R: van der Waerden's normal scores test

vanWaerden.test {PMCMR}

R Documentation

van der Waerden's normal scores test

Description

Performs a van der Waerden's normal scores test.

Usage

vanWaerden.test(x, ...)

## Default S3 method:
vanWaerden.test(x, g, ...)

## S3 method for class '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 `NA`s. Defaults to `getOption("na.action")`.
`...`	further arguments to be passed to or from methods.

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.

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.

Note

A tie correction is not applied in this function.

Author(s)

Thorsten Pohlert

References

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

Examples

##
require(stats) 
data(InsectSprays)
attach(InsectSprays)
vanWaerden.test(count, spray)
posthoc.vanWaerden.test(count, spray, "bonferroni")
detach(InsectSprays)
rm(InsectSprays)

[Package PMCMR version 4.3 Index]