phi2poly

probability of the predictor -- the so called selection ratio

probability of the criterion -- the so called success rate.

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?Given a two x two table of counts <tabular>lll</tabular>{
	a 	b 	c 	d }
The phi coefficient is (a - (a+b)*(a+c))/sqrt((a+b)(a+c)(b+d)(c+c)).This function reproduces the cell entries for specified marginals and then calls John Fox's polychor function.

models

A number of routines for personality, psychometrics and
        experimental psychology.  Functions are primarily for scale
        construction using factor analysis, cluster analysis and
        reliability analysis, although others provide basic descriptive
        statistics. Item Response Theory is done using factor analysis
        of tetrachoric and polychoric correlations. Functions for
        simulating particular item and test structures are included.
        Several functions serve as a useful front end for structural
        equation modeling.  Graphical displays of path diagrams, factor
        analysis and structural equation models are created using basic
        graphics. Some of the functions are written to support a book
        on psychometrics as well as publications in personality
        research. For more information, see the
        personality-project.org/r webpage.

phi2poly: Convert a phi coefficient to a polychoric correlation

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Examples