n2 {analogue}

Calculate Hill's N2 diversity measure

Description

Hills N2 is a measure of species diversity, commonly referred to as "effective" diversity. If computed on the rows (samples) then the "effective" number of species in each row is returned, whereas, if computed on the columns (species) then the "effective" number of occurences of each species in the data set is returned.

Usage

n2(x, ...)

## Default S3 method:
n2(x, which = c("species", "sites"), ...)

Arguments

x

matrix or data frame of species data

which

character; compute N2 on the rows ("sites") or the columns ("species") of x

...

arguments passed to other methods

Value

A numeric vector of N2 values.

Author(s)

Gavin L. Simpson

Examples

data(swapdiat)
sppN2 <- n2(swapdiat, "species")
head(sppN2)
sampN2 <- n2(swapdiat, "sites")
head(sampN2)