abdiv (version 0.2.0)

mcintosh_d: McIntosh dominance index D

Description

McIntosh dominance index D

Usage

mcintosh_d(x)

Arguments

x

A numeric vector of species counts.

Value

The McIntosh dominance index, \(0 \leq D < 1\). The index is undefined when the total number of counts is 1 or 0, in which case we return NaN.

Details

For a vector x of raw species counts, the McIntosh dominance index is defined as $$D = \frac{N - U}{N - \sqrt{N}},$$ where \(N\) is the total number of counts and \(U = \sqrt{\sum_i x_i^2}\).

This index is appropriate only for raw counts, not transformed counts or proportions.

Equivalent to mcintosh_d() in skbio.diversity.alpha.

References

McIntosh RP. An index of diversity and the relation of certain concepts to diversity. Ecology. 1967;48:1115-1126.

Examples

# NOT RUN {
x <- c(15, 6, 4, 0, 3, 0)
mcintosh_d(x)
# }