entropy {BioQC} | R Documentation

## Shannon entropy

### Description

Shannon entropy

### Usage

    entropy(vector)

### Arguments

`vector` | A vector of numbers, or characters. Discrete probability of each item is calculated and the Shannon entropy is returned.

### Value

Shannon entropy

Shannon entropy can be used as measures of gene expression specificity, as well as measures of tissue diversity and specialization. See references below.

We use `2` as base for the entropy calculation, because in this base the unit of entropy is bit.

### Author(s)

Jitao David Zhang <jitao_david.zhang@roche.com>

### References

Martinez and Reyes-Valdes (2008) Defining diversity, specialization, and gene specificity in transcriptomes through information theory. PNAS 105(28):9709–9714

### Examples

    myVec0 <- 1:9
    entropy(myVec0) ## log2(9)
    myVec1 <- rep(1, 9)
    entropy(myVec1)

    entropy(LETTERS)
    entropy(rep(LETTERS, 5))

[Package BioQC version 1.18.0 Index]