CzekanowskiSkew Niche Overlap Metric

Usage

czekanowski_skew(m = matrix(rpois(80, 1), nrow = 10))

Arguments

m
a matrix of resource utilization values.

Value

Returns the skewness of the average pairwise niche overlap.

Description

Takes a niche utilization matrix returns the skew of the Czekanowski pairwise niche overlap index.

Details

A large positive value for skewness implies that there are more species pairs with high than low niche overlap. A large negative value for skewness implies there are more species pairs with low than high niche overlap. The performance of this algorithm has not been thoroughly tested with real data sets.

Note

The resource utilization matrix (rows = species, columns = discrete resource categories) may include zeroes, but no negative numbers or missing values. Relative resource within a species is first calculated, so the rows need not sum to 1.0.

References

Winemiller, K.O. and E.R. Pianka. 1990. Organization in natural assemblages of desert lizards and tropical fishes. Ecological Monographs 60: 27-55.

Examples

obsSkew <- czekanowski_skew(m=matrix(rpois(40,0.5),nrow=8))

See also

czekanowski niche overlap index.