[GRASSLIST:3792] Re: Vector Manipulation

[Radim Blazek]

On Wednesday 29 May 2002 09:57 pm, Christoph Simon wrote:
> Hi!
>
> I just joined this list. I was wondering if there is any grass tool
> like r.mapcalc for vector data. In particular, I would need a way to
> do two things: one is to join several adjacent area polygons into one
> bigger. I found an add-on tool called v.rmedge which does exactly the
> inverse of what I'm trying to do. 

v.reclass -d 
(warning: area labels may be incorrect some times - you can get
more labels in one area - no problem because they are of the same
category; i'm not sure but i worry that you can get even not labeled
areas - problem)

> And the other one is to select or
> deselect certain lines in a resulting map C depending on their
> presence in map A and/or B (with or without a snapdistance).
>
> Thanks in advance.

I would use:
v.to.rast  (A,B,C)
r.report or r.mapcalc (or something)
v.reclass or v.extract (based on results of r.* modules)

Radim