[GRASS-user] handling raster resolution with r.reclass

[nik at nikosalexandris.net]

Chiara Scaini wrote:

> Hello!
> 
> my name is Chiara, I'm currently using grass to postprocess netcdf data
> and peroform spatial analysis

Hello Chiara!


> I import netcdf bands separately, then reclassify the values (with
> external tables) and finally convert the area that i'm interested in
> into polygons.
> 
> while using r.reclass, the output raster has a lower resolution that
> the initial one.

In general, the resolution and extent of "new" raster maps derived from raster 
processing modules, are the ones of the current region (aka computational 
region) which are set by the user with the "g.region" module.


> this parameter does not seem to be customizable.

Not from "within" the r.reclass module, and, in general not "within from" 
almost all raster processing modules. It is g.region that controls that.


> Of course I could change the resolution afterwords, but it would imply an
> interpolation, while the values of the initial raster are more
> reliable...

> how could I solve this problem?

Right!  This will not be necessary, of course, if the user has properly set 
from the beginning...

g.region rast=Some_NETCDF_Band -p

Best of success with your work,

Nikos