Hi Steven, You should check the projections of your datasets (summary()).
When I do the same kind of analyses, I use: readOGR(), to read the shp proj4string(), to assign a projection overlay(), to make spatial overlay analysis spplot(), to plot more than one spatial layer hope this help Sam On Tue, Apr 9, 2013 at 9:10 AM, Steven Ranney <steven.ran...@gmail.com>wrote: > All - > > My apologies for what is likely a neophyte questions but I'm new to spatial > plotting in R and to .shp files in general. I don't know all the > terminology which makes reading the help files that much more difficult. > > I've been asked to do a "point.in.polygon" analysis of some dolphin > resighting data. I have recapture coordinates for these sightings and can > convert them into SpatialPoints() objects. I have a .shp file (along with > all of the ancillary files that go with a .shp: .prj, .dbf, .sbn, .sbx, > .shx, .xml) with three different polygons. I read in the .shp file with > readShapePoly(). I can plot the .shp and the coordinates independently but > when I ask for an over() of the coordinates and polygons, I get "NA" for > each of my resighting events. > > I'm sure my inability to do what I thought was a simply analyses has to do > with my lack of familiarity with the spatial side of R. Can anyone give me > a hand with this? I'd like to be able to share data but unfortunately it's > rather sensitive and will be part of a litigation. > > Thanks in advance for your assistance. > > SR > Steven H. Ranney > > [[alternative HTML version deleted]] > > _______________________________________________ > R-sig-Geo mailing list > R-sig-Geo@r-project.org > https://stat.ethz.ch/mailman/listinfo/r-sig-geo > [[alternative HTML version deleted]] _______________________________________________ R-sig-Geo mailing list R-sig-Geo@r-project.org https://stat.ethz.ch/mailman/listinfo/r-sig-geo
