On Mon, Oct 29, 2012 at 9:13 AM, Jonsson <amen.alya...@bordeaux.inra.fr> wrote: > This code will read binary file and display it as a map. may problem is that > this code is using a continuous colour scheme, even though I have discrete > data (which is a classification scheme). How can I map numbers to colours > with raster? Please > > require(raster) > conne <- file("C:\\lai.bin", "rb") > sd<- readBin(conne, integer(), size=1, n=360*720, signed=F) > y<-t(matrix((data=sd), ncol=360, nrow=720)) > r = raster(y) > extent(r) = extent(c(xmn=-180,xmx=180,ymn=-90,ymx=90)) > plot(r) >
The raster package can handle categorical rasters, but it seems poorly documented. If I read in a categorical raster (land cover classification from CORINE) then I get a raster that plots using the colour table defined in the GeoTIFF. This comes from a 'legend' attribute which the raster object has. This is an undocumented object of class ".RasterLegend". I think Robert "Raster" Hijmans has been meaning to document all this at some point, I've been meaning to dig into it too. Its probably worth asking further questions on R-sig-geo. Barry ______________________________________________ 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.