GRASS and Sextante

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Revision as of 04:57, 14 April 2011 by Neteler (talk | contribs) (Updated to gvSIG 1.10+)

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GRASS has been integrated into Sextante as extension. Sextante itself is commonly used within gvSIG. Through this integration, gvSIG users have access to the wealth of well tested algorithms provided by GRASS.

Note: the GDAL-GRASS plugin must be installed.

How to install (tuned OADE version)

  1. Download OADE gvSIG binaries from here
  2. Download Sextante binaries from here


Now you have three files, for example: gvsig-oade-2010-1.0.0.b2-linux-installer.bin and

You have to run (follow the dialogs; we assume that you install it in your HOME directory as predefined in the dialog). Install at least gvSIG, andthe included demo data:

chmod a+x gvsig-oade-2010-1.0.0.b2-linux-installer.bin

To update the pre-installed Sextante with the newer content of

rm -rf $HOME/gvsig-oade-2010-1.0.0/bin/gvSIG/extensiones/es.unex.sextante
mkdir  $HOME/gvsig-oade-2010-1.0.0/bin/gvSIG/extensiones/es.unex.sextante
cd $HOME/gvsig-oade-2010-1.0.0/bin/gvSIG/extensiones/es.unex.sextante
unzip /PATH/TO/ "core/*"
mv core/* .
rmdir core
unzip /PATH/TO/ "bindings/gvsig_1_9/*"
mv bindings/gvsig_1_9/* .
rmdir bindings/gvsig_1_9  bindings

rm -f jts-1.9.jar
# help:
cd ../sextante_help
rm -rf en/ es/ de/
unzip /PATH/TO/ "help/*"
mv help/* .
rmdir help

Now you can launch gvSIG, from the Desktop or via (adjust path if you didn't use the default installation directory):






Alternative: How to install (original gvSIG version)

From gvSIG 1.10 onwards, Sextante is included:

  1. download gvSIG binaries from here (download the All-included version)
  2. run the installer
  3. start gvSIG

Activating GRASS in Sextante

(modified after grass_sextante.html)

Configuring Sextante to use GRASS takes just a few easy steps. Once you have configured the system, you will be able to execute GRASS algorithms from any Sextante component like the toolbox or the graphical modeller, just like you do with any other Sextante geo-algorithm.

Only two parameters must be set, namely:

  • The path to the GRASS installation folder. It is needed by Sextante to execute GRASS commands.
  • The path to a GRASS mapset. The mapset doesn't have to contain any data at all, since data will be imported automatically each time you execute an algorithm. The only important part of the mapset is the location information, particularly the Coordinate Reference System. You must set the same CRS that is used by the layers that you want to process using GRASS algorithms. If, for instance, you have layers with data in the EPSG 23030 reference system, you must set the mapset to that same reference system. When data is imported into the mapset, no reprojection is performed, and layers are assumed to be in the same projection as the mapset itself.
  • Open the Sextante Toolbox icon
  • Go to Sextante settings (open icon -> right of the "Search" bar at bottom of the window)
  • Go to "GRASS"
  • Set therein
  GRASS folder: /path/to/grass-binary-installation/  (e.g., /usr/local/grass-6.4.0svn/ )
  GRASS mapset: /path/to/grassdata/location/mapset  (e.g., /home/neteler/grassdata/nc_spm_08/sextante ) The mapset doesn't have to contain any data at all!

Note: you need to create this mapset with GRASS

  grass64 -c /path/to/grassdata/location/mapset  (e.g., grass64 -c /home/neteler/grassdata/nc_spm_08/sextante )
  • Click on "Setup GRASS" to register the raster and vector commands
  • Now click on the "Help" button to know that it is there and what it contains
  • Finally click "OK" to leave the dialog. Now 5xx Sextante/GRASS commands should be available

How to use

GRASS is used in an internal temporary session.

Sample session:

  1. File -> open Project -> $HOME/gvsig-oade-2010-1.0.0/sample_data/north_carolina.gvp
  2. Open Sextante dialog
  3. Go to "Indices and other hydrological parameters"
  4. Start (double click) r.topidx, select as Input "Elevation", as output write "topidx.tif" (it will go into your current directory; check with browse button), click OK
  5. It should have generated a new map.

See also