Glynn Clements ha scritto: > The entire notion of "least cost" is based upon the assumption that > the cost must always be non-negative.
Bingo, you got it! I had (by my mistake in mapcalc parameters) a few negative cells. Now r.cost runs, and I'doing further testing. I think your suggestions should be implemented: in the current situation the user doesn't have a clue of what is the problem. Thanks a lot! -- Paolo Cavallini: http://faunalia.it/pc _______________________________________________ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user