custom header test
czekanowski_var(m = matrix(rpois(80, 1), nrow = 10))
Takes a niche utilization matrix returns the variance of the Czekanowski niche overlap index
A large value for variance implies that some species pairs show high niche overlap and others show low niche overlap. A low value for variance implies that niche overlap (high or low) is very similar among all species pairs.
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.
Winemiller, K.O. and E.R. Pianka. 1990. Organization in natural assemblages of desert lizards and tropical fishes. Ecological Monographs 60: 27-55.
obsVar <- czekanowski_var(m=matrix(rpois(40,0.5),nrow=8))
czekanowski
niche overlap index.