I'm trying to put data that doesn't come from affymetrix into affy. I now have a 'fake' cdf object and an affybatch object. The problem with my affybatch object is that it doesn't know which probes are pm/mm. I've tried to tell it by using the pm, mm accessor methods of the affybatch object, but it doesn't like that. I suspect that the root of the problems is my probesets, because the probeset function of my affybatch also gives the wrong output. I can't figure out where the probeset information is kept, or how to update it. Please point me to any resource, etc. Thank you, *Abby Scott