polychor.matrix {psych}

R Documentation

Phi or Yule coefficient matrix to polychoric coefficient matrix

Description

A set of deprecated functions that have replaced by Yule2tetra and Yule2phi.

Some older correlation matrices were reported as matrices of Phi or of Yule correlations. That is, correlations were found from the two by two table of counts:

	a	b
	c	d

Yule Q is (ad - bc)/(ad+bc).

With marginal frequencies of a+b, c+d, a+c, b+d.

Given a square matrix of such correlations, and the proportions for each variable that are in the a + b cells, it is possible to reconvert each correlation into a two by two table and then estimate the corresponding polychoric correlation (using John Fox's polychor function.

Usage

Yule2poly.matrix(x, v)  #deprectated
phi2poly.matrix(x, v)     #deprectated
Yule2phi.matrix(x, v)     #deprectated

Arguments

x	a matrix of phi or Yule coefficients
v	A vector of marginal frequencies

Details

These functions call Yule2poly, Yule2phi or phi2poly for each cell of the matrix. See those functions for more details. See phi.demo for an example.

Value

A matrix of correlations

Author(s)

William Revelle

Examples

#demo <- phi.demo() 
#compare the phi (lower off diagonal and polychoric correlations (upper off diagonal)
#show the result from poly.mat
#round(demo$tetrachoric$rho,2)
#show the result from phi2poly
#tetrachorics above the diagonal, phi below the diagonal 
#round(demo$phis,2) 

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