Never tried this. I am generally very cautious with snapping. Not knowing exactly how grass handles it but one should be aware of possible topological alterations, duplicate features, etc.
Vincent > > Dear Vincent, > > I was able to reproduce your code. This is definitely an improvement! > For the test data this solution works. > I applied the snapping code to a larger data set. There was only (or > still) one case left where a polygon dissapeared. I guess the reason > was, that there was a problematic overlap but no vertices within the > snapping threshold. In this case it would be desirable that snapping > could also be done with boundaries. > > I think a snapping option in the manner of your suggestion should be an > option in the v.overlay and v.patch tools. Disappearing polygons are > really problematic for my work and this could be a solution. > > Actually a friend told me that in PostGIS there is an option to snap all > vector data to a grid. This would be possible in Grass if you would > produce a vector grid (maybe from a raster file with an appropriate > resolution) and use it as a bgmap. Did you ever try this? > > Falko > _______________________________________________ > 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
