RVAideMemoire (version 0.9-45-2)

perm.bartlett.test: Permutational Bartlett's test of homogeneity of variances

Description

Performs a permutational Bartlett's test of homogeneity of k variances.

Usage

perm.bartlett.test(formula, data, nperm = 999)

Arguments

formula

a formula of the form a ~ b where a gives the data values and b the corresponding groups.

data

an optional data frame containing the variables in the formula formula. By default the variables are taken from environment(formula).

nperm

number of permutations.

Value

• method
  name of the test.
• data.name
  a character string giving the name(s) of the data.
• statistic
  test statistics of the parametric test.
• permutations
  number of permutations.
• p.value
  p-value of the permutational test.

Details

The function deals with the limitted floating point precision, which can bias calculation of p-values based on a discrete test statistic distribution.

See Also

bartlett.test

Examples

response <- c(rnorm(12),rpois(12,1),rnorm(12,2,1))
fact <- gl(3,12,labels=LETTERS[1:3])
perm.bartlett.test(response~fact)