[GRASS-user] Clipping Raster Map

[Hamish]

> > 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.
!


Hamish