randomizing a community phylogenetics matrix: '3x' of Hardy (2008)
resamp.3x is used for resampling data within a community dataset
a community dataset in spacodiR format (see
a proportion specifying the extent of data shuffling
A resampling procedure for a species-by-plots matrix, based on Gotelli swapping.
Shuffles abundances within species and for a pair of plots. The
the degree of sampling, with larger values dictating a higher level of reshuffling.
For instance, if
level = 0.1 and the dataset involves 20 species and 20 plots,
a total of 40 (
0.1x20x20) Gotelli-like swaps are performed. The number of swaps is always rounded up such that at least one swap is performed (i.e., when
A shuffled dataset
HARDY OJ. 2008. Testing the spatial phylogenetic structure of local communities: statistical performances of different null models and test statistics on a locally neutral community. Journal of Ecology 96:914-926.
GOTELLI NJ. 2000. Null model analysis of species co-occurrence patterns. Ecology 81:2606-2621.
spacodi.by.nodes for permutation tests of community diversity and additional randomization methods;
spacodi.calc for the main underlying function;
1 2 3 4 5 6