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which function in R can extract the coordinats of ploygon's center and create Dirichlet tessellation/Delaunay triangulation of points?
2 messages · zhijie zhang, Roger Bivand
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: http://article.gmane.org/gmane.comp.lang.r.geo/1275 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, Roger
If u know how to do it, please let me know. Thanks very much.
Roger Bivand Economic Geography Section, Department of Economics, Norwegian School of Economics and Business Administration, Helleveien 30, N-5045 Bergen, Norway. voice: +47 55 95 93 55; fax +47 55 95 95 43 e-mail: Roger.Bivand at nhh.no