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)
--
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Hello, Did you check the arguments fo the function "plot", from the "raster" package? For example, the "col" argument. Regards, Pascal Le 29/10/2012 18:13, Jonsson a ?crit :> 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) > > > > > > -- > View this message in context: http://r.789695.n4.nabble.com/How-can-I-map-numbers-to-colours-with-raster-tp4647742.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > R-help at 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. >
On Mon, Oct 29, 2012 at 9:13 AM, Jonsson <amen.alyaari at 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
see the function level() in raster. also levelplot in rastervis package. you basically create a raster attribute table coerce the raster to factor class and plot. check geo sig i have posted the same question there On Oct 29, 2012 2:15 AM, "Jonsson" <amen.alyaari@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) > > > > > > -- > View this message in context: > http://r.789695.n4.nabble.com/How-can-I-map-numbers-to-colours-with-raster-tp4647742.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. >[[alternative HTML version deleted]]