Re: st: Mata not computing eigenvectors/values

[Matthew J Baker <matthew.baker@hunter.cuny.edu>]

While I am not sure about why the symeigensystem command isn't working, the problem might have something to do with the "A" matrix being rank deficient. In any case, I find that the commands:

eigensystem(A,X=.,L=.)

and

lefteigensystem(A,Y=.,M=.)

both generate values for eigenvalues and eigenvectors for the aforementioned A matrix (collected in X and L, and Y and M, respectively). 

Matt Baker

---- Original message ----
>Date: Sun, 9 Jan 2011 17:45:19 -0500
>From: owner-statalist@hsphsun2.harvard.edu (on behalf of Zachary Neal <zpneal@gmail.com>)
>Subject: st: Mata not computing eigenvectors/values  
>To: statalist@hsphsun2.harvard.edu
>
>Running the commands below, mata does not yield any eigenvectors or
>eigenvalues.  Computing eigenvectors/values in stata using matrix
>symeigen seems to work without a problem.  Any help would be
>appreciated.
>
>mata
>A = (0,0,0,0,0,1,0,1,0,0,0,0,0 \ ///
>     0,0,0,0,0,0,0,1,0,1,0,0,0 \ ///
>     0,0,0,1,0,1,1,0,1,0,1,1,1 \ ///
>     0,0,1,0,0,0,1,0,0,0,0,0,0 \ ///
>     0,0,0,0,0,0,0,1,0,0,0,0,0 \ ///
>     1,0,1,0,0,0,0,0,0,0,0,1,0 \ ///
>     0,0,1,1,0,0,0,0,0,0,0,0,0 \ ///
>     1,1,0,0,1,0,0,0,0,0,0,0,0 \ ///
>     0,0,1,0,0,0,0,0,0,0,0,0,0 \ ///
>     0,1,0,0,0,0,0,0,0,0,0,0,0 \ ///
>     0,0,1,0,0,0,0,0,0,0,0,0,0 \ ///
>     0,0,1,0,0,1,0,0,0,0,0,0,0 \ ///
>     0,0,1,0,0,0,0,0,0,0,0,0,0)
>eigenvector = 0
>eigenvalue = 0
>symeigensystem(network,eigenvector,eigenvalue)
>eigenvector
>eigenvalue
>end
>
>-- 
>Zachary Neal, PhD
>Department of Sociology
>Michigan State University
>zpneal@msu.edu
>http://www.msu.edu/~zpneal
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