On Wed, 2008-03-19 at 10:20 -0700, John C. Tull wrote: > I have a road network where I want to convert the road lines into > boundaries, then turn the resulting spaces inside of roads into areas. > Converting the roads to boundaries was no problem using v.type and > v.clean tool=snap, but getting centroids into the polygons is > trickier. Apparently, v.centroids will not add centroids to areas > where there are boundaries that terminate inside a polygon (i.e., dead- > end roads inside what I am hoping to turn into an area), so I end up > with far fewer areas than I want. Do boundaries have to be contiguous > without dangles (is that the right use of the terminology?)? > > Is there a way to get centroids into areas such as these where the > road dangles are ignored? I don't want to drop those dead-end roads > because they are informative, but I guess I may have to do so and then > use v.overlay or similar at a later stage. There are also too many > potential areas to try and manually add the centroids with v.digit. > Perhaps there is a means in v.edit unknown to me. Any ideas or > suggestions would be greatly appreciated. I am using GRASS 6.3rc5.
John, maybe you could try v.clean with type=line,boundary,centroid,area tool=snap,break,rmdupl thresh=.01 Not sure but I suspect the "break" tool is what you might need. _______________________________________________ grass-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-user
