You might consider using -s flag to smooth the corners. Otherwise, I can't see why it doesn't work.
R. Sab > Hi, > > I've created subcatchments using r.watershed and I would like to > convert these to polygons. My result at the moment contains too many > polygons - 194. The original raster had only 9 areas, which should all > have been contiguous seeing that they came from r.watershed. > > Here is the sequence of commands that I use, starting with r.report > for the information about the subcatchments raster: > ----- > | Type of Map: raster Number of Categories: 18 > | Data Type: CELL > | Rows: 33443 > | Columns: 33008 > | Total Cells: 1103886544 > | Projection: Transverse Mercator > | N: -3122229.69982072 S: -3155672.30728643 Res: > 0.99998826 > | E: -33474.90929218 W: -66483.27873573 Res: 1.00001119 > | Range of data: min = 2 max = 18 > ----- > > # Set the resolution to 25m > g.region rast=c83a_border res=25 > > # Convert the subcatchment raster to vector > r.to.vect --overwrite > input=c83a_dem_25m_clipped_basins_100000_clip...@permanent > output=c83a_subcatchme...@permanent feature=area > > v.report for the resulting vector gives me 194 categories. The > original raster had only 9 areas, which should all have been > contiguous seeing that they come from r.watershed. > > What am I doing wrong? I want an output vector with 9 polygons > corresponding to the original 9 areas in the subcatchment raster. > > Thanks > Hanlie > _______________________________________________ > grass-user mailing list > grass-user@lists.osgeo.org > http://lists.osgeo.org/mailman/listinfo/grass-user > _______________________________________________ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user