[GRASS-user] Clipping Raster Map
hamish_b at yahoo.com
Fri Jan 1 20:49:24 EST 2010
> > g.region -p
> GRASS 6.4.0svn (Oregon):/usr4/grassbase/Oregon >
> g.region -p
> projection: 99 (Lambert Conformal Conic)
> zone: 0
> datum: nad83
> ellipsoid: grs80
> north: 1334419.25160578
> south: 1279151.24118496
> west: 769192.9282895
> east: 819255.92362222
> nsres: 0.00175298
> ewres: 0.00133118
> rows: 31528020
> cols: 37608092
> cells: 1185708676737840
2,750 sq-km at 1mm resolution!
thar's yer problem.
start with 'g.region rast=dem -p' to reset the region to the bounds
of your master map and zoom from there.
anything larger than about 50000x50000 rows x cols starts to lag and
wants a 64bit OS and lots of hard drive space..
> Well, after about 3 minutes it may move off 0% to
> 3%. After 5 or 6 minutes I hit ^C to kill the process.
well, on the positive side, it is some proof that grass's raster
engine scales rather well and it is just a matter of throwing faster
and faster computers at it as they become available.
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