Hi, The latter method seems good to me. I haven't found any other alternative for this purpose.
2011/10/18 Agustin Lobo <alobolis...@gmail.com> > Hi! > > Given a Sp Points DF and an Sp Polygons DF, I want to add a field of > number of points for each polygon > to the Sp Pol. DF table. This is what I'm doing (using objects from > the help page for sp::overlay() > (meuse is the Sp Points DF and srdf the Sp Pol. DF) > > > delme3 <- overlay(meuse,srdf) > > delme3 > [1] 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 > 1 1 > [38] 1 1 1 1 1 1 2 1 2 2 2 2 2 2 1 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 3 3 3 > 3 3 > [75] 3 3 3 3 3 3 3 3 2 1 2 2 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 2 2 2 2 2 2 2 > 2 2 > [112] 2 2 2 2 2 2 3 2 2 2 2 2 1 2 2 2 2 1 1 2 2 1 2 2 2 2 3 3 3 3 3 3 3 3 3 > 3 3 > [149] 3 3 3 3 3 3 3 > newdata <- data.frame(srdf@data,nppoints=table(delme3)) > srdf2 <- srdf > srdf2@data <- newdata > > An alternative: > newdatap <- data.frame(meuse@data, nbp=rep(1,nrow(meuse))) > meuse2 <- meuse > meuse2@data <- newdatap > delme4 <- overlay(meuse2[,13],srdf,fn=sum) > newdata <- data.frame(srdf@data,nppoints=delme4) > srdf2 <- srdf > srdf2@data <- newdata > > I wonder if there is a better way or, best, an standard R spatial > function doing that already. > > Thanks! > > Agus > > _______________________________________________ > 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
