[GRASS-user] identification of cats of vector areas within current region

[Hamish]

Nikos a écrit:
> > My question is whether it is possible to automatically identify which
> > features (=areas) of a vector map lie within (read: even if their 
> > bigest part is not within) the "current" region and extract
> > them (as a whole, not cut-off the part that is outside of the
> > "region") or... not?!
....
> > Data:
> > 
> > R -> region == some sample
> > a, b, c -> features (areas) in the source map
> >  _______
> > |       |
> > | R    |==| |==|
> > | |==| |b | |c |
> > | |a | |==| |==|
> > | |==|  |
> > |_______|
> > 
> > 
> > Goal:
> > 
> > Identify the cats of a, b (NOT c) with *some* command without visually
> > inspecting their "cats"?
> > 
> > or
> > 
> > Directly extract a and b (NOT c) (with v.extract)?

Vincent wrote:
> I understand the point is to identify a cat list of features falling
> withing the displayed region. In this case, I guess areas whom centroids
> are outside the frame won't match... perhaps it would be interesting to
> retrieve these values through an intermediate v.overlay (operator=and).
> In fact, I don't know how v.overlay behaves with cats, but it may be a
> new lead for your purpose!


use v.in.region + 'v.select op=overlap'.

v.overlay clips, v.select doesn't.


Hamish