Randomizes a binary matrix speciesData by reshuffling all
elements. Rows are equiprobable, and columns are proportional to column sums.
Makes a call to the vector_sample function.
Returns a binary presence-absence matrix with the same
dimensions and fill as the input matrix.
Details
This algorithm assumes that species are equiprobable, but that
differences in suitability among sites are proportional to observed species
richness (=colsums).
References
Gotelli, N.J. 2000. Null model analysis of species co-occurrence
patterns. Ecology 81: 2606-2621.