It's not r.mapcalc fault. I imagine it's probably a limitation due to the number of bits in your image. For instance, 8 bit images can have up to 256 values. 16 bit images can have 65,535. So, if you have too many values, you will have problems. Not sure how to avoid this in your case but, maybe you will need to work with categories after all. Are you planing on doing any math operations in the concatenated values or is it more for displaying pourposes?
Cheers Daniel http://en.wikipedia.org/wiki/Integer_(computer_science) On Tue, Nov 23, 2010 at 4:34 PM, Gabriele N. <gis...@libero.it> wrote: > > I have a new problem, this time I would like to concatenate two maps A and B. > A is with 8 digits, B is with 4 digits. So I do as usual: > > r.mapcalc "output" = "((" A "* 10000) (" B "))" > > But I get strange values with negative values. I did several tests but > without resolve. Perhaps r.mapcalc may have problems with numbers greater > than 10 digits > > > Thanks > > Gabriele > -- > View this message in context: > http://osgeo-org.1803224.n2.nabble.com/Values-from-multiple-raster-to-link-together-tp5741032p5767794.html > Sent from the Grass - Users mailing list archive at Nabble.com. > _______________________________________________ > grass-user mailing list > grass-user@lists.osgeo.org > http://lists.osgeo.org/mailman/listinfo/grass-user > _______________________________________________ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
