polychor.matrix {psych} | R Documentation |
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.
Yule2poly.matrix(x, v) #deprectated phi2poly.matrix(x, v) #deprectated Yule2phi.matrix(x, v) #deprectated
x |
a matrix of phi or Yule coefficients |
v |
A vector of marginal frequencies |
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.
A matrix of correlations
William Revelle
#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)