Woolf Test For Homogeneity in 2x2xk Tables
Test for homogeneity on 2 x 2 x k tables over strata (i.e., whether the log odds ratios are the same in all strata).
WoolfTest(x)
x |
a 2 x 2 x k table, where the last dimension refers to the strata. |
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. |
This function was previously published as woolf_test() in the vcd package and has been integrated here without logical changes.
David Meyer, Achim Zeileis, Kurt Hornik, Michael Friendly
Woolf, B. 1955: On estimating the relation between blood group and disease. Ann. Human Genet. (London) 19, 251-253.
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)Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.