[R-sig-Geo] which function in R can extract the coordinats of ploygon's center and create Dirichlet tessellation/Delaunay triangulation of points?
Roger.Bivand at nhh.no
Tue Mar 6 19:51:20 CET 2007
On Tue, 6 Mar 2007, zhijie zhang wrote:
> Dear friends,
> I can't find the functions in R to do the following tasks:
> 1. extract the coordinats of ploygon's center ;
The coordinate() method for a SpatialPolygons or SpatialPolygonsDataFrame
object returns the centroid of the largest member polygon.
> 2. create Dirichlet tessellation and Delaunay triangulation for a set of
> points sp,spdep,tripack,et al, seem not to be able to finish it.
Please review the following recent posting, where the deldir package is
used to extract a tesselation:
It ought to cover your question (it is more difficult to recover the outer
polygons of the tesselation from tripack as closed polygons).
Hope this helps,
> If u know how to do it, please let me know.
> Thanks very much.
Economic Geography Section, Department of Economics, Norwegian School of
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e-mail: Roger.Bivand at nhh.no
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