shannon {pgirmess}

Computes Shannon's and equitability indices

Description

Computes Shannon's and equitability indices

Usage

shannon(vect, base=2)

Arguments

vect

a probability vector whose sum = 1 or a frequency vector

base

logarithm base used (default=2)

Details

Computes Shannon's and equitability indices. The vector passed can be a probability vector whose sum equal 1 or a vector of frequencies (e.g. the number of food item of each category).

Value

A vector of two values: Shannon's and equitability indices. The base logarithm used is stored as attribute

See Also

shannonbio

Examples

x<-c(0.1,0.5,0.2,0.1,0.1)
sum(x)
shannon(x)

x<-rpois(10,6)
shannon(x, base=exp(1))