This function compute the scaled log-ratios from raw probe intensities, as done by Nimblegen for scaling of ChIP-chip data.
Object of class
further arguments passed on to
Nimblegen provides scaled log-ratios as normalized values for the probes. log.ratio = log2(R)-log2(G) scaled.ratio = log.ratio - tukey.biweight(log.ratio)
MAList, with the M slot of the list holding the
scaled log ratios.
for more details on the Tukey biweight estimator: Statistical Algorithms Description Document, 2002, Affymetrix.