On Tue, 12 Jun 2007, Rick Reeves wrote: > > Hello, > > Using R 2.5.0 with PBSmapping package version 2.09: > > When I try to read in a polygon shapefile (eight polygons, the file was > written by the > Feature Class to Shapefile command in ArcMap GIS 9.2) using the command: > > importShapefile("TriCountyPolyDD") > > The following error occurs: > > Error in x[[jj]][iseq] <- vjj : incompatible types (from NULL to integer) in > subassignment type fix
Please always (by reflex, don't even think why!) say traceback() after every error. The output of traceback() may not help you, but it certainly helps those who read the error report. Probably vjj is NULL, but vjj does not appear in importShapefile, so only traceback() would show where the error occurred. > > Using read.shape on the same file yields > >> TriCounty <-read.shape("TriCountyPolyDD.shp") > Shapefile type: Polygon, (5), # of Shapes: 8 >> > Yet I wish to work with this shapefile using the PBSmapping tools. > > Has anyone else encountered and/or repaired this? > Plan B would be to convert the Map object TriCounty into > a PolySet or PolyData used by PBSmapping package, but > so far I have not worked this out. Any suggestions? > To get to PolySet: library(maptools) library(PBSmapping) # NC example shapefile included with maptools xx <- readShapePoly(system.file("shapes/sids.shp", package="maptools")[1], IDvar="FIPSNO", proj4string=CRS("+proj=longlat +ellps=clrk66")) xx_PS <- SpatialPolygons2PolySet(xx) class(xx_PS) For PolyData, cast xx to data.frame: xx_df <- as(xx, "data.frame") xx_df1 <- cbind(PID=1:nrow(xx_df), xx_df) xx_df1$col <- paste("grey", 100-(2*(xx_df1$SID74+1)), sep="") xx_PD <- as.PolyData(xx_df1, projection=attr(xx_PS, "projection")) plotMap(xx_PS, polyProps=xx_PD) which corresponds to: spplot(xx, "SID74", col.regions=grey(99:1/100)) Now this assumes that Arc hasn't done something odd to your shapefile, of course. Hope this helps, Roger > Thanks, Rick Reeves > NCEAS / UC Santa Barbara > > -- Roger Bivand Economic Geography Section, Department of Economics, Norwegian School of Economics and Business Administration, Helleveien 30, N-5045 Bergen, Norway. voice: +47 55 95 93 55; fax +47 55 95 95 43 e-mail: [EMAIL PROTECTED] _______________________________________________ R-sig-Geo mailing list R-sig-Geo@stat.math.ethz.ch https://stat.ethz.ch/mailman/listinfo/r-sig-geo