[BioC] avgdiff in place of avdiff

["Hölter, Tanja"]

Hello, we work with the affy package and we try to compare the results
from bioconductor with the results from Affymetrix. 
In the function expresso you can choose the avgdiff as summary method.
We noticed that the function avgdiff uses the median of the probes, but
the Affymetrix 4 Algorithmen uses a trimmed mean. In the source code
there is a function called avdiff, which calculates the expression value
in the same manner as Affymetrix. Why does this function is not
implemented in the expresso? I think to take the median, as the function
avgdiff does, is very different to the method proposed fby Affymetrix.

Tanja Hölter



Dipl. Statistikerin Tanja Hölter
Institut für Medizinische Informatik,
Biometrie und Epidemiologie
Universitätsklinikum Essen
D-45122 Essen
Tel:(49)201-723-4654
FAX: (49)201-723-5933