randomizeSample {picante}R Documentation

Null models for community data matrix randomization

Description

Various null models for randomizing community data matrices

Usage

randomizeSample(samp, null.model = c("frequency", "richness", "both"))

Arguments

samp Community data matrix
null.model Null model
frequency
Randomize community data matrix abundances within species (maintains species occurence frequency)
richness
Randomize community data matrix abundances within samples (maintains sample species richness)
both
Randomize community data matrix by drawing species from sample pool with probability weighted by occurrence frequency (maintains both species occurrence frequency and sample species richness)

Value

Randomized community data matrix

Warning

Null model both currently only works with presence-absence data. Convert your data to presence-absence before using this null model (e.g. decostand(x,method="pa"))

Author(s)

Steve Kembel <skembel@berkeley.edu>

References

Gotelli, N.J. 2000. Null model analysis of species co-occurrence patterns. Ecology 81: 2606-2621.

Examples

data(phylocom)
randomizeSample(phylocom$sample, null.model="richness")

[Package picante version 0.2-0 Index]