[GRASSLIST:2404] Re: The g3.region settings ....

[Glynn Clements]

Geotronix wrote:

> > > I'm trying to get s.vol.rst to work for the computation of rainfall map
> > > using a 50m resolution cell (1000x1000 cells grid).
> > > Now, the site file that's input for s.vol.rst has 4 columns
> > > x|y|z|%rainfall(mm/year)
> > > 
> > > When I tried to launch s.vol.rst the first time it told me that I had to
> > > set the 3D region. SO I launched g3.createregion which reead the
> > > defaults from the current 2D region. I gave him the following options:
> > > 
> > > g3.createregion t=2500 b=0 dres=1
> > > 
> > > as to resemble:
> > > 
> > > t=2500 --> max altitude in meters that I have on my dem;
> > > b=0  --> min altitude on my dem ;
> > > dres=1 -->vertical resolution on 1 meter.
> > > 
> > > Now, I used the maskmap option for s.vol.rst so as to narrow the
> > > computation only to a subarea of the 1000x1000 cell area while all
> > > rainfall station (25) fall in the 1000x1000 cell area.
> > > 
> > > I launched the program and it is takeing a hell of a long time to
> > > compute. After 4 hours it's still at 0%.
> > > 
> > > Did I miss something in the settings of the 3D region or does it simply
> > > take so much time to compute? Yet, 1000x1000 cells don't seem to be much
> > 
> > It's a volume, not an area: 1000x1000x2500 = 2.5x10^9 cells.
> 
> Do you mean that 2500 I set is in cells? I thought it was in meters.....
> The 1000x1000 is a grid with 50 meter resolution. So to set z=2500 must
> I give it 2500/50=50? So that I get 1000x1000x50?

Note:

> > > g3.createregion t=2500 b=0 dres=1

> > > t=2500 --> max altitude in meters that I have on my dem;

> > > dres=1 -->vertical resolution on 1 meter.

2500 metres with 1-metre resolution => 2500 cells.

> Or maybe the vertical scale resolution is indipendant from the x,y ones?

Yes; that is what dres=... is for.

-- 
Glynn Clements <glynn.clements at virgin.net>