[GRASS-dev] test of skeleton functionality in v.voronoi

[Markus Metz]

Moritz Lennert wrote:
> Markus M,
>
> I know this is still very fresh, but I was excited about seeing your
> addition to v.voronoi allowing to calculate skeletons and longest lines for
> areas. Amongst others, this could be useful for calculating some shape
> parameters of polygons for region-based classification.
>
> So, just a quick feedback. I ran the module on the entire urbanarea map, in
> order to test scalability. The results are really nice and I haven't found
> evident errors, yet.

I found evident errors in some other test data. The voronoi algorithm
suffers from problems related to floating point representation errors,
also sometimes apparent when calculating voronoi diagrams for areas.

> It takes quite a while, though:

Yes, because it is a brute force approach. The problem of finding the
center line for areas, or an area skeleton from which the center line
can be extracted, must have been solved previously. A literature
research might help. On first glance, I did not find a solution,
though. Only for straight skeletons which are not suitable to extract
a center line.

Markus M