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GRASS 4.2 Sites Commands

1. parameters value value Parameter s of distribution If the distribution is uniform only one parameter the maxi mum is needed For a normal distribution two parameters the mean and standard deviation are required NOTES The uniform distribution is always centered about zero The associated parameter is constrained to be positive and specifies the maximum of the distribution the minimum is the negation of that parameter Usually the mean first parameter of the normal distribution is zero i e the distribution is centered at zero The standard deviation second parameter is naturally constrained to be positive Output sites are not guaranteed to be contained within the current geographic region SEE ALSO g region s rand s univar s kcv AUTHOR James Darrell McCauley Agricultural Engineering Purdue University Random number generators originally written in FORTRAN by Wes Peterson and translated to C using f2c 29 s probplot NAME s probplot Normal probability plot of a GRASS site list GRASS Sites Program SYNOPSIS s probplot s probplot help s probplot alq sites name width value graph name DESCRIPTION s probplot does normal or lognormal probability plots of site values OPTIONS Flags a Use all sites found in the named sites file rather than limiting output to sites falling within the current geographic region l Lognormal probability plot instead of normal q Quiet Cut out the chatte
2. ESC will allow entry of another site number and CTRL C will exit to the main menu 10 Use this selection to add a new site record to the data base A new site is one whose site number does not currently exist in the open data base After making this selection the data base layout will be displayed and you should enter the available information appropriate to each field the only required entry is the site number field If values for numeric fields are not entered zero values will be stored Unused portions of text fields are stored as strings of spaces 11 After making this selection and specifying the site number to change field information for the data is entered as for choice 10 except that the site number cannot be changed The command version of the program has provision for making bulk changes after a find or query see change 12 To delete a single record enter its site number when requested All site records chosen by the last find query opera tion may be deleted by entering list in place of the site number BE CAREFUL with this deleted records are really gone 13 This choice starts a new menu with less commonly used functions See MANAGEMENT MENU section below 14 The program will prompt you for one line Shell Commands until you enter just a amp lt RETURN amp gt to return to the main menu Often useful for changing the GRASS region setting a MASK etc FIND QUERY TARGET MENU This is the screen to set up the reg
3. and characters Logical comparisons may also be combined with those operators above The permitted logical operators are and or not The following complex example should be examined The line breaks can occur between any tokens words values operators except within quoted strings where name like Jones or name Smith and site lt 300 and not site 251 or site eq 15 or east lt 601000 5 This choice will display the site records resulting from the last find query one at a time on the terminal Use ESC or enter a number to display another record and CTRL C to end the display 6 Ifa graphics monitor is active the locations of the selected sites will be displayed The user may choose to erase the screen display raster vector and or site maps or display the selected sites from the data base These maps are requested through the following interactive screen Just enter ESC to skip this step If no data base sites are currently selected that section of the menu will not appear but the menu can still be used to display the other types of maps This display function is a major added function of the interactive version of the program display is not so easy in the command version 11 SELECTION MENU FOR ITEMS TO DISPLAY Enter raster and or vector map names if desired Raster map to display Vector map to display in color Site list to display Dpoints with size 3_ type box color white _ Di
4. s surf tps program interpolates the values to grid cells from point data digitized contours climatic stations drill holes etc given in a sites file named input The output raster file is elev As an option simultaneously with interpolation topographic parameters slope aspect profile curvature measured in the direction of steepest slope tangential curvature measured in the direction of a tangent to contour line or mean curvature are computed and saved as raster files as specified by the options slope aspect pcurv tcurv mcurv respectively User can define a raster file named maskmap which will be used as a mask The interpolation is skipped for cells which have zero value in mask Zero values will be assigned to these cells in all output raster files Data points are checked for identical points and points that are closer to each other then the given dmin1 are removed this is necessary especially for digitized contours Parameter zmult allows the user to rescale the z values for sites useful e g for transformation of elevations given in feet to meters so that the proper values of slopes and curvatures can be computed Regularized spline with tension is used for the interpolation The tension parameter tunes the character of the resulting surface from thin plate to membrane Higher values of tension parameter reduce the overshoots that can appear in surfaces with rapid change of gradient see suggested values for different types of
5. where clause in the select command especially the quotes required for matching character string fields and the allowed comparison operators 3 In the where clauses of the examples density date county east and name are field names column names in RIM defined when the user initially makes the data base 4 Each query or find resets the internal site list even unsuccessful ones unless the a or d flags are used read_site re site_list comment_field This command reads an existing GRASS site list and creates a data base record for each site If the comment or descrip tion field of all entries in the site list begin with and a number the number becomes the site number in the data base If some of the sites in the GRASS site list do not have a at the beginning of the comment field the sites are numbered sequentially starting with 1 These options are similar to the way the GRASS sites to raster in s menu works if a data base field name comment_field is entered on the command line the comment will be stored in that field for each site If an integer or float field is specified and attempt is made to interpret the comment as that type of number if this interpretation fails 0 or 0 0 is stored If the site number duplicates one already in the data base or found earlier in the site list it is not added Once the sites have been loaded by read_site use change or the inter
6. accuracy of the plating method of estimating the density of bacterial populations Annals of Applied Biology 9 325 359 1922 M Lloyd Mean crowding Journal of Animal Ecology 36 1 30 1967 M Morista Measuring the dispersion and analysis of distribution patterns Memoires of the Faculty of Science Kyushu University Series E Biology 2 215 235 1959 AUTHOR James Darrell McCauley Agricultural Engineering Purdue University 32 s rand NAME s rand Randomly generate a GRASS sites list GRASS Sites Program SYNOPSIS s rand s rand help s rand r d n value sites name DESCRIPTION s rand randomly generates sites using the selected random number generator OPTIONS Flags r Use rand the default l Use drand48 Parameters n value Positive integer value indicating the number of sites to be created sites name Name ofa sites file to store random points in SEE ALSO UNIX man pages for rand 3 and drand48 3 AUTHOR James Darrell McCauley Agricultural Engineering Purdue University 33 s sample NAME s sample Sample a raster file at site locations GRASS Sites Program SYNOPSIS s sample s sample help s sample BCcdlq input name output name rast name z name DESCRIPTION s sample samples a GRASS raster map at the site locations in the input file by either cubic convolution interpolation bilinear interpolation or nearest neighbor sampling default Categories values are sampled
7. cells to represent a site The minimum is one cell per site The alternatives are squares around the site 3x3 5x5 7x7 etc The number of categories present in the new raster map layers will depend on the format of your site list file see sites format You can create a non binary raster map layer representation of your site list by creating the site list in the format E N n label where E is the Easting N is the Northing and n label is the description field The descrip tion field consists of a pound sign followed by the category value n to be associated with the site s cell location and the category label label for n If the user does not include a description field starting with n beside the Easting and Northing on every line in the sites list file a binary raster map layer will be created instead In the binary raster file each site will be represented as the category value 1 Non site cells will be coded as category value 0 Note that only sites within the current geographic region will be considered However if the size of the sites is more than one cell 3x3 5x5 etc and a site lies near an edge of the geographic region some of the cells for the site may fall outside the geographic region These cells will not appear in the raster map layer and the site will no longer be 3x3 or 5x5 but will be clipped to fit the geographic region 23 7 Convert site list file to raster file frequency of occurrence You can a
8. fields is also possible but requires even more experience and knowledge The user needs to carefully design the data base fields and form layout and check the operation with a few pieces of test data before loading data for a large number of sites COMMANDS Note For each of the dot commands i e make described below there is a menu choice to selected when running the interactive version The interactive menus are described in the SECTION TWO of this document Some display capabili ties exist in the interactive version which are not directly implemented in the command version The commands are given alphabetically here for easy reference The make command is required to create a data base and therefore will be the first to be entered by a new user Abbreviations down to the string shown in are accepted this is primarily for those giving s db rim commands from a terminal but abbreviations may also be used in batch files Each command is introduced with an input record line which starts with a period and is followed by one of the words shown below for some commands the command line also contains one or more required or optional parameters Addi tional or optional input instructions data for a command are supplied on successive lines a end line is needed by some commands to signify the end of these input lines Alphabetical Command Summary command This is the only s db rim command not starting with a period co
9. locations and optionally category labels these should be entered to the program via standard input NOTES Other GRASS programs can be used to produce output in a format suitable for input to s in ascii For example the user might pipe output produced by d where into s in ascii to create a site list file called my sites containing site locations pointed to with the mouse as illustrated below In this example it was unnecessary to specify the field separator used in the input since d where output separates the easting and northing values with spaces and spaces are the default field separator assumed by s in ascii d where s in ascii sites my sites SEE ALSO d points d sites d what rast d where s out ascii AUTHOR Michael Shapiro U S Army Construction Engineering Research Laboratory 18 s in grid NAME s in grid convert Arc GRIDASCII output to site list GRASS Shell Script SYNOPSIS s in grid file DESCRIPTION s in grid is a awk script that reads the output of Arc INFO s GRIDASCII command and converts it to a GRASS site list Parameters file Name of the output of GRIDASCII EXAMPLE Typing the following Arc GRIDASCI nitrates tmp Arc quit GRASS GRID amp gt s in grid tmp s in ascii nitrates fs GRASS GRID amp gt rm tmp This procedure exports the GRID file nitrates from Arc INFO and imports it as the GRASS site list nitrates NOTES awk may not be able to handle large ASCII grids In these insta
10. name outvarz name model name npoints count range semivariogram range power exponetial power nugget semivariogram nugget sill semivariogram sill max_lag max_lag Parameters input name Name of input site map outz name Name of output z value raster map outvarz name Name of output z variance raster map model type Type of semivariogram model to be used options power spherical exp log gaussian npoints value Number of interpolation points default 12 range value Not used with log or power models default 1 0 power value Only for use with the power model default 1 0 nugget value The variogram nugget variance default 0 0 sill value The variogram sill scaled to the sample variance default 1 0 max_lag value The max lag is only used with the power model default 1000 0 NOTE You have to play with the parameters to get a reasonable result and not a segmentation violation AUTHORS Chris Skelly School of Earth Sciences Macquarie Univerity North Ryde 2109 NSW Australia Darrel McCauley 36 S surf tps NAME s surf tps Interpolates and computes topographic analysis from given site data to GRASS raster format using spline with tension GRASS Raster Program SYNOPSIS s surf tps s surf tps help s surf tps input name elev name slope name aspect name pcurv name tcurv name mcurv name maskmap name dmin1 val zmult val tension val smooth val segmax val npmin val DESCRIPTION
11. required This input may be from a text file or may be entered directly using the editor of your choice the former is recommended See make for the way to define a data base and record form layout NOTES This program is included in the GRASS 4 2 release but is not automatically compiled with other GRASS commands The user must compile this program separately s db rim interfaces to the RIM program Both rim and s db rim contain FORTRAN code The user must have access to a FORTRAN compiler in order to compile and use s db rim See the FILES section below for the location of source code A date type field should be added to future versions This version only allows storing of dates as strings unless the user codes them to integers and thus only string type searches can be made for dates BUGS On LINUX I have some problems If You select menu 13 8 and hit ESC there is no output to the screen s db rim expects here the name of the site file or the keyword list If You select menu 8 You hould be asked for the site_list filename but the screen remains empty Simply enter the name FILES The source code for RIM is located under GISBASE src related rim The source code for s db rim is located under GISBASE src garden grass rim s db rim SEE ALSO The RIM User s Manual by Jim Fox Academic Computing Services Univ of Washington See especially Appendix B on redistribution of RIM The RIM Installers manual G
12. until an end of file is reached or until a exit command is found Input files may call other input files to a nesting depth of eight Without a file name stdin is used as the input file list 1 Lists the available data bases in the current mapset search path make Using the nake command you create a new data base in the current mapset by specifying the following items which define the screen page layout for displaying and printing the site records as well as the information fields 1 The fixed text part of the screen layout 2 The positions types names and lengths of data fields Three fields must always exist in a data base each of these field types may only occur once in a data base layout 1 Type s Site identification number field an integer 2 Type x Easting coordinate of the site a double float 3 Type y Northing coordinate of the site a double float The other field types which may occur in any combination and order are 4 type i An integer field 5 type f A double precision float field 6 type t A text field Each of the fields can be positioned anywhere within the screen layout which has a limit of 19 lines by 80 columns A maximum of 70 fields may be defined within this space A field is specified in the screen layout by a tilde a field type character a field name and enough trailing tildes to fill out the desired field length 6 Each line fol
13. user will be prompted for parameter values and flag settings using the standard GRASS parser interface Parameters input name Use the existing site file name as input elev name Output elevation values to raster file named name 37 slope name Output slope values to raster file named name aspect name Output aspect values to raster file named name pcurv name Output profile curvature values to raster file named name tcurv name Output tangential curvature values to raster file named name mcurv name Output mean curvature values to raster file named name maskmap name Use the existing raster file name as a mask dminl val Set min distance between points to val Default value is set to 0 5 grid cell size zmult val Convert z values using conversion factor val Default value is 1 tension val Set tension to val Default value is 40 appropriate for smooth surfaces smooth val Set smoothing parameter to val Default value is 0 no smoothing is performed segmax val Set max number of points per segment to val Default value is 40 npmin val Set min number of points for interpolation to val Default value is 150 for data with heterogeneous spatial distribution higher value is suggested NOTES There are some peculiar differences between s surf tps for LINUX and for SUN The usage of the same parameters is causing a segmentation violation on LINUX on SUN s surf tps is running well e g the interpolation of the heroldsberg el
14. 1410 00 reference Jones 1987 end backup b file_name The backup command is used to dump the entire data base from the RIM binary files to a text file format see UNLOAD in the RIM User s Manual The file_name can be a relative path name or full path name The file will contain the data base definition screen layout information and tabular data This text file is transportable to RIM or s db rim running on any other computer it may also be reloaded to recreate the s db rim data base A message will be output if there is any problem writing the backup file Backup can only be done on data bases in the user s current mapset To reload your data base from the backup file normally not necessary GRASS 4 2 gt cd LOCATION rim sites right directory GRASS 4 2 gt rm db_name rimdb1 remove data base or mv to somewhere GRASS 4 2 gt rm db_name rimdb2 remove data base or mv to somewhere GRASS 4 2 gt rm db_name rimdb3 remove data base or mv to somewhere GRASS 4 2 gt rim run RIM manually RIM gt input path file RIM rebuilds data base from data written by backup RIM gt exit change c 1 Without the 1 flag each line following change is in the same format as for the add command The site number field is required and the site number must match an existing site in the data base Only those fields for which lines are provided are changed in the record After the end the changed record is st
15. After selecting A or B complete one of these 1 x to select target point with mouse x 2 Enter site number for target point 3 Target coordinates east 0 00 north 0 00 Append Delete to current FIND QUERY site list a d Reset to default choices for this menu _ AFTER COMPLETING ALL ANSWERS HIT lt ESC gt TO CONTINUE OR lt Ctr1l C gt TO CANCEL QUERY COMMAND MENU The following screen completes the information for a query choice 4 It may be left blank if no where clause is required After a successful query the selected records are displayed one at a time by hiting escape CTRL C will quit the display and return to the main menu where several choices of operation on the retrieved sites are offered QUERY COMMAND CONSTRUCTION SCREEN Data base lt A gt in mapset lt rim_test gt open 25 records The SQL select query will use the current region and a target clause of distance from 596463 15 4919041 88 where date 10 16 89 Enter show on a line to review screen layout and field names AFTER COMPLETING ALL ANSWERS HIT lt ESC gt TO CONTINUE OR lt Ctrl C gt TO CANCEL 13 MANAGEMENT MENU Choice 13 from the main menu presents this menu Each item is discussed below s db rim DATA BASE MANAGEMENT MENU Data base lt A gt in mapset lt rim_test gt open 15025 records Make a New Data Base in Current Mapset List Available Data Bases Remove PERMANENTLY Data Base from Curre
16. GRASS 4 2 Reference Manual Section VIII GRASS 4 2 Sites Commands S F Clamons and B W Byars GRASS Research Group Baylor University Waco Texas OPEN GIS Copyright 1997 GRASS Research Group Baylor University Table of Contents SEAT UI EEEE AE E EEE TE EE E EE T ENEE EN TO A E A TE 3 RL A AE EE S EIE IS SE SEA 16 SIN ASCU add a 18 SULT EEE AE AES EES E AIS NEATE 19 EMO di ad ERE A 20 AAA EEEIEE rd 22 SSTLOV TIAL AA ierse as ie nEs EEn ESSENS EE E EE EESE EE aS 26 SO dis 27 DOI Do a id ai 29 SDEODPLO A A aid 30 ECON A A A a a 32 A A A A ENE 33 SSP A in daa 34 RII A E EAE E E O A EE AEEA 35 SSA dd daa 36 SSA A ds 37 SV aaa daa 41 A VASE RRE A E A T AEA 42 SAO VECI AA A EOE AE OE a 43 UNIV ARA NO EE eI a a ati 44 s db rim NAME s db rim RIM data base management query interface for GRASS sites data GRASS Sites Management Program SYNOPSIS s db rim s db rim data_base DESCRIPTION For some informations on LINUX and RIM look at the BUGS section s db rim allows users to create manage and query information about site locations sites across the landscape Required inputs can be entered interactively or from the command line Command line input may be entered through a prepared text file or from the keyboard standard input The s db rim command language is defined in SECTION ONE below The menu driven interactive version is described in SECTION TWO of these manual pages These programs are actually a ma
17. RASS 4 2 Installation Guide by Jim Westervelt and Michael Shapiro U S Army Construction Engineering Research Laboratory d icons d points g mapsets g region r mask s in ascii s menu s out ascii v db rim AUTHORS James Hinthorne and David Satnik GIS Laboratory Central Washington University Ellensburg WA 15 s geom NAME s geom Computes Delaunay triangulation MinMax Angle triangulation MinMax Slope triangulation MaxMin Height triangulation Regular triangulation planesweep triangulation Voronoi diagram and convex hull of sites in 2 and 2 1 2 dimensions SYNOPSIS s geom s geom help s geom input name output name precision value operation name DESCRIPTION s geom takes a sites file as input and computes various triangulations the Voronoi diagram or the convex hull of the sites The z coordinate is read from the description field if it is specified otherwise 0 is assumed The z coordinate is used for the MinMax slope triangulation and for the regular triangulation where it is interpreted as the weight of the site For all other computations the z coordinate is ignored The MinMax angle triangulation is the triangulation for the sites which minmizes lexicographically the sorted vector of all the angles of triangles in the triangulation The MaxMin height and MinMax slope triangulations are similar The algorithms used for the computations are not heuristics they actually achieve the optimum The regular tr
18. The optional find command line parameter specifies the current MASK m if any or the current region r as a filter on the retrieved sites m automatically implies r as the MASK is not defined outside the current region If the a flag is given the retrieved sites will be appended to those previously retrieved with a query or find duplicates will be automati cally discarded The d flag causes the retrieved sites to be deleted from the internal site list if present there Very complex selections can be done by interspersing appends and deletes to arrive at a final list of sites For instance selecting those sites within 2000 meters of a target and then deleting those within 1500 meteres of the target will give a final list of those from 1500 to 2000 meters The single required line following the find line gives the program the necessary target information The following examples show the possibilities find gt 602793 90 4379010 00 will find the one site nearest these coordinates and store it on the internal site list find gt 619840 4599000 10 will find the 10 sites or fewer if there are not that many closest to the given location find gt site 132 10 will find the 10 sites closest to the location of site 132 in the data base including site 132 If site 132 does not exist no action is taken find gt distance from 472910 06 5732001 0 5000 will find all sites within 5000 meters in UTM or Lat Long coordinates of the targe
19. This program may be especially useful when sampling for cross validation of interpolations whose output is a raster map OPTIONS Flags B Use bilinear interpolation C Use cubic convolution interpolation c Use numeric category labels instead of category values d Calculate difference between raster value and site value raster minus site l Tf site is in the E N n label format instead of the E N label format use the numeric label as the site value Implies the d flag q Quiet Cut out the chatter Parameters input name Name of sites list defining sample points output name Optional name of sites list in which output will be stored Standard output is used if this is missing rast name Name of raster map to be sampled z value Option scaling factor for values read from raster map Sampled values will be multiplied by this factor If omitted this is set to 1 0 NOTES If any of cdl are specified 1t is important that the raster category label and or the site description are numeric No error checking is done except for no data values as raster category labels In this instance a warning is issued and a zero value is assumed When interpolation is done 1 e the BC flags are used values are assumed to be located at the centroid of grid cells Therefore current resolution settings are important This program may not work properly with lat long data when the BC flags are used SEE ALSO s rand s kcv g regi
20. active version to add data to other fields for those sites remove This command which requires a y as confirmation on the next line entirely removes the three binary files which constitute your RIM data base Use with care Backup files must be removed individually by the user if desired from the LOCATION rim sites directory show sh This command is used to output the screen or page layout as defined for the current data base It serves as documentation of the data base definition and as a reminder for field names types and lengths By using an editor to surround the output of show with make and end lines it can be used to reload the data base definition with input site _list si file_name field_name This command writes the site locations and the site numbers to the specified file in the site_list directory in the current mapset If the file exists the sites are appended to the current list otherwise a new site list file is created A field name may be optionally specified if so the contents of that field retrieved from the appropriate site record are inserted as the comment following a in the site list The site number is used if no field name is supplied A comment line is inserted in the site_list file with the current date and time and the name of the data base producing the site locations The format used for each site is easting northing comment tables t Print
21. ault is half of nominal distance direction value Direction of semivariogram Default is omnidirectional semivariogram angtol value Angular tolerance on direction graph name_ Basename to save graphing data commands files Graphs are saved in the current working directory with the extensions gp and dat Implies the p flag If unspecified semivariogram is written to standard output NOTES Without the p flag three columns of data are written to standard output lag distance h semivariogram value gamma and the number of data pairs used to compute it N h When the graph parameter is set these same three columns of data are written to name dat Therefore to replot a sample semivariogram use g gnuplot name gp To plot a histogram of N h simply edit name gp and redo the previously given command SEE ALSO s univar s normal g gnuplot m svfit Semivariogram Modeling A GRASS Tutorial on Exploratory Data Analysis and Semivariogram Modeling BUGS Will not work correctly with lat long data Should G_azimuth be used to calculate the angle between points Only Matheron s classical estimator is available with s sv Others may be added in the future AUTHOR James Darrell McCauley Agricultural Engineering Purdue University 41 S to rast NAME s to rast Converts a site file to a cell file GRASS Sites Program SYNOPSIS s to rast s to rast help s to rast v input name output name DESCRIPTION s to rast
22. brief ASCII listing and fs is the field separator to be placed between output fields The user can also the a and d options to use all sites in the named sites file and to include site descriptions in the output Alternately the user can simply type s out ascii on the command line without program arguments In this case the user will be prompted for parameter values using the standard GRASS parser interface NOTES The output from s out ascii may be placed into a file by using the UNIX redirection mechanism e g s out ascii sites archsites amp gt out file 27 s out ascii output may also be redirected into other programs e g s out ascii sites archsites d points color red size 10 type diamond SEE ALSO d points d sites m ll2u m u2ll s in ascii AUTHOR Michael Shapiro U S Army Construction Engineering Research Laboratory 28 s perturb NAME s perturb Random location perturbations of GRASS sites GRASS Sites Program SYNOPSIS s perturb s perturb help s perturb q input name output name distribution uniform normal parameters value value DESCRIPTION s perturb reads a site list and writes the same list but perturbs the eastings and northings by adding either a uniform or normal delta value OPTIONS Flags q Quiet Cut out the chatter Parameters input name Name of an existing sites file output name Name of output sites file distribution uniform normal Distribution of perturbation
23. cimal digits BUGS Some fields of the header in the output file are not properly set 16 REFERENCES M Bern H Edelsbrunner D Eppstein S Mitchel T S Tan Edge Insertion for Optimal Triangulations In Proc Ist Latin American Sympos Theoret Informatics 1992 46 60 H Edelsbrunner Algorithms in Combinatorial Geometry Springer Verlag Heidelberg Germany 1987 H Edelsbrunner N R Shah Incremental Flipping Works for Regular Triangulations In Proc 8th Ann Sympos Comput Geom 1992 43 52 H Edelsbrunner T S Tan and R Waupotitsch An O n 2 log n Time Algorithm for the MinMax Angle Triangulation SIAM J Sci Statist Comput 13 1992 994 1008 SEE ALSO v geom AUTHOR Roman Waupotitsch 17 s in ascii NAME s in ascii Converts an ASCII listing of site locations and their descriptions into a GRASS site list file GRASS Sites Program SYNOPSIS s in ascii s in ascii help s in ascii sites name input name fs character space tab DESCRIPTION s in ascii converts an ASCII listing of site locations and category labels into a file in GRASS site list file format Input can be entered via standard input or from the file input name Each line of input should contain the easting northing and optionally the category label associated with a site The fs name option where name is either a charac ter a space or a tab can be used to specify the use of a particular field separator between these three
24. converts a GRASS site file to a GRASS cell file The program uses a subset of the functions in s menu The quad size ie the number of cells used to represent one site is fixed to 0 ie one cell site If the output file already exists the program exits gracefully OPTIONS Flag v Run the program verbosely Parameters input name Name of input site list output name Name of output cell file SEE ALSO S menu AUTHOR Katarina Johnsson CCRS 42 S to vect NAME s to vect Converts a GRASS site_lists file into a vector file GRASS Sites Program SYNOPSIS S to vect s to vect help s to vect input name output name DESCRIPTION s to vect converts GRASS site_lists file into vector files The resulting vector file can be treated as any other vector file The requirements of the site_lists file are standard 1 e a regular site_lists file format is required site_lists file values are used as dig cats category values OPTIONS Parameters input name Name of input GRASS lt KBD gt site_lists lt KBD gt file to be converted output name Name to be assigned to the vector output file AUTHOR R L Glenn USDA SCS NHQ CGIS 43 s univar NAME s univar Univariate statistics for a GRASS sites list GRASS Sites Program SYNOPSIS S univar s univar help s univar aglq sites name DESCRIPTION s univar calculates univariate statistics of sites lists This includes the number of sites mean standard deviatio
25. ded inputs and option choices using the standard GRASS parser interface OPTIONS Parameters input name Name of an input site list file that contains a set of irregularly spaced data values i e some cells contain known data values while the rest contain zero 0 output name Name to be assigned to the new output raster map layer containing a smooth surface generated from the known data values in the input site list file npoints count The number of points to use for interpolation By default the 12 nearest points are used for interpola tion Default 12 NOTES The amount of memory used by this program is related to the number of non zero data values in the input sites list file If the input site list is very dense 1 e contains many non zero data points the program may not be able to get all the memory it needs from the system The time required to execute increases with the number of input data points If the user has a mask set then interpolation is only done for those cells that fall within the mask However all non zero data points in the input map are used even if they fall outside the mask SEE ALSO d sites g region r mask r surf contour r surf idw r surf idw2 s db rim s menu AUTHOR Michael Shapiro U S Army Construction Engineering Research Laboratory 35 s surf krig NAME s surf krig Surface interpolation from site data via kriging SYNOPSIS s surf krig s surf krig help s surf krig input name outz
26. denote the extent of the site since for example an archeologic site which takes up two hectares would be represented as a single point The information reported for each site is displayed by raster map layer and within each map layer gives the categories i e characteristics that occurred at the site as well as a count of the number of cells in each category This can easily generate a massive amount of information which is difficult to handle or digest quickly Therefore option 2 produces a synopsis of the information 2 Site occurrence report This report provides aggregate site characteristic information organized by raster map layer The report produces chi square statistics for each raster map layer measuring number of expected sites assuming a random distribution of sites against actual site occurrence The site characteristic is the most frequently occurring cell category in the site 1 e the statistical mode See the GRASS manual entry for sites occur for details on this report 3 Convert data to S input format This function converts the GRASS data extracted for the sites into a form usable by the S statistical package The user provides a file to contain the information Once the file is written the user must exit s menu run S on an S data base and issue the S command source file to bring the data into the S data base Of course file would be the name of the actual file supplied by the user See manual entry sites S
27. ds SQL Show selected site records on Terminal Display maps selected sites on graphics terminal Output selected site records to Printer or File Create a site list from selected records Add Edit Site Records 9 View a single site record 10 Add a site record 11 Change a site record 12 Delete a single record or all selected records Other functions Shell Command Exit 13 Make a new data base amp Management Functions 14 Execute a shell command oN DAUA 0 Done Exit from s db rim AFTER COMPLETING ALL ANSWERS HIT lt ESC gt TO CONTINUE OR lt Ctrl C gt TO EXIT THIS PROGRAM 1 Open a data base Ifa data base is already open it is closed before the requested one is opened Only data bases in the user s current mapset may be modified others are opened in read only mode this will be indicated on line 2 2 List available data bases For each mapset in the current GRASS mapset search path the names of the existing data bases are listed 3 Find sites in the data base relative to a specified target location This is used to select sites based on proximity to the target and optionally sites within the current region and optionally sites falling in active cells within the current GRASS mask Two modes of targeting are provided the N sites closest to the target and all sites within or outside a 10 circle of specified radius from the target The FIND QUERY TARGET MENU discussed below accepts region mask
28. e stored is re moved 4 Check site list for duplicate sites It is not desirable that a site list contain multiple references to the same site This option attempts to recognize duplicate sites Duplicates are displayed to the user and can be removed automatically if the user desires Duplicates can also be removed by hand using option 5 edit 5 Edit site list using a UNIX editor The user can modify the current site list or create a new site list by hand using a UNIX editor You will be asked to specify the text editor you prefer to use You should exercise some care if you select this option Lines in the site list which have invalid formats will be silently ignored by s menu See the GRASS manual entry sites format for a descrip tion of the site list format Note This option will only modify the site list copied into the server It does not modify the original site list stored under a GRASS mapset If you wish to modify a stored site list file you will have to combine options read 5 edit and 3 save 6 Convert site list file to raster file 0 1 You can create a raster data representation of the site list in your GRASS mapset Once created this raster map layer can be used with other raster map layers in further analyses Allowing the user to create a raster map layer of sites opens up the full analysis capabilities for site data that are available for raster map layers within GRASS You have the option of specifying the number of
29. evation maps was using on SUN a temporary space of 170Mb on LINUX approx 80Mb Please play with the parameters for a reasonalble result s surf tps uses regularized spline with tension for interpolation from point data The implementation has an improved segmentation procedure based on quadtrees which enhances the efficiency for large data sets Special color tables are created by the program for output raster files Topographic parameters are computed directly from the interpolation function so that the important relationships between these parameters are preserved The equations for computation of these parameters and their interpretation Slopes and aspect are computed in degrees 0 90 and 1 360 respectively The aspect raster file has value 0 assigned to flat areas with slope less than 0 1 and to singular points with undefined aspect Aspect points downslope and is 90 to the North 180 to the West 270 to the South and 360 to the East the values increase counterclockwise Curvatures are positive for convex and negative for concave areas Original values of curvatures are multiplied by 100000 to conform with GRASS integer raster files Therefore any curvature lower than 0 00001 will be zero Flat areas have zero curvatures and singular points have codes 1000000 2000000 3000000 for peak pit and saddle respectively We suggest to use these codes only to distinguish areas grid cells with undefined curvature because the codes are assigned
30. f indices or multiple thereof Sample skewness and kurtosis Geary s a statistic and an approximate normal transformation Extreme normal deviates D Agostino s D statistic Modified Kuiper V statistic Modified Watson U 2 statistic Durbin s Exact Test modified Kolmogorov Modified Anderson Darling statistic Modified Cramer Von Mises W 2 statistic Kolmogorov Smirnov D statistic modified for normality testing Chi Square test statistic equal probability classes and the number of degrees of freedom Shapiro Wilk W Test Weisberg Binghams W similar to Shapiro Francia s W Royston s extension of W for large samples Kotz Separate Families Test for Lognormality vs Normality EXAMPLE s normal input soils tests 1 3 14 computes the sample skewness and kurtosis Geary s a statistic and an approximate normal transformation extreme normal deviates and Royston s W for the soils site list SEE ALSO s univar AUTHOR James Darrell McCauley Agricultural Engineering Purdue University 26 s out ascii NAME s out ascii Converts a GRASS site list file into an ASCII listing of site locations and their descriptions GRASS Sites Program SYNOPSIS S out ascii s out ascii help s out ascii ad sites name fs character space tab DESCRIPTION s out ascii converts an existing site list file sites name into an ASCII listing of site locations and optionally their category labels in a format suitable for i
31. for an explanation of the S data structures created by this interface 4 Produce machine readable data file This option provides a mechanism for the user to write his her own reports The data is written into a user specified file as a text file which has a format readable by UNIX utilities e g awk or user written programs See GRASS manual entry sites report for details on this format 24 FILES LOCATION site_list amp lt file amp gt SEE ALSO d icons d graph d points d sites p icons rrandom d what rast d what vect rwhat s in ascii s out ascii s db rim s surfiidw s surf tps v db rim v mkquads v to sites sites format sites report sites occur sites S AUTHORS Michael Shapiro U S Army Construction Engineering Research Laboratory James Farley Arkansas Archeological Survey University of Arkansas contributed the frequency of occurrence sites to cell function 25 s normal NAME s normal tests for normality for sites GRASS Sites Program SYNOPSIS s normal s normal help s normal q input name tests rangef range DESCRIPTION s normal computes tests of normality on a site list OPTIONS Flag q Quiet Cut out the chatter when reading site list Parameters input name Name of sites list tests range range Tests of normality requested see below NOTES The tests that s normal performs are listed below The tests that are performed are specified by giving an index ranges o
32. g Purdue University 21 s menu NAME s menu Accesses and manipulates GRASS site location data GRASS Sites Program SYNOPSIS S menu DESCRIPTION The s menu program provides the user with the capability of interfacing site location data with the geographic data in raster map layers Two types of spatial analysis reports on sites can be generated and an interface to the S statistical package is provided The s menu program is an interface to functions that allow the user to manipulate GRASS site lists A site list is a list of eastings and northings describing the location of some point feature It can also contain a category value and category label for each site location The program is interactive After typing s menu on the command line the user selects site functions from a menu The main menu is shown below SITES MAIN MENU current list no sites LOCATION spearfish REGION 4928000 00 N 4914000 00 S 100 00 RES MAPSET PERMANENT 609000 00 E 590000 00 W 100 00 RES MASK none Please select one of the following 1 Read an existing site list 2 Mask current site list 3 Save the current site list in your mapset 4 Check site list for duplicate sites 5 Edit site list using a UNIX editor 6 Convert site list to raster file 0 1 7 Convert site list to raster file frequency of occurrence 8 Run reports on the current site list stop Leave the s menu program At the top of the menu is general infor
33. hooses n circular quadrats of radius r such that they are completely within the bounds of the current region and no two quadrats overlap The number of sites falling within each quadrat are counted and indices are calculated to estimate the departure of site locations from complete spatial randomness OPTIONS Flags c Print count data for each quadrat in a sites list format E N n desc where E is the easting and N is the northing of the quadrat center n is the quadrat number desc is an integer indicating the number of sites contained within the quadrat i Suppress printing table of indices default is to print indices and not the count data q Quiet Cut out the chatter Parameters input name Name of sites list defining qcount points n value Number of quadrats integer r value Radius of quadrats floating point NOTES This program may not work properly with lat long data It uses hypot in two files count c and findquads c SEE ALSO s rand Noel A C Cressie Statistics for Spatial Data Wiley Series in Probability and Mathematical Statistics John Wiley amp Sons New York NY 1st edition 1991 Brian D Ripley Spatial Statistics John Wiley amp Sons New York NY 1981 F N David and P G Moore Notes on contagious distributions in plant populations Annals of Botany 18 47 53 1954 J B Douglas Clustering and aggregation Sankhya B 37 398 417 1975 R A Fisher H G Thornton and W A Mackenzie The
34. iangulation is the weighted version of the delaunay triangulation weights are assigned to the sites the delaunay triangulation corresponds to the regular triangulation where all the sites have identical weights The output is saved in vector file format OPTIONS Parameters input name Input vector level 2 file output name Output vector file precision value Number of significant positions after the decimal point default is 0 operation name One of the following sweep delaunay angle height slope hull These correspond to the planesweep triangulation Delaunay triangulation MinMax angle triangulation MaxMin height triangulation MinMax slope triangulation regular triangulation Voronoi diagram and convex hull respectively default is Delaunay triangulation NOTES Only the sites which fall into the current region are used for the computations The computation times for the various operations depends strongly on the algorithm used The plansweep triangulation and convex hull computation require O n log n operations in the worst case The Delaunay heuristic needs O n 2 time in the worst case however it performs much faster in practice The MinMax angle and MaxMin height triangulations need O n 2 log n operations and the MinMax slope triangulation needs O n 3 opera tions Internally the coordinates of the sites are stored in fix point format Therefore the number of decimal digits cannot exceed 64 bit or apprx 16 de
35. ile rather than limiting output to sites falling within the current geographic region e Store row column and all effects in output file s Write results to a sites list file default is to write points in a binary vector file q Quiet Cut out the chatter Parameters sites name Name of an existing sites file vect name Name of the grid file binary vector file output name Name of the output file binary vector file or sites list report name Name of an ASCII file which shows original and residual data in tabular form thresh n Threshold to determine when convergence of median polish is obtained default 1 s medp can be run either non interactively or interactively The program will be run non interactively if the user specifies the name of an existing sites list file name for a vect file and name of an output file using the form s medp aeqs sites name vect name output name report name thresh n 20 Alternately the user can simply type s medp on the command line without program arguments In this case the user will be prompted for parameter values using the standard GRASS parser interface NOTES When using the report option the tabular report may be more than 128 columns wide Therefore it may be useful to add a TeX or PostScript wrapper before printing e g enscript h r fCourier Bold5 p report ps report so that the page is in landscape orientation and a very small font is used The input vector fi
36. input fields This is useful when input is obtained from other programs see NOTES below Output is stored in the file sites name and placed in the site_lists directory under the user s current mapset The GRASS program s out ascii can be used to perform the reverse function converting a file in GRASS site list format into an ASCII listing of eastings northings and category labels associated with site locations Parameters sites name Name of the new GRASS site list file to be output input name Name of an existing ASCII file containing site locations and labels fs character space tab The field separator separating the easting northing and category label in each line of the input file The field separator can be a character a space or a tab Default space s in ascii can be run either non interactively or interactively The program will be run non interactively if the user specifies a name to be assigned to the sites file output the name of an existing ASCII file containing input and option ally a field separator fs appearing in the input file using the form s in ascii sites name input name fs character space tab Alternately the user can simply type s in ascii on the command line without program arguments In this case the user will be prompted for parameter values using the standard GRASS parser interface described in the manual entry for parser If the user does not specify the name of an input file containing site
37. interpolation of DEM from digitized contours tension 20 80 smoothing 0 01 1 0 segmax 40 npmin 200 300 low tension was used for relatively flat terrain high tension was necessary for terrain with sharp changes in slope low value of smoothing is usually sufficient for dense and accurately digitized contours for less dense and not very carefully digitized contours higher smoothing is suggested interpolation of precipitation from climatic stations tension 40 150 smoothing 0 2 segmax 40 npmin 200 39 interpolation of concentration of chemicals tension 20 60 smoothing 0 5 5 0 The user must run g region before the program to set the region for interpolation SEE ALSO v to sites g region r surf contour rsurfidw r surfiidw2 s surf idw AUTHOR Original version of program in FORTRAN Helena Mitasova Illinois Natural History Survey and US Army CERL Champaign Illinois Comenius University Bratislava Czechoslovakia Lubos Mitas Department of Physics University of Illinois at Urbana Champaign Illinois Institute of Physics Bratislava Czechoslovakia Modified program translated to C adapted for GRASS segmentation procedure Irina Kosinovsky US Army Construction Engineering Research Laboratory Dave Gerdes U S Army Construction Engineering Research Laboratory REFERENCES Hutchinson M K and Gessler P E 1992 Splines More than just a smooth interpolator Geoderma M
38. ion mask target information for the find choice 3 and the query choice 4 except that item B is omitted for choice 4 The choice to append or delete selected records will only be given after a successful find or query has stored some records on the internal record list See find and query for more information If a graphics monitor is not active the mouse item is omitted from the screen and if a mask is not set that choice is 12 omitted The choices entered on this example screen will result in all the sites within a 1500 meters radius of the target point to be chosen with the mouse being selected and stored on the internal site list by find or query They are stored in order of proximity to the target Ifa site is used as the target it is always the first in the retrieved list useful for just selecting one site by number If a mouse is chosen to select the target point a menu to display reference maps is pre sented exactly as in choice 6 prior to actually activating the mouse QUERY FIND REGION MASK TARGET SELECTION MENU Data base lt arch gt READONLY in mapset lt PERMANENT gt open 113 records Mark requests with x and enter required values Respect current region a Respect current MASK x forces current region A Find all sites within or outside a circular target x and give the radius negative for outside 1500 00 OR B Find a number of sites nearest a point and the number of sites requested
39. itasova H and Mitas L in press Interpolation by regularized spline with tension I Theory and implementation Mathematical Geology Mitasova H and Hofierka L in press Interpolation by regularized spline with tension II Application to terrain modeling and surface geometry analysis Mathematical Geology Mitasova H 1992 New capabilities for interpolation and topographic analysis in GRASS GRASSClippings v 6 No 2 summer p 13 Mitasova H 1992 Surfaces and modeling GRASSclippings v 6 No 3 winter pp 16 18 Talmi A and Gilat G 1977 Method for smooth approximation of data Journal of Computational Physics 23 pp 93 123 Wahba G 1990 Spline models for observational data CNMS NSF Regional Conference series in applied mathematics 59 SIAM Philadelphia Pennsylvania 40 SSV NAME s sv Sample semivariogram of a GRASS sites list GRASS Sites Program SYNOPSIS S SV s sv help s sv alq sites name lag value lagtol value direction value angtol value graph name DESCRIPTION s sv calculates a sample semivariogram and either plots it or writes it to standard output OPTIONS Flags q Quiet Cut out the chatter p Plot the sample semivariogram in the GRASS graphics window requires g gnuplot Parameters sites name Name of an existing sites file Default is standard input with no field separators lag value Nominal lag distance lagtol value Tolerance on lag distance Def
40. ites or the user can use UNIX 22 programs like awk and sed to format other GRASS programs output in the form of a site list file d what rast and d what vect 2 Mask current site list The site list can be reduced to a subset that includes only sites which fall in specific categories within a specified raster map layer The user will be asked to specify the name of a raster map layer to form the basis for the mask and will then be allowed to specify categories from this raster map that will limit the site list As with zmask the category values selected designate the areas of the map in which information will remain Areas assigned category values not selected will be re assigned to category value 0 no data Note This masking operation is performed only against the site list itself and not against other raster map layers If the user wishes to analyze masked raster map layers a mask should be create using the rmask program 3 Save the current site list in your mapset The current site list can be stored permanently in your current mapset with this option You will be asked to name the saved site list and to provide a short description of it Saved site lists can be retrieved option 1 during later runs of s menu Once saved these site list files can be used with other GRASS programs like d sites d points d icons p icons s surf idw and s db rim Note Saved lists will be removed if the GRASS mapset under which they ar
41. le defining the grid should be large enough so that the extreme east west and north south nodes for non rotated grids can be used to store row and column effects Otherwise when residuals and effects are written to the output file residuals may share the same spatial location as effects when written to a vector output file Currently nothing is done with the residuals but I would like implement some sort of analysis of these in the future suggestions Kriging using these residuals as new data set is being planned BUGS The s flag is yet to be implemented This should probably be re written to use points in a vector file as input thus creating v medp Ideally I would also like to output three data files for plotting by a graphing program e g g gnuplot but I never got around to doing this The classic plot is to show three surfaces data trend residuals The trend can be obtained by extrapolation and or interpolation Extrapolating and interpolating using the row column and all effects to create a raster file would be a nice feature to include in the future Instead I am considering retrieving the effects from the output file and creating the surface with separate program Please send all bug fixes and comments to the author SEE ALSO v mkgrid v transform Cressie Noel A C 1991 Statistics for Spatial Data New York NY John Wiley amp amp Sons pp 186 187 AUTHOR James Darrell McCauley Agricultural Engineerin
42. lowing the make command is taken to define a line of the screen layout until a end is reached If a mistake is made on any of the input lines the make will fail The make information may be prepared in advance as a text file this facilitates fixing mistakes and the input command can be used to read in this file An example text file for a data base screen layout follows with some important explanatory notes make Archaeological Sites Database Site sSite Entered By tEnter_by Description C 14 Date iAge tDescript _ _ __ A tDescript 2 n tDescript 3 AAA Type tType Should be Arch or Hist Date tEnter_Date Square Miles fArea 4 North yNorth East xEast 1 end Notes 1 Any text not preceded by a tilde character is taken to be part of the constant or fixed text portion of the form 2 A field definition begins with a tilde character immediately followed by a single character which indicates the data type of the field s x y 1 f or t Immediately following the data type character is the field name of 1 to 16 characters Field names can be composed of any characters from the following set A Z a z 0 9 the RIM program and library do not distinguish upper and lower case in field names so you should avoid making names which differ only in case Field names may not begin with a numeral 0 9 The rest of the field length is padded with tilde charac
43. lso create a frequency of occurrence raster map layer representation of the site list file The raster category values will be coded as the number of sites that fall within the cell In this function you do NOT have the option of specifying the number of cells to represent a site 8 Run reports on the current site list The current list of sites is passed to the report server after removing sites which do not fall within the geographic region of the user s current GRASS mapset see lt A HREF g region html gt g region lt A gt The user then selects the names of one or more raster map layers for analysis Data at or near the sites extracted from these raster map layers form the basis for all reports The user specifies the size of a site in cells The size may be specified as a single cell or as a 3x3 square around the site or 5x5 or 7x7 etc where the size is an odd integer The following menu of reports is then presented SITES REPORT MENU Please select one of the following Site characteristics report 2 Site occurrence report 3 Convert data to S input format 4 Produce machine readable data file stop return to SITES MAIN MENU 1 Site characteristics report This report provides geographic information about each site Each site is identified by description and locational information The description is an identification of the site The site location is an easting and a northing The location does not
44. mation about the user s current MAPSET LOCATION etc Note the above message in parentheses current list no sites This message will vary depending on the status of the list For example after the user reads the existing site list file arch_sites the message would read given the geographic region indicated current list 25 sites 24 in current region 1 Read an existing site list This option will copy an existing site list file into the current site list within the sites server Existing site lists are stored under a GRASS data base and are pulled into the s menu server via this option Other sites menu functions operate only on the current site list file in the server you must therefore read an existing site list file BEFORE performing any of the other sites menu functions Note Site lists can be created and placed into a GRASS data base using s menu option 5 edit followed by option 3 save However the user can also create site lists using other methods or programs One simple way to do this is to create a site list file in the appropriate format using any text editor e g v1 and to put this site list file under the site_lists directory under the user s current GRASS mapset i e under SLOCATION site_lists The user can do this either inside of GRASS or outside of GRASS Alternately the user can run other GRASS programs which format their output as a GRASS site list file random s db rim v mkquads v to s
45. mmand is a single shell command line which is executed by a G_system call see GRASS gis library Many UNIX utilities e g vi ls print and most GRASS commands e g d rast d points g list g region d zoom rmask may be executed It is permitted and often useful to change region and MASK within s db rim Multiple commands may be separated by in the standard UNIX way Note that a cd directory ls will change to the specified directory and list files but the effective working directory for s db rim will not be changed when the command terminates add a Add a new site record row to the open data base Each line following contains a field name followed by spaces and or tabs then the value or character string to store for that field Field information lines end with end Some fields may be absent and fields may appear in any order Checks are made for the input of data for the one required field site number for string length for string type fields and for duplicate site numbers If split fields are used in the data base layout see make text data for each split field must be added as a separate line If there are any problems the record will not be stored and a message will be output This format makes it relatively easy to import data from most other DBMS The print a command see below outputs data in this list format Example add site id 204 north 4690673 30 east 60
46. n coefficient of variation mininum first quartile median third quartile and maximum OPTIONS Flags a Use all sites found in the named sites file rather than limiting output to sites falling within the current geographic region g Print the statistics in shell script style similar to g region l Use site descriptions category labels for z values Sites must be in the E N n desc format for this to work Default format is just three pipe separated floating point numbers E N desc q Quiet Cut out the chatter Parameters sites name Name of an existing sites file SEE ALSO s normal BUGS Needs to do as many calculations as possible without storing individual site records requires a lot of memory AUTHOR James Darrell McCauley Agricultural Engineering Purdue University 44
47. nces try using nawk or better yet gawk FILES GISBASE scripts s in grid SEE ALSO s in ascii AUTHOR James Darrell McCauley Agricultural Engineering Purdue University 19 s medp NAME s medp Median polish for a GRASS sites list GRASS Sites Program SYNOPSIS s medp s medp help s medp aeqs sites name vect name output name report name thresh n DESCRIPTION s medp performs median polish on an existing sites list The sites are overlayed onto a grid vect name and each site is associated with the closest node Therefore sites do not necessarily have to be oriented on a grid Each node may be associated with zero one or more sites and the grid may be rotated Also the length of each box does not have to be equal to width of each box defining the grid Once sites are associated with nodes on a p by q grid p q 1 extra storage locations are created initialized to zero to store all row and column effects The median of each row is removed from the data and added to the extra p cells Then medians are removed from the data as well as from the p cells containing row effects The medians of data in this pass are stored in the extra q cells column effects and the median of the row effects is stored in the extra p 1 q 1 cell all effect This is repeated until each successive iteration leaves each site unchanged within a tolerance described by thresh n OPTIONS Flags a Use all sites found in the named sites f
48. nput to other programs e g d points m u2ll etc Each line of output consists of the easting northing and category label for a site listed in the named sites file The fs name option where name is either a character a space or a tab can be used to place a particular field separator between these three output fields This is useful when output is to be manipulated by other programs like awk or sed The GRASS program s in ascii can be used to perform the reverse function converting a UNIX file containing eastings northings and category labels associated with site locations into GRASS site list file format OPTIONS Flags a Output all sites found in the named sites file rather than limiting output to sites falling within the current geographic region d Include site descriptions category labels in the output Parameters sites name Name of an existing site list file fs character space tab The field separator to be placed between the easting northing and optionally category label on each line of output The field separator can be a character a space or a tab Default space s out ascii can be run either non interactively or interactively The program will be run non interactively if the user specifies the name of an existing site list file and optionally a value for fs using the form s out ascii ad sites name fs character space tab where name is the name of an existing site list file to be converted to a
49. nt Mapset Recover a Data Base from a RIM ASCII File Show Screen Layout of Current Data Base Backup UNLOAD Data Base to RIM ASCII Format File Pack the Current Data Base Read a Site list into the Current Data Base AINAHAHBWN EP 0 Return to Main Menu 0_ Your selection AFTER COMPLETING ALL ANSWERS HIT lt ESC gt TO CONTINUE OR lt Ctrl1 C gt TO CANCEL 1 Use this choice to create a new s db rim data base in the current GRASS mapset See section below on MAKE A NEW DATA BASE 2 List available data bases Like 2 on MAIN MENU 3 Delete an entire data base from the current mapset The name of the data base and additional confirmation of the action are prompted for 4 Choice 6 allows backup of the definition and data parts of a data base to a transportable text file To rebuild or build for the first time a s db rim data base from one of these text files do the following steps see if the rim directory exists Is LOCATION rim sites if the directory was not found make it mkdir LOCATION rim sites change directory to it cd LOCATION rim sites have rim build the binary data base files rim RIM amp gt input path to your textfile RIM amp gt exit The data base is thus created in the current mapset Several s db rim commands should be run to verify the integrity of the newly created data base 5 This merely shows the screen layout of the currently open data base It is a useful way to quickly see the la
50. on Image Sampling Methods GRASS Tutorial on s sample available as s sample tutorial ps gz AUTHOR James Darrell McCauley Agricultural Engineering Purdue University 34 s surfiidw NAME s surf idw Surface generation from sites data program GRASS Raster Program SYNOPSIS s surf idw input name output name npoints count DESCRIPTION s surf idw fills a raster matrix with interpolated values generated from a set of irregularly spaced data points using numerical approximation weighted averaging techniques The interpolated value of a cell is determined by values of nearby data points and the distance of the cell from those input points In comparison with other methods numerical approximation allows representation of more complex surfaces particularly those with anomalous features restricts the spatial influence of any errors and generates the interpolated surface from the data points It is the most appropriate method to apply to most spatial data This program allows the user to use a GRASS site list file rather than a raster map layer as input The program will be run non interactively if the user specifies the values of needed program parameters and any desired optional parameter values on the command line using the form s surf idw input name output name npoints count Alternately the user can simply type s surf idw on the command line without program arguments In this case the user will be prompted for nee
51. ored if all is ok otherwise a message is output If the 1 flag for list is given the site number field is omitted and the specified field values are changed for all sites currently selected by find and or query delete d This command is used to delete data records for sites Deletion of sites is permanent A backup of the data base or copies of the data base files are the ways to protect your valuable data The lines following the delete command should contain only the site numbers with a end line being last The following command sequence will delete all the sites currently on the internal site list the result of the last query or find command after asking for approval delete end end e Ends multi line input for several other commands exit ex Use exit to end operation of s db rim cleanly In general do not use CTRL C to exit unless absolutely necessary When exit is encountered in a batch file input will revert back to the previous file or the terminal if any which called the batch file find a d m r P The find command is used to find the site s closest to a given point the target The target can be defined in one of several ways The found sites are stored on an internal sites list for output by other commands however see note 2 below The found sites are stored on the internal sites list in order of proximity to the target location
52. othing splines with kriging The program writes the values of parameters used in computation into the comment part of the history file elev as well as the following values which help to evaluate the results and choose the suitable parameters minimum and maximum z values in the data file zmin_data zmax_data and in the interpolated raster map zmin_int zmax_int maximum differ ence between the given and interpolated z value in a given point errtotal rescaling parameter used for normalization dnorm which influences the tension see Mitasova 1992 Ifa visible connection of segments appears the program should be rerun with higher npmin to get more points from the neighborhood of the given segment If the number of points in a site file is less then 400 segmax should be set to 400 so that segmentation is not performed when it is not necessary The program gives a warning when the user wants to interpolate outside the rectangle given by the minimum and maxi mum coordinates in the site file zooming into the area where the points are is suggested in this case When a mask is used the program takes all points in the given region for interpolation including those in the area which is masked out to ensure proper interpolation along the border of the mask It therefore does not mask out the data points if this is desirable it must be done outside s surf tps The program was used for various applications with the following parameters
53. r Parameters sites name Name of an existing sites file width value Width of bins graph name Basename to save graphing data commands files Graphs are saved in the current working directory with the extensions gp and dat EXAMPLE Given a sites file named example in the following format 83 8 92 2 3 5689 83 8 82 2 3 9269 83 8 80 2 3 5389 83 8 69 2 3 7452 Suppose that we wish to examine normality of the site values third column The first step is to examine minimum and maximum and determine with the histogram bin width using s univar s univar gq sites example This command outputs n 216 min 1 489 max 3 9419 30 along with other useful statistics For this range and number of observations we randomly select 0 1 as the histogram bin width Then the following command graphs a probability plot in the GRASS graphics window and saves it in the current working directory with a basename of myplot s probplt q sites example width 0 1 graph myplot To view the graph again try g gnuplot myplot gp Using g gnuplot the graphs may be output as PostScript LaTeX FrameMaker MIF or many other formats SEE ALSO s univar s normal AUTHOR James Darrell McCauley Agricultural Engineering Purdue University 31 s qcount NAME s qcount indices for quadrat counts of sites lists GRASS Sites Program SYNOPSIS s qcount s qcount help s qcount ciq input name n value r value DESCRIPTION s qcount c
54. r decimal places output o file or process Causes all output except some error messages from s db rim including that from the print command to go to the named path file may be a full or relative path name or to be used as standard input by the process a pipe If no parameter is given output returns to stdout usually the user s terminal An example of the pipe usage would be output grep easting wc l gt tmp my_count A pipe is closed whenever the output command is given again or on a exit command pack pa This should be used when numerous data records have been deleted to recover disk space in the RIM binary data base files It works by doing a backup to a temporary file moving the data base files to new names bakdb running RIM to rebuild the data base and if the rebuilt data base can be opened and read the temporary files are deleted The user is informed if this process fails Packing can only be done on an open data base located in the user s current mapset print p a 1 This command outputs the full site records for the sites currently stored on the internal sites list result of last query or find Without the flag the screen layout format is used With the 1 flag for list format the field name followed by the contents are output one field per line The a flag also outputs in the list format but with a add line and a end line surrounding each site reco
55. rd printed data files in this form can be read with input thus they form one kind of backup mechanism and can be used to transfer data not the data base layout from one GRASS system to another The destina tion for the output is set by a previous output command default is stdout query q a d m r P The query command is used to retrieve sites via an SQL like request to RIM including a user specified where clause All fields for each site meeting the selection criteria are retrieved The optional query command line parameters cause points not in the region r and or mask m to be rejected so these conditions need not be tested in the where clause The a flag causes the retrieved sites to be appended to those previously retrieved by query or find duplicate entries are automatically discarded The d flag causes selected sites to be deleted from the current list if present After the query command line any number of lines may be entered to define the SQL where clause A end line is required to finish the request and begin data retrieval See examples below The distance from clause may also be used as additional selection criteria exactly as described in the examples and notes for find It must be entered as a separate line to the query prompt The retrieved records may be printed at time of retrieval rather than after the completion of the query command by including a print p line
56. rriage of the GRASS environment and the programmer s interface library of the rela tional data base management program RIM distributed publically by the University of Washington Academic Computing Services as FORTRAN 77 code Your system must have a FORTRAN 77 compiler to use s db rim SECTION ONE THE COMMAND VERSION The command line driven version of s db rim is run by typing the below command where data_base is the name of an existing RIM sites data base s db rim data_base The sites data bases are stored in a subdirectory named rim sites in the user s current mapset Data bases in other mapsets selectable through the GRASS g mapsets command can be accessed for read only retrieval of records Each mapset may have many data bases Each data base within a mapset must have a different name user supplied names for data bases are limited to seven 7 characters in order to maintain compatibility with the standard version of RIM As with other GRASS commands mapsets are searched in the mapset SEARCH_PATH order when a data base needs to be opened Each site data base is composed of multi field records rows or tuples in DBMS jargon Each field and its position in the site form is defined via input to the make command when a data base is originally defined It is possible to add new fields or change the length of existing fields after data has been loaded however this is not straightforward and is not described here deleting of
57. s the table structure of the currently opened RIM data base This is the same output generated by a list command when running RIM manually The information for the table named data is useful for review of the user s field defini tions The information for the two other tables is for internal use by s db rim SECTION TWO THE INTERACTIVE VERSION MENUS AND COMMENTS SYNOPSIS s db rim DESCRIPTION The interactive version of s db rim allows you to create manage and query information about site locations sites across the landscape Operations are done on a data base through a series of menus explained below Most of the menus use VASK screens the user should become familiar with keys that move the cursor among the fields to be entered RETURN ENTER CTRL L CTRL K etc THE MAIN MENU Below is the main menu Option 1 is the default Note the status line at the top of the menu and the fact that 8 records have been selected by the latest find or query operation between items 2 and 3 Note also that CTRL C can be used to exit from this menu and most other menus in the program back to the GRASS prompt The specifics of each menu choice are described below s db rim MAIN MENU Version 1 4 Data base lt water gt in mapset lt rono gt open 25 records 1 Open a data base 2 List available data bases Retrieve Output Site Records 8 currently Find sites in proximity to a Target point Query to select site recor
58. splay currently selected sites enter x d sites with size 6_ type x color red _Erase graphics screen enter x d erase black AFTER COMPLETING ALL ANSWERS HIT lt ESC gt TO CONTINUE OR lt Ctrl C gt TO CANCEL 7 This selection results in a screen prompting for the name of the file to output the selected site records to and for optional formatting selection If the file name is lp the site records are sent to the printer The optional formatting choices are for export of data in list format see print in the first part of this manual page for s db rim for information and examples 8 Using this choice you can write or append the currently selected sites to a GRASS site_list file in your current mapset A short menu prompts for the name of the site_list file and also for the name of a field to be used for the comment in the site_list the site number is the default field The current date and time and the names of the mapset and data base in use are entered as an information line in the site_list file Note that various kinds of raster map layers can be produced from a s db rim data base by writing site_lists with different fields as comments then converting the site_lists to raster files with s menu 9 Choices 9 12 operate on only a single site and do not use or modify the internal list of sites selected by find query choices 3 or 4 Choice 9 is the way to view a single site record selected by site number After viewing
59. surfaces given in notes For noisy data it is possible to define a smoothing parameter smooth With the smoothing parameter set to zero smooth 0 the resulting surface passes exactly through the data points If the number of given points is greater than 400 segmented processing is used The region is split into rectangular segments each having less than segmax points and interpolation is performed on each segment of the region To ensure the smooth connection of segments the interpolation function for each segment is computed using the points in a given segment and the points in its neighborhood The minimum number of points taken for interpolation is controlled by npmin the value of which must be larger than segmax and less than 400 This limit of 400 was selected to ensure the numerical stability and efficiency of the algorithm The program writes important values related to the computation to the history file of raster map elev OPTIONS The user can run this program either interactively or non interactively The program will be run non interactively if the user specifies program arguments and flag settings on the command line using the form s surf tps input name elev name slope name aspect name pcurv name tcurv name mcurv name maskmap name dminl val zmult val tension val smooth val segmax val npmin val Alternatively the user can simply type s surf tps on the command line without program arguments In this case the
60. t location find gt distance from site 16 2500 will find all sites greater than 2500 meters from the location of site 16 Notes for find 1 All sites found are stored on the site list in order of proximity to the target location sorted by distance from target 2 The number of sites found is automatically printed to the active output device file 3 If mask is specified the effective region is automatically set to the current region because the GRASS mask is only defined for the current region 4 Region and mask filtering uses the current resolution for the region to test if a point falls within a cell in the masking map 5 In the last two examples the string distance from must be exactly matched Also the word site must be exactly matched 6 If the distance from radius is given as a negative value points outside the target circle are selected whereas if a positive value is given points inside the circle are selected 7 The current region may be changed with g region or d zoom prior to doing a find and the mask may be set or removed with a variety of GRASS commands 8 The find gt prompt is given only when input is from a terminal help h Prints a help screen to the output device or file Useful to have when using s db rim from a terminal or when writing a script file of commands input 1 file The lines in the file given are read and processed as commands or data
61. target specifications from the user The selected sites are then displayed one at a time until CTRL C is entered then other operations choices 5 8 can be done with these sites The line on the menu between 2 and 3 shows the number of sites currently selected by choices 3 or 4 4 Query sites in the data base using an SQL like where clause including specifications for region mask target circle only as in 3 above see FIND QUERY TARGET MENU section below The where clause can test for ranges or matches for numeric data base fields or matches on full strings or substrings for text fields The selected sites are then displayed one at a time until CTRL C is entered then other operations choices 5 8 can be done with these sites This clause is entered on a menu described below see QUERY COMMAND MENU section below The where clause may use parentheses to control the order of comparisons Field names are not case sensitive within where clauses The following comparison operators are valid for all types of fields eq or ne or lt gt ge or gt le or lt gt or gt It or lt String comparisons are case sensitive and are done character by character Substrings comparisons may be done with the like operator as in where name like Jones Note that the string being tested against the name field for each record is in quotes single or double and that wild card comparisons can be done in the standard way with
62. ters to the required maximum length 3 The minimum field width is three characters e g tA Be sure field widths for all fields are wide enough for the values and strings you expect to store there e g UTM northings require at least 11 spaces 4 For text fields it is possible to continue a field across more than one line This is done by appending a 1 to the field name forming first portion of this split field a 2 for the second portion etc This text field splitting affects how information is organized for input and output the composite text string is concatenated unused portions of fields are retained as spaces and treated as a unit for storage and queries to the data base 5 For the double precision floating point fields types x y and f the number of decimal places to print may be specified by appending n to the field name where n is the number of decimals places required Values of n from 1 to 12 may be used Two decimal places is the default if n is not specified Be certain that you make the field wide enough to print the integer and decimal portions of the values that will be stored in the field include space for a sign and the decimal point If it is desired to print zero decimals whole numbers use an 1 type field In the example above the northing coordinate y would be output with two decimals the easting x would have only one decimal place and the Area would be printed with fou
63. using the theorems from differential geometry but have never been tested 38 The program gives warning when significant overshoots appear and higher tension should be used However with tension too high the resulting surface changes its behavior to membrane rubber sheet stretched over the data points resulting in a peak or pit in each given point and everywhere else the surface goes rapidly to trend Smoothing can also be used to reduce the overshoots if the resulting surface should be smooth For data with values changing over several magnitudes sometimes the concentration or density data it is suggested to interpolate the log of the values rather than the original ones The program checks the numerical stability of the algorithm by computation of values in given points and prints the maximum difference found into the history file of raster map elev Significant increase in tension is suggested if the difference is unacceptable For computation with smoothing set to 0 this difference should be 0 With smoothing parameter greater than zero the surface will not pass through the data points and the higher the parameter the closer the surface will be to the trend The maximum difference between the given and approximated value in this case reflects the smoothing effect on data For theory on smoothing with splines and their statistical interpretation see Talmi and Gilat 1977 Wahba 1990 and Hutchinson 1992 where you can find also a comparison of smo
64. with the same options for print format as in the print command see above e g p a to output in the list add format The print clause must be entered as a separate line to the query prompt This feature is most useful when working with very large data bases where retreval time is significant See example 2 below Example query gt where density amp lt 20 and date 10 14 89 query gt or county eq San Marcos query gt end Example 2 query gt where east amp 1t 600000 and name like Jones query gt distance from site 12 3000 query gt print a query gt end Example 3 query gt end The where and distance from clauses are each optional If both are omitted only the mask and region on the query command line restrict the search if mask and region are also omitted all sites will be retrieved Example 3 When querying for sites the where clause is processed first the current region and mask tested next if requested then the distance from clause is applied a site must pass all tests to be put on the internal site list for output by other commands Notes Also see Notes for find 1 The retrieved sites are stored on the internal site list in the order returned from the data base by RIM not necessarily in site number order or the order the data was loaded A distance from clause results in a final sorting by proximity to target 2 See the RIM User s Manual for additional information on the
65. yout and review the field names and types 6 When backing up to a text file the RIM UNLOAD command is run with the output directed to a file of the user s choice See 4 above It is wise to do this operation after extensive changes or additions of data records The resulting text file can be written to tape for preservation or shared with other GRASS systems if desired 7 After deleting a large number of site records some wasted disk space will be present in the binary data base files This procedure will perform an unload and a reload automatically to recover this unusable disk space If there is any problem reopening the data base after packing the user is notified and can recover in various ways depending on the backups which have been done 14 8 Data may be loaded into a data base from an existing GRASS site_list This procedure will prompt for the site_list name and then add the sites to the currently open data base If all sites in the list have a comment field of the form value the value is used as the data base site number otherwise the sites are numbered sequentially beginning with 1 Only the site number and location coordinates are loaded for each site record by this procedure other fields may be later added with the change function See read_sites MAKE A NEW DATA BASE After entering the name of the new data base you wish to create 7 characters maximum you then decide how to input the information

GRASS 4.2 Sites Commands

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