Yes, Bert, you are right and I do know I might run into a non-positive definite intercorrelation matrix. But if I do, then I can go back to those for whom I am doing the analysis and tell them that. Not before. This sad truth being said - can I do it directly in the function, without building a intercorrelation matrix manually? Thank you! Dimitri
On Wed, Mar 20, 2013 at 7:04 PM, Bert Gunter <gunter.ber...@gene.com> wrote: > Well, you can do this, but there's no guarantee that the resulting > correlation matrix will be positive definite. And what would principle > components based on this mean even if it is positive definite? > > -- Bert > > On Wed, Mar 20, 2013 at 3:14 PM, Dimitri Liakhovitski < > dimitri.liakhovit...@gmail.com> wrote: > >> Hello! >> I am running principle components analysis using princomp function in >> pacakge psych. >> >> mypc <- princomp(mydataforpc, cor=TRUE) >> >> Question: I'd like to use pairwise deletion of missing cases when >> correlations are calculated. I.e., I'd like to have a correlation between >> any 2 variables to be based on all cases that have valid values on both >> variables. >> >> What should my na.action be in this case? >> >> Thank you very much! >> -- >> Dimitri Liakhovitski >> >> [[alternative HTML version deleted]] >> >> ______________________________________________ >> 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<http://www.r-project.org/posting-guide.html> >> and provide commented, minimal, self-contained, reproducible code. >> > > > > -- > > Bert Gunter > Genentech Nonclinical Biostatistics > > Internal Contact Info: > Phone: 467-7374 > Website: > > http://pharmadevelopment.roche.com/index/pdb/pdb-functional-groups/pdb-biostatistics/pdb-ncb-home.htm > > -- Dimitri Liakhovitski [[alternative HTML version deleted]] ______________________________________________ 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.
