[BioC] More iterations for median polish using Expresso

[jchayes at mcb.umass.edu]

My name is James and I am having trouble normalizing some microarray data.  I
have three microarray sets that I am trying to normalize using expresso.  Here
is what I type and the error message which follows:

cphy.prenorm <- expresso(cphy.data, bgcorrect.method="rma",
+ normalize=FALSE,pmcorrect.method="pmonly",
+ summary.method="medianpolish")
background correction: rma
PM/MM correction : pmonly
expression values: medianpolish
background correcting...done.
11092 ids to be processed
|                    |
|####################|
Warning message:
In medpolish(log2(x), trace.iter = FALSE, ...) :
  medpolish() did not converge in 10 iterations

Can I increase the number of iterations in expresso or do I have to do each step
one at a time?  Any help you can give me would be greatly appreciated.

Best Regards,

James