R/permutatedWinScores.R

In CSAR: Statistical tools for the analysis of ChIP-seq data

`permutatedWinScores` <-
function(nn=1,control,sample,fileOutput,chr=c("chr1","chr2","chr3","chr4","chr5"),chrL="TAIR9",w=300L,considerStrand="Minimum",uniquelyMapped=TRUE,uniquePosition=FALSE,norm=3*10^9,backg=-1,t=1,g=100,times=1e6,digits=2,test="Ratio"){ 
if(uniquelyMapped){sample<-sample[sample$Nhits==1L,];control<-control[control$Nhits==1L,];};
if(uniquePosition){sample<-sample[!duplicated(paste(sample$pos,sample$strand)),];control<-control[!duplicated(paste(control$pos,control$strand)),]};
whichsample<-sample(c(rep(TRUE,length(sample[,1])),rep(FALSE,length(control[,1]))))
whichcontrol<-whichsample[(1:length(control[,1]))+length(sample[,1])]
whichsample<-whichsample[1:length(sample[,1])]

NhitsC<-mappedReads2Nhits(rbind(sample[!whichsample,],control[!whichcontrol,]),file=paste(fileOutput,"-PermutatedSet",nn,"-Control",sep=""),chr=chr,chrL=chrL,w=w,considerStrand=considerStrand,uniquelyMapped=uniquelyMapped,uniquePosition=uniquePosition)
NhitsS<-mappedReads2Nhits(rbind(sample[whichsample,],control[whichcontrol,]),file=paste(fileOutput,"-PermutatedSet",nn,"-Sample",sep=""),chr=chr,chrL=chrL,w=w,considerStrand=considerStrand,uniquelyMapped=uniquelyMapped,uniquePosition=uniquePosition)
rm(sample,control,whichsample,whichcontrol);gc(verbose=FALSE)
test<-ChIPseqScore(control=NhitsC,sample=NhitsS,backg=backg,file=paste(fileOutput,"-PermutatedSet",nn,sep=""),norm=norm,test=test,times=times,digits=digits)
unlink(NhitsC$filenames);unlink(NhitsS$filenames);
win<-sigWin(experiment=test,t=t,g=g)
file=paste(fileOutput,"-",nn,".permutatedWin",sep="")
cat(values(win)$score,file=file)
unlink(test$filenames)
message(paste("Win file for permutation",nn,"can be found at",file))
}