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Subject: Re: eignevalue decomposition
Date: Mon, 9 Feb 2009 01:49:01 +0000 (UTC)
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"vagrom Jiang" <vagrom@mytum.de> wrote in message <gmnhr2$bij$1@fred.mathworks.com>...
> Hi,
>    i want to apply the eigvenvalue decomposition to a 3*3*3 matrix. The eigenvalues are  supposed to be in asending order. And how can i find their corresponding eigen vectors?  
> Thanks!
> Xin

  What do you mean by "the eigvenvalue decomposition to a 3*3*3 matrix"?  It is my understanding that the term 'eigenvalue' applies only to square n-by-n matrices.  A three-dimensional array is not even a matrix.

  As for obtaining eigenvalues in ascending order, that has been discussed very frequently in this newsgroup.  You should look up some of them.

  The correspondence between eigenvalues and eigenvectors obtained with matlab's 'eig' function is just that of corresponding columns in the returned V and D of

 [V,D] = eig(A)

The k-th column of V is the eigenvector corresponding to the eigenvalue in the k-th column of D at its diagonal.

Roger Stafford