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1 Visualizing rastermaps

The visualization of raster data is conducted in a so called X monitor by the module d.rast. GRASS can manipulate up to 7 different monitors (x0,x1,x2,..,x6) in parallel:

d.mon x0
d.rast

Use the d.zoom module to get a more detailed view of a regional cutout:

d.zoom

A particular cutout or the total work area can be defined via the module g.region. The setting of the default region with a resolution of 10 m can be achieved using:

g.region -d res=10.0 -pa
d.erase
d.rast rastermap

Note that the settings changed by g.region must be passed to the monitor by the module d.erase in order to be take effect. It is also possible to adjust region and resolution settings directly from a raster map:

g.region rast=rastermap -p
d.redraw

Visual overlapping of two raster files

d.rast rastermap1
d.rast -o rastermap2

A pixel of the underlying rastermap1 is only visible if the corresponding pixel of the overlay rastermap2 contains a NULL-values, indicating a data gap. The module d.his also overlays maps - e.g. for the visual verification of the georeferenced TK24 of the Spearfish sample dataset.

d.his -n h_map=roads i_map=tk24

Visualization of a rastermap with legend

A rastermap with appropriate legend can be displayed quickly by entering the following command:

d.rast.leg rastermap