R: Crossings Interaction of Factors

Crossings {vcdExtra} | R Documentation

## 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(...)

### Arguments

`...` | Two factors

### Value

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

### Author(s)

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)

[Package vcdExtra version 0.7-1 Index]