The PCA of two variables out of three is unrelated to the PCA of all three, so your example code does not do what you describe.
If you want to plot two of the components of a full PCA, see ?biplot.princomp: and note that it says this is not a true biplot for other than the first two components. (And really you should have been able to find this yourself: please do study the posting guide.) On Sun, 13 May 2007, Soare Marcian-Alin wrote: > Hello everybody, > > How could I extract the components of of a PCA to plot it into a biplot? > I want to make pairwise biplots of the first three main components: > > biplot(princomp(x, cor=TRUE)) > biplot(princomp(x[,c(1,2)], cor=TRUE)) > biplot(princomp(x[,c(1,3)], cor=TRUE)) > biplot(princomp(x[,c(2,3)], cor=TRUE)) > > Is this the only way, how I could plot them? > I thought, that it could be possible to extract them of the full PCA .. > > KR, > Alin > > [[alternative HTML version deleted]] > > ______________________________________________ > [email protected] 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. > -- 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://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.
