From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 29293 invoked by alias); 13 May 2002 23:02:50 -0000 Mailing-List: contact gsl-discuss-help@sources.redhat.com; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gsl-discuss-owner@sources.redhat.com Received: (qmail 29264 invoked from network); 13 May 2002 23:02:47 -0000 Received: from unknown (HELO facstaff.wesleyan.edu) (129.133.1.61) by sources.redhat.com with SMTP; 13 May 2002 23:02:47 -0000 Received: (from nobody@localhost) by facstaff.wesleyan.edu (8.11.2/8.10.2) id g4DN2kh22309 for gsl-discuss@sources.redhat.com; Mon, 13 May 2002 19:02:46 -0400 (EDT) X-Authentication-Warning: facstaff.wesleyan.edu: nobody set sender to jdwright@wesleyan.edu using -f To: Subject: nonsymmetric nondefective matrix eigenvalues and eigenvectors Message-ID: <1021330966.3ce046167752a@mail.wesleyan.edu> Date: Tue, 31 Dec 2002 09:55:00 -0000 From: MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit User-Agent: IMP/PHP IMAP webmail program 2.2.0-pre13 X-SW-Source: 2002/txt/msg00534.txt.bz2 Dear GSL-users, Can GSL provide the eigen-values and eigen-vectors of a non-defective, non-symmetric matrix? As far as I can tell, GSL lacks this ability. If GSL can accomplish this task, could someone let me know the name of the appropriate function? If GSL cannot accomplish this task has someone created a patch for this problem? Tao Pang in his work "An Introduction to Computational Physics" clearly states on page 114, "For a nondefective matrix, we can always obtain a complete set of eigenvectors, including the degenerate eigenvalue cases." Tao defines a nondefective matrix on page 112. "A matrix is nondefective if it can be diagonalized under a matrix transformation and its eigenvectors can form a complete vector space." He goes on to say "we hardly encounter defective matrices in physics." He then presents two different methods for finding the eigenvalues and eigenvectors of a general matrix. Thus I think other physicists like myself may have an interest in such methods. Although Tao has some code at his web-site "www.physics.unlv.edu/~pang/cp.html" I did not find a complete C-implementation of the method he describes in his book. I did find a complete routine in "Numerical Recipes in C". However, this routine merely provides the eigen-vectors. Nonetheless, I will try to use it as a first step. Now comes a more concrete question. If I have a variable H defined with the statement "gsl_matrix * H = gsl_matrix_alloc(100,100)" how can I pass this object into a function with the prototype "void hqr(float **a, int n, float wr[], float wi[])"? Is it possible or do I have to modify the routine to use gsl functions like gsl_matrix_get and gsl_matrix_set? If anyone has any experience with this matter I would love to hear from you. Thanks, David Wright Graduate Student Physics Department Wesleyan University jdwright@wesleyan.edu From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 29293 invoked by alias); 13 May 2002 23:02:50 -0000 Mailing-List: contact gsl-discuss-help@sources.redhat.com; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gsl-discuss-owner@sources.redhat.com Received: (qmail 29264 invoked from network); 13 May 2002 23:02:47 -0000 Received: from unknown (HELO facstaff.wesleyan.edu) (129.133.1.61) by sources.redhat.com with SMTP; 13 May 2002 23:02:47 -0000 Received: (from nobody@localhost) by facstaff.wesleyan.edu (8.11.2/8.10.2) id g4DN2kh22309 for gsl-discuss@sources.redhat.com; Mon, 13 May 2002 19:02:46 -0400 (EDT) X-Authentication-Warning: facstaff.wesleyan.edu: nobody set sender to jdwright@wesleyan.edu using -f To: Subject: nonsymmetric nondefective matrix eigenvalues and eigenvectors Message-ID: <1021330966.3ce046167752a@mail.wesleyan.edu> Date: Mon, 13 May 2002 23:31:00 -0000 From: MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit User-Agent: IMP/PHP IMAP webmail program 2.2.0-pre13 X-SW-Source: 2002-q2/txt/msg00161.txt.bz2 Message-ID: <20020513233100.tLqHiLCMxI4FuvOCkzxq0X52PlJXKo37eSpwzkNPgzg@z> Dear GSL-users, Can GSL provide the eigen-values and eigen-vectors of a non-defective, non-symmetric matrix? As far as I can tell, GSL lacks this ability. If GSL can accomplish this task, could someone let me know the name of the appropriate function? If GSL cannot accomplish this task has someone created a patch for this problem? Tao Pang in his work "An Introduction to Computational Physics" clearly states on page 114, "For a nondefective matrix, we can always obtain a complete set of eigenvectors, including the degenerate eigenvalue cases." Tao defines a nondefective matrix on page 112. "A matrix is nondefective if it can be diagonalized under a matrix transformation and its eigenvectors can form a complete vector space." He goes on to say "we hardly encounter defective matrices in physics." He then presents two different methods for finding the eigenvalues and eigenvectors of a general matrix. Thus I think other physicists like myself may have an interest in such methods. Although Tao has some code at his web-site "www.physics.unlv.edu/~pang/cp.html" I did not find a complete C-implementation of the method he describes in his book. I did find a complete routine in "Numerical Recipes in C". However, this routine merely provides the eigen-vectors. Nonetheless, I will try to use it as a first step. Now comes a more concrete question. If I have a variable H defined with the statement "gsl_matrix * H = gsl_matrix_alloc(100,100)" how can I pass this object into a function with the prototype "void hqr(float **a, int n, float wr[], float wi[])"? Is it possible or do I have to modify the routine to use gsl functions like gsl_matrix_get and gsl_matrix_set? If anyone has any experience with this matter I would love to hear from you. Thanks, David Wright Graduate Student Physics Department Wesleyan University jdwright@wesleyan.edu