pairwise.wilcox.test          package: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'). 

  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.adj = "bonf")
     detach()

