[GRASS-user] Calling GRASS command in multi-threads

Paul Meems bontepaarden at gmail.com
Mon Dec 31 02:37:13 PST 2012

Thanks Paulo,

That page really helps.
I'll have a look at the Python multithreading example.

I also noticed something about r.sun and OpenCL:
This page doesn't say if it is already implemented in the current version
of GRASS. I do think I need to use GRASS7, am I right?
I have a ATI Radeon HD 4800 with 4GB, this should speed up r.sun, right?
I've looked at the download page of GRASS, but didn't see a GRASS7
installer for Windows. Isn't this available? I really don't hope I need to
compile it myself ;)



2012/12/29 Paulo van Breugel <p.vanbreugel at gmail.com>

>  Perhaps this will give you some useful pointers:
> http://grasswiki.osgeo.org/wiki/Parallel_GRASS_jobs
> On 12/29/2012 01:03 PM, Paul Meems wrote:
>      Hi list,
>  Last night my test script successfully finished processing my small area
> and created a annual solar radiation raster.
> I did a comparison with the solar radiation produced by ArcMap and noticed
> its radiation is almost twice as high as the one produced by Grass.
> Probably I'm not using the correct output files.
>  I'm using glob_rad from r.sun as my result. I will have a closer look why
> this difference is happening.
>  If anyone can give me some pointers that would be must appreciated.
>  My real question today is how to speed up the process. My script took 7
> hours to finish, but only used a fraction of the available resources. While
> running the script (on Windows) only 30% of my quadcore CPU was used and
> only 3GB of my 8GB RAM.
>  Since I'm looping on r.sun, calling it 365 times I was thinking of
> calling it several times at once.
>  Is this possible? Calling r.sun 4 or 5 times at once will decrease the
> time for the script to workable proportions.
> Probably this is more of a Python question than a GRASS question but any
> pointers would be very helpful.
>  Thanks,
>  Paul
> _______________________________________________
> grass-user mailing listgrass-user at lists.osgeo.orghttp://lists.osgeo.org/mailman/listinfo/grass-user
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