WoolfTest: Woolf Test For Homogeneity in 2x2xk Tables

In DescTools: Tools for Descriptive Statistics

Woolf Test For Homogeneity in 2x2xk Tables

Description

Test for homogeneity on 2 \times 2 \times k tables over strata (i.e., whether the log odds ratios are the same in all strata).

Usage

WoolfTest(x)

Arguments

x	a 2 \times 2 \times k table, where the last dimension refers to the strata.

Value

A list of class "htest" containing the following components:

statistic	the chi-squared test statistic.
parameter	degrees of freedom of the approximate chi-squared distribution of the test statistic.
p.value	p-value for the test.
method	a character string indicating the type of test performed.
data.name	a character string giving the name(s) of the data.
observed	the observed counts.
expected	the expected counts under the null hypothesis.

Note

This function was previously published as woolf_test() in the vcd package and has been integrated here without logical changes.

Author(s)

David Meyer, Achim Zeileis, Kurt Hornik, Michael Friendly

References

Woolf, B. 1955: On estimating the relation between blood group and disease. Ann. Human Genet. (London) 19, 251-253.

See Also

mantelhaen.test, BreslowDayTest

Examples

migraine <- xtabs(freq ~ .,
            cbind(expand.grid(treatment=c("active","placebo"),
                               response=c("better","same"),
                               gender=c("female","male")),
                  freq=c(16,5,11,20,12,7,16,19))
            )

WoolfTest(migraine)

DescTools documentation built on Sept. 26, 2024, 1:07 a.m.