Hi Ricardo, It is hard to tell what is going from without looking at your input file, but you do seem to using r.cost correctly. My guess would be that the differences between cells are not great enough to cause the cost surface to deviate from a linear trajectory. To test this, try using r.mapcalc to amplify the pattern on the r_vias surface, ie. "r_vias_x100=r_vias*100" (100 might be too much), then re-run r.cost with the r_vias_x100 as the input.
r.cost does take a relatively long time to run, especially on surfaces which are relatively smooth (I think that's true). The result should be relatively identical to arc's cost weighted function. -Colin On Wed, Mar 25, 2009 at 10:59 AM, Ricardo Almendra <[email protected]> wrote: > Hello > > I'm trying to built a cost surface. I've already built a raster with the > pixel cost, but i can´t get the cost that is required to arrive to point A. > I'm trying - "r.cost input=r_v...@12_03 output=exp start_rast=h_r...@12_03 > max_cost=0 percent_memory=100" but it takes a lot of time and the result > it's linear, it do not reflect the differences in the original raster. > > I' trying to do something similar to the cost weighted function in arcgis. > > > Tks > > _______________________________________________ > grass-user mailing list > [email protected] > http://lists.osgeo.org/mailman/listinfo/grass-user > > _______________________________________________ grass-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-user
