[GRASS-user] Slope categories from DEM ?
emma at seleeg.org
Sat Nov 6 17:47:44 EDT 2010
On 6-Nov-10, at 10:41 PM, Martin Landa wrote:
> 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 ...
Right, this solved the problem! Thanks
More information about the grass-user