The problem with applying prcomp to binary data is that it's not clear what problem you are solving.
The standard principal components and factor analysis models assume that the observations are linear combinations of unobserved "common" factors (shared variability), normally distributed, plus normal noise, independent between observations and variables. Those assumptions are clearly violated for binary data. RSiteSearch("PCA for binary data") produced references to 'ade4' and 'FactoMineR'. Have you considered these? I have not used them, but FactoMineR included functions for 'Multiple Factor Analysis for Mixed [quantitative and qualitative] Data' Hope this helps. Spencer Graves Josh Gilbert wrote: > I don't understand, what's wrong with using prcomp in this situation? > > On Sunday 10 June 2007 12:50 pm, Ranga Chandra Gudivada wrote: > >> Hi, >> >> I was wondering whether there is any package implementing Principal >> Component Analysis for Binary data >> >> Thanks chandra >> >> >> --------------------------------- >> >> >> [[alternative HTML version deleted]] >> >> ______________________________________________ >> R-help@stat.math.ethz.ch 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. >> > > ______________________________________________ > R-help@stat.math.ethz.ch 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. > ______________________________________________ R-help@stat.math.ethz.ch 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.