Dear BioConductor users, I am trying to use the gcrma background subtraction in expresso. I found a post on the BioConductor archives and tried to repeat it. But I am getting error "couldn't find function "bgcorrect.methods" Can someone give me some tips and check my code? > dat<- ReadAffy(filenames=list.celfiles()) # creates an Affybatch > library(gcrma) > bgcorrect.methods <- c(bgcorrect.methods, "gcrma") > pmcorrect.methods <- c(pmcorrect.methods, "gcrma") > eset<- expresso(dat, bgcorrect.method="gcrma", normalize.method="qspline", + pmcorrect.method="gcrma", summary.method="medianpolish") background correction: gcrma normalization: qspline PM/MM correction : gcrma expression values: medianpolish background correcting...Error in bg.correct(afbatch, method = bgcorrect.method) : Unknown method (cannot find function bg.correct.gcrma ) thank you very much, Edmund Chang