| mantelhaen.test {ctest} | R Documentation |
Mantel-Haenszel Chi-Square Test for Count Data
Description
mantelhaen.test performs a Mantel-Haenszel chi-square test of
the null that x and y are conditionally independent in
each stratum.
Usage
mantelhaen.test(x, y = NULL, z = NULL, correct = TRUE)
Arguments
x |
either an array of dimension 2 by 2 by s, where s is the number of strata, or a dichotomous factor object. |
y |
a dichotomous factor object; ignored if x is an array. |
z |
a factor object idenitifying to which stratum the
corresponding elements in |
correct |
a logical indicating whether to apply continuity correction when computing the test statistic. |
Details
If x is an array, it must be of dimension 2 by 2 by s, and
the entries should be nonnegative integers. NA's are not
allowed. Otherwise, x, y and z must have the
same length. Triples containing NA's are removed. Both
x and y must be dichotomous (take exactly 2 values).
Value
A list with class "htest" containing the following components:
statistic |
the Mantel-Haenszel chi-square statistic. |
parameter |
always 1, the degrees of freedom of the approximate chi-square distribution of the test statistic. |
p.value |
the p-value of the test. |
method |
a string indicating the method employed, and whether or not continuity correction was used. |
data.name |
a character string giving the names of the data. |
References
Alan Agresti (1990). Categorical data analysis. New York: Wiley. Pages 230–234.
Examples
data(UCBAdmissions)
mantelhaen.test(UCBAdmissions)
## No evidence for association between admission and gender
## when adjusted for department