Hi, I am also doing PCA. Is the following right for extracting the scores?
library(psych) pca<-principal(data,nfactors=,rotate="varimax",scores=T) pca$loadings pca$score Best regards, He On Tue, Nov 30, 2010 at 10:22 AM, Liviu Andronic <landronim...@gmail.com> wrote: > Dear all > I'm unable to find an example of extracting the rotated scores of a > principal components analysis. I can do this easily for the un-rotated > version. > > data(mtcars) > .PC <- princomp(~am+carb+cyl+disp+drat+gear+hp+mpg, cor=TRUE, data=mtcars) > unclass(loadings(.PC)) # component loadings > summary(.PC) # proportions of variance > mtcars$PC1 <- .PC$scores[,1] # extract un-rotated scores of 1st > principal component > mtcars$PC2 <- .PC$scores[,2] # extract un-rotated scores of 2nd > principal component > head(mtcars[, c('PC1', 'PC2')]) > > However, I no longer understand how to do so if I want to use > ?principal in 'psych' and any of the GPArotation methods. For example, > require(psych) > r <- cor(mtcars[,c("am","carb","cyl","disp","drat","gear","hp","mpg")]) > pca <- principal(r, nfactors = 8, residuals = T, rotate="none") # or > 'varimax' or any other GPArotation supported rotation > pca > > I've turned the 'pca' object and ?principal help page upside down and > I still cannot find anything that would resemble a 'scores' value. I'm > pretty sure it's one matrix computation away, but I cannot find which > one. > > Ideas? Thank you > Liviu > > > > -- > Do you know how to read? > http://www.alienetworks.com/srtest.cfm > http://goodies.xfce.org/projects/applications/xfce4-dict#speed-reader > Do you know how to write? > http://garbl.home.comcast.net/~garbl/stylemanual/e.htm#e-mail > > ______________________________________________ > 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.