[GRASS-user] vector operations based on rasters

[Tim Michelsen]

Hello,
I have calculated raster file based on a DEM with some r.mapcalc commands.
As a result, my raster file with the areas of interest is smaller than the whole
region.
How do I intersect the landcover vector of the whole region to get a new
landcover vector with only those polygons contained within the areas of interest
of the raster?

Basically, I'd like to run v.extract/v.overlay not on a vector-to-vector basis
but on a vector-to-raster basis.

If I convert my raster to a vector file the GRASS program freezes the computer
because the calculted rasters seem too many values.

I would highly appreciate to receive hints on this issue.

The only past post I found was this. but it pointed to non GRASS solution:
http://www.nabble.com/Intersection-of-Vector-polygons-with-raster-ts19496096.html

Kidn regards,
Timmie