On Wed, Jun 22, 2011 at 7:32 PM, puffbunnyn <[email protected]> wrote: > Hello > > I have merged three CORINE vector maps for coniferous, broad-leaved and > mixed forests in order to create one general map for all forests as I need > to calculate the length of the forest edges. > > After using v.patch (with flag e) to merge the maps I have tried my best to > remove all lines lying inside of boundaries so that only the outer > boundaries would be left - with no luck. The main problem should be that the > adjacent boundaries from the three maps have only been put next to another > and not really "merged" (this is not a problem concerning double > boundaries). Does anyone know how to cope with this? I have not been able to > find any posts regarding this problem and would really appreciate your help. > When patching areas, a bit of cleaning is needed before anything else can be done.
Try v.clean tool=bpol,rmdupl if there are any incorrect boundaries or duplicate centroids left, try v.clean tool=break,rmdupl,rmsa repeat this until tool=rmsa makes no modifications If you want to remove the inner boundaries, you could prepare the vector for v.dissolve with v.category op=del cat=-1 followed by v.category op=add cat=1 step=0 type=centroid Now all areas have the same category and you can use v.dissolve or v.extract -d to remove the inner boundaries. Markus M _______________________________________________ grass-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-user
