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Performs a permutation Bartlett's test of homogeneity of k variances.
perm.bartlett.test(formula, data, nperm = 999, progress = TRUE)
name of the test.
a character string giving the name(s) of the data.
test statistics of the parametric test.
number of permutations.
p-value of the permutation test.
a formula of the form a ~ b where a gives the data values and b the corresponding groups.
a ~ b
a
b
an optional data frame containing the variables in the formula formula. By default the variables are taken from environment(formula).
formula
environment(formula)
logical indicating if the progress bar should be displayed.
Maxime HERVE <maxime.herve@univ-rennes1.fr>
The function deals with the limitted floating point precision, which can bias calculation of p-values based on a discrete test statistic distribution.
bartlett.test
response <- c(rnorm(12),rpois(12,1),rnorm(12,2,1)) fact <- gl(3,12,labels=LETTERS[1:3]) perm.bartlett.test(response~fact)
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