Hello list; I am working with a dataset containing animal locations over time for a large number of individuals. I would like to compute a center of activity by finding the minimum harmonic mean on a grid overlaying the points of an animal (a "standard" to express center of activity in animal ecology). I have searched the archives at Jonathan Barons server but have not been able to find any package that seem to include such a function. Do anyone of you know of such a function? Yours Tomas Willebrand Wildlife Ecologist PS I am aware of the dedicated home range programs available but planned to do most analysis in R.