wrMisc (version 1.14.2)

moderTest2grp: Moderated pair-wise t-test from limma

Description

Runs moderated t-test from package 'limma' on each line of data. Note: This function requires the package limma from bioconductor. The limma contrast-matrix has to be read by column, the lines in the contrast-matrix containing '+1' will be compared to the '-1' lines, eg grpA-grpB . Local false discovery rates (lfdr) estimations will be made using the CRAN-package fdrtool (if available).

Usage

moderTest2grp(
  dat,
  grp,
  limmaOutput = TRUE,
  addResults = c("lfdr", "FDR", "Mval", "means"),
  testOrientation = "=",
  silent = FALSE,
  callFrom = NULL
)

Value

This function returns a limma-type object of class MArrayLM

Arguments

dat

matrix or data.frame with rows for multiple (independent) tests, use ONLY with 2 groups; assumed as log2-data

grp

(factor) describes column-relationship of 'dat' (1st factor is considered as reference -> orientation of M-values !!)

limmaOutput

(logical) return full (or extended) MArrayLM-object from limma or 'FALSE' for only the (uncorrected) p.values

addResults

(character) types of results to add besides basic limma-output, data are assumed to be log2 ! (eg "lfdr" using fdrtool-package, "FDR" or "BH" for BH-FDR, "BY" for BY-FDR, "bonferroni" for Bonferroni-correction, "qValue" for lfdr by qvalue, "Mval", "means" or "nonMod" for non-moderated test and he equivaent all (other) multiple testing corrections chosen here)

testOrientation

(character) for one-sided test (">","greater" or "<","less"), NOTE : 2nd grp is considered control/reference, '<' will identify grp1 < grp2

silent

(logical) suppress messages

callFrom

(character) allow easier tracking of message(s) produced

See Also

lmFit and the eBayes-family of functions in package limma, p.adjust

Examples

set.seed(2017); t8 <- matrix(round(rnorm(1600,10,0.4),2), ncol=8,
  dimnames=list(paste("l",1:200),c("AA1","BB1","CC1","DD1","AA2","BB2","CC2","DD2")))
t8[3:6,1:2] <- t8[3:6,1:2]+3     # augment lines 3:6 for AA1&BB1
t8[5:8,5:6] <- t8[5:8,5:6]+3     # augment lines 5:8 for AA2&BB2 (c,d,g,h should be found)
t4 <- log2(t8[,1:4]/t8[,5:8])
## Two-sided testing 
fit4 <- moderTest2grp(t4,gl(2,2))
# If you have limma installed we can now see further
if("list" %in% mode(fit4)) limma::topTable(fit4, coef=1, n=5)    # effect for 3,4,7,8

## One-sided testing
fit4in <- moderTest2grp(t4,gl(2,2),testO="<")
# If you have limma installed we can now see further
if("list" %in% mode(fit4)) limma::topTable(fit4in, coef=1, n=5)