Hi! Thank you all. I finally understood the way to solve the problem from Barry's mail.
>From the file created with coordinates(Lat,Long) using fan, everything looks ok (wgs84). I will now try Bryan's approach in R. Ana On Fri, Jul 29, 2011 at 4:22 PM, Barry Rowlingson <b.rowling...@lancaster.ac.uk> wrote: >> float lat(rlat, rlon) ; >> lat:standard_name = "latitude" ; >> lat:long_name = "latitude" ; >> lat:units = "degrees_north" ; >> float lon(rlat, rlon) ; >> lon:standard_name = "longitude" ; >> lon:long_name = "longitude" ; >> lon:units = "degrees_east" ; > > These two previous variables are grids of lat-lon values that > correspond to the data. I nabbed a .ncdf file of runoff values from a > site: > > library(ncdf) > r = open.ncdf("runoff.SMHI.MPIB2.nc") > dim(get.var.ncdf(r,"lat")) > [1] 90 86 > dim(get.var.ncdf(r,"lon")) > [1] 90 86 > > so when you get the 90x86 grids of runoff values, the lat-long > coordinates are the corresponding ones in the "lat" and "lon" > variables. > > lon = get.var.ncdf(r,"lon") > lat = get.var.ncdf(r,"lat") > # get data for t = 1: > t1 = get.var.ncdf(r,"runoff",start=c(1,1,1),count=c(90,86,1)) > > now you have three 90x86 matrices. To get (x,y,runoff) matrix, we > just put them together, something like: > > library(sp) > xyr = data.frame(cbind(as.vector(lat),as.vector(lon),as.vector(t1))) > > names(xyr)=c("lat","lon","runoff") > coordinates(xyr)=~lon+lat > spplot(xyr,"runoff") > > - shows how non-griddy the projection really is - it should look like > a fan since now we are showing the data on true lat-long points, not > the transformed rlat rlong points. > > The rlat and rlon variables are the grid coordinate system, which > appears to be some non-standard conical projection. Climate > scientists! > > Details: http://prudence.dmi.dk/public/DDC/areas.html > > 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.