Re: Fold Change Calculation in XCMS
Reply #1 –
Umm.... I guess you could take the median or really just about any other stat. If there was reason to believe that the distribution was not normal then the median would make sense.
If could just be a difference be due to normalisation. (?) There are other ways of calculating the fold change, including bayesian methods (ref below). I just did a quick pubmed search I'm sure there are more.
Cheers,
Paul
J Comput Biol. 2001;8(6):585-614.
Bayesian estimation of fold-changes in the analysis of gene expression: the PFOLD algorithm.
http://www.ncbi.nlm.nih.gov/pubmed/11747614