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Re: st: Mata not computing eigenvectors/values
From
Steven Samuels <[email protected]>
To
[email protected]
Subject
Re: st: Mata not computing eigenvectors/values
Date
Mon, 10 Jan 2011 14:14:16 -0500
Zachary
What happens if you run Mathew's Mata commands (below)?. All three
Mata versions and your Stata matrix commands produce the same values
for me. In any case, perhaps there is something wrong with your Mata
installation. Try re-installing Stata and bringing it up to date. If
that doesn't work, I suggest that you contact support.
Steve
**********
eigensystem(A,X=.,L=.)
L'
lefteigensystem(A,Y=.,M=.)
M
***********
I would bet there
On Jan 10, 2011, at 1:39 PM, Zachary Neal wrote:
Sorry, that was a careless typo in my original message. Steven is
right, it should have read:
symeigensystem(A,eigenvector,eigenvalue)
However, even with that correction, the outputs - eigenvector and
eigenvalue - are empty.
In contrast, if I attempt the same thing in stata, using:
matrix 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)
matrix symeigen eigenvectors eigenvalues = A
matrix list eigenvectors
matrix list eigenvalues
I am able to get the correct eigenvectors/values.
I'm still not sure why this seems to work in stata, but not in mata.
On Mon, Jan 10, 2011 at 10:15 AM, Steven Samuels <[email protected]>
wrote:
-
Zachary's code works for me if I substitute "A" for "network" in the
-symeigensytem()- command:
symeigensystem(A,eigenvector,eigenvalue)
Steve
Stata 11,1 OS X 10.5.8
On Jan 9, 2011, at 9:22 PM, Matthew J Baker wrote:
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: [email protected] (on behalf of Zachary Neal
<[email protected]>)
Subject: st: Mata not computing eigenvectors/values
To: [email protected]
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
[email protected]
http://www.msu.edu/~zpneal
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--
Zachary Neal, PhD
Department of Sociology
Michigan State University
[email protected]
http://www.msu.edu/~zpneal
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