Try x <- mean(PCA$scores[,1]) and y <- mean(PCA$scores[,2]) which should be the same as x <- 0, y <- 0 within rounding error.
---------------------------------------------- David L Carlson Associate Professor of Anthropology Texas A&M University College Station, TX 77843-4352 > -----Original Message----- > From: r-help-boun...@r-project.org [mailto:r-help-bounces@r- > project.org] On Behalf Of mary > Sent: Tuesday, January 22, 2013 3:40 AM > To: r-help@r-project.org > Subject: Re: [R] Ellipse in PCA with parameters "a" and "b"defined. > > Ok... > so, in my model my "a" is built using the standard deviation of the > first > principal component and "b" with the second, so my "x" and "Y" should > be : > PCA $ scores [, 1], PCA $ scores [, 2] > but in this way I do not get out a confidence interval set on my > parameters > but many ellipses. > > Thanks > Mary > > > > -- > View this message in context: http://r.789695.n4.nabble.com/Ellipse-in- > PCA-with-parameters-a-and-b-defined-tp4656215p4656242.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > 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. ______________________________________________ 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.