May I suggest you take a look at the Spatial Task View? r-project.org -> CRAN -> Select Mirror -> Task Views -> Spatial. -- Edzer
Linda Smith wrote: > Could you please let me know more details about rgval package? I have never > used it before. I only tried image.plot() where if you have regular lat and > lon, a map() function can be used later to overlay state map onto it. > > On 4/5/07, Roger Bivand <[EMAIL PROTECTED]> wrote: > >> On Thu, 5 Apr 2007, Vladimir Eremeev wrote: >> >> >>> If your country or state borders are polygons or polylines, you could >>> convert them to desired projection using the function project from the >>> package rgdal. >>> >>> Latitude-longitude grid also could be added by generating desired >>> polylines in lat-lon and converting them to the desired projection using >>> project. >>> >>> >> Yes, the route would be to plot the image in its native projection, and >> project the vector data (shorelines, countries) to the same projection. >> Similar topics have been discussed on the R-sig-geo list, including the >> reading of netcdf files (which are a bit picky) with functions in the >> rgdal package which import the coordinate reference system directly. >> >> Please follow this up on R-sig-geo if you need more help. >> >> >>> Linda Smith wrote: >>> >>>> I have a netcdf gridded file with LCC projection. I can easily use >>>> image.plot to visualize it. However, as the axises are in X,Y, not Lat >>>> >> and >> >>>> Lon, I could not add state or country maps onto it (or lat lon >>>> information). >>>> I do have a grid2d file that describes the lat and lon for each (X,Y) >>>> grid, >>>> but the lat and lon are not regularly spaced, so I could not use >>>> image.plot. >>>> >>>> Does anyone know how to plot this type of gridded data so that country >>>> >> or >> >>>> state borders can be easily added? Thanks a lot! >>>> >>>> >>> What do you mean by "grid2d file that describes the lat and lon for each >>> (X,Y) grid"? >>> If this are two rasters of the same size having corresponding latitude >>> >> and >> >>> longitude values in each raster cell, then you could use contourLines to >>> >> get >> >>> lat-lon grid. However, you, probably, will want to smooth it. >>> >>> >> -- >> Roger Bivand >> Economic Geography Section, Department of Economics, Norwegian School of >> Economics and Business Administration, Helleveien 30, N-5045 Bergen, >> Norway. voice: +47 55 95 93 55; fax +47 55 95 95 43 >> e-mail: [EMAIL PROTECTED] >> >> ______________________________________________ >> R-help@stat.math.ethz.ch 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]] > > _______________________________________________ > R-sig-Geo mailing list > R-sig-Geo@stat.math.ethz.ch > https://stat.ethz.ch/mailman/listinfo/r-sig-geo > _______________________________________________ R-sig-Geo mailing list R-sig-Geo@stat.math.ethz.ch https://stat.ethz.ch/mailman/listinfo/r-sig-geo
