On Wednesday, February 22, 2012, Paolo Cavallini wrote: > Il 22/02/2012 15:54, Roger Bivand ha scritto: > > Using the improved raster graphics handling for square cells with image() > > rather than spplot() and useRaster=TRUE - equivalent to > > image.SpatialGridDataFrame() and useRasterImage=TRUE with the same matrix > > takes 1.2 seconds on x11/cairo. You didn't say which version of R you are > > using - the raster graphics facilities have been improved recently. > 2.14.1-1 on Debian testing. > > Did you try using image() instead of spplot() if your cells are square, and > > if rasterImage() is available in your version of R? > Yes, image() is resonably fast, but misses automatic legend, etc. > Thanks a lot for your reply. > > -- > Paolo Cavallini > See: http://www.faunalia.it/pc > > _______________________________________________ > grass-user mailing list > [email protected] > http://lists.osgeo.org/mailman/listinfo/grass-user >
Check out the plot() function from the raster package, or the related rasterViz (?) package. They have some neat stuff in there. Roger already mentioned this, but I'll add a little more. Now that we have powerful computers and nice packages like spgrass6 it is very simple to load large raster files into R without much effort. However, just because we can fit a linear model on that massive stack of pixels doesn't mean that one should. This is even more important with regard to plotting functions. I have found that coarsening the region resolution a bit before loading in raster that only need to be plotted helps considerably. If you really must work with stacks of large grids, the best approach I have found is the raster package. Cheers, Dylan -- Dylan E. Beaudette USDA-NRCS Soil Scientist California Soil Resource Lab http://casoilresource.lawr.ucdavis.edu/ _______________________________________________ grass-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-user
