library(affy)
 
set.seed(123)
name.cel <- "test.cel"
n.cel <- 20

read.affybatch <- read.affybatch2

for (n.cel in c(5,10,15,20,25,30,35,40,50,60,70,80,90,100,125,150,175,200)){
  pheno.d <- new("phenoData", pData=data.frame(cov1=rep("a", n.cel)), varLabels=list("cov1"))
  
  
  st1 <- system.time(abatch <- ReadAffy(filenames=rep(name.cel, n.cel), phenoData=pheno.d))
  gc()
  st2 <- system.time(eset <- rma(abatch))
  gc()
  rm(eset)
  gc()
  st3 <- system.time(eset <- expresso(abatch,bgcorrect.method="rma",normalize.method="quantiles",summary.method="medianpolish",pmcorrect.method="pmonly"))
  gc()
  rm(eset)
  gc()
  rm(abatch)
  gc()
  st4 <- system.time(eset <- just.rma(filenames=rep(name.cel, n.cel), phenoData=pheno.d))
  gc()
  rm(eset)
  gc()
  st5 <- system.time(eset <- just.rma2(filenames=rep(name.cel, n.cel), phenoData=pheno.d))
  gc()
  rm(eset)
  gc()
  cat("\n\n\n\tfor ",n.cel,"arrays \n","Reading time is :",st1,"\n","rma()     :",st2,"\n","expresso() :",st3,"\n","Method 1   :",st1+st2,"\n","Method 2   :",st1+st3,"\n","Method 3   :",st4,"\n","Method 4   :",st5,"\n\n\n",sep="\t")
}