vcdExtra (version 0.8-5)

Crossings: Crossings Interaction of Factors

Description

Given two ordered factors in a square, n x n frequency table, Crossings creates an n-1 column matrix corresponding to different degrees of difficulty in crossing from one level to the next, as described by Goodman (1972).

Usage

Crossings(...)

Value

For two factors of n levels, returns a binary indicator matrix of n*n rows and n-1 columns.

Arguments

...

Two factors

Author

Michael Friendly and Heather Turner

References

Goodman, L. (1972). Some multiplicative models for the analysis of cross-classified data. In: Proceedings of the Sixth Berkeley Symposium on Mathematical Statistics and Probability, Berkeley, CA: University of California Press, pp. 649-696.

See Also

glm, gnm for model fitting functions for frequency tables

Diag, Mult, Symm, Topo for similar extensions to terms in model formulas.

Examples

data(Hauser79)
# display table
structable(~Father + Son, data=Hauser79)

hauser.indep <- gnm(Freq ~ Father + Son, 
                    data=Hauser79, 
                    family=poisson)

hauser.CR <- update(hauser.indep, 
                    ~ . + Crossings(Father,Son))
LRstats(hauser.CR)

hauser.CRdiag <- update(hauser.indep, 
                        ~ . + Crossings(Father,Son) + Diag(Father,Son))
LRstats(hauser.CRdiag)