[R] PCA

[Lucke, Joseph F]

Neola
I'm a bit rusty on this, but I believe you can conduct on singular-value decomposition on the 436 by 518 matrix.  The squares of your singular values (max of 436, 518-436 will be zero) will be your eigenvalues, the same as in the PC analysis.  The post-eigenvectors will be your components.  As I have said, my knowledge is not completely trustworthy at this point, but SVD would be worth looking into.
Joe 

-----Original Message-----
From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org] On Behalf Of Noela Sánchez
Sent: Thursday, November 06, 2008 1:10 PM
To: stephen sefick
Cc: r-help at r-project.org
Subject: Re: [R] PCA

My matrix have 436 registers and 518 variables. I need to do a PCA analyst.

Usually I use princomp command to perform PCA analyst, but this time i can't because of my variables are more than my registers.

2008/11/6 stephen sefick <ssefick at gmail.com>

> would you please provide a dummy example that explains your problem.
> Then maybe I can help you.
> thanks
>
> Stephen
>
> On Thu, Nov 6, 2008 at 1:42 PM, Noela Sánchez <noesanchez at udc.es> wrote:
> > I need perform PCA analyst with a matrix with more variables than units.
> >
> > The princomp command don't match with this matrix.
> >
> > Anybody knows a good command to do it?
> >
> > --
> > Noela
> >
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>
> --
> Stephen Sefick
> Research Scientist
> Southeastern Natural Sciences Academy
>
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>                                                                -K. 
> Mullis
>



--
Noela
Grupo de Recursos Marinos y Pesquerías
Universidad de A Coruña

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