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Subject: Re: Eigen value and Eigen vector?
Date: Fri, 17 Aug 2007 14:08:46 +0000 (UTC)
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Thanks for all the responses, guys.

I am a little confused now as I look at the results. I 
have an Excel VBA program which could calculate the 
Eigenvalues in descending order and the associated 
Eigenvetors. If I use the suggested method to calculate 
the same things in Matlab, some values of Eigenvector are 
exactly the same while some values of Eigenvector are the 
same in absolute terms but have opposite signs (plus vs 
minus).  I use formula V*D*V&#8217; to check if they are getting 
the same correlation matrix, and they are. 

Does anyone have any idea what&#8217;s going on here?

Thanks,
Stephen




"us " <us@neurol.unizh.ch> wrote in message 
<fa3kac$rlr$1@fred.mathworks.com>...
> Titus:
> <SNIP the big easy...
> 
> > > D = D(length(D(1,:)):-1:1,length(D(:,1)):-1:1) ;
> 
> > slightly easier: use "end" instead of length:
> > D = D(end:-1:1,end:-1:1)
> 
> ... or, yet another solution
> 
>      D=rot90(D,2)
> 
> us