Hallo Everybody I have a SpatialPolygonsDataFrame where residential stands in a town are given as polygons. The streets are "represented" by the empty space between the polygons. I want to dissolve the stand boundaries within a street block to get just the outer extent of a street block. My aim is this to move from a map of individual houses to a map of street blocks.
The criterion for merging is that they touch an neighbouring polygon (queen). Merging should continue until there are no polygons left touch each other i.e until you only have the street blocks separated by the empty space where the streets are. I have tried to use unionSpatialPolygons but have not found a way in which is can define which polygons to merge since I do not know how to define the "IDs" argument correctly. I had a feeling that I could specify which polygons to merge with poly2nb but poly2nb does not work recursively - i.e. the same polygon can be found in more than one entry on the nb list. I was also looking for a data set to build a self-contained example with (like a map of the world where one can dissolve the country boundaries and end up only with continents) but could not find one Can anyone offer me some advice Regards Christiaan _______________________________________________ R-sig-Geo mailing list R-sig-Geo@stat.math.ethz.ch https://stat.ethz.ch/mailman/listinfo/r-sig-geo
