> El 26 oct 2017, a las 18:36, Franck Houssen <franck.hous...@inria.fr> > escribió: > > Here is a stack I end up with when trying to solve an eigen problem (real, > sym, generalized) with SLEPc. My understanding is that, during the Gram > Schmidt orthogonalisation, the projection of one basis vector turns out to be > null. > First, is this correct ? Second, in such cases, are there some recommended > "recipe" to test/try (options) to get a clue on the problem ? (I would > unfortunately perfectly understand the answer could be no !... As this > totally depends on A/B). > > With arpack, the eigen problem is solved (so the matrix A and B I use seems > to be relevant). But, when I change from arpack to krylovschur/ciss/arnoldi, > I get the stack below. > > Franck > > [0]PETSC ERROR: #1 BV_SafeSqrt() > [0]PETSC ERROR: #2 BVNorm_Private() > [0]PETSC ERROR: #3 BVNormColumn() > [0]PETSC ERROR: #4 BV_NormVecOrColumn() > [0]PETSC ERROR: #5 BVOrthogonalizeCGS1() > [0]PETSC ERROR: #6 BVOrthogonalizeGS() > [0]PETSC ERROR: #7 BVOrthonormalizeColumn() > [0]PETSC ERROR: #8 EPSFullLanczos() > [0]PETSC ERROR: #9 EPSSolve_KrylovSchur_Symm() > [0]PETSC ERROR: #10 EPSSolve()
Is this with SLEPc 3.8? In SLEPc 3.8 we relaxed this check so I would suggest trying with it. Jose
