Re: [R] PCA analysis and bootstraped loadings

Dear All, Thank You for the quick responses. Managed to solve my problem through: http://www.faculty.biol.ttu.edu/strauss/multivar/R/SamplePCABootstrap.R.txt or http://r.789695.n4.nabble.com/bootstrapped-eigenvector-method-following-prcomp-td877655.html Used the first one however, code is too long

Re: [R] PCA analysis and bootstraped loadings

psych does not currently have bootstrapped confidence intervals for loadings. That is a reasonable request and I will try to add it, perhaps in the “real soon now” version of 1.5.4 (almost finished), perhaps in the next release, Bill > On Apr 13, 2015, at 2:38 PM, stephen sefick wrote: > > H

Re: [R] PCA analysis and bootstraped loadings

Hi, Please search the mailing list archives for this, or type bootstrapped PCA R into google. Please provide a minimal self-contained example of what you are trying to solve. Please read the posting guide that is referenced at the end of every email. kind regards, Stephen On Mon, Apr 13, 2015 at

Re: [R] pca analysis: extract rotated scores?

Hi He Zhang, >> Is the following right for extracting the scores? >> ... >> pca$loadings >> pca$score Yes. But you should be aware that the function principal() in package psych is standardizing your data internally, which you might not want. That is, the analysis is being based on the correla

Re: [R] pca analysis: extract rotated scores?

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 wrote: > Dear all > I'm unable to find an example of extra

Re: [R] pca analysis: extract rotated scores?

Hi Liviu, >> However, I'm still confused on how to compute the scores when rotations >> (such as 'varimax' or other methods in GPArotation) are applied. PCA does an orthogonal rotation of the coordinate system (axes) and further rotation is not usually done (in contrast to factor analysis). Nei

Re: [R] pca analysis: extract rotated scores?

Take 2 on this. Below I'm pasting the code to perform PCA in R (without any rotation), manually; using ?princomp; and using ?principal. I also point out some differences in teh output and terminology of the two functions. In short, I found how to compute the scores of principal components when no r

Re: [R] PCA analysis

Hi Mona, I cannot get it done with the princomp and the biplot commands either (maybe somebody can), but there are always many ways to Rome. This is how you can do it (below). However, the label=rep... below assumes that your values are in order, i.e. that you really want to plot the first fifty ro

Re: [R] PCA analysis

I am not entirely sure after reading your email, but I thought you wanted to do something like this: ###Start of example ###create random data for the example x=rnorm(100,100,10) ##create Xs e=rnorm(100,0,5) ##create Errors y=x+e##create Ys ###plot plot(y~x,pch=NA) ##plo