Hi fiolks, any hint on why I get the error :

Error in log2(exprs(eSet)) : 
  non-numeric argument to mathematical function

>abatch<-ReadAffy()

>eSet<-mas5(abatch)

>eSet

ExpressionSet (storageMode: lockedEnvironment) assayData: 22283 features, 8 samples element names: exprs, se.exprs protocolData sampleNames: GSM31867_SKNMC.CEL GSM31867_SKNMC.CEL.gz ... GSM31870_SHSY5Y.CEL.gz (8 total) varLabels: ScanDate varMetadata: labelDescription phenoData sampleNames: GSM31867_SKNMC.CEL GSM31867_SKNMC.CEL.gz ... GSM31870_SHSY5Y.CEL.gz (8 total) varLabels: sample varMetadata: labelDescription featureData: none experimentData: use 'experimentData(object)' Annotation: hgu133a

> SI<-log2(exprs(eSet)) Error in log2(exprs(eSet)) : non-numeric argument to mathematical function

Is it exprs function - clash with dplyr problem (conflict with dplyr::exprs()) ?

Thank you very much Mr. Morgan. I have solved the problem by adding 

exprs=Biobase::exprs

to the top of the script.