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From |
Zachary Neal <zpneal@gmail.com> |

To |
statalist@hsphsun2.harvard.edu |

Subject |
Re: st: Mata not computing eigenvectors/values |

Date |
Mon, 10 Jan 2011 13:39:41 -0500 |

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 <sjsamuels@gmail.com> 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: 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 >> * >> * For searches and help try: >> * http://www.stata.com/help.cgi?search >> * http://www.stata.com/support/statalist/faq >> * http://www.ats.ucla.edu/stat/stata/ > > * > * For searches and help try: > * http://www.stata.com/help.cgi?search > * http://www.stata.com/support/statalist/faq > * http://www.ats.ucla.edu/stat/stata/ > > * > * For searches and help try: > * http://www.stata.com/help.cgi?search > * http://www.stata.com/support/statalist/faq > * http://www.ats.ucla.edu/stat/stata/ > -- Zachary Neal, PhD Department of Sociology Michigan State University zpneal@msu.edu http://www.msu.edu/~zpneal * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/

**Follow-Ups**:**Re: st: Mata not computing eigenvectors/values***From:*Steven Samuels <sjsamuels@gmail.com>

**References**:**st: Mata not computing eigenvectors/values***From:*Zachary Neal <zpneal@gmail.com>

**Re: st: Mata not computing eigenvectors/values***From:*Matthew J Baker <matthew.baker@hunter.cuny.edu>

**Re: st: Mata not computing eigenvectors/values***From:*Steven Samuels <sjsamuels@gmail.com>

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