[GRASS-user] Extrac values with r.mapcalc

[Markus Neteler]

2011/4/13 Gaspar Reyes Póndigo <gos47 at hotmail.com>:
> Hello, Dear grass_user. My first forum participation in the grass_user list
> email.

Welcome!

> How to extract values of map raster with r.mapcalc? I need make new map
> raster based on specific value  of other raster.

Please take a look at the if() conditions:

http://grass.osgeo.org/grass64/manuals/html64_user/r.mapcalc.html

Therein is also a section EXAMPLES.

Markus