Dear Grass users,
I need help in using r.mapcalc for my application. I would like to
use r.mapcalc in assigning different equations to different
categories within the same map coverage. For example, I would like
assign eqn A to category 1, eqn B to category 2, eqn C to category 3
and eqn D to category 4 within the same map coverage. How can I do
this using r.mapcalc or is there any other grass comands that I can
use for the purpose mentioned above.
Thanks for any help.
Cheers,
Kamarul
On Thu, 6 Jul 1995, K.A.MOHD NASIR wrote:
Dear Grass users,
I need help in using r.mapcalc for my application. I would like to
use r.mapcalc in assigning different equations to different
categories within the same map coverage. For example, I would like
assign eqn A to category 1, eqn B to category 2, eqn C to category 3
and eqn D to category 4 within the same map coverage. How can I do
this using r.mapcalc or is there any other grass comands that I can
use for the purpose mentioned above.
Yes, r.mapcalc is your tool. You need to use "if-then-else" statements,
like the following:
mapcalc> newmap = if(map==1, eqn_A, if(map==2, eqn_B, if(map==3, eqn_C)))
where eqn_A would be something like "map/(4+map)" or whatever.
Regards,
----
Malcolm D. Williamson - GIS Specialist E-mail: malcolm@cast.uark.edu
Center for Advanced Spatial Technologies Telephone: (501) 575-6159
Ozark Rm. 12 Fax: (501) 575-5218
University of Arkansas
Fayetteville, AR 72701