[GRASSLIST:8282] Average raster values under a region

[Hernán De Angelis]

Dear list,

I am very new to GRASS so I apologize if this topic sounds stupid. What I want 
to do is to found the average elevation of a certain area of interest. This 
is what I have:

1. a raster containing the DEM of a certain region (floating point)
2. a vector containing a polygon with the area of interest (originally .shp 
imported to GRASS)

This is what I did:

1. convert the vector layer to a raster layer using v.to.rast
2. apply r.average with the DEM as "base" and the new raster as "cover"
3. r.stat to find out the values

However it doesn't seem to work since the results are not reasonable. Could 
someone explain to me what I am doing wrong? or if there is a better way to 
do that?

Many thanks

Hernán

PD: I am using GRASS 6.0.1 in SuSE Linux 9.3

-- 

Hernán De Angelis
hernan.deangelis at glocalnet.net