R functions for generating restricted permutations of data

 Implements a set of restricted permutation designs for freely exchangeable,
 line transects (time series), and spatial grid designs plus permutation of
 blocks (groups of samples). ‘permute’ also allows split-plot designs, in which
 the whole-plots or split-plots or both can be freely-exchangeble or one of the
 restricted designs. The permute package is modelled after the permutation
 schemes of Canoco 3.1 by Cajo ter Braak.