[GRASS-user] Re: cutting issue (again): r.mapcalc vs. r.resample

[Tim Michelsen]

> I tried this again:
> 
> Approach 1: r.mapcalc
> 	
> 	r.mapcalc "cut=if(boundary_raster, large_map,
> null())"
> 
> Approach 2: r.resample
> 
> 	r.resample input=large_map output=cut
> 
> I notice the that using Approach 2, the areas that was outside the set
> region is white. The underlayung rasters are not visible (or only if I
> set the opacity of "cut" to a low value).
> If I use Approach 1 with r.mapcalc, the areas outside the region are
> really NULL() (=transparent) and underlaying larger rasters are visible.
> Only that the result "cut" from r.mapcalc has a new colortable.
> 
some illustrations to my problem:
Spearfish: soils cut on top of elevation

r.mapcalc result:
http://img197.yfrog.com/i/cutmapcalc.png/

r.resample result:
http://img197.yfrog.com/i/cutresample.png/

Regards,
Timmie