[GRASS-user] v.to.points - work on region only

Hamish hamish_nospam at yahoo.com
Fri May 18 07:09:51 EDT 2007

Jaros³aw Jasiewicz wrote:
> I have simple problem - I need to convert linear featrue from huge 
> dataset (rivers and streams in all country - Poland over 400000 
> features) into points - but in lot of small regions across dataset. 
> Problems is because v.to.points converts all dataset into points 
> ignoring region definition
> The only solution I know is to cut rivers to actual region (v.area and
> v.overlay) and next - convert it to points. But the solution is very 
> slow - every v.overlay takes over 20 min for every region.
> Has anybody another (faster) idea??

Running 'v.in.region + v.select' before 'v.in.region + v.overlay' will
be much faster. Then the overlay only is attempted against nearby

a dirtier way but fast (in grass 6.3) would be 'v.out.ascii
format=standard' + 'grep -v' to clean out the "^L " lines + 'v.in.ascii
-r format=points'.


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