Dear friends, do you know how to calculate the CONCAVE hull of a set of points? is that possible in R? (We a "smoothing" parameters of course) Best, -- Corrado Topi Global Climate Change & Biodiversity Indicators Area 18,Department of Biology University of York, York, YO10 5YW, UK Phone: + 44 (0) 1904 328645, E-mail: ct529 at york.ac.uk