[petsc-users] KspTrueResidualNorm

[Barry Smith]

   The simplest thing is to simply run with -ksp_monitor_true_residual and see how the convergence is going in the true residual norm also.

   You can also switch to right preconditioning with gmres and then the residual used by gmres is the true residual norm.  Use -ksp_preconditioner_side right -ksp_norm_type unpreconditioned

   Barry



On Feb 1, 2011, at 2:14 PM, Ataollah Mesgarnejad wrote:

> Dear all,
> 
> I'm using Ksp gmres with boomeramg preconditioning and I suspect that even though it converges in preconditioned norm it doesn't converge in true norm, but as I understand KSPSetNormType gmres does not support true residual norm? Is that correct and If it is, is there any other way to monitor the true norm? Do I need to Introduce my own convergence test?
> 
> Best,
> A. Mesgarnejad