# first, let affy/expresso know that the method exists
 express.summary.stat.methods <- c(express.summary.stat.methods, "trimMean")
 example not run, as it would take a while
 RawData <- ReadAffy(celfile.path=FilePath)
 expresso(RawData, 
   bgcorrect.method="rma",
   normalize.method="quantiles",
   normalize.param = list(type= "pmonly"),
   pmcorrect.method="pmonly",
   summary.method="trimMean")
  
 step1 <- bg.correct(RawData, "rma")
 step2 <- normalize.AffyBatch.quantiles(step1)
 step3 <- computeExprSet(step2, "pmonly", "trimMean")Run the code above in your browser using DataLab