[BioC] Normalizing data (that is not in microarray "format")

[Emmanuel Levy]

Dear All,

I am trying to normalize data that looks like absolute mRNA expression
values (although it's not).
This means that I do not have an affy object.

I' tried normalize.loess, which partially worked as it gave me the
following warning (when I set missing values to 1 it disappears):

50: In means[, k] - aux ... :
  longer object length is not a multiple of shorter object length


I'd like to use other methods (linear or non linear), but I've got a
problem because I do not have an expression object.
--> for example,  maNorm doesn't work and I've got the following error:

Error in slot(mnorm, "maNormCall") <- match.call() :
  object "mnorm" not found

Any idea on which functions to use, or on how to "transform" my
data.frame into an affy object would be great.

Thanks,

Emmanuel