I think you almost got there. the IF condition would be this:
> r.mapcalc "output = if((isnull(a)),b,if(isnull(b),c),a)" so if A is null, use B, otherwise test if B is null. if it is, use C, otherwise use A. (note: this is from the top of my mind, I didn't tried it) Hope this helps. Carlos On Sun, Jan 16, 2011 at 14:35, Gabriele N. <[email protected]> wrote: > > Ciao grass users. > > I have three maps A, B, C. > > I would use r.mapcalc to combine them according to this logic: > Put the values of A and if A is null you put the values of B and if B is > null you put the values of C. > > I have tried in various ways without success. .. now I'm trying with a > double IF... > r.mapcalc "output = if((isnull(a)),b,if(isnull(b)),c)" .....but in this > case I do not put the values of A > > > Help / advice? > > Thanks > -- > View this message in context: > http://osgeo-org.1803224.n2.nabble.com/r-mapcalc-3-maps-tp5929440p5929440.html > Sent from the Grass - Users mailing list archive at Nabble.com. > _______________________________________________ > grass-user mailing list > [email protected] > http://lists.osgeo.org/mailman/listinfo/grass-user > -- Prof. Carlos Henrique Grohmann - Geologist D.Sc. Institute of Geosciences - Univ. of São Paulo, Brazil http://www.igc.usp.br/pessoais/guano http://lattes.cnpq.br/5846052449613692 Linux User #89721 ________________ Can’t stop the signal. _______________________________________________ grass-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-user
