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## Re: Extracting the dominant eigenvector

 From: Mike Miller Subject: Re: Extracting the dominant eigenvector Date: Wed, 27 Mar 2002 22:24:53 -0600 (CST)

```On Thu, 28 Mar 2002, Stefan Jonsson wrote:

> Hello octave users
>
> I have what I hope is a simple problem
>
> I have a square matrix, A, currently 10by10, may at
> later time have different dimensions.
>
> asking for eigenvalues and eigen vectors
>
> [vect, val] =eig(A);
>
> I need the dominant eigenvalue and corresponding eigenvector

I suppose this will work for square matrix A of any size:

k=size(A,1);
[V,D]=eig(A);
[S,I]=sort(diag(D));
val=S(k);
vec=V(:,I(k));

You could write it as a function like this: [val, vec] = maxeig(A)

I use the 'sort' function which returns index I.  Read "help sort".

Regards,

Mike

--
Michael B. Miller, Ph.D.
Assistant Professor
Division of Epidemiology
University of Minnesota
http://taxa.epi.umn.edu/~mbmiller/

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