[petsc-dev] [petsc-users] Any suggestion for this kinds of matrix?

[Barry Smith]

   Maybe in the debug version of PETSc -ksp_monitor should turn on true residual monitoring? 

   Barry

On Nov 10, 2011, at 2:49 PM, Jed Brown wrote:

> On Thu, Nov 10, 2011 at 14:45, Bao Kai <paeanball at gmail.com> wrote:
> PCFIELDSPLIT seems a little more complex, I will try that. 
> 
> I tried some different preconditioners, only lu can get right results. 
> 
> With some pc, some wrong results can be obtained, such as the following one.  
> 
> tutorials]$ time ./ex78 -Ain A_in -rhs rhs -solu solu -noshift -pc_type hypre -pc_hypre_type parasails -ksp_gmres_restart 600 -ksp_rtol 1e-5 -ksp_typ gmres
> 
> Always run with -ksp_monitor_true_residual -ksp_converged_reason when checking whether a preconditioner is working.