phicoef {GenomicRanges} | R Documentation

## Calculate the "phi coefficient" between two binary variables

### Description

The `phicoef` function calculates the "phi coefficient" between two binary variables.

### Usage

    phicoef(x, y=NULL)

### Arguments

`x, y` | Two logical vectors of the same length. If `y` is not supplied, `x` must be a 2x2 integer matrix (or an integer vector of length 4) representing the contingency table of two binary variables.

### Value

The "phi coefficient" between the two binary variables. This is a single numeric value ranging from -1 to +1.

### Author(s)

H. Pagès

### References

http://en.wikipedia.org/wiki/Phi_coefficient

### Examples

    set.seed(33)
    x <- sample(c(TRUE, FALSE), 100, replace=TRUE)
    y <- sample(c(TRUE, FALSE), 100, replace=TRUE)
    phicoef(x, y)
    phicoef(rep(x, 10), c(rep(x, 9), y))

    stopifnot(phicoef(table(x, y)) == phicoef(x, y))
    stopifnot(phicoef(y, x) == phicoef(x, y))
    stopifnot(phicoef(x, !y) == - phicoef(x, y))
    stopifnot(phicoef(x, x) == 1)

[Package GenomicRanges version 1.30.3 Index]