[GRASS-dev] Multi-threading and use of multiple processors

[Markus Neteler]

On Wed, Apr 8, 2009 at 3:44 AM, Colin Nielsen <colin.nielsen at gmail.com> wrote:
> A colleague of mine would like to run a cost analysis (with either
> r.walk or r.cost) on a very very large raster, ~ 1500 km x 800 km with
> about 30 m resolution equals about 40 billion cells.

[ see my other today's email about r.terracost now in Addons ]

...
> Is there any plan to add multi-threading to these or other modules (I
> think I remember something about r.mapcalc and another a while back)?

Yann Chemin parallelized i.atcorr for me with openMP which required
the addition of a few lines and a gcc >= 4.2 compiler. For hints, see

http://grass.osgeo.org/wiki/OpenMP

Perhaps this can be introduced at library level at some point. The
behavior or a pixel oriented module such as i.atcorr is of course
different from that of r.cost which has to consider more than a pixel
in a cycle.

Markus