thinning algorithms in GRASS

[Wendelin Reich]

On Tue, 19 Sep 1995, Gillian Bowser wrote:

> I am curious about the accuracy/precision of translating raster files to vector
> files. I am creating paths from point A to B and I need to know the length of
> the path followed between those points.  The paths are being generated by
> building first a cost surface, then draining (r.drain) that surface.

Sounds interesting... can you tell me how you _generate_ the cost 
surface? Are there any helpful tools in GRASS?

Thanx in advance, Wendelin