MKmisc (version 1.9)

oneWayAnova: A function for Analysis of Variance

Description

This function is a slight modification of function Anova of package "genefilter".

Usage

oneWayAnova(cov, na.rm = TRUE, var.equal = FALSE)

Value

oneWayAnova returns a function with bindings for cov that will perform a one-way ANOVA.

The covariate can be continuous, in which case the test is for a linear effect for the covariate.

Arguments

cov

The covariate. It must have length equal to the number of columns of the array that the result of oneWayAnova will be applied to.

na.rm

a logical value indicating whether NA values should be stripped before the computation proceeds.

var.equal

a logical variable indicating whether to treat the variances in the samples as equal. If TRUE, then a simple F test for the equality of means in a one-way analysis of variance is performed. If FALSE, an approximate method of Welch (1951) is used, which generalizes the commonly known 2-sample Welch test to the case of arbitrarily many samples.

Author

Matthias Kohl

Details

The function returned by oneWayAnova uses oneway.test to perform a one-way ANOVA, where x is the set of gene expressions. The F statistic for an overall effect is computed and the corresponding p-value is returned.

The function Anova instead compares the computed p-value to a prespecified p-value and returns TRUE, if the computed p-value is smaller than the prespecified one.

References

R. Gentleman, V. Carey, W. Huber and F. Hahne (2006). genefilter: methods for filtering genes from microarray experiments. R package version 1.13.7.

See Also

oneway.test, Anova

Examples

set.seed(123)
af <- oneWayAnova(c(rep(1,5),rep(2,5)))
af(rnorm(10))