António Rocha: > > I applied this expression: > if( gro...@national ==null(),1,0) > > but from this output I obtain only NULLS.
NULL-values in any arithmetic or logical operation result in NULL [1]. The null() function represents the NULL value, thus a NULL value is always present in the logical operation "gro...@national == null()" and the result will always be NULL. try if(isnull(gro...@national),1,0) Markus M [1] http://grass.osgeo.org/grass64/manuals/html64_user/r.mapcalc.html _______________________________________________ grass-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-user
