PMCMR (version 4.3)

vanWaerden.test: van der Waerden's normal scores test

Description

Performs a van der Waerden's normal scores test.

Usage

vanWaerden.test(x, …)
# S3 method for default
vanWaerden.test(x, g, …)
# S3 method for formula
vanWaerden.test(formula, data, subset, na.action, …)

Arguments

x

a numeric vector of data values, or a list of numeric data vectors.

g

a vector or factor object giving the group for the corresponding elements of x. Ignored if x is a list.

formula

a formula of the form response ~ group where response gives the data values and group a vector or factor of the corresponding groups.

data

an optional matrix or data frame (or similar: see model.frame) containing the variables in the formula formula. By default the variables are taken from environment(formula).

subset

an optional vector specifying a subset of observations to be used.

na.action

a function which indicates what should happen when the data contain NAs. Defaults to getOption("na.action").

…

further arguments to be passed to or from methods.

Value

A list with class "htest" that contains the following components:

statistic

the van der Waerden chi-squared statistic.

parameter

the degrees of freedom of the approximate chi-squared distribution of the test statistic.

p.value

the p-value of the test.

method

the character string "Van der Waerden normal scores test".

data.name

a character string giving the names of the data.

Details

vanWaerden.test performs a van der Waerden test of the null that the location parameters of the distribution of x are the same in each group (sample). The alternative is that they differ in at least one.

See vignette("PMCMR") for details.

References

W. J. Conover and R. L. Iman (1979), On multiple-comparisons procedures, Tech. Rep. LA-7677-MS, Los Alamos Scientific Laboratory.

See Also

kruskal.test

Examples

# NOT RUN {
##
require(stats) 
data(InsectSprays)
attach(InsectSprays)
vanWaerden.test(count, spray)
posthoc.vanWaerden.test(count, spray, "bonferroni")
detach(InsectSprays)
rm(InsectSprays)
# }