[R] eigen vector question

[Jari Oksanen]

On Fri, 2005-02-18 at 11:26 +0100, Uwe Ligges wrote:
> Jessica Higgs wrote:
> 
> > Sorry to bother everyone, but I've looked in all of the help files and 
> > manuals I have and I can't find the answer to this question.  I'm doing 
> > principle component analysis by calculating the eigen vectors of a 
> > correlation matrix that I have that is composed of 21 parameters.  I 
> > have the eigen vectors and their values that R produced for me but I'm 
> > not sure how to tell which eigen vector/value corresponds to which 
> > parameter because when R produces eigen vectors it does so in decreasing 
> > order of significance, meaning that the eigen vector that explains the 
> > most of the variance is listed first, followed by the next eigen vector, 
> > etc etc. Any help would be appreciated. Feel free to write back if you 
> > need more information on my problem.  Thanks!
> > 
> > ______________________________________________
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> > PLEASE do read the posting guide! 
> > http://www.R-project.org/posting-guide.html
> 
> 
> Have you considered to use princomp()?
> 
It is really weird that people always recommend using princomp, although
it is numerically inferior to prcomp and fails with rank deficit data.
The natural solution would be to define functions:

loadings <- 
function(x) UseMethod("loadings")

loadings.princomp <- 
function (x) x$loadings

loadings.prcomp <- 
function(x) structure(x$rotation, class="loadings")

cheers, jari oksanen
-- 
Jari Oksanen <jarioksa at sun3.oulu.fi>