[GRASS-dev] r.watershed and swap memory

ivan marchesini marchesini at unipg.it
Wed Mar 19 10:43:36 EDT 2008

Hi Hamish...
yes.. my threshold is really small (30 cells, because I need a very
detailed stream network in output), and this can probably have a strong
effect on the time of analysis...
However I'm really surprised of your results with 170000000 of cells...
and 2 Gb of ram...!! 
really impressive...
I have tried over two different computers (with 2 Gb of ram), but the
result is the same... so I think that the problem is not on the quality
of the ram or other similar thinks but on the dimension of the

I will try with different resolution as soon as possible... but at the
end I need this resolution because I have "cleaned" the dem with
v.breach to obtain a hydrologically correct dem and now I must use this
dem to derive the drainage...

Many thanks for your interest....


Il giorno mar, 18/03/2008 alle 18.05 -0700, Hamish ha scritto:
> e region slightly or
> run with a slightly coarser resolution to see where the memory limit
> is?
Ti prego di cercare di non inviarmi files .dwg, .doc, .xls, .ppt.
Preferisco formati liberi.
Please try to avoid to send me .dwg, .doc, .xls, .ppt files.
I prefer free formats.

Ivan Marchesini
Department of Civil and Environmental Engineering
University of Perugia
Via G. Duranti 93/a 
Perugia (Italy)
Socio fondatore GFOSS "Geospatial Free and Open Source Software" http://www.gfoss.it
e-mail: marchesini at unipg.it
        ivan.marchesini at gmail.com
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