Did you call KSPSetInitialGuessNonzero() or use the option
-ksp_initial_guess_nonzero? Otherwise I think Petsc zeroes out your initial
guess when you call KSPSolve().
From: petsc-users-boun...@mcs.anl.gov [petsc-users-boun...@mcs.anl.gov] on
behalf of Kaushik
[jro...@dsic.upv.es]
Sent: Wednesday, November 02, 2016 3:29 AM
To: Peetz, Darin T
Cc: petsc-users@mcs.anl.gov
Subject: Re: [petsc-users] Provide Matrix Factorization to EPS for Generalized
Eigenvalue Problem
> El 1 nov 2016, a las 20:42, Peetz, Darin T <pee...@illinois.edu> escribi
your help,
Darin
From: Jose E. Roman [jro...@dsic.upv.es]
Sent: Tuesday, November 01, 2016 6:14 AM
To: Peetz, Darin T
Cc: petsc-users@mcs.anl.gov
Subject: Re: [petsc-users] Provide Matrix Factorization to EPS for Generalized
Eigenvalue Problem
> E
Hello,
I'm wondering how I could go about providing a matrix factorization calculated
in Petsc to the eigenvalue routines in Slepc. I'm trying to solve the
eigenvalue problem for stability, where the solution to KU=F is needed to
construct the A-matrix (K_sigma) in the eigenvalue problem.
I've come across an irregularity when extracting the eigenvectors when using
the CISS method to solve the eigenvalue problem. I'm solving a generalized
hermitian problem, and it looks like the resulting eigenvectors are
M-orthogonalized with each other (the M-inner products of different
