Hi, you can use another if-clause,to test, if the other map is null using "isnull(railroads)" eg.
Another way could be to use ||| (3x"|") to handle null-values (for that see: http://grass.itc.it/grass64/manuals/html64_user/r.mapcalc.html section "sull support"). achim Fulvio Mastrogiovanni schrieb: > Hi everyone, > > I hope you can help me in solving this issue. Basically, what I want to do is > to > create a new raster map whose cells are simply given by the "or" of other two > maps (possibly for specific categories), as follows: > > r.mapcalc test=if(vegcover==1 || railroads==1) > > However, maps like railroads are null() when not equal to 1. The resulting map > "test" is null() wherever cells in railroads are null(), therefore making > null() also cells where vegcover is 1. > > How can I solve this issue? > > Thanks! > > Fulvio > > _______________________________________________ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user