[R] Normalization based on PM values only

[narinder.singh]

I have been asked to look some data generated on affy-platform. Due to 
biological reasons the data owners want to look at PM values only, i.e ignore 
the MM values. Hence my question is:

What is the best option available for normalizing affy data using the PM 
intensities only.

I appologize if this question has been asked and answered on this group 
earlier. 

Narinder S. Sahni