## Usage

sim1(speciesData)

## Arguments

- speciesData
- binary presence-absence matrix
(rows = species, columns = sites).

## Value

Returns a binary presence-absence matrix with the same
dimensions and percent fill as the input matrix.

## Description

Randomizes a binary matrix speciesData by reshuffling
all of its elements equiprobably.

## Details

This algorithm assumes species and sites are equiprobable.
It preserves the total matrix fill, but places no other constraints on
row or column totals.

## Note

This is the simplest of all randomization algorithms for a presence-
absence matrix. However, it assumes that both species and sites are
equiprobable, and has poor Type I error frequencies when tested with
purely random matrices. If the input matrix is sparse, it will often
generate null matrices with empty rows or columns. Not recommended for
co-occurrence analysis.

## References

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

## Examples

randomMatrix <- sim1(speciesData=matrix(rbinom(40,1,0.5),nrow=8))