Flexibly outlining a set of points with alphahull

December 6, 2012
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(This article was first published on is.R(), and kindly contributed to R-bloggers)

We’ve previously covered the convex hull here at is.R(), and in that post I admitted that I was somewhat hard-pressed to come up with a common use-case — at least for Political Science applications.

Well, today’s Gist illustrates the use of something even cooler than the convex hull, in fact it’s the generalization of the convex hull: the alpha hull, as implemented in the alphahull package.

By altering the alpha parameter, you can change the “sensitivity” of the outlining, which is based on a Delaunay triangulation / Voronoi tesselation, which can be seen when plotting an alpha hull object.

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