _ when leaving _ never Log File BY Figura 14 6 GPS tracking options window You can activate Automatically save added features when you are in editing mode Or you can can activate Automatically add points to the map canvas with a certain width and color 14 2 Live GPS tracking 119 QGIS User Guide Release 1 8 Activating Cursor you can use a slider to shrink and grow the position cursor on the canvas Activating 22 Map centering allows to decide in which way the canvas will be updated This includes always when leaving if your recorded coordinates start either to move out of canvas or never to keep map extent Finally you can activate Log file and define a path and a file where log messages about the gps tracking a logged If you want to set a feature manually you have to go back to A position and click on Add Point or Add track point 120 Cap tulo 14 Working with GPS Data CAPITULO 15 GRASS GIS Integration The GRASS plugin provides access to GRASS GIS see GRASS PROJECT Literature and Web References databases and functionalities This includes visualization of GRASS raster and vector layers digitizing vector layers editing vector attributes creatin
353. standard RGB order to something else Also scaling of colors are available Tip Viewing a Single Band of a Multiband Raster If you want to view a single band for example Red of a multiband image you might think you would set the Green and Blue bands to Not Set But this is not the correct way To display the Red band set the image type to grayscale then select Red as the band to use for Gray Contrast enhancement Note When adding GRASS rasters the option Contrast enhancement will be always set to automatically to stretch to min max regardless if the Quantum GIS general options this is set to another value 12 2 Raster Properties Dialog 101 QGIS User Guide Release 1 8 12 2 2 Transparency Tab QGIS has the ability to display each raster layer at varying transparency levels Use the transparency slider to indicate to what extent the underlying layers if any should be visible though the current raster layer This is very useful if you like to overlay more than one rasterlayer e g a shaded relief map overlayed by a classified rastermap This will make the look of the map more three dimensional Additionally you can enter a rastervalue which should be treated as NODATA This can be done manually or with he 9 Add values from display icon An even more flexible way to customize the transparency can be done in the Custom transparency options section The transparency of every pixel can be set here As an e
354. sults tweak the settings and then test again by clicking Apply A buffer of 1 points seems to give a good result Notice you can also specify the buffer size in map units if that works out better for you The advanced entries inside the Label tab allow you control the appearance of the labels using attributes stored in the layer The entries beginning with Data defined allow you to set all the parameters for the labels using fields in the layer Note that the Label tab provides a preview box where your selected label is shown 11 2 The Vector Properties Dialog 71 QGIS User Guide Release 1 8 11 2 5 New Labeling 4 The new lt Labeling core application provides smart labeling for vector point line and polygon layers and only requires a few parameters This new application will replace the current QGIS labeling described in section Labels Tab and also supports on the fly transformated layers Using new labeling 1 Start QGIS and load a vector point line or polygon layer S 2 Activate the layer in the legend and click on the SE Labeling icon in the QGIS toolbar menu Labeling point layers First step is to activate the Y Label this layer checkbox and select an attribute column to use for labeling Click if you want to define labels based on expressions After that you can define the text style and the scale based visibility in the Label settings tab see Figure_labels_1 Choose the Advanced tab for the label
355. t CRS CopyrightL_abel Draws copyright information Diagram Overlay Da Aplugin for placing diagrams on vector layers Displacement plugin Ea Adds a new renderer that automatically handles point displacement in case they have the same position Dxf2Shp Converter Converts from dxf to shp file format EZ EasyPrint Version 0 0 10 Create printable maps Plugin Directory ust lib64 qgis SelectAll ClearAll O Cancel Figura 19 1 Plugin Manager A Loading an external QGIS Plugin External QGIS plugins are written in Python They are by default stored in either the Official QGIS Repository or in various other external repositories maintained by individual authors The Official QGIS Repository is added by default in Python Plugin installer Detailed documentation about the usage minimum QGIS version homepage authors and other important in formation are provided for the Official QGIS Repository at http plugins qgis org plugins For other external repositories they might be available with the external plugins themselves In general it is not included in this manual Note Updates of core python plugins may be available in this repository as external overlays Note fTools Mapserver Export and the Plugin Installer are Python plugins but they are also part of the QGIS sources and are automatically loaded and enabled inside the QGIS Plugin Manager see Section Loading an external OGIS Plugin
356. t for raster sublayers Some rasters support sublayers they are called subdatasets in GDAL An example is netcdf files if there are many netcdf variables GDAL sees every variable as a subdataset The option is to control how to deal with sublayers when a file with sublayers is opened You have the following choices Always always ask if there are existing sublayers If needed ask if layer has no bands but has sublayers Never never prompt will not load anything Load all never prompt but load all sublayers v Scan for valid items in the browser dock The Check extension option was designed to speed up the loading of a directory which can be time consuming when Check file contents is activated and there are many files tens or hundreds av e Scan for contents of compressed files zip in browser dock This option was also designed to speed up the loading of a directory You have the following choices Basic Scan checks that the extension is supported by one of the drivers Full Scan opens every file to check it is valid Passthru don t use this option it will be removed in the next QGIS version 8 3 2 GDAL tab GDAL is a data exchange library for raster files In this tab you can define which GDAL driver to be used for a raster format as in some cases more than one GDAL driver is available 8 3 3 Plugins tab e Add Path s to
357. taset To create a rule activate an existing row by clicking on it or click on and click on the new rule Then press the Edit button In the Rule properties dialog you can define a label for the rule Press the button to open the Expression builder In the Function List click on Fields and Values to view all attributes of the attribute table to be searched To add an attribute to the Field calculator Expression field double click its name in the Fields and Values list Generally you can use the various fields values and functions to construct the calculation expression or you can just type it into the box see Field Calculator Point displacement 11 2 The Vector Properties Dialog 67 QGIS User Guide Release 1 8 40 E JOE wy Style labels Fields 4 General 4 Metadata gf Actions e Joins Diagrams Old symbology Label Min scale Max scale mm Rulel LENGTH lt 1000 00 Rule LENGTH gt 1000 00 Add Jy Edit Remove Rendering order Restore Default Style Save As Default Load Style Save Style P Her OK 2 Apply Cancel Figura 11 11 Rule based Symbolizing options The point displacement renderer offers to visualize all features of a point layer even if they have the same location To do this the symbols of the points are placed on a displacement circle around a center symbol LG EEEF JODE af Style labels fields 4 General J Metadata gf Actions o jo
358. te button on the toolbar menu As an example we use the QGIS alaska dataset see Section Sample Data It includes a small sample GRASS LOCATION with 3 vector layers and 1 raster elevation map 1 Create a new folder grassdata download the QGIS alaska dataset qgis_sample_data zip from http download osgeo org qgis data and unzip the file into grassdata 2 Start QGIS 3 If not already done in a previous QGIS session load the GRASS plugin clicking on Plugins A Manage Plugins and activate Y GRASS The GRASS toolbar appears in the QGIS main window 4 In the GRASS toolbar click the Boren mapset icon to bring up the MAPSET wizard 5 For Gisdbase browse and select or enter the path to the newly created folder grassdata 6 You should now be able to select the LOCATION h alaska and the MAPSET h demo 7 Click OK Notice that some previously disabled tools in the GRASS toolbar are now enabled 8 Click on Ry Add GRASS raster layer choose the map name gt opo30 and click OK The elevation layer will be visualized 9 Click on Ry Add GRASS vector layer choose the map name alaska and click OK The alaska boundary vector layer will be overlayed on top of the gtopo30 map You can now adapt the layer properties as described in chapter The Vector Properties Dialog e g change opacity fill and outline color 10 Also load the other two vector layers rivers and airports and adapt their properties As you see it is very
359. te capture dialog appears as shown in Figure figure coordinate capture 1 4 Click on the Click to the select the CRS to use for coordinate display con and select a different CRS from the one you selected above 5 To start capturing coordinates click on Start capture You can now click anywhere on the map canvas and the plugin will show the coordinates for both of your selected CRS 6 To enable mouse coordinate tracking click the mo se tracking icon 7 You can also copy selected coordinates to the clipboard 19 4 DB Manager Plugin The DB Manager Plugin is officially part of QGIS core and intends to replace the SPIT Plugin and the PostGIS Manager Plugin and additionally to integrate all other database formats supported by QGIS in one user interface The DB Manager Plugin provides several features You can drag layers from the QGIS Browser into the DB Manager and it will import your layer into your spatial database You can drag and drop tables between spatial databases and they will get imported You can also use the DB Manager to execute SQL queries against your spatial database and then view the spatial output for queries by adding the results to QGIS as a query layer The Database menu allows to connect to an existing database to start the SQL window and to exit the DB Manager Plugin The Schema menu includes tools to create and delete empty schemas and if topology is available e g PostGIS 2 to start a Topo Viewer The menu
360. ted location until at least one year after the last time you distribute an Opaque copy directly or through your agents or retailers of that edition to the public It is requested but not required that you contact the authors of the Document well before redistributing any large number of copies to give them a chance to provide you with an updated version of the Document 4 MODIFICATIONS You may copy and distribute a Modified Version of the Document under the conditions of sections 2 and 3 above provided that you release the Modified Version under precisely this License with the Modified Version filling the role of the Document thus licensing distribution and modification of the Modified Version to whoever possesses a copy of it In addition you must do these things in the Modified Version 1 Use in the Title Page and on the covers if any a title distinct from that of the Document and from those of previous versions which should if there were any be listed in the History section of the Document You may use the same title as a previous version if the original publisher of that version gives permission 2 List on the Title Page as authors one or more persons or entities responsible for authorship of the modifi cations in the Modified Version together with at least five of the principal authors of the Document all of its principal authors if it has fewer than five unless they release you from this requirement State on the
361. tems 18 9 Raise lower and align elements Raise or lower functionalities for elements are inside the Raise selected items pulldown menu Choose an element on the print composer canvas and select the matching functionality to raise or lower the selected element compared to the other elements see table_composer_1 There are several alignment functionalities available within the l Align selected items pulldown menu see ta ble_composer_1 To use an alignment functionality you first select some elements and then click on the matching alignment icon All selected will then be aligned within to their common bounding box 18 10 Creating Output Figure_composer_22 shows the print composer with an example print layout including each type of map element described in the sections above Ze Composer 12 File View Layout Sea4aWeaSVQAQOnr Rs dEn pnas a eR Scalebar map units per segment Airports Alaska Scalebar style changed Scalebar segments left Scalebar unit text Change item position Composition Item Properties Composition Paper and quality Size A4 210x297 mm Width 297 00 Heignt210 00 mm Orientation Landscape Print as raster Quality 300 dpi Snapping Snap to grid E E Spacing 0 00 X offset 0 00 5 Y offset 0 00 Pen width 0 50 Figura 18 20 Print Composer with map view legend scalebar coordinates and text added A 192 Cap tulo
362. ter Plugin eVis Plugin fTools Plugin GPS Plugin GRASS GIS Integration GDAL Tools Plugin Georeferencer Plugin Heatmap Plugin Interpolation Plugin MapServer Export Plugin Offline Editing Plugin OpenStreetMap Oracle GeoRaster Plugin Using the QGIS Python Plugin Installer Raster Terrain Analysis Plugin Road Graph Plugin Importing Data into PostgreSQL SQL Anywhere Plugin Spatial Query Plugin Zonal Statistics Plugin 19 2 Using QGIS Core Plugins 199 QGIS User Guide Release 1 8 19 3 Coordinate Capture Plugin The coordinate capture plugin is easy to use and provides the ability to display coordinates on the map canvas for two selected Coordinate Reference Systems CRS Coordinate Capture ax gt Copy to clipboard 4 Start capture Figura 19 3 Coordinate Capture Plugin A 1 Start QGIS select Project Properties from the Settings KDE Windows or File Gnome OSX menu CRS status and click on the Projection tab As an alternative you can also click on the icon in the lower right hand corner of the statusbar 2 Click on the Enable on the fly projection checkbox and select a projected coordinate system of your choice see also Working with Projections 3 Load the coordinate capture plugin in the Plugin Manager see Loading a OGIS Core Plugin and ensure that the dialog is visible by going to View Panels and ensuring that Coordinate Capture is enabled The coordina
363. tered by four number representing its xmin xmax ymin ymax limits Clicking on the button on the right hand side of the value selector a pop up menu will appear giving you two option to select the value from a layer or the current canvas extent or to define it by dragging directly onto the map canvas Use layer canvas extent Select extent on canvas Figura 17 8 SEXTANTE Extent 7 If you select the first option you will see a window like the next one 17 2 The SEXTANTE toolbox 155 QGIS User Guide Release 1 8 Use extent from Canvas dempart2 dempart1 dem grat points lines 3cuencas Figura 17 9 SEXTANTE Extent List 7 If you select the second one the parameters window will hide itself so you can click and drag onto the canvas Once you have defined the selected rectangle the dialog will reappear containing the values in the extent text box Figura 17 10 Extent Drag 7 A list of elements whether raster layers vector ones or tables to select from the list of the ones available in QGIS To make the selection click on the small button on the left side of the corresponding row to see a dialog like the following one e A small table to be edited by the user These are used to define parameters like lookup tables or convolution kernels among others Click on the button on the right side to see the table and edit its values Depending on the algorithm
364. that we can now understand the first line of our example script the first line not starting with a Python comment pts spsample polyg numpoints type random The variable polygon already contains a SpatialPolygonsDataFrame object so it can be used to call the spsample method just like the numpoints one which indicates the number of points to add to the created sample grid Since we have declared an output of type vector named out we have to create a variable named out and store a Spatial DataFrame object in it in this case a SpatialPointsDataFrame You can use any name for your intermediate variables Just make sure that the variable storing your final result has the same name that you used to declare it and contains a suitable value In this case the result obtained from the spsample method has to be converted explicitly into a SpatialPointsDataFrame object since it is itself an object of class ppp which is not a suitable class to be retuned to SEXTANTE If you algorithm does not generate any layer but a text result in the console instead you have to tell SEXTANTE that you want the console to be shown once the execution is finished To do so just start the command lines that produce the results you want to print with the gt greater sign The output of all other lines will not be shown For instance here is the description file of an algorithms that performs a normality test on a given field column of the attributes o
365. the output raster Default horizontal and vertical resolution is 1 The Use 0 for transparency when needed can be activated if pixels with the value 0 shall be visualized transparent In our example toposheet all white areas would be transparent Finally Load in QGIS when done loads the output raster automatically into the QGIS map canvas when the transformation is done Show and adapt raster properties Clicking on the Raster properties dialog in the Settings menu opens the raster properties of the layer that you want to georeference Configure the georeferencer You can define if you want to show GCP coordiniates and or IDs e As residual units pixels and map units can be chosen e For the PDF report a left and right margin can be defined and you can also set the paper size for the PDF map e Finally you can activate to show georeferencer window docked Running the transformation After all GCPs have been collected and all transformation settings are defined just press the button gt Start georeferencing to create the new georeferenced raster 19 12 Interpolation Plugin The Interplation plugin can be used to generate a TIN or IDW interpolation of a point vector layer It is very simple to handle and provides an intuitive graphical user interface for creating interpolated raster layers See Figure_interpolation_1 The plugin requires the following parameters to be specified before running 19 12 Interpolation Plugin 223 QG
366. the By default new layers added to the map should be displayed checkbox Any layer added to the map will be off invisible by default Stopping Rendering To stop the map drawing press the ESC key This will halt the refresh of the map canvas and leave the map partially drawn It may take a bit of time between pressing ESC and the time the map drawing is halted Note It is currently not possible to stop rendering this was disabled in qt4 port because of User Interface UT problems and crashes 34 Capitulo 7 General Tools QGIS User Guide Release 1 8 Updating the Map Display During Rendering You can set an option to update the map display as features are drawn By default QGIS does not display any features for a layer until the entire layer has been rendered To update the display as features are read from the datastore choose menu option Settings Options click on the Rendering tab Set the feature count to an appropriate value to update the display during rendering Setting a value of O disables update during drawing this is the default Setting a value too low will result in poor performance as the map canvas is continually updated during the reading of the features A suggested value to start with is 500 Influence Rendering Quality To influence the rendering quality of the map you have 2 options Choose menu option Settings Options click on the Rendering tab and select or deselect following checkboxes
367. the Toolbox with the A Open GRASS tools button In the list of tool categories double click Raster Surface Management Generate vector contour lines e Now a single click on the tool r contour will open the tool dialog as explained above Working with GRASS modules The gtopo30 raster should appear as the Name of input raster 1 00 gt e Type into the Increment between Contour levels the value 100 This will create contour lines at intervals of 100 meters e Type into the Name for output vector map the name ctour_100 e Click Run to start the process Wait for several moments until the message Successfully finished appears in the output window Then click View Output and close Since this is a large region it will take a while to display After it finishes rendering you can open the layer properties window to change the line color so that the contours appear clearly over the elevation raster as in The Vector Properties Dialog Next zoom in to a small mountainous area in the center of Alaska Zooming in close you will notice that the contours have sharp corners GRASS offers the v generalize tool to slightly alter vector maps while keeping their 132 Capitulo 15 GRASS GIS Integration QGIS User Guide Release 1 8 overall shape The tool uses several different algorithms with different purposes Some of the algorithms i e Douglas Peuker and Vertex reduction simplify the line by removing some of the vertices T
368. the map canvas 7 6 1 Form annotations Additionally you can also create your own annotation forms The Form Annotation tool is useful to dis play attributes of a vector layer in a customized qt designer form see figure custom annotation It is similar to the designer forms for the Identify features tool but displayed in an annotation item Also see QGIS blog http blog qgis org node 143 for more information name of municipality Solothurn postal code home marcoftmp gem ul v Map position fixed Map marker a Frame width 1 00 o Y OK Abbrechen L schen Figura 7 9 Customized qt designer annotation form 4S Note If you press Ctr1 T while an Annotation tool is active move annotation text annotation form annota tion the visibility states of the items are inverted 7 7 Spatial Bookmarks Spatial Bookmarks allow you to bookmark a geographic location and return to it later 7 7 1 Creating a Bookmark To create a bookmark 1 Zoom or pan to the area of interest 2 Select the menu option View New Bookmark or press Ct r1 B 3 Enter a descriptive name for the bookmark up to 255 characters 4 Press Enter to add the bookmark or Delete to remove the bookmark Note that you can have multiple bookmarks with the same name 7 7 Spatial Bookmarks 39 QGIS User Guide Release 1 8 7 7 2 Working with Bookmarks To use or manage bookmarks select the menu opt
369. the name you see in the toolbox but rather a unique command line name To find the right name for your algorithm you can use the algslist method Type the following line in you console gt gt gt sextante alglist You will see something like this Accumulated Cost Anisotropic gt saga accumulatedcost anisotropic Accumulated Cost Isotropic gt saga accumulatedcost isotropic Add Coordinates to points gt saga addcoordinatestopoints Add Grid Values to Points gt saga addgridvaluestopoints Add Grid Values to Shapes gt saga addgridvaluestoshapes Add Polygon Attributes to Points gt saga addpolygonattributestopoints Aggregat gt saga aggregate Aggregate Point Observations gt saga aggregatepointobservations Aggregation Index gt saga aggregationindex Analytical Hierarchy Process gt saga analyticalhierarchyprocess Analytical Hillshading gt saga analyticalhillshading Average With Mask 1 gt saga averagewithmask1l Average With Mask 2 gt saga averagewithmask2 Average With Thereshold 1 gt saga averagewiththeresholdl Average With Thereshold 2 gt saga averagewiththereshold2 Average With Thereshold 3 gt saga averagewiththereshold3 B Spline Approximation gt saga b splineapproximation That s a list of all the available algorithms alphabetically ordered along with their corresponding command line names You can use a string as a parameter for this method Instead
370. the number of rows can be modified or not using the buttons on the right side of the window You will find a Help button in the lower part of the parameters dialog If a help file is available it will be shown giving you more information about the algorithms and detailed descriptions of what each parameter does Unfortunately most algorithms lack good documentation but if you feel like contributing to the project this would be a good place to start A note on projections SEXTANTE and also most of the external applications whose algorithms are available from SEXTANTE does not perform any reprojection on input layers and assumes that all of them are already in a common coordinate system and ready to be analized Whenever you use more than one layer as input to an algorithm whether vector or raster it is up to you to make sure that they are all in the same coordinate system 156 Capitulo 17 SEXTANTE QGIS User Guide Release 1 8 Multiple selection Figura 17 11 Multiple Selection 7 Figura 17 12 Fixed Table 7 17 2 The SEXTANTE toolbox 157 QGIS User Guide Release 1 8 Note that due to QGIS s on the fly reprojecting capabilities although two layers might seem to overlap and match that might not be true if their original coordinates are used without reprojecting them onto a common coor dinate system That reprojection should be done manually and then use the r
371. ther source or binary form with the major components compiler kernel and so on of the operating system on which the executable runs unless that component itself accompanies the executable If distribution of executable or object code is made by offering access to copy from a designated place then offering equivalent access to copy the source code from the same place counts as distribution of the source code even though third parties are not compelled to copy the source along with the object code 4 You may not copy modify sublicense or distribute the Program except as expressly provided under this License Any attempt otherwise to copy modify sublicense or distribute the Program is void and will automatically terminate your rights under this License However parties who have received copies or rights from you under this License will not have their licenses terminated so long as such parties remain in full compliance 5 You are not required to accept this License since you have not signed it However nothing else grants you permission to modify or distribute the Program or its derivative works These actions are prohibited by law if you do not accept this License Therefore by modifying or distributing the Program or any work based on the Program you indicate your acceptance of this License to do so and all its terms and conditions for copying distributing or modifying the Program or works based on it 6 Each time you redistr
372. they are displayed in three different layer types Point layer Line layer and Polygon layer It is not possible to remove any of these layers and work with the other ones A Point layer displays all features of type Node that stands alone That means that only Nodes that are not included in any Way belongs to the Point layer A Line layer displays those OSM features of type Way that are not closed That means none of these Ways starts and ends with the same Node e A Polygon layer displays all Ways that are not included in Line layer OpenStreetMap has one more data primitive in addition to the three mentioned above This is called Relation There is purposely no vector layer to display Relations A Relation defines a connection between any number of data primitives After a Point Line or Polygon is identified on a map the plugin shows a list of all relations which the identified feature is part of It was challenging to design the connection between OSM data and the standard QGIS editing tools These tools are made to edit a single vector layer at a time no matter of what feature types it displays This means that if OSM data are loaded to QGIS through the plugin you could theoretically edit the Point layer Line layer or Polygon layer with these standard tools separately A Line layer consists of two different types of OSM features Ways and Nodes In OSM format a Way is composed of Nodes If you start editing a Line layer and chang
373. tings will be ignored and the minimum extent that covers all the input layers will be used The cellsize of the target layer is the maximum of all cellsizes of the input layers For algorithms that do not use multiple raster layers or for those that do not need a unique input grid system no resampling is performed before calling SAGA and those parameters are not used Limitations for multi band layers Unlike QGIS SAGA has no support for multiband layers If you want to use a multiband layer such as an RGB or multispectral image you first have to split it into singlebanded images To do so you can use the SAGA Grid Tools Split RGB image algorithm which creates 3 images from an RGB image or the SAGA Grid Tools Extract band algorithm to extract a single band Limitations in cellsize SAGA assumes that raster layers have the same cellsize in the X and Y axis If you are working with a layer with different values for its horizontal and vertical cellsizes you might get unexcepted results In this case a warning will be added to the SEXTANTE log indicating that an input layer might not be suitable to be processed by SAGA Logging When SEXTANTE calls SAGA it does it using its command line interface thus passing a set of commands to perform all the required operation SAGA show its progress by writing information to the console which includes the percentage of processing already done along with additional content This o
374. tions Dialog e Here you can define color and outline width for the element frame set a background color and opacity for the legend The Position and size button opens the Set item position dialog and allows to set the map canvas position using reference points or coordinates Furthermore you can select or unselect to display the element frame with the Show frame checkbox Use the Item ID to create a relationship to other print composer items 18 4 4 Scalebar item properties tab Scalebar and General options dialog To add a scalebar click the E Add new scalebar icon place the element with the left mouse button on the print composer canvas and position and customize their appearance in the scalebar Item Properties tab Scalebar dialog 188 Cap tulo 18 Print Composer QGIS User Guide Release 1 8 The Scalebar dialog of the scalebar Item Properties tab provides following functionalities see fig ure_composer_13 Scale bar Segment size map 20 0000 A units Y Map units per bar 9 00 A unit Y lt gt 4 Left segments O 4 Right segments Style Line Ticks Middle w Map map O v Alignment Left v Height 5 mm Line width 1 00 mm Label space 3 00 mm lt gt o lt gt lt gt Box space 1 00 mm Unit label Font Color Figura 18 13 Scalebar Options Dialog A e The Scalebar dialog allows to define the segment size of the scalebar in map units the map units used per bar
375. tive of the exercise If you don t want to change statistics of the image you might want to choose Nearest neighbour whereas a Cubic resampling will likely provide a more smoothed result It is prossible to choose between five different resampling methods 1 Nearest neighbour 2 Linear 3 Cubic 222 Capitulo 19 Plugins QGIS User Guide Release 1 8 4 Cubic Spline 5 Lanczos Define the transformation settings There are several options that need to be defined for the georeferenced output raster The checkbox Create world file is only available if you decide to use the linear transformation type because this means that the raster image actually won t be transformed In this case the field Output raster is not activated because only a new world file will be created For all other transformation type you have to define an Output raster As default a new file file name _modified will be created in the same folder together with the original raster image As a next step you have to define the Target SRS Spatial Reference System for the georeferenced raster see section Working with Projections If you like you can generate a pdf map and also a pdf report The report includes information about the used transformation parameters An image of the residuals and a list with all GCPs and their RMS errors Furthermore you can activate the Set Target Resolution checkbox and define pixel resolution of
376. to other print composer items 18 4 2 Image item properties tab Picture options and General options dialog 1 To add an image click the _4 Add imase icon place the element with the left mouse button on the print composer canvas and position and customize their appearance in the image Item Properties tab Picture options dialog The Picture options dialog of the image Item Properties tab provides following functionalities see fig ure composer 5 a Picture options Preloaded images 8 A SDS NOMS Y e 7120 Y is amoo Bla i e tB DAR Pa Load another ia Options Width 27 0478 Height 27 9968 Rotation 0 00 __ Sync with map Search directories Figura 18 8 Picture Options Dialog Dialog A The Preloaded Images field then shows all pictures stored in the selected directories The Options area shows the current selected picture and allows to define width height and clockwise rotation of the picture Itis also possible to add a user specific SVG path Activating the Sync with map checkbox synchronizes the rotation of a picture in the QGIS map canvas i e a rotated north arrow with the appropriate print composer image 186 Cap tulo 18 Print Composer QGIS User Guide Release 1 8 The Search directories area allows to add and remove directories with images in SVG format to the picture database General options dialog The General options dialog of the image Item Properties tab provides
377. tributes O Refresh Ctrl R Map Navigation Tile scale slider see Tilesets Tile scale 6 1 5 Layer Menu Option Shortcut Reference Toolbar New gt see Creating a new Vector layer Manage Layers Embed Layers and Groups see Nesting Projects Add Vector Layer Ctrl Shift V see Working with Vector Data Manage Layers amp Add Raster Layer Ctrl Shift R see Loading raster data in QGIS Manage Layers Add PostGIS Layer Ctrl Shift D see PostGIS Layers Manage Layers Add SpatiaLite Layer Ctrl Shift L see SpatiaLite Layers Manage Layers Add MSSOL Spatial Layer Ctrl Shift M see MSSOL Spatial Layers Manage Layers Add WMS Layer Ctrl Shift 9wW see WMS Client Manage Layers al Add Delimited Text Layer see Delimited Text Plugin Manage Layers P Create new GPX layer see GPS Plugin Manage Layers 8 Add Oracle GeoRaster layer see Oracle GeoRaster Plugin Manage Layers vad Add SQL Anywhere Layer see SQL Anywhere Plugin Manage Layers Add WES Layer Manage Layers x Copy style see Style Tab Continued on next page 24 Capitulo 6 QGIS GUI QGIS User Guide Release 1 8 Tabela 6 1 continued from previous page Menu Option Shortcut Reference Toolbar B Paste style Open Attribute Table Save edits A Toggle editing Save as Remove Layer Set CRS of Layer s Set project CRS from Layer Properties Query Se Labeling tA WK Add to Overview ad Add All To Overview O Show All Layer
378. tries grouped according to their date of execution making it easier to find information about an algorithm executed at any particular moment CI zx E Ji INFO Fe Thu Mar 15 2012 0 SAGA execution commands J WARNING ALGORITHM E Thu Mar 15 2012 09 37 52 Sextante runalg saga gaussianlandscapes 100 0 100 0 100 0 0 0 0 None B J ERROR E Tue Mar 13 2012 00 30 46 Could not load R script C Users Volaya qgis python plugins sextante scripts Quad E Tue Mar 13 2012 00 30 46 Could not load R script C JUsers Volaya qgis python plugins sextante y scripts K_func E Tue Mar 13 2012 00 30 46 Could not load R script C JUsers Volaya qgis python plugins sextante Y iscriptsIG_func E Tue Mar 13 2012 00 30 46 Could not load R script C Users Volaya qois python plugins sextante y scriptsiF_func 83 Tue Mar 13 2012 00 25 27 Could not load R script Quadrat_analysis rsx E Tue Mar 13 2012 00 25 27 Could not load R script K_function_ Ripley_K rsx E Tue Mar 13 2012 00 25 27 Could not load R script G_function_ _distance to nearest event rsx E Tue Mar 13 2012 00 25 27 Could not load R script F_function_ _distance_from_a_point_to nearest event rsx SAGA execution commands recreations_fractals Gaussian Landscapes NX 100 0 NY 100 0 H 100 0 METHOD 0 M 0 0 GRID C WsersWolayalsextante tempdata 1331800672 151 tif sgrd io_gdal 1 GRIDS C users Wolaya sextante tempdata 1331800672 151 tifsgrd FO
379. try Tools see fTools Plugin Geoprocessing Tools see fTools Plugin GPS gt see GPS Plugin Vector Research Tools see fTools Plugin Road Graph see Road Graph Plugin Spatial Query gt see Spatial Query Plugin Vector 6 1 9 Raster Menu Option Shortcut Reference Toolbar Raster calculator see Raster Calculator Georeferencer see Georeferencer Plugin Raster Heatmap see Heatmap Plugin Raster Interpolation gt see Interpolation Plugin Raster 7 Terrain Analysis see Raster Terrain Analysis Plugin Zonal Statistics see Zonal Statistics Plugin Raster Projections gt see GDAL Tools Plugin Conversion gt see GDAL Tools Plugin Extraction gt see GDAL Tools Plugin Analysis see GDAL Tools Plugin Miscellaneous see GDAL Tools Plugin GdalTools settings see GDAL Tools Plugin 6 1 10 Database Menu Option Shortcut Reference Toolbar DB manager gt see DB Manager Plugin Database eVis gt see eVis Plugin Database Offline Editing gt see Offline Editing Plugin Database Spit see SPIT Plugin Database 6 1 11 Web Menu Option Shortcut Reference Toolbar MapServer Export see MapServer Export Plugin Web OpenStreetMap see OpenStreetMap OpenStreetMap 26 Capitulo 6 QGIS GUI QGIS User Guide Release 1 8 6 1 12 Help Menu Option Shortcut Reference Toolbar Y Help Contents F1 Help R What s This Shift F1 Help API Documentation Q QGIS Home Page Ctrl H w Check OGIS Version
380. ts built from the attributes of a feature or passing parameters to a web reporting tool 11 2 The Vector Properties Dialog 75 QGIS User Guide Release 1 8 Layer Properties alaska AE o Tu Create Spatial Index EPSG 2964 NAD27 Alaska Albers SpecifycRS o 0 000000 100000000 000000 Figura 11 20 General tab in vector layers properties dialog A Layer Properties climate age Climate data Alaska This layer is part of the QGIS training dataset It shows climate information min max and mean General Storage type of this layer ESRI Shapefile Source for this layer igrassdata qgis_sample_data climate climate shp Geometry type of the features in this layer Point The number of features in this layer 14 Editing capabilities of this layer Add Features Delete Features Change Attribute Values Add Attributes Delete Attributes Create Spatial Index FastAccess to Features atID Change Geometries Extents In layer spatial reference system units xMin yMin 1759042 86 2008976 82 xMaxyMax 4637397 39 7728392 26 Layer Spatial Reference System proj aea lat_1 55 lat_2 65 lat_0 50 lon_0 154 x_0 0 y_0 0 datum NAD27 units us ft no_defs Figura 11 21 Metadata tab in vector layers properties dialog Cap tulo 11 Working with Vector Data QGIS User Guide Release 1 8 4 Layer Properties lakes PROROKA ay Style Labels Fields A General Q Metadata amp A
381. ts new geometry has only two vertexes And because there cannot exist polygon with only two vertices as described above the feature type is automatically changed to Line If the parent feature was a line with two vertexes its new geometry has only one vertex And because there cannot exist a line with only one vertex the feature type is automatically changed to Point 16 8 Editing relations Thanks to existence of OSM relations we can join OSM features into groups and give them common properties in such way we can model any possible map object borders of a region as group of ways and points routes of a 16 8 Editing relations 145 QGIS User Guide Release 1 8 bus etc Each member of a relation has its specific role There is a pretty good support for OSM Relations in our plugin Let s see how to examine create update or remove them 16 8 1 Examining relation If you want to see relation properties first identify one of its members After that open the Relations tab on the OSM Feature widget At the top of the tab you can see a list of all relations the identified feature is part of Please choose the one you want to examine and look at its information below In the first table called Relation tags you find the properties of the selected relation In the table called Relation members you see brief information on the relation members If you click on a member the plugin will make a rubberband on it in the map 16
382. ttp geopole orgiwms search search 1 amp lype rss Timeout for network requests ms 60000 P Help e OK Cancel ta Figura 8 2 Proxy settings in QGIS Use proxy for web access and define Host Port User and Password li V e Set the Proxy type according to your needs Default Proxy Proxy is determined based on the application proxy set using 8 3 Options 45 QGIS User Guide Release 1 8 Socks5Proxy Generic proxy for any kind of connection Supports TCP UDP binding to a port in coming connections and authentication HttpProxy Implemented using the CONNECT command supports only outgoing TCP connections supports authentication HttpCachingProxy Implemented using normal HTTP commands it is useful only in the context of HTTP requests FtpCachingProxy Implemented using an FTP proxy it is useful only in the context of FTP requests e Define Cache settings path and size Define WMS search address default is http geopole org wms search search 1 amp type rss e Define Timeout for network requests ms deeingebundenfault is 60000 Excluding some URLs can be added to the text box below the proxy settings see Figure_Network_Tab by press ing the Add button After that double click into the just created URL field and enter the URL you would like to exclude from using the proxy Obviously the button Remove removes the selected entry If you
383. tulo 9 Working with Projections CAPITULO 10 QGIS Browser The QGIS Browser is a new panel in QGIS that lets you easily navigate in your database You can have ac cess to common vector files e g ESRI shapefile or MapInfo files databases e g PostGIS or MSSQL Spatial and WMS WFS connections You can also view your GRASS data to get the data into QGIS see GRASS GIS Integration Aw QGIS Browser O Refresh oe Manage WMS New Shapefile A Set layer CRS v E shapefiles airports shp G alaska shp E builtups shp G grassland shp lakes shp E landice shp 6 majrivers shp pipelines shp popp shp 6 railroads shp E regions shp E rivers shp Ss storagep shp amp swamp shp 6 trails shp E trees shp 6 tundra shp schulung Es software 7 ssh E Videos Vorlagen Favourites Paran Metadata Preview Attributes General Storage type of this layer ESRI Shapefile Source for this layer Mome junek qgis_sample_data shapefiles airports shp Geometry type of the features in this layer Point The number of features in this layer 76 Editing capabilities of this layer Add Features Delete Features Change Attribute Values Add Attributes Delete Attributes Create Spatial Index Fast Access to Features at ID Change Geometries Extents In layer spatial reference system units xMin yMin 4480198 52 1433525 80 xMax yMax 4615124 98 6502586 83 Layer Spatial Reference System proj aea lat 1 55
384. ture You can remove features or add new ones All changes on nodes and ways are remembered by Undo Redo all changes can be easily uploaded to the OpenStreetMap server 16 7 1 Changing feature tags Changing the property tag of an OSM feature can be done directly in the table of feature tags The Tags table of basic features can be found on the OSM Feature widget Don t forget to identify feature first If you want to change a tag value just double click in the appropriate row of column Value and type or select a kzv new value If you want to remove a tag click in the relevant row then use the button X Remove selected tags On the right bottom under the table To add new tags just type the key and value into the last row of the table where lt next tag value gt is written Notice that you cannot change the key of an existing tag pair Conveniently there are some combo boxes of all existing tag keys and their typical values 16 6 Viewing OSM data 143 QGIS User Guide Release 1 8 Quantum GIS 1 2 0 Unstable Trunk File Edit View Layer Settings Plugins Tools Help 2 A22 908 0 BEBE BER a E y OSM Feature ax dl Rl e seie lol m Feature TYPE ID Line 16785997 CREATED 09 06 27 20 44 USER Petr Dlouhy Properties Relations Key Value a created_by Potlatch 0 10b g highway residential 4 lt new tag here gt E OSM Feature Layers PAUSED Left
385. tyle 5 colormap Transparency amp General Metadata Pyramids Histogram Render as e Single band gray _ Th Invert color map Single band properties Gray band Band 1 v Color map Grayscale Y Custom min max values Min 0 Max 255 _ Use standard deviation Note Minimum Maximum values are estimates user defined or calculated from the current extent Load min max values from band _ Estimate faster Actual slower _ Current extent Contrast enhancement Default No Stretch Restore Default Style Save As Default Load Style Save Style Help OK Apply Cancel lt gt Figura 12 1 Raster Layers Properties Dialog A e Grayscale default e Pseudocolor e Freak Out e Colormap s e gt v When selecting the entry Colormap from Color map combobox the tab Colormap becomes available For more information see Colormap QGIS can restrict the data displayed to only show cells whose values are within a given number of standard deviations of the mean for the layer This is useful when you have one or two cells with abnormally high values in a raster grid that are having a negative impact on the rendering of the raster This option is only available for pseudocolor and freak out images Three band color This selection offers you a wide range of options to modify the appearance of your rasterlayer For example you could switch color bands from the
386. u can change relation tags members or even its type After submitting the dialog your changes will be committed 16 9 Downloading OSM data To download data from OpenStreetMap server click on the En Download OSM data button If there is no such button the OSM toolbar may be disabled in your QGIS instalation You can enable it again at Settings Toolbars gt OpenStreetMap After clicking the button a dialog occurs and provides following functionalities Extent Specifies an area to download data from intervals of latitude and longitude degrees Because there is some restriction of OpenStreetMap server on how much data can be downloaded the intervals must not be too wide More detailed info on extent specification can is shown after clicking the Help button on the right Download to Here you are expected to write a path to the file where data will be stored If you can t remember the structure of your disk don t panic The browse button will help you 146 Cap tulo 16 OpenStreetMap QGIS User Guide Release 1 8 Download OSM data Extent Latitude From 50 1182495512 To 50 1185802588 Longitude From 14 4088703963 To 14 4092977338 OK Area is probably acceptable to server 2 Download to tmp 090902_091352_downloaded osm Open data automatically after download Replace current data current layer will be removed X Use custom renderer Small sca
387. ublished at least four years before the Document itself or if the original publisher of the version it refers to gives permission 11 For any section Entitled Acknowledgements or Dedications Preserve the Title of the section and pre serve in the section all the substance and tone of each of the contributor acknowledgements and or dedica tions given therein 12 Preserve all the Invariant Sections of the Document unaltered in their text and in their titles Section numbers or the equivalent are not considered part of the section titles 13 Delete any section Entitled Endorsements Such a section may not be included in the Modified Version 14 Do not retitle any existing section to be Entitled Endorsements or to conflict in title with any Invariant Section 15 Preserve any Warranty Disclaimers If the Modified Version includes new front matter sections or appendices that qualify as Secondary Sections and contain no material copied from the Document you may at your option designate some or all of these sections as invariant To do this add their titles to the list of Invariant Sections in the Modified Version s license notice These titles must be distinct from any other section titles You may add a section Entitled Endorsements provided it contains nothing but endorsements of your Modified Version by various parties for example statements of peer review or that the text has been approved by an organ
388. uces SEXTANTE the powerful geospatial analysis framework of QGIS SEXTANTE is a geoprocessing environment that can be used to call native and third party algorithms from QGIS making your spatial analysis tasks more productive and easy to accomplish In the following sections we will review how to use the graphical elements of SEXTANTE and take the most out of each one of them 17 1 1 Basic elements of the SEXTANTE GUI There are four basic elements in the SEXTANTE GUI which are used to run SEXTANTE algorithms for different purposes Choosing one tool or another will depend on the kind of analysis that is to be performed and the particular characteristics of each user and project All of them except for the batch processing interface which is called from the toolbox as we will see can be accessed from the SEXTANTE menu item you will see more than four entries The remaining ones are not used to execute algorithms and will be explained later in this chapter e The SEXTANTE toolbox The main element of the SEXTANTE GUL it is used to execute a single algorithm or run a batch process based on that algorithm SEXTANTE Toolbox ex Modeler 0 geoalgorithms H R 8 geoalgorithms SAGA 300 geoalgorithms g Scripts 0 geoalgorithms 4 Tools E ftools 23 geoalgorithms 22 mmagis 7 geoalgorithms Figura 17 1 SEXTANTE Toolbox 7 The SEXTANTE graphical modeler Several algorithms can be combined graphically using the modeler
389. units and how many left and right segments units from O should be used You can define the scalebar style available is single and double box line ticks middle up and down and a numeric style Furthermore you can define height line width label and box space of the scalebar Add a unit label and define the scalebar font and color General options dialog The General options dialog of the scalebar Item Properties tab provides following features see figure_composer_7 b General options Frame color Background color Opacity Outline width 0 30 Position and size V Show frame Item ID Figura 18 14 General Options Dialog A e Here you can define color and outline width for the element frame set a background color and opacity for the scalebar The Position and size button opens the Set items position dialog and allows to set the map canvas position using reference points or coordinates Furthermore you can select or unselect to display the element frame with the Show frame checkbox With the Item ID you can create a relationship to the other print composer items 18 5 Navigation tools For map navigation the print composer provides 4 general tools a Zoom in 18 5 Navigation tools 189 QGIS User Guide Release 1 8 Q Zoom out K a a A Zoom to full extend Nu O Refresh the view jf you find the view in an inconsistent state 18 6 Revert and Restore tools Dur
390. up a new window see figure vector 1 55 QGIS User Guide Release 1 8 g Add vector layer 2 Y X Source type e File Directory Database Protocol Encoding System v Source Dataset data qgis_sample_data vmapO_shapefiles alaska shp Help Y Open Cancel Figura 11 1 Add Vector Layer Dialog A From the available options check File Click on button Browse That will bring up a standard open file dialog see figure_vector_2 which allows you to navigate the file system and load a shapefile or other supported data V source The selection box Filter allows you to preselect some OGR supported file formats You can also select the Encoding type for the shapefile if desired Places x gt 4 e LZ J A EE Home gt grassdata gt qgis sample data gt shapefiles Network 9 s airports shp pipelines shp trails shp B Root p alaska shry popp shp trees shp Tash builtups shp railroads shp tundra shp 931 5 GIB grassland shp s regions shp 298 1 GiB lakes shp s rivers shp a 120 0 GiB landice shp storagep shp 805 0 GiB majrivers shp swamp shp Name ES alaska shp av L Open Filter ESRI Shapefiles OGR gv Cancel Figura 11 2 Open an OGR Supported Vector Layer Dialog A Selecting a shapefile from the list and clicking Open loads it into QGIS Figure_vector_3 shows QGIS after loading the alaska shp file Tip Layer Colors When you add a layer to the map it is
391. ure al MO oexi15 130732 download Y oe wo mb v amp 091115_130712_downloade Y 091115_130712_downloade Feature TYPE ID CREATED USER Properties Relations OSM Edit History Coordinate 14 431301 50 077835 Scale 1 2336 v Render kg Figura 16 2 OSM plugin user interface 16 4 1 OSM Features widget The OSM Feature widget helps to identify OSM features It shows basic information on the feature type and identifier as well as information on who has changed a feature and when The OSM Feature widget also provides all editing tools in the top part of it More information on those tools can be found in the sections below The widget is initially disabled It activates itself after successful loading some OSM data 16 4 2 OSM Undo Redo widget This Undo Redo widget is used to undo and redo edit actions It consists not only a classic Undo and Redo button but also shows a list with a brief description of the edit actions that were done The OSM Undo Redo widget is initially closed You can show it using a button on the OSM Feature widget 16 3 Installation 141 QGIS User Guide Release 1 8 16 4 3 Toolbar menu icons LO Load OSM from file is used to load data from a special OpenStreetMap XML file lo Show Hide OSM Feature Manager is used to show or hide the OSM Feature widget The OSM Feature widget is a panel that helps with OSM feature identification and with OSM data editi
392. us QGIS won t find and select any vertex for editing and it will pop up an annoying warning to that effect Snap tolerance and search radius are set in map units or pixels so you may find you need to experiment to get them set right If you specify too big of a tolerance QGIS may snap to the wrong vertex especially if you are dealing with a large number of vertices in close proximity Set search radius too small and it won t find anything to move The search radius for vertex edits in layer units can be defined in the Digitizing tab under Settings s Options The same place where you define the general project wide snapping tolerance 11 3 2 Zooming and Panning Before editing a layer you should zoom in to your area of interest This avoids waiting while all the vertex markers are rendered across the entire layer Apart from using the Y pan and a RR Q zoom out icons on the toolbar with the mouse navigating can also be done with the mouse wheel spacebar and the arrow keys Zooming and panning with the mouse wheel While digitizing you can press the mouse wheel to pan inside of the main window and you can roll the mouse wheel to zoom in and out on the map For zooming place the mouse cursor inside the map area and roll 1t forward away from you to zoom in and backwards towards you to zoom out The mouse cursor position will be the center of the zoomed area of interest You can customize the behavior of the mouse wheel zoom using the Ma
393. used File name Simplifies the selection by adding a file chooser dialog 74 Capitulo 11 Working with Vector Data QGIS User Guide Release 1 8 Value map a combo box with predefined items The value is stored in the attribute the description is shown in the combo box You can define values manually or load them from a layer or a CSV file Enumeration Opens a combo box with values that can be used within the columns type This is currently only supported by the postgres provider Immutable The immutable attribute column is read only The user is not able to modify the content Hidden A hidden attribute column is invisible The user is not able to see its content Checkbox Displays a checkbox and you can define what attribute is added to the column when the check box is activated or not Text edit This opens a text edit field that allows multiple lines to be used Calendar Opens a calendar widget to enter a date Column type must be text Value Relation Offers values from a related table in a combobox You can select layer key column and value column UUID Generator Generates a read only UUID Universally Unique Identifiers field if empty 11 2 7 General Tab a The General tab is essentially like that of the raster dialog There are several options available Change the display name of the layer Set a display field to be used for the Identify Results dialog Define a certain Edit User Interface for t
394. ustangens of y x using the signs of the two arguments to determine the quadrant of the result replace this with that in string a replace the regular expression this with that len characters of string ax starting from from first character index is 1 atan2 y x replace xax replacethis withthat regexp replace a this that substr xax from len a b concatenate strings a and b rownum number current row Sarea area of polygon Sperimeter perimeter of polygon Slength length of line Sid feature id x x coordinate of point Sy y coordinate of point xat n X coordinate of the point of an n th line indeces start at 0 negative values refer to the line end yat n y coordinate of the point of an n th lin indeces start at 0 negative values refer to the line end a b a and b are equal a b and a lt gt b a and b are not equal a gt a is larger than or equal to b a lt b a is less than or equal to b a gt b a is larger than b a lt b a is smaller than b a b a matches the regular expression b a LIKE b a equals b a ILIKE b a equals b without regard to case sensitive a wedge b a raised to the power of b axb a multiplied by b a b a divided by b a b a plus b a b a minus b ta positive sign a negative value of a The field calculator Function list with the Selected Function Help Operators and Expression menu are also available through the rule based rendering in the Sty
395. uted repositories including the central QGIS Contributed Repository and other external repositories by clicking the Add button The added repositories contain a large number of useful plugins which are not maintained by the QGIS Development Team As such we cannot take any responsibility for them You can also manage the repository list manually that is add remove and edit the entries Temporarily disabling a particular repository is possible by clicking the Edit button Options tab The Options tab is where you can configure the settings of the Plugin Installer The Check for updates on startup checkbox tells QGIS to automatically look for plugin updates and news By default if this feature is enabled all repositories listed and enabled in the Repositories tab are checked for updates each time the program is started The frequency of update checking can be adjusted using the dropdown menu and may be adjusted from once a day right up to once a month If a new plugin or update is available for one of the installed plugins a notification will appear in the Status Bar If the checkbox is disabled looking for updates and news is performed only when the Plugin Installer is manually launched from the menu Although the plugin installer update can handle ports different from 80 some internet connections will cause problems when attempting to automatically check for updates In these cases a Looking for new plugins indi cator will rema
396. utput contains areas not intersecting the clip layer B Dissolve Merge features based on input field All features with identical input values are combined to form one single feature Table Ftools 3 fTools Geoprocessing tools 19 9 fTools Plugin 215 QGIS User Guide Release 1 8 19 9 4 Geometry tools Icon Tool Purpose y Check geometry Check polygons for intersections closed holes and fix node ordering Export Add Add vector layer geometry info to point XCOORD YCOORD line geometry columns Polygon centroids Delaunay triangulation Voronoi Polygons Simplify geometry Densify geometry Multipart to singleparts Singleparts to multipart Polygons to lines Lines to polygons Extract nodes LENGTH or polygon AREA PERIMETER layer Calculate the true centroids for each polygon in an input polygon layer Calculate and output as polygons the delaunay triangulation of an input point vector layer Calculate voronoi polygons of an input point vector layer Generalize lines or polygons with a modified Douglas Peucker algorithm Densify lines or polygons by adding vertices Convert multipart features to multiple singlepart features Creates simple polygons and lines Merge multiple features to a single multipart feature based on a unique ID field Convert polygons to lines multipart polygons to multiple singlepart lines Convert lines to polygons multipart lines to multiple singl
397. utput is filtered by SEXTANTE and used to update the progress bar while the algorithm is running Both the commands sent by SEXTANTE and the additional information printed by SAGA can be logged along with other SEXTANTE log messages and you might find them useful to track in detailed what is going on when SEXTANTE runs a SAGA algorithm You will find two settings namely Log console output and Log execution commands to activate that logging mechanism Most other providers that use an external application and call it through the command line have similar options so you will find them as well in other places in the SEXTANTE settings list 17 7 3 Rand R scripts R integration in SEXTANTE is different from that of SAGA in that there is not a predefined set of algorithms you can run except for a few examples Instead you should write your scripts and call R commands much like you would do from R and in a very similar manner to what we saw in the chapter dedicated to SEXTANTE scripts This chapter shows you the syntax to use to call those R commands from SEXTANTE and how to use SEXTANTE objects layers tables in them The first thing you have to do as we saw in the case of SAGA is to tell SEXTANTE where you R binaries are located You can do so using the R folder entry in the SEXTANTE configuration dialog Once you have set that parameter you can start creating your own R scripts and executing them Once again this is different in Linux and
398. ve this set to nothing Deficient layers may be rendered strangely WGS 84 Bounding Box The bounding box of the layer in WGS 84 coordinates Some WMS servers do not set this correctly e g UTM coordinates are used instead If this is the case then the initial view of this layer may be rendered with a very zoomed out appearance by QGIS The 13 1 Working with OGC Data 109 QGIS User Guide Release 1 8 WMS webmaster should be informed of this error which they may know as the WMS XML elements LatLonBoundingBox EX_GeographicBoundingBox or the CRS 84 BoundingBox Available in CRS The projections that this layer can be rendered in by the WMS server These are listed in the WMS native format Available in style The image styles that this layer can be rendered in by the WMS server WMS Client Limitations Not all possible WMS Client functionality had been included in this version of QGIS Some of the more notable exceptions follow Editing WMS Layer Settings Once you ve completed the e Add WMS layer procedure there is no ability to change the settings A workaround is to delete the layer completely and start again WMS Servers Requiring Authentication Currently public accessible and secured WMS services are supported The secured WMS servers can be accessed by public authentication You can add the optional credentials when you add a WMS server See section Select ing WMS Servers for details
399. ver Export Plugin you need to arrange the raster and vector layers you want to use in MapServer and save this status in a QGIS project file Quantum GIS 1 1 0 Pan Unstable alaska File Edit View Layer Plugins Tools Help Layers a x 2 airports Mk majrivers cu lakes u Hvi Overview E NS 2732789 5372173 Scale 133972301 M Render ig Figura 19 20 Arrange raster and vector layers for QGIS project file a In this example we demonstrate the four steps required to create a simple project file which can be used to create the MapServer map file We use raster and vector files from the QGIS sample dataset Sample Data 1 Add the raster layer landcover ti f clicking on the Add Raster Layer Fcon 2 Add the vector Shapefiles lakes shp majrivers shp and airports shp from the QGIS sample dataset clicking on the Add Vector Layer icon 3 Change the colors and symbolize the data as you like for example see figure_mapserver_export_1 4 Save a new project named mapserverproject qgs using File gt a Save Project 19 13 2 Creating the Map File To use the Mapserver Export plugin from within QGIS you need to enable the MapServer Export Plugin first using the Plugin Manager see Loading a OGIS Core Plugin 19 13 MapServer Export Plugin 225 QGIS User Guide Release 1 8 MapServer Export Save project to MapFile y Use current project home dassau qgis_project qg i Browse
400. vironment storing passwords in your QGIS settings may be a security risk Your customized settings for QGIS are stored based on the operating system A the settings are stored in your home directory in qgis e 7 the settings are stored in the registry Loading a PostGIS Layer Once you have one or more connections defined you can load layers from the PostgreSQL database Of course this requires having data in PostgreSQL See Section Importing Data into PostgreSQL for a discussion on importing data into the database To load a layer from PostGIS perform the following steps If the Add PostGIS layers dialog is not already open click on the Add PostGIS Layer toolbar button Choose the connection from the drop down list and click Connect Select or unselect Y Also list tables with no geometry Optionally use some Search Options to define which features to load from the layer or use the Build query button to start the Query builder dialog Find the layer s you wish to add in the list of available layers Select it by clicking on it You can select multiple layers by holding down the Shift key while clicking See Section Query Builder for information on using the PostgreSQL Query Builder to further define the layer Click on the Add button to add the layer to the map Tip PostGIS Layers Normally a PostGIS layer is defined by an entry in the geometry_columns table From version 0 9 0 on QGIS can load layer
401. will ensure that the konqueror application will be executed when the action is invoked The second example uses the notation which does not rely on a particular field for its value When the action is invoked the will be replaced by the value of the selected field in the identify results or attribute table Using Actions Actions can be invoked from either the Identify Results dialog an Attribute Table dialog or from Run Fea ture Action recall that these dialogs can be opened by clicking LP identity Features or Open seat Table a de Run Feature Action To invoke an action right click on the record and choose the action from the popup menu Ac tions are listed in the popup menu by the name you assigned when defining the actions Click on the action you wish to invoke If you are invoking an action that uses the notation right click on the field value in the Identify Results dialog or the Attribute Table dialog that you wish to pass to the application or script Here is another example that pulls data out of a vector layer and inserts them into a file using bash and the echo command so it will only work 4b or perhaps X The layer in question has fields for a species name taxon_name latitude 1at and longitude 1ong I would like to be able to make a spatial selection of a localities and export these field values to a text file for the selected record shown in yellow in the QGIS map area Here is the action to achieve this bash c
402. wns by entering population gt 100000 in the SQL box of the Query builder Fig ure_attributes_2 shows an example of the Query builder populated with data from a PostGIS layer with attributes stored in PostgreSQL The Fields Values and Operators sections help the user to construct the SQL like query g earch query builder alaska Fields Values cat EE 0 095759 a NAME 0 136504 AREA MI 0 153697 0 168541 0 173643 0 184467 0 209257 0 225724 0251122 ly Sample All Operators lt gt LIKE IN NOTIN lt gt l ILIKE AND OR NOT SQL where clause q g Search results VS AREA_MI gt 0 251123 O Found 487 matching feature s Help Test Clear Save Load Cancel Figura 11 34 Query Builder A The Fields list contains all attribute columns of the attribute table to be searched To add an attribute column to the SQL where clause field double click its name in the Fields list Generally you can use the various fields values and operators to construct the query or you can just type it into the SQL box The Values list lists the values of an attribute table To list all possible values of an attribute select the attribute in the Fields list and click the all button To list the first 25 unique values of an attribute column select the attribute 94 Cap tulo 11 Working with Vector Data QGIS User Guide Release 1 8 column in the Fields list and click the Sample button To add a value to the SQL where
403. xample we want to set the water of our example raster file landcover tif to a transparency of 20 The following steps are neccessary 1 Load the rasterfile landcover 2 Open the Properties dialog by double clicking on the raster name in the legend or by right clicking and choosing Properties from the popup menu 3 Select the Transparency tab 4 Click the El Add values manually button A new row will appear in the pixel list 5 Enter the raster value we use O here and adjust the transparency to 20 6 Press the Apply button and have a look at the map You can repeat the steps 4 and 5 to adjust more values with custom transparency As you can see this is quite easy to set custom transparency but it can be quite a lot of work Therefore you can use the button Ea expor to fe to save your transparency list to a file The button 9 Import from file Toads your transparency settings and applies them to the current raster layer 12 2 3 Colormap The Colormap tab is only available when you have selected a singleband rendering within the Style tab see Style Tab Three ways of color interpolation are available 1 Discrete 2 Linear 3 Exact The button Add Entry adds a color to the individual color table Button Delete Entry deletes a color from the individual color table and the Sort button sorts the color table according to the pixel values in the value column Double clicking on the value column lets you insert a specific va
404. xmin ymin xmax ymax set initial map extent nologo hide splash screen noplugins don t restore plugins on startup nocustomization don t apply GUI customization optionspath path use the given QSettings path configpath path use the given path for all user configuration help this text FILES 5 4 Starting and Stopping QGIS 17 QGIS User Guide Release 1 8 Files specified on the command line can include rasters vectors and QGIS project files qgs 1 Rasters Supported formats include GeoTiff DEM and others supported by GDAL 2 Vectors Supported formats include ESRI Shapefiles and others supported by OGR and PostgreSQL layers using the PostGIS extension Tip Example Using command line arguments You can start QGIS by specifying one or more data files on the command line For example assuming you are in the qgis_sample_data directory you could start QGIS with a vector layer and a raster file set to load on startup using the following command qgis raster landcover img gml lakes gml Command line option snapshot This option allows you to create a snapshot in PNG format from the current view This comes in handy when you have a lot of projects and want to generate snapshots from your data Currently it generates a PNG file with 800x600 pixels This can be adapted using the width and height command line arguments A filename can be added after snapshot Command line option
405. xpect the WMS data to be photographic in nature and or you don t mind some loss in picture quality This trade off typically reduces by 5 times the data transfer requirement compared to PNG Use PNG if you want precise representations of the original data and you don t mind the increased data transfer requirements Options The Options field provides a text field where you can add a Layer name for the WMS layer This name will be presented in the legend after loading the layer Below the layer name you can define Tile size if you want to set tile sizes eg 256x256 to split up the WMS request into multiple requests The Feature limit for GetFeatureInfo defines what features from the server to query If you select a WMS from the list a field with the default projection provided by the mapserver appears If the Change button is active you can click on it and change the default projection of the WMS to another CRS provided by the WMS server Layer Order The tab Layer Order lists the selected layers available from the current connected WMS server You may notice that some layers are expandable this means that the layer can be displayed in a choice of image styles You can select several layers at once but only one image style per layer When several layers are selected they will be combined at the WMS Server and transmitted to QGIS in one go Tip WMS Layer Ordering 13 1 Working with OGC Data 107 QGIS User Gu
406. y and Geoprocessing Tools as well as several useful Data Management Tools 19 9 1 Analysis tools Icon Tool Purpose Distance Measure distances between two point layers and output results as a Square distance Matrix matrix b Linear distance matrix or c Summary of distances Can limit distances to the k nearest features G Sum line Calculate the total sum of line lengths for each polygon of a polygon vector layer length Points in Count the number of points that occur in each polygon of an input polygon vector layer polygon List unique List all unique values in an input vector layer field values E a Basic Compute basic statistics mean std dev N sum CV on an input field statistic e ne Nearest Compute nearest neighbor statistics assess the level of clustering in a point vector layer Neighbor analysis de f a Mean Compute either the normal or weighted mean center of an entire vector layer or coordinate s multiple features based on a unique ID field a Line Locate intersections between lines and output results as a point shapefile Useful for intersections locating road or stream intersections ignores line intersections with length gt 0 Table Ftools 1 fTools Analysis tools 214 Cap tulo 19 Plugins QGIS User Guide Release 1 8 19 9 2 Research tools o O 5 Tool Purpose OF 2 BP de E op Random selection Rando
407. y specific keywords Basically this option is a frontend to the API of http geopole org Tilesets When using WMS C Cached WMS Services like http labs metacarta com wms c Basic py you are able to browse through the tab Tilesets given by the server Additional information like tile size formats and supported CRS are listed in this table In combination with this feature you can use the tile scale slider from the View Tile scale slider which gives you the available scales from the tileserver with nice slider docked in Using the Identify Tool Once you have added a WMS server and if any layer from a WMS server is queryable you can then use the ad Identify too to select a pixel on the map canvas A query is made to the WMS server for each selection made The results of the query are returned in plain text The formatting of this text is dependent on the particular WMS server used Viewing Properties Once you have added a WMS server you can view its properties by right clicking on it in the legend and selecting Properties Metadata Tab The tab Metadata displays a wealth of information about the WMS server generally collected from the Capabil ities statement returned from that server Many definitions can be cleaned by reading the WMS standards see OPEN GEOSPATIAL CONSORTIUM Literature and Web References but here are a few handy definitions Server Properties WMS Version The WMS version supported by the server
408. y window Generic Event Browser Displaying records 06 of 56 2 x Display Options Configure External Applications About Save y G Attribute Containing Path to File 250 L rot tree T 9 tio compar Brg Ena o al Compass Offset O Manual c foo Ef o From atebute o ej The base path or url from which images and documents can be relative Base Path C UmagesWernan DJ E bap opel eerie bad ae O F _ Apply Path to Image rules when loading docs in external applications C Figura 19 10 The eVis Options window 7 206 Cap tulo 19 Plugins QGIS User Guide Release 1 8 about the different options for specifying the file location are noted in the section Specifying the location and name of a photograph below 2 Compass bearing display field A dropdown list to specify the attribute field that contains the compass bearing associated with the photograph being displayed If compass bearing information is available it is necessary to click the checkbox to the left of the dropdown menu title 3 Compass offset setting Compass offsets can be used to compensate for declination adjust bearings col lected using magnetic bearings to true north bearings Click the b Manual radiobutton to enter the offset in the text box or click the 24 From Attribute radiobutton to select the attribute field containing the offsets For both of these options east declinations should be entered using pos
409. yer in any QGIS supported format Two lines with a common point are considered connected Please note it is required to use layer CRS as project CRS while editing roads layer This is due to the fact that recalculation of the coordinates between different CRS introduce some errors that can result in discontinuities even when snapping is used In the layer attribute table the following fields can be used speed on road section numeric field e direction any type that can be casted to string Forward and reverse directions are correspond to the one way road both directions two way road If some fields don t have any value or do not exist default values are used You can change defaults and some plugin settings in plugin settings dialog 19 18 1 Using the plugin After plugin activation you will see an additional panel on the left side of the main QGIS window Now make some definitions to the Road graph plugin settings dialog in the menu Vector Road Graph Select a Start and a Stop point in the road network layer and click on Calculate 236 Capitulo 19 Plugins QGIS User Guide Release 1 8 19 19 Spatial Query Plugin e The va Spatial Query plugin allows to make a spatial query select features in a target layer with reference to another layer The functionality is based on the GEOS library and depends on the selected source feature layer Possible operators are Contains Equals Overlap
410. you can define three Edit actions to open an editor and the users can only see and execute the one Edit action for their platform to run the editor There are several examples included in the dialog You can load them clicking on Add default actions An example is performing a search based on an attribute value This concept is used in the following discussion Defining Actions Attribute actions are defined from the vector Layer Properties dialog To define an action open the vector Layer Properties dialog and click on the Actions tab Select Generic as type and provide a descriptive name for the action The action itself must contain the name of the application that will be executed when the action is invoked You can add one or more attribute field values as arguments to the application When the action is invoked any set of characters that start with a followed by the name of a field will be replaced by the value of that field The special characters will be replaced by the value of the field that was selected from the identify results or attribute table see using_actions below Double quote marks can be used to group text into a single argument to the program script or command Double quotes will be ignored if preceded by a backslash If you have field names that are substrings of other field names e g col1 and co110 you should indicate so by surrounding the field name and the character with square brackets e
411. you do not want to use any data object use None Selection If an algorithm has a selection parameter the value of that parameter should be entered using an integer value To know the available options you can use the algoptions command as shown in the following example gt gt gt sextante algoptions Saga slopeaspectcurvature METHOD Method O 0 Maximum Slope Travis et al 1975 1 1 Maximum Triangle Slope Tarboton 1997 2 2 Least Squares Fitted Plan Horn 1981 Costa Cabral amp Burgess 1996 3 3 Fit 2 Degree Polynom Bauer Rohdenburg Bork 1985 4 4 Fit 2 Degree Polynom Heerdegen amp Beran 1982 5 5 Fit 2 Degree Polynom Zevenbergen amp Thorne 1987 6 6 Fit 3 Degree Polynom Haralick 1983 In this case the algorithm has one of such such parameters with 7 options Notice that ordering is zero based e Multiple input The value is a string with input descriptors separated by semicolons As in the case of single layers or tables each input descriptor can be the data object name or its filepath 17 5 Using SEXTANTE from the console 169 QGIS User Guide Release 1 8 e Table Field from XXX Use a string with the name of the field to use This parameter is case sensitive e Fixed Table Type the list of all table values separated by commas and enclosed between quotes Values start on the upper row and go from left to right You can also use a 2D array
412. zed outside the selected multipolygon Delete Ring The B Delete Ring too allows to delete ring polygons inside an existing area This tool only works with polygon layers It doesn t change anything when it is used on the outer ring of the polygon This tool can be used on polygon and multi polygon features Before you select the vertices of a ring adjust the vertex edit tolerance Delete Part The W Delete Part too allows to delete parts from multifeatures e g to delete polygons from a multipolygon feature It won t delete the last part of the feature this last part will stay untouched This tool works with all multi part geometries point line and polygon Before you select the vertices of a part adjust the vertex edit tolerance Reshape Features You can reshape line and polygon features using the dx Reshape Features con on the toolbar It replaces the line or polygon part from the first to the last intersection with the original line With polygons this can sometimes lead to unintended results It is mainly useful to replace smaller parts of a polygon not major overhauls and the reshape line is not allowed to cross several polygon rings as this would generate an invalid polygon For example you can edit the boundary of a polygon with this tool First click in the inner area of the polygon next to the point where you want to add a new vertex Then cross the boundary and add the vertices outside the polygon To finish right cl

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