On Wed, Jun 9, 2010 at 9:22 PM, Sean Gillies <[email protected]> wrote:
> Try shapely.ops.cascaded_union
>
>  >>> q = cascaded_union(MultiPolygon([p2, p3, p4, p5]))
>  >>> q
>  <shapely.geometry.polygon.Polygon object at 0x16584fb0>
>
> I used descartes.patch.PolygonPatch to render ``q`` with matplotlib
> and see the thin donut shape you're looking for. I haven't tried
> Polygon.union yet, but you should almost always be using
> cascaded_union instead.
>

I've tried the approach of accumulating unions one at a time and that
works too. I suspect that your problem is simply one of plotting the
final polygon without accounting for the interior ring.

Cheers,

-- 
Sean
_______________________________________________
Community mailing list
[email protected]
http://lists.gispython.org/mailman/listinfo/community

Reply via email to