n2: Calculate Hill's N2 diversity measure

In analogue: Analogue and Weighted Averaging Methods for Palaeoecology

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)

Example output

Loading required package: vegan
Loading required package: permute
Loading required package: lattice
This is vegan 2.4-3
analogue version 0.17-0
   AC001A    AC002A    AC004A    AC013A    AC014A    AC014B 
 8.248589 12.128209 10.997128 46.072440  3.025195  9.190233 
     1.21     10.21        11    113.21    115.11     12.11 
15.501849 11.026197  6.702897 10.712509 11.370488 15.094376 

analogue documentation built on June 21, 2021, 1:08 a.m.