[GRASS-user] clipping line data to a polygon

[Hamish]

Mark wrote:
> Is the best way to clip data to use the v.overlay command with the "and"
> operator?
> 
> it works great, but seems quite slow on larger datasets.  Additionally as an
> example, if i have topographic contour lines, and i want to clip them to a
> polygon, and only want the topo line attributes (elevation) outputted, is
> there a way to do this?  Is there another way to clip line data to within a
> polygon that might be a bit faster?


run v.select, then v.overlay. That way the intensive v.overlay operation only
happens for relevant vector features. Then it will speed up hugely.

I wonder if v.select functionality could be built into v.overlay as a
preprocessing step?


Hamish



       
____________________________________________________________________________________
Moody friends. Drama queens. Your life? Nope! - their life, your story. Play Sims Stories at Yahoo! Games.
http://sims.yahoo.com/