phi2poly {psych}R Documentation

Convert a phi coefficient to a polychoric correlation

Description

Given a phi coefficient (a Pearson r calculated on two dichotomous variables), and the marginal frequencies (in percentages), what is the corresponding estimate of the polychoric correlation?

Usage

phi2poly(ph, cp, cc)

Arguments

ph phi
cp probability of the predictor – the so called selection ratio
cc probability of the criterion – the so called success rate.

Details

Uses John Fox's polycor package, which in turn requires the mvtnorm package

Value

a polychoric correlation

Author(s)

William Revelle

See Also

polychor.matrix

Examples

#phi2poly(.3,.5,.5)
#phi2poly(.3,.3,.7)

[Package psych version 1.0-33 Index]