[R-sig-Geo] polygon adjacency testing
b.rowlingson at lancaster.ac.uk
Fri Aug 13 18:14:41 CEST 2010
On Fri, Aug 13, 2010 at 4:59 PM, Nikhil Kaza <nikhil.list at gmail.com> wrote:
> I havent looked at poly2nb code, but would eliminating polygons from the
> polygon list based on area, perimeter or ratio of these two, before
> constructing the neighbour list work? This would be similar, not identical,
> to eliminate in ArcInfo.
That's okay for general cleanups of slivers etc, but it wont catch
other problems that might manifest themselves via adjacency. My
substantive problem uses polygon adjacency in its model, so I was
hoping for a way of assessing the correctness of the adjacency graph.
I'm pretty sure I can do it with LinesIntersections from rgeos now,
its just a bit of a grind to get rid of all the intersections from
coincident endpoints. nb2lines is also useful.
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