[BioC] Affy : Cel/Cdf files

[Willy Wynant]

Hi,

I am trying to understand the affy package and more specially the rma 
function. I type :


> data<-ReadAffy()
> toto<-rma(data,subset=NULL,verbose=TRUE,destructive=TRUE,normalize=TRUE,backgrounbackground=TRUE,bgversion=1)

and I've got as result :


Note: You did not specify a download type.  Using a default value of: Win32
This will be fine for almost all users

[1] "Attempting to download mgu74av2cdf from 
http://www.bioconductor.org/data/cdfenvs/repos/"
[1] "Download complete."
[1] "Installing mgu74av2cdf"
Note: Running R version 1.8.1 and package mgu74av2cdf was built for R 
version 1.8.0
  , installing anyway.

[1] "Installation complete"
Background correcting
Normalizing
Calculating Expression


How should I decide which download type I have to specify? What are the 
differences between all of these "cdf-types" ?

Could you help me?

Thank you.