Thanks - that sounds interesting. So there is no way of doing that without a loop?
Rainer On Thu, Jun 12, 2008 at 7:25 PM, Martin Wegmann <[EMAIL PROTECTED]> wrote: > Hello Rainer, > > On Donnerstag, 12. Juni 2008 19:13:18 Rainer M Krug wrote: >> Hi >> >> I have two vector layers - one with polygons and one with points, both >> in UTM 34 S. >> >> Now I would like to calculate the area of the polygons in circles >> around the points, i.e. how much area in a 500m circle around the >> points is covered by the polygons, and store this in the attribute >> table of the point layer. >> >> Is there any easy way of achieving this? If I simply buffer the >> points, the circles overlap sometimes and form one polygon, and I want >> to have the results for each point - so that doesn't work. > > perhaps if you create a loop: > > v.to.rast your points output=points use=cat > > max=`r.info -r "points" | grep max | cut -f2 -d=` > > COUNTER=`r.info -r "points" | grep min | cut -f2 -d=` > > while [ "$COUNTER" -le "$max" ]; do > > r.mapcalc "tttemp_1 = if(points == "$COUNTER",1,null())" > > r.buffer input=tttemp_1 output=tttemp_buffer distances=100 --o > > # your query > # patch result with previous query > # redo it until all patches are analysed > > let "COUNTER=COUNTER+1" > > done > > > hope this helps, Martin > > > -- Rainer M. Krug, PhD (Conservation Ecology, SUN), MSc (Conservation Biology, UCT), Dipl. Phys. (Germany) Plant Conservation Unit Department of Botany University of Cape Town Rondebosch 7701 South Africa _______________________________________________ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
