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

[Tim Michelsen]

Hello,
I while ago I asked how to cut a small map from a larger one using the
region settings as boundary for the small map:
http://n2.nabble.com/r-mapcalc-changes-color-table-td4072836.html#a4072836

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.

Am I doing something wrong?
Why is the no such command r.cut?

Thanks in advance for your help,
Timmie