Hi Hong, > On 6 Nov 2015, at 16:09, Hong <[email protected]> wrote: > > Denis: > Do you use shift-and-invert method for solving eigenvalue problem? no, it’s just shift with zero value. So for GHEP one inverts B-matrix.
> If so, the linear problems would be extremely ill-conditioned, for which the > direct solver, such LU or Cholesky are usually the only working option. Depends on the shift, i would say. In any case the same problem works with jacobi preconditioner no no other changes, so i would not relate it to any settings on SLEPc part. > You may run your petsc/slepc code with option '-ksp_monitor' to observe > convergence behavior. Will do, thanks. Regards, Denis.
