Hi, sorry for late answer, I had overlooked this email
On Fri, Mar 7, 2014 at 7:30 AM, Hamish <[email protected]> wrote: > maning wrote: > > > I'm testing r.hazard.flood and noticed that it computes the flood and > > mti layers on the full region of the elevation raster instead of the > > pre-defined region settings. > > > > The relvant code I found from the r.hazard.flood is this: > > # Detect cellsize of the DEM > > info_region = grass.read_command('g.region', flags = 'p', > > rast = > > '%s' % (r_elevation)) > > dict_region = grass.parse_key_val(info_region, ':') > > resolution = (float(dict_region['nsres']) + > > float(dict_region['ewres']))/2 > > grass.message("Cellsize : %s " % resolution) > > > > Would it be possible to either respect the current region settings or > > add a flag to choose between the dem region settings or current region > > settings? > > > if it needs to detect the original raster cell resolution (usually that's > only needed to avoid aliasing artifacts in certain situations) it should > use r.info to get the answer. I'm guessing due to the averaging of the ew > and ns resolutions avoiding aliasing isn't the case. > > if a module wants to change the region (and almost none should ever do > that except for g.region by itself) it should set up a temporary > WIND_OVERRIDE first, in the case of python scripting there is an easy grass > python function to make that and clean it up at the end. (otherwise > parallel jobs get their regions messed up mid-run, and region changes > without you expecting it will) > > I suspect grass.raster's raster_info() is the better way for > r.hazard.flood to do what it's trying to do now. But also just querying the > current g.region info without changing anything is probably even better, as > that is what the other raster commands will expect to use. If the user > should align perfectly with the input map first, it should be noted in the > help page for them to do it manually before running the module. > Thanks for suggestion, applied in r59879 Cheers, madi -- Best regards, Dr. Margherita DI LEO Scientific / technical project officer European Commission - DG JRC Institute for Environment and Sustainability (IES) Via Fermi, 2749 I-21027 Ispra (VA) - Italy - TP 261 Tel. +39 0332 78 3600 [email protected] Disclaimer: The views expressed are purely those of the writer and may not in any circumstance be regarded as stating an official position of the European Commission.
_______________________________________________ grass-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-user
