Hello all, I downloaded a .grd file from http://pubs.usgs.gov/of/2005/1413/gisdata/data/NAMrad_U.grd and would like to open it in R. Can anyone please tell me how to open .grd type files in R. I tried to read with raster, ncdf and also rgdal, but couldnt. Thanks a lot for your time. Swagath