pairwise.wilcox.test {stats}

R Documentation

Pairwise Wilcoxon Rank Sum Tests

Description

Calculate pairwise comparisons between group levels with corrections for multiple testing.

Usage

pairwise.wilcox.test(x, g, p.adjust.method = p.adjust.methods,
                      paired = FALSE, ...)

Arguments

x	response vector.
g	grouping vector or factor.
p.adjust.method	method for adjusting p values (see p.adjust). Can be abbreviated.
paired	a logical indicating whether you want a paired test.
...	additional arguments to pass to wilcox.test.

Details

Extra arguments that are passed on to wilcox.test may or may not be sensible in this context. In particular, only the lower triangle of the matrix of possible comparisons is being calculated, so setting alternative to anything other than "two.sided" requires that the levels of g are ordered sensibly.

Value

Object of class "pairwise.htest"

See Also

wilcox.test, p.adjust

Examples

attach(airquality)
Month <- factor(Month, labels = month.abb[5:9])
## These give warnings because of ties :
pairwise.wilcox.test(Ozone, Month)
pairwise.wilcox.test(Ozone, Month, p.adjust.method = "bonf")
detach()

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