I've just been hacking image.SpatialGridDataFrame to support transparency, either via specifying an alpha band or a constant value of alpha:
image(foo,red=1,green=2,blue=3,alpha="band4",add=TRUE) image(foo,red=1,green=2,blue=3,alpha=0.5,add=TRUE) I don't think what I've done works properly with NAs in the data though. Has anyone else implemented transparency for SGDFs to save me spending time fixing little awkward bits like that? Roger? Barry _______________________________________________ R-sig-Geo mailing list R-sig-Geo@stat.math.ethz.ch https://stat.ethz.ch/mailman/listinfo/r-sig-geo
