Flexibly outlining a set of points with alphahull

December 6, 2012

(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.

To leave a comment for the author, please follow the link and comment on their blog: is.R().

R-bloggers.com offers daily e-mail updates about R news and tutorials on topics such as: Data science, Big Data, R jobs, visualization (ggplot2, Boxplots, maps, animation), programming (RStudio, Sweave, LaTeX, SQL, Eclipse, git, hadoop, Web Scraping) statistics (regression, PCA, time series, trading) and more...

If you got this far, why not subscribe for updates from the site? Choose your flavor: e-mail, twitter, RSS, or facebook...

Comments are closed.

Search R-bloggers


Never miss an update!
Subscribe to R-bloggers to receive
e-mails with the latest R posts.
(You will not see this message again.)

Click here to close (This popup will not appear again)