mantel.test: Mantel-Haenszel test for two-way tables

In lazyWeave: LaTeX Wrappers for R Users

Description

Performs a Mantel-Haenszel test for linear trend in two way tables

Usage

mantel.test(x, byVar, row.scores = c("equal", "midrank"),
  col.scores = c("equal", "midrank"))

Arguments

x	Either a vector of data or a two way table. If a vector is given, it should be a factor variable
byVar	If x is a vector, then byVar is a factor variable to be tabulated against x.
row.scores	choice of scores for the row variable. May be "equal", "midrank", or user defined.
col.scores	Choice of scores for the column variable. May be "equal", "midrank", or user defined.

Details

Currently, there is no check to ensure that either variables submitted are factors.

Data should be ordinal. Nominal data may not have any practical meaning in this test. Sometimes, when a nominal variable has only two levels, this test may still be appropriate, i.e. Yes vs. No.

In 2xJ tables, when arbitrary scores (i.e., 0, 1) are applied to the rows and midranks applied to the columns, this test is equivalent to the Wilcoxon, or Mann-Whitney test.

In Ix2 tables, when monotone scores are applied to the rows and abitrary scores applied to the columns, this test is equivalent to the Cochran-Armitage test. See the reference for further details.

Value

Returns an object of type htest.

statistic	M^2, a Chi-square statistic with 1 degree of freedom.
parameter	degrees of freedom for M^2
p.value	p-value for the test
method	Type of test performed.
correlation	correlation coefficient of linear trend

References

Alan Agresti, An Introduction to Categorical Data Analysis, 1996, pp. 34 - 39.

Examples

mantel.test(mtcars$gear,mtcars$cyl)

mantel.test(table(mtcars$gear,mtcars$cyl))

mantel.test(table(mtcars$gear,mtcars$cyl), row.scores="midrank")

mantel.test(table(mtcars$gear,mtcars$cyl), col.scores="midrank")

Example output

	Mantel Haenszel Chi-Square Test for Two Way Tables

data:  
M^2 = 7.5249, df = 1, p-value = 0.006085


	Mantel Haenszel Chi-Square Test for Two Way Tables

data:  
M^2 = 7.5249, df = 1, p-value = 0.006085


	Mantel Haenszel Chi-Square Test for Two Way Tables

data:  
M^2 = 9.739, df = 1, p-value = 0.001804


	Mantel Haenszel Chi-Square Test for Two Way Tables

data:  
M^2 = 7.6211, df = 1, p-value = 0.005769

lazyWeave documentation built on May 2, 2019, 12:35 p.m.