r.combine

[William Albert]

I am a new GRASS user, so my knowledge may be a bit lacking now..

I want to overlay two maps where each cell reatins its value where there
is no intersection with the other map. Where there is an intersection
a new value is created. The "OR" operator doesn't work for this. The
"OVER" operator seems to be restricted to four colors. Also, what about
finding what the values were for each cell that intersected?

Any suggestions GRASS users?

Bill Albert
Dept of Geography
Boston Univ. 
walbert at crsa.bu.edu