On Fri, 2008-06-27 at 21:43 +0200, Dan Bolser wrote: > 2008/6/27 Prof Brian Ripley <[EMAIL PROTECTED]>: <snip /> > > > > I forgot to answer that: just ask R to show you stats:::biplot.prcomp > > Ah! I never knew the ::: trick!
In this case you also need to know that biplot.prcomp is in stats. getAnywhere() is a more general solution: getAnywhere(biplot.prcomp) The following R News article by Uwe Ligges covers aspects of finding the sources for R functions: Uwe Ligges. R help desk: Accessing the sources. R News, 6(4):43-45, October 2006. HTH G > > I got it working after looking at the code - > > > my.df <- > data.frame(A=(x <- rnorm(100,mean=100, sd=10)), > B=(y <- x + rnorm(100,mean=10, sd=10))) > > plot(my.df) > > my.pc <- > prcomp(my.df, center=TRUE, scale=TRUE) > > biplot(my.pc) > > attributes(my.pc) > > head(scores <- my.pc$x) > > lam <- my.pc$sdev > > n <- nrow(my.pc$x) > > lam <- lam * sqrt(n) > > my.x <- (my.pc$x)[,1] / lam[1] > my.y <- (my.pc$x)[,2] / lam[2] > > plot(my.x, my.y, type="n") > text(my.x, my.y, labels=1:100) > > > > >>> What am I missing? > >> > >> Reading the references on ?biplot.prcomp, or a good book on the subject > >> (such as MASS or Gower & Hand). > >> > >> A biplot is a specific type of plot and the help page does not spell out > >> the rather mathematical details (and there are several variants). > >> > >>> > >>> Dan. > >>> > >>> [[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. > >>> > >> > >> -- > >> 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 > >> > > > > -- > > 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 > > > > > -- %~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~% Dr. Gavin Simpson [t] +44 (0)20 7679 0522 ECRC, UCL Geography, [f] +44 (0)20 7679 0565 Pearson Building, [e] gavin.simpsonATNOSPAMucl.ac.uk Gower Street, London [w] http://www.ucl.ac.uk/~ucfagls/ UK. WC1E 6BT. [w] http://www.freshwaters.org.uk %~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~% ______________________________________________ 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.