[GRASS-dev] Streams extraction from streams map

Hamish hamish_nospam at yahoo.com
Wed May 2 07:35:10 EDT 2007

Markus Neteler wrote:
> > I have a network of streams (say, Spearfish or better the new
> > NC data set at http://mpa.itc.it/grasstutor/data_menu3rd.phtml )
> > and want to extract a single stream system. Names are lacking,
> > is there any trick to extract topologically connected lines
> > into a new map?
> Probably we need some equivalent to the "sides" operator in
> v.to.db (which tells you the cats of the left and right polygon).
> Some magic which finds the lines which are connected and writes
> out some related attribute(s).

how about v.net.iso? disconnected networks will have infinite cost.


More information about the grass-dev mailing list