[GRASS-user] Raster map Calculator

[Moritz Lennert]

On 19/03/12 20:42, Michiel Kunzel wrote:
> Hello list,
>
> I am trying to create a series of ratio images using grass 6.4.1 and I
> can't get the syntax for the raster calculator figured out.
> What I've got at the moment is:
>
> 'Bar45rastfl = 1.0 * BarB40 at PERMANENT / BarB50 at PERMANENT'
>
> I've tried varying the equation above but to no avail. The resulting
> maps do not contain any values.
>
> What am I doing wrong?

Have you set your region correctly ?

I.e. g.region rast=BarB40

before running r.mapcalc ?

Moritz