[GRASS-user] Slope categories from DEM ?

[Martin Landa]

2010/11/6 Emma <emma at seleeg.org>:
> Now I also tried to use r.mapcalc instead of r.reclass as follows:
> r.mapcalc 'new_slope_30_bis = if(new_slope > 30, 1, 0)'
>
> However for some reason the resulting map new_slope_30_bis has:
> Rows:         20
> Columns:      20
> Total Cells:  400
>
> while the original new_slope, as well as new_slope_30 have both Total Cells:
>  47212692. So you can imagine the result is not very nice...

raster modules operate on the computational region, try to set up the
region based on slope map before you run r.mapcalc

g.region rast=new_slope
r.mapcalc ...

Martin

-- 
Martin Landa <landa.martin gmail.com> * http://geo.fsv.cvut.cz/~landa