[BioC] custom PM only chips and CDF files

[Ben Bolstad]

> You may have problems constructing the cdf environment using the  
> stuff in the makecdfenv package. As I recall, the code explicitely  
> tries to find the the two probes in a probepair. If you use that  
> package make sure that you check what you get. You should at least be  
> able to parse the file using the affxparser package and then you will  
> need to do some post-processing to actually construct the cdf env.
> 

Actually the functions for making cdfenv packages and environments in
makecdfenv should quite happily process a CDF file with PM only
probesets. I have done it a number of times in the past, so you should
not have any problems.

Ben