On Mon, 16 Feb 2004, Maurice McHugh wrote: > I have used several methods to calculate principal components rotated > using the varimax procedure. This is simple enough. But I would like > to calculate the % of variance explained associated with each PC before > and after rotation. > > factanal returns the % of variance explained associated with each PC but > I cannot seem to get it to change after rotation.
factanal does factor analysis, not principal component analysis. Factor rotation makes sense for factor analysis (the latent variables are rotationally equivariant) but not much sense for PCA (where successive PCs maximize the variance). factanal() does a varimax rotation by default so that a further varimax rotation does nothing. What the print method for factanal reports is the same as the print method for loadings(). So to continue example(varimax) loadings(fa) new <- varimax(fa$loadings, normalize = FALSE) class(new$loadings) <- "loadings" loadings(new) Your description is confused, but it is hard for us to know where the confusion lies. > Many thanks for your help! > > Maurice > > [EMAIL PROTECTED] > > Maurice McHugh > Department of Geography and Anthropology > Louisiana State University > Baton Rouge, LA -- Brian D. Ripley, [EMAIL PROTECTED] Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595 ______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
