oneWayAnova {MKomics}

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)

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.

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 of package genefilter 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.

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.

Note

A first version of this function appeared in package SLmisc.

Author(s)

Matthias Kohl [e-mail]

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, twoWayAnova

Examples

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