[GRASS-user] v.patch drops adjacent polygons

Markus GRASS markus.metz.giswork at googlemail.com
Fri Jun 5 11:18:28 EDT 2009

A. Marcia BARBOSA wrote:
> Hi all,
> I'm trying to v.patch two contiguous UTM 10*10-km grid maps, but the
> polygons in the zones of contact between these maps do not appear in
> the output map... 
What does v.info on the two vectors and the patched vector say in terms
of extends and number of objects, in this case only boundaries,
centroids, areas, islands?
> I understand I would have to v.clean the output map
> to eliminate overlapping boundaries, 
Not necessarily, sometimes it may be desired to have slightly
overlapping areas, e.g. Landsat footprints aka WRS2 grid.
> but I don't even get the chance
> to do it, as the polygons whose boundaries would overlap are excluded
> for some reason.
As above, v.info on the patched map could help to find the problem.

Markus M

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