[GRASSLIST:8174] Cut a polygon (Area/boudary) into two?

GRASS GRASS user
1

Hi all,

I have an area vector layer and a want to draw a line across it and cut it into two sperate polygons. How do I do this?

I know it's a silly question but must say that I amost exclusively have only ever used Grass for raster manaipulations. I normaly use ArcGis for vectors. Now that Grass has the new vector format I think I might be able to get more use from it with vectors.

thanks,

Phil

2

From: "Phillip J. Allen" <paallen@attglobal.net>

I have an area vector layer and a want to draw a line across it and cut it into two sperate polygons. How do I do this?

<snip>

Sorry if I didn't understand your problem, but isn't v.digit (or better the QGIS Grass digit plugin) enough for this purpose?

Break the boundary in two locations, draw a boundary line to connect your break points, digitize a centroid withing the "new" area. Assign attributes as needed.

Best,
Maciek

3

Hello Phillip,

On Mon, 05 Sep 2005 11:56:51 -0500 "Phillip J. Allen"
<paallen@attglobal.net> wrote:

Hi all,

I have an area vector layer and a want to draw a line across it and
cut it into two sperate polygons. How do I do this?

I know it's a silly question but must say that I amost exclusively
have only ever used Grass for raster manaipulations. I normaly use
ArcGis for vectors. Now that Grass has the new vector format I think
I might be able to get more use from it with vectors.

Try
v.digit [1]

or the digitize-module for GRASS-vectors in Quantum GIS [2].

Best
  Stephan

[1]: http://grass.itc.it/grass61/manuals/html61_user/v.digit.html
[2]: http://www.qgis.org
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