\name{08.Tests} \alias{08.Tests} \title{Hypothesis Testing for Linear Models} \description{ LIMMA provides a number of functions for multiple testing across both contrasts and genes. The starting point is an \code{MArrayLM} object, called \code{fit} say, resulting from fitting a linear model and running \code{eBayes} and, optionally, \code{contrasts.fit}. See \link{06.LinearModels} or \link{07.SingleChannel} for details. } \section{Multiple testing across genes and contrasts}{ The key function is \code{\link{decideTests}}. This function writes an object of class \code{\link[limma:TestResults]{TestResults}}, which is basically a matrix of \code{-1}, \code{0} or \code{1} elements, of the same dimension as \code{fit$coefficients}, indicating whether each coefficient is significantly different from zero. A number of different multiple testing strategies are provided. The function calls other functions \code{\link{classifyTestsF}}, \code{\link{classifyTestsP}} and \code{\link{classifyTestsT}} which implement particular strategies. The function \code{\link{FStat}} provides an alternative interface to \code{classifyTestsF} to extract only the overall moderated F-statistic. \code{\link{selectModel}} chooses between linear models for each probe using AIC or BIC criteria. This is an alternative to hypothesis testing and can choose between non-nested models. A number of other functions are provided to display the results of \code{decideTests}. The functions \code{\link{heatDiagram}} (or the older version \code{\link{heatdiagram}} displays the results in a heat-map style display. This allows visual comparison of the results across many different conditions in the linear model. The functions \code{\link{vennCounts}} and \code{\link{vennDiagram}} provide Venn diagram style summaries of the results. Summary and \code{show} method exists for objects of class \code{TestResults}. The results from \code{decideTests} can also be included when the results of a linear model fit are written to a file using \code{\link{write.fit}}. } \section{Gene Set Tests}{ Competitive gene set testing for an individual gene set is provided by \code{\link{wilcoxGST}} or \code{\link{geneSetTest}}, which permute genes. The gene set can be displayed using \code{\link{barcodeplot}} or \code{\link{barcodeplot2}}, the latter for directional gene sets with both up and down genes. Self-contained gene set testing for an individual is provided by \code{\link{roast}}, which uses rotation technology, analogous to permuting arrays. Gene set enrichment analysis for a battery of gene sets is provided by \code{\link{romer}}. The functions \code{\link{alias2Symbol}} and \code{\link{alias2SymbolTable}} are provided to help match gene sets with microarray probes by way of official gene symbols. } \section{Global Tests}{ The function \code{\link{genas}} can test for associations between two contrasts in a linear model. Given a set of p-values, the function \code{\link{convest}} can be used to estimate the proportion of true null hypotheses. When evaluating test procedures with simulated or known results, the utility function \code{\link{auROC}} can be used to compute the area under the Receiver Operating Curve for the test results for a given probe. } \author{Gordon Smyth} \keyword{documentation}