On Wed, Nov 25, 2009 at 11:39 PM, Remko Duursma <remkoduur...@gmail.com> wrote: > See the function 'convhulln' in the 'geometry' package. It uses this > algorithm : http://www.qhull.org/
That looks like a CONVEX hull, the original poster asked about CONCAVE hulls (and in all CAPS to emphasise this!). I've seen various algorithms for generating 'concave hulls' of point sets, the one that tops google searches is not available in source code but there is a web applet and set of java class files which appear to be based on a patented algorithm. There's a lot of discussion on algorithms for this, and some implementations by processing the point data with GRASS. There main discussion appears to be to first generate the convex hull and then replace single edges with two edges based on some minimum or maximum distance criteria... Couldn't find an implementation in R or Python though... Barry ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.