Markus, Thank you. I'm pretty sure this is the way. So I run:
r.to.vect input=mainchannel output=points feature=point --o v.to.db map=points option=coor col=x,y (like the man page suggests) but I get a number of errors like: Column 'x' not found Error in db_execute_immediate() where am I wrong now? 2010/6/2 Markus Neteler <nete...@osgeo.org> > > If you treat them as vectors, perhaps this could help? > > > v.to.db > ... > slope: slope steepness of vector line or boundary > I calculate slope as S = (z2-z1)/(sqrt((x2-x1)^2+(y2-y1)^2))*100 where x1,y1 are the coords of point 1, x2,y2 are the coords of point 2, and z1, z2 are the elevations in the raster map associate at the points 1 and 2 respectively. Margherita > ? > > Markus >
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