[GRASS-user] new addon: r.patch.many

[Hamish]

Hi,

for anyone running big r.patch jobs (e.g. 100 maps) on a multi-core system, I just added a new addon for grass 6 called r.patch.many which allows it to automatically run in parallel. Obviously if you have fewer maps than cores it won't help much; I'm not sure how many maps you need to make it worth the extra processing overhead, maybe 2x or 3x the number of cores. This just aids wall-clock processing time; cumulative CPU time will be some fraction worse than r.patch alone.

You can use the g.md5sum addon script to test that the results of r.patch and r.patch.many are identical.



The same technique could easily be adapted for 'r.series max=' and similar operations, btw.


testers welcome.


Hamish