[GRASS-user] how to clean vector file after reprojection

Hamish hamish_nospam at yahoo.com
Wed Feb 7 18:19:40 EST 2007

Moritz Lennert wrote:
> > Yes, try "v.clean tool=snap". Or before reprojection "v.clean
> > tool=break".
> 'break' on the source map does not find any intersections to break.
> 'snap' on target map (v.clean in=nuts2 out=nuts2_snap_0_001 tool=snap 
> thresh=0.001 - which if I calculated correctly should snap anything 
> within a bit more than 100 meters) gives me an even worse result (even
> less areas are recognized):

try making snap very small in the lat/lon location. The default is
intended to be 1mm, not 1degX10-3. so try 1e-8. Based on your other
screenshots what about enlarging the snap thresh to 0.1 or so (in the
source loc'n) to get those lines to connect before reprojection? I take
it the same lines do not connect with d.vect+d.zoom? It is very odd.

Note that if you zoom waaaaaay in on a corner with d.vect+d.zoom in an
xmon sometimes one of the lines going off screen will disappear but the
area remains filled. That's a rendering bug & I've never seen it miss a
line segment with both ends on screen.


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