[GRASS-user] Extracting non-overlapping lines

[Markus Neteler]

On Wed, Jul 22, 2009 at 1:06 AM, Dwight Needels<needels at translucida.com> wrote:
> Hi all,
>
> I have two nearly identical line vectors, and I would like to extract the
> lines that differ between the two vectors into a third vector. Specifically,
> I want to isolate the connecting lines that were generated by v.net
> operation=connect. Something like:
>
> [map_C = map_A   NOT   map_B]  for line features.
>
> I thought I would be able to use v.overlay with operator=not, but it it
> appears to require that btype=area. It also appears that v.select allows
> only operator=overlap.
>
> Can someone point me in the right direction?
>
> I am using William Kyngesburye's 6.4.0RC3 on MacOS 10.5.7.

Since GRASS 6.5 there is GEOS support with more functionality available
in v.select, see also
http://lists.osgeo.org/pipermail/grass-user/2009-June/051142.html

This may be a way.

Markus