How-To Test GRASS6

Scope of this page

This pages is intended to users and developers who want to test a GRASS installation (test protocol). As side effect, you can also showcase GRASS 6 using these commands.

Requirements

• GRASS 6 installation (source code and ​binaries download)
• Educational data set: OSGeo Educational data set North Carolina: ​data and ​description.

Extract the NC sample data set for GRASS:

mkdir $HOME/grassdata
tar xvfz nc_spm_07_2007_dec20.tar.gz

Start of the program

GRASS 6 is started either from the menu (if installed therein) or from command line. In all cases, select mapset "user1".

# show available options
grass63 --help

Expected result: the help text should be shown.

# start with old Tcl/Tk based graphical user interface (d.m)
grass63 -oldtcltk

# start with current Tcl/Tk based graphical user interface (g.gis)
grass63 -tcltk

# start with wxPython based graphical user interface
grass63 -wxpython

Expected result: the selected graphical user interface should come up.

# start with text based interface
grass63 -text

Expected result: the text user interface should come up.

Re-launch of GUI from command line

# start with old Tcl/Tk based graphical user interface (d.m)
g.gui oldtcltk

# start with current Tcl/Tk based graphical user interface (g.gis)
g.gui tcltk

# start with wxPython based graphical user interface
g.gui wxpython

Expected result: the selected graphical user interface should come up.

Using gis.m graphical user interface

• Click in GIS manager on "Add raster" button,
• click on word "raster" which appears in the canvas,
• select "Raster name" button, select map "elevation",
• click "ok", map name should appear in canvas,
• click on "world map" button: should open GRASS map display
• and show elevation map.
• Try to zoom, to create a profile etc.

Expected result: it should just work.

Using wxPython graphical user interface

• Click in Layer manager on "Add raster map" button,
• select raster map "elevation" in properties dialog and click "ok",
• right mouse click in layer tree and choose from contextual menu "Zoom to selected map", map should appear in canvas.
• Try to zoom, to create a profile etc.

Expected result: it should just work.

Display various maps in GRASS monitor (not native winGRASS)

g.region rast=elevation
d.mon x0
d.rast elevation
d.vect roadsmajor

Expected result: GRASS monitor should open and show the selected maps

d.his i=elevation_shade h=elevation
d.vect roadsmajor

# set barscale position per mouse click into map:
d.barscale -mt

3D visualiztion with NVIZ

# raster map and 2D vector lines map
 nviz elevation vect=roadsmajor

# raster map and 2D vector lines map and 3D vector points
nviz elevation vect=roadsmajor points=precip_30ynormals_3d

Tests: navigate with the puck, interrogate map, etc. (ADD MORE)

Expected result: should not crash at all but show maps as expected

Simple raster analysis

• TDB

Raster algebra

Normalized Differences Vegetation Index (NDVI) from LANDSAT-TM7:

# set current region/resolution to map:
g.region rast=lsat7_2002_40 -p
# display metadata:
r.info -h lsat7_2002_40
# generate NDVI:
r.mapcalc "ndvi = 1.0 *  (lsat7_2002_40 - lsat7_2002_30) / (lsat7_2002_40+ lsat7_2002_30)"
r.info -r ndvi
r.colors ndvi color=ndvi

# display 2D:
d.mon x0
d.rast.leg ndvi
d.vect streets_wake
# display 3D:
nviz elevation col=ndvi vect=streets_wake

Expected results: the NDVI map should be colorized in near natural colors

Raster statistics

• r.univar

Simple vector analysis

• TBD

Extracting from vector maps

• extract large streets from "streets_wake"

SQL support

g.region vect=schools_wake -p
d.erase

# show all schools in Wake County
d.vect schools_wake col=red icon=basic/circle siz=5

# show a subset of all elementary schools in Raleigh
d.vect schools_wake where="ADDRCITY='Raleigh' and GLEVEL='E'"

Vector statistics

• v.univar

Transfer raster slope to vector segments

• v.split, v.to.db

Shortest path routing

• NC bus routes... map "busroutesall"

Using QGIS' GRASS toolbox

Start "qgis" within GRASS shell.

• Go menu "Plugins, Pluginmanager, activate "GRASS plugin", OK button: a set of new buttons should appear
• click "Add GRASS raster layer" button, select "elevation" map
• click "Add GRASS raster layer" button, select "elevation_shade" map
• click right mouse button in legend on "elevation_shade" map, move transparency to 40%
• click "Add GRASS vector layer" button, select "roadsmajor" map, select layer "1-line" (level 1 is the topological level), OK