[GRASS-dev] v.category option=print: fails to print area's categories

Maciej Sieczka tutey at o2.pl
Sun Nov 26 14:16:39 EST 2006

Michael Barton wrote:

> Why list area and centroid separately?

Because you can have "broken areas" - there is a centroid inside, but
the boundary is not closed (eg. after importing a non-topological
shapefile; or due to an error during digitizing). Listing areas and
centroids separately can help you debug the issue.

> The second would be even better (IMHO) if adding cats to lines included the
> lines bordering and defining areas. If boundaries can be conceptually
> differentiated from lines

If they were not, any closed line without a centroid would be an
invalid area according to GRASS topological model. The boundaries type
enables to distinguish the closed lines from incomplete areas (closed
boundaries missing the centroid).

>, then the first might be preferable, but I'm still
> not sure.


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