[GRASSLIST:242] Re: Confused about v.extract

[Hamish]

> I'm trying to take a vector map of areas produced from r.to.vect and 
> turn it into a vector map of just lines, not areas. I am using grass61
> cvs updated earlier today (and again a few minutes ago).
>
> I was thinking I could v.extract only the boundaries (no centroids)
> then v.type the boundaries into lines.  But I can't seem to extract
> boundaries at all without also extracting centroids, no matter what I
> try.

v.extract only works on features with a category number. Use v.category
on your boundaries, then you can extract them. 

note added to the v.extract man page in CVS.



Hamish