RankingWilcEbam: Ranking based on the empirical bayes approach of Efron

Description Usage Arguments Value Note Author(s) References See Also Examples

Description

The function is a wrapper for the function wilc.ebam from the package siggenes that implements an empirical bayes mixture model approach in combination with the Wilcoxon statistic.

Usage

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RankingWilcEbam(x, y, type = c("unpaired", "paired", "onesample"), 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 alternatively an object of class ExpressionSet.
If type = paired, the first half of the columns corresponds to the first measurements and the second half to the second ones. For instance, if there are 10 observations, each measured twice, stored in an expression matrix expr, then expr[,1] is paired with expr[,11], expr[,2] with expr[,12], and so on.

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.
If type = paired, take care that the coding is analogously to the requirement concerning x

type
"unpaired":

two-sample test.

"paired":

paired test. Take care that the coding of y is correct (s. above)

"onesample":

y has only one level. Test whether the true mean is different from zero.

gene.names

An optional vector of gene names.

...

Further arguments to be passed to wilc.ebam, s. package siggenes.

Value

An object of class GeneRanking.

Note

p-values are not computed - the statistic is a posterior probabiliy.

Author(s)

Martin Slawski
Anne-Laure Boulesteix

References

Efron, B., Tibshirani, R. (2002).
Empirical Bayes Methods and False Discovery Rates for Microarrays Genetic Epidemiology, 23, 70-86

Schwender, H., Krause, A. and Ickstadt, K. (2003).
Comparison of the Empirical Bayes and the Significance Analysis of Microarrays. Techical Report, University of Dortmund.

See Also

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

Examples

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

GeneSelector documentation built on May 1, 2019, 11:35 p.m.