[BioC] vsn problem again...

[Edmund Chang]

Hi all,
Sorry to bother you again, but after I typed in the requisite line to 
bring vsn into affy, I still got an error.
Thanks again for all your help,
Ed

 > normalize.AffyBatch.methods <- c(normalize.AffyBatch.methods, "vsn")
 > eset <- expresso(Data, bg.correct = FALSE, normalize.method = "vsn", 
pmcorrect.method = "pmonly", summary.method = "medianpolish")
normalization: vsn
PM/MM correction : pmonly
expression values: medianpolish
normalizing...Error in do.call(method, alist(object, ...)) :
        couldn't find function "normalize.AffyBatch.vsn"