On Fri, 8 Aug 2003 [EMAIL PROTECTED] wrote: > R version: 1.7.1 > OS: Red Hat Linux 7.2 > > When "covmat" is supplied in princomp(), the output value "center" is all > NA's, even though the input matrix was indeed centered. I haven't read > anything about this in the help file for princomp().
You *did* try to read the help page? You seem to have failed to read the description of `value', which says center: the means that were subtracted. > See code below for an example: pc2$center is all NA's. > x <- rnorm(6) > y <- rnorm(6) > X <- cbind(x,y) > pc1 <- princomp(X) > pc1$scores %*% t(pc1$loadings)-X > pc1$center > pc2 <- princomp(X,covmat=cov(X)*5/6) If you had read either the help page or the code, you would have seen that x is not used when you supply covmat. So although means were subtracted, they were done by you not princomp(), and NA is the right answer. -- 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-devel
