To answer the question I would need more information. - Is your B matrix symmetric? Is it symmetric positive-definite? - Do your A and B matrices have a special block structure? - Is your spectrum symmetric with respect to the origin? - How many eigenvalues do you need? (in percentage)
Jose > El 19 ene 2026, a las 11:17, TARDIEU Nicolas via petsc-users > <[email protected]> escribió: > > Dear PETSc team, > > I am using SLEPc to solve a generalized non-symmetric eigenvalue problem. The > underlying physical problem—coupled vibrations of an acoustic fluid enclosed > in an elastic container—is actually conservative, so all eigenvalues and > eigenvectors are real. The literature shows that a change of basis exists > that makes the problem symmetric, but this transformation is computationally > expensive. > > Since I need to compute a large number of eigenvalues, I would like to use > spectrum slicing, which is only available for symmetric matrices. I am not > familiar with the internal workings of spectrum slicing in SLEPc, and I am > wondering whether it could be possible to force the algorithm to handle these > (pseudo-)non-symmetric matrices, given that the actual spectrum is real. > > Thanks, > Regards, > -- > Nicolas Tardieu > Ing PhD Computational Mechanics > EDF - R&D Dpt ERMES > PARIS-SACLAY, FRANCE > > Ce message et toutes les pièces jointes (ci-après le 'Message') sont établis > à l'intention exclusive des destinataires et les informations qui y figurent > sont strictement confidentielles. Toute utilisation de ce Message non > conforme à sa destination, toute diffusion ou toute publication totale ou > partielle, est interdite sauf autorisation expresse. > Si vous n'êtes pas le destinataire de ce Message, il vous est interdit de le > copier, de le faire suivre, de le divulguer ou d'en utiliser tout ou partie. > Si vous avez reçu ce Message par erreur, merci de le supprimer de votre > système, ainsi que toutes ses copies, et de n'en garder aucune trace sur > quelque support que ce soit. Nous vous remercions également d'en avertir > immédiatement l'expéditeur par retour du message. > Il est impossible de garantir que les communications par messagerie > électronique arrivent en temps utile, sont sécurisées ou dénuées de toute > erreur ou virus. > ____________________________________________________ > This message and any attachments (the 'Message') are intended solely for the > addressees. The information contained in this Message is confidential. Any > use of information contained in this Message not in accord with its purpose, > any dissemination or disclosure, either whole or partial, is prohibited > except formal approval. > If you are not the addressee, you may not copy, forward, disclose or use any > part of it. If you have received this message in error, please delete it and > all copies from your system and notify the sender immediately by return > message. > E-mail communication cannot be guaranteed to be timely secure, error or > virus-free.
