[GRASSLIST:1833] Re: two categories in one raster-map?

[Andrea Aime]

Grass raster approach is to store on category for each
raster map: if you want two attributes you'll use two raster
maps. If they refer to the same phenomena, you may use a
map name convention, such as a common prefix:

r.mapcalc test = if(raster_a1 == 1 and raster_a2 == 3, 1, 0)

Hope this helps
Andrea Aime

Dieter Lehmann wrote:
> 
> Hi,
> is it possible to refer to different
> categorie-values in a single raster-map? (maybe stored in
> a database with the database-interface) I want to do a
> mapcalc expression somehow like:
> 
> r.mapcalc test = 'if(raster==1 and raster$tabelinfo2 == 3,1,0)'
> 
> Thanks,
> Dieter
> 
> ----------------------------------
> Dieter Lehmann
> University of applied Sciences
> Schelmenwasen 4-8
> D-72622 Nuertingen, Germany
> lehmann at fh-nuertingen.de
> Phone: +49 (0) 7022 404 Ext. 207
> Fax: +49 (0) 7022 404 Ext. 209
> 
> Date: 11-May-01
> Time: 13:57:20
> 
> ----------------------------------