About unpreconditioned residuals in Left Preconditioned GMRES

[Dave May]

Hi,
    You can use the function

PetscErrorCode PETSCKSP_DLLEXPORT KSPSetConvergenceTest(KSP
ksp,PetscErrorCode
(*converge)(KSP,PetscInt,PetscReal,KSPConvergedReason*,void*),void
*cctx)

to define your own convergence test.

Cheers,
    Dave.





2008/2/2 jiaxun hou <jiaxun_hou at yahoo.com.cn>:

> Hi everyone,
>
> I want to use the Left Preconditioned GMRES to solve a linear system, and
> the stopping criterion  must  be  based on the  actual residuals (b-Ax). But
> the  GMRES codes of PETSc seems to use the preconditioned residuals
> (B^-1(b-Ax)) only. In addition,  when I set
> KSPSetNormType(ksp,KSP_NORM_UNPRECONDITIONED), I receive the error message:
> "Currently can use GMRES with only preconditioned residual (right
> preconditioning not coded)". So, is there any way to set stopping criterion
> based on the actual residuals?
>
> Best regards,
> Jiaxun
>
> ------------------------------
> 雅虎邮箱传递新年祝福，个性贺卡送亲朋！<http://cn.mail.yahoo.com/gc/index.html?entry=5&souce=mail_mailletter_tagline>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20080203/0f526776/attachment.htm>