Dear list, I have a question regarding the included polygon in the khat function of the splancs library defining the area where points appear. I have not only one simple polygon included, my map includes several islands. I read my map which was a shape file by readShapeSpatial of the maptools library. Then I split up the SpatialPolygonsDataFrame into the included polygons by coor <- NULL for (i in 1:[number of polygons]) coor<- rbind(coor,map@polygons[[1]]@Polygons[[i]]@coords) I am using now this newly generated polygon "coor" in the khat command. k_funk_ca <- khat(as.points(cases), coor,s=0:1000) I do not know if there is a problem using multiple polygons that way or if khat produces then only results for the "first" polygon or even completely wrong results. Does anyone know the answer? Thanks a lot, Sven Schmiedel PhD student at Copenhagen Unversity Danish Cancer Society Institute for Cancer Epidemiology [[alternative HTML version deleted]]