Hi everybody, I am trying to create a neigbourhood matrix based on a shapefile of postal code areas that was created in ArcMap. Normally this works fine using the 'readShapePoly' and 'poly2nb' commands. However, the postal code areas change over the years or are made up of 2 or mory polygons because they are situated on both sides of a large waterway. I correct these difficulties by merging postal code areas in ArcMap, so that I end up with a shapefile in which each postal code area is represented by just 1 polygon with an unique area ID. I again import the updated shapefile in R using readShapePoly. But then the problems start. When I create a neighbourhood matrix using poly2nb, the areas that have been merged behave very strange: they don't recognize their neighbours. Sometimes they recognize none, sometimes a few. When I couldn't find a solution I tried to create the nb using GeoDa. This gave exactly the same problems. Then I turned to GeoBugs and - surprise - the nb was created without any problems.
Does anyone recognize these problems or has a solution for me? Thanks, Oscar ____________________________________________________________________________ DISCLAIMER: http://www.rivm.nl/disclaimer.htm\ ...{{dropped:2}} _______________________________________________ R-sig-Geo mailing list [email protected] https://stat.ethz.ch/mailman/listinfo/r-sig-geo
