Thanks very much for showing me these functions, In prcomp(), the documentation says that Value: x is "the data multiplied by the 'rotation' matix". Using sample data:
data(iris) iris<-as.matrix(iris[,1:4]) pcprim<-prcomp(iris, scale=TRUE) Why does iris%*%pcprim$rotation (the data multiplied by the rotation matrix) not equal pcprim$x? Thanks very much, Scott On Mon, 14 Jun 2004, Prof Brian Ripley wrote: > Why are you using the OPRHANED multiv library for a facility covered by > princomp() and prcomp() in base R? The list might be able to help you > with the latter, but no one is supporting multiv (hence its status). > > On Sun, 13 Jun 2004, Scott Robbins Loarie wrote: > > > I am having trouble using the pca function in the multiv library. > > I am trying to generate the values found in $rproj by using $evecs to > > calculate linear combinations of my input data. However, I have been not > > been able to correctly calculate the $rproj values. > > > > Using the following standard sample data, why does iris%*%pcprim$evecs[,] > > not equal pcprim$rproj? > > > > data(iris) > > iris<-as.matrix(iris[,1:4]) > > pcprim<-pca(iris) > > -- > 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
