GeneSelector (version 2.22.0)

RankingWelchT: Ranking based on the Welch t statistic.

Description

Performs univariate (rowwise) Welch tests on a gene expression matrix. The Welch t statistic is a better alternative to the 'ordinary' t statistic in the two sample, unequal variances setting.

Usage

RankingWelchT(x, y, type = "unpaired", pvalues = TRUE, gene.names = NULL, ...)

Arguments

x

A matrix of gene expression values with rows corresponding to genes and columns corresponding to observations or alternatively an object of class ExpressionSet.

y

If x is a matrix, then y may be a numeric vector or a factor with at most two levels. If x is an ExpressionSet, then y is a character specifying the phenotype variable in the output from pData.

type

Only the two sample case, type="unpaired" is possible. Otherwise, use RankingTstat. Variances are assumed to be unequal.

pvalues

Should p-values be computed ? Default is TRUE.

gene.names

An optional vector of gene names.

...

Currenly unused argument.

Value

GeneRanking.

See Also

RepeatRanking, RankingTstat, RankingFC, RankingWilcoxon, RankingBaldiLong, RankingFoxDimmic, RankingLimma, RankingEbam, RankingWilcEbam, RankingSam, RankingShrinkageT, RankingSoftthresholdT, RankingPermutation

Examples

## Load toy gene expression data
data(toydata)
### class labels
yy <- toydata[1,]
### gene expression
xx <- toydata[-1,]
### run RankingWelch
welchT <- RankingWelchT(xx, yy, type="unpaired")