[GRASS-user] Patch raster maps very slow - Is there a way to
speed this up?
hamish_b at yahoo.com
Mon Jan 11 21:44:58 EST 2010
> I have generated DEM tiles (65ish) from LIDAR data in its
> natural projection NC state plane feet (the area covered is
> about 300 squared miles). I have reprojected them into UTM 17
> nad 83. These DEMs are 1m resolution.
so the region is like 50000 x 50000 rows,columns?
> I am using r.patch and it has been running for three
> days now and it is 45% done... Would it be faster to
> stop this process,
if it is half done and seems to be working, if it were me I'd
just renice it to low priority & let it finish.
> patch them in there native projection and then reproject them
> to UTM?
that's probably good policy regardless.
another faster way might be to split up the tiles into 4
quadrants and run the r.patch in each of those then finally
just patch the last 4 quadrant maps together. that should
probably be done in the native projection to avoid chopped off
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