On Wednesday 15 April 2009, Glynn Clements wrote: > Dylan Beaudette wrote: > > 3. Allow the user to specify what they would like NULL cells encoded as. > > Unless I am overlooking something, it would seem reasonable to export a > > CELL map to a signed integer format, and use some obvious negative value > > for NULL: > > If you're exporting to a 32-bit (signed or unsigned) integer format, > the obvious choice for null is 0x80000000. That's what GRASS uses > internally, so it can never occur as a legitimate value (if a > computation ends up producing that value, it will get treated as a > null in all regards).
Thanks Glynn. It would be good to know about 'obvious' values for any given datatype. Cheers, Dylan -- Dylan Beaudette Soil Resource Laboratory http://casoilresource.lawr.ucdavis.edu/ University of California at Davis 530.754.7341 _______________________________________________ grass-dev mailing list grass-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-dev
