[GRASSLIST:3806] Re: Vector Manipulation

[Radim Blazek]

On Friday 31 May 2002 02:12 pm, Christoph Simon wrote:
> I'm at the very beginning of the attempt to learn about GIS and Grass
> teaching myself. I decided to start collecting data from the Internet,
> join them and at least visualize some maps. I thought this might be a
> first step. Now I have lots of data from many different places, mostly
> incomplete and almost incompatibe.

You started with the most dificult task (using "ready for use" data :)

> For instance, I've got one shape
> file for some pieces of a political boundary with very nice
> resolution, and another which is almost complete, including
> subdivisions, but which is much coarser. So I try to cut out pieces
> and join them together. At this point, I would like to keep the
> original vertices. I didn't try it yet, but I guess, if I convert a
> vector map to raster and back to vector, I might get more points with
> less precision. Right?

For this task my proposal is not useful.
You would need v.cutter with inverted function, which is not
available. In theory, should be possible to add rectangle to
the map with boundary of area you want to cut out, then label
area between your potato and rectangle and use v.cutter to extract
lines in this labeled area.

Radim