[R-sig-Geo] How to extract part of Map object using maptools

Hisaji Ono hi_ono2001 at ybb.ne.jp
Thu Nov 20 14:15:55 CET 2003


 Rmap can extract parts of Map object as follows.

 columbus<- shapefile("columbus.shp") " load shapefile

 plot(columbus[columbus$CRIME > mean(columbus$CRIME)]) # filter by attribute
& plot

 But I don't know how to do this by maptools.


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