rarefy.N

rarefy.N randomly draw a given number of individuals from a given community and returns an index (eg. number of species) for this random subset. The functions creates as many random subsets of n individuals as requested and can return any index from a community in each random subset (eg. PIE index). The function Estimate.S returns the expected number of species in a random subset of n individuals using an analytical approximation, then is more precise and run faster (but just estimate S and do not provide confidence intervals). Both functions require as input a vector with the number of individuals per species <br><br>