On Thu, Apr 05, 2012 at 07:46:52AM -0700, ali_protocol wrote: > Hi all, > > I have a matrix (n*2), I want to compare 2 operators (2 normalization for > array results) on these matrix. > The 2 columns should ideally become the same after operations > (normalization). So to compare operations, > I do this for each normalization: > > s= sum (apply (normalized.matrix, 2,sd)) > c= cor (normalized[,1],normalized [,2], method='pearson') > > > I expect that if normalization 1 is superior, s should be less and c greater > than normalization2, but both s and c change in 1 direstion. Is this > possible or am I doing something wrong?
Hi. Is "normalized.matrix" and "normalized" the same matrix? Can you specify, which operators you use for normalization? Without having this information, i guess that comparing the correlations alone can be used, since it does not depend on the scaling the numbers. By an appropriate scaling factor, the sd may be changed to any value, but this does not say much about the amount of information in the data. On the other hand, the correlation does not change by scaling, so it may be a more reliable measure. Note that apply(normalized.matrix, 2, sd) is the same as sd(normalized.matrix) Hope this helps. Petr Savicky. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
