abdiv (version 0.2.0)

margalef: Margalef's richness index

Description

Margalef's richness index

Usage

margalef(x)

Arguments

x

A numeric vector of species counts.

Value

The value of Margalef's index, \(D \geq 0\). This 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 species counts, Margalef's index is $$D = \frac{S -1}{\log N},$$ where \(S\) is the total number of species observed and \(N\) is the total number of counts.

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

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

References

Margalef R. Information theory in ecology. General Systems 3. 1958;36-71.

Examples

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