This message should have had a more informative subject, and, given its specialist character, been sent to R-sig-geo, as is recommended on the Spatial Task View. From initial trials, the file you are using includes far too much boundary detail, and appears to have been assembled from disparate state/county maps (Florida is added late, not in sequence). With a malformed input map intended for display only, you shouldn't be surprised that the topology is wrong. I'll investigate whether there is a code issue, but the real problem is the choice of a very inappropriate input map of an object size of 64Mb for 56 objects, where you do not need all of the coastal detail.
Roger Philip A. Viton wrote: > > I downloaded a US states+territories shapefile from > http://www.weather.gov/geodata/catalog/national/html/us-state.htm > and unzipped it into my working directory. > Then in R (version 12.2.0 for ms-win32): > > library(rgdal) # Version: 0.6-28 > library(spdep) # Version: 0.5-24 (loads sp: Version: 0.9-72) > > # read in the data > states<-readOGR(".","s_01de10") > summary(states) > > # now create a neighbors list > states_nb<-poly2nb(states) > # create a 0/1 matrix of the neighbors > nb_mat<-nb2mat(states_nb,style="B",zero.policy=TRUE) > # add names > nms<-as.character(states$NAMES) > # set the matrix names > dimnames(nb_mat)<-list(nms,nms) > > # now see which states have no neighbors > rowSums(nb_mat) > # it turns out that Florida seems to have zero neighbors. > > I then repeated it with > states_nb<-poly2nb(states,useC=FALSE) > > and this time -- the computation takes a lot longer, of course > --- Florida has 2 neighbors (correctly: AL and GA). > > > Can anyone tell me what's going wrong here? > > > Thanks! > > > ------------------------ > Philip A. Viton > City Planning, Ohio State University > 275 West Woodruff Avenue, Columbus OH 43210 > vito...@osu.edu > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide > http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > ----- Roger Bivand Economic Geography Section Department of Economics Norwegian School of Economics and Business Administration Helleveien 30 N-5045 Bergen, Norway -- View this message in context: http://r.789695.n4.nabble.com/spdep-poly2nb-problem-tp3506042p3511103.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.