[BioC] Affymetrix data double normalisation

[Jun Han [guest]]

Hi, 
I would like to use gcrma to do a within group normalization first (30 groups in total), then input all the normalised 30 groups to do another global gcrma. 
Is this possible? Does the gcrma accept the inputs from the first normalisation output?
Many thanks.
Jun

 -- output of sessionInfo(): 

> gcrma12<-gcrma(gcrma1,gcrma2)
Error in function (classes, fdef, mtable)  : 
  unable to find an inherited method for function "indexProbes", for signature "ExpressionSet", "character"

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