Thank you Luis! Guillermo, if you believe it would help to document this a bit better (i.e. more explicitly regarding input and output vectors/matrices) in PDL::LinearAlgebra, please open an issue there and spell out your thoughts.
Best regards, Ed From: Guillermo P. Ortiz<mailto:gor...@exa.unne.edu.ar> Sent: 05 July 2022 21:57 To: Guillermo P. Ortiz<mailto:gor...@exa.unne.edu.ar>; pdl-general@lists.sourceforge.net<mailto:pdl-general@lists.sourceforge.net>; pdl-de...@lists.sourceforge.net<mailto:pdl-de...@lists.sourceforge.net> Subject: Re: [Pdl-devel] meigen sort criteria for eigenvalue and eigenvectors. Yes, Dear Luis, your are fast and right ! just confirm that using meigen() to obtain eigenvectors (right) if you perform matrix multiplication (x) the vector are in the rows but if you want to see they you need the transpose Thanks ! El mar, 5 jul 2022 a las 16:10, Luis Mochan (<moc...@icf.unam.mx<mailto:moc...@icf.unam.mx>>) escribió: Dear Guillermo, I guess the eigenvectors are the rows, not the columns, and they are normalized! Regards, Luis On Tue, Jul 05, 2022 at 03:05:16PM -0300, Guillermo P. Ortiz wrote: > Dear PDL developers, > > Trying to use meigen() for eigenvalue problem with matrix 4x4 without > threading for now, I realize that eigenvalues seems did not have any > ordered output, is not it? > > In the first example below the second eigenvalue is larger than the first > > =========== > Matrix: > > [ > [ 0 1 0 > 0] > [ 1.19256986494742 0 -0.00449505340171719 > 0] > [ 0 0 0 > -1] > [ 0.00449505340171719 0 -1.20412391559198 > 0] > ] > > Eigenvalue: > > [1.09134187427168 1.09802854880944 -1.09134187427168 -1.09802854880944] > > Right Eigenvector (tranposed matrix) > > [ > [ 0.638990630564561 0.697357232402369 0.219312399660024 > -0.23934480529599] > [ 0.218583370045276 0.240010780604692 -0.636866523154502 > 0.699297624204653] > [-0.638990630564568 0.697357232402378 -0.219312399660001 > -0.239344805295965] > [-0.218583370045231 0.240010780604642 0.636866523154517 > 0.69929762420467] > ] > > In the second example, neither, and also the eigenvectors seem not be > normalized > Matrix: > > [ > [ 0 1 0 > 0] > [ 1.18623905553229 0 -3.55105833627078e-10 > 0] > [ 0 0 0 > -1] > [ 3.55105833627078e-10 0 -1.21150887543497 > 0] > ] > > [1.08914602121676 -1.08914602121676 1.10068563878838 -1.10068563878838] > > > Thank you in advance. > Regards > > -- > > > Dr. Guillermo P. Ortiz > Electromagnetismo Aplicado > Dto. Física, Facultad de Ciencias Exactas > Universidad Nacional del Nordeste > Avda Libertad 5460, W3404AAS Corrientes, > Argentina. > (+54) 379-4424678 interno 4613 > gortiz* at *unne edu ar > _______________________________________________ > pdl-devel mailing list > pdl-de...@lists.sourceforge.net<mailto:pdl-de...@lists.sourceforge.net> > https://lists.sourceforge.net/lists/listinfo/pdl-devel -- o W. Luis Mochán, | tel:(52)(777)329-1734 /<(*) Instituto de Ciencias Físicas, UNAM | fax:(52)(777)317-5388 `>/ /\ Av. Universidad s/n CP 62210 | (*)/\/ \ Cuernavaca, Morelos, México | moc...@fis.unam.mx<mailto:moc...@fis.unam.mx> /\_/\__/ GPG: 791EB9EB, C949 3F81 6D9B 1191 9A16 C2DF 5F0A C52B 791E B9EB
_______________________________________________ pdl-general mailing list pdl-general@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/pdl-general
