s.voronoi

... I would think that there are other ways around the
problem, for example never going to polygons in the first place. How
about building a network instead of a bunch of polygons. You should never
have to re-build any given segment more than once anyway. if you are,
I would think you are doing twice the necessary work.

   Could you please spell out the correct way to create a network in
GRASS ? Often , I do not create areas properly if I don't resort to poly-
gons. Each area appears to need a unique node, as a rule. If I permute
the points in one of the area lines there's no problem.
  That is, A 4 0 0 0 1 1 1 0 0 and
        A 4 0 0 0 1 -1 -1 0 0
will not form 2 areas , but the permutation
        A 4 0 1 -1 -1 0 0 0 1 will work, but this is still
a polygon representation duplicating line 00 01.

  Where is the correct protocol for a network representation ?

          Murray