[petsc-dev] KSP rtol

[Mark F. Adams]

Mark

On Dec 14, 2011, at 1:57 PM, Matthew Knepley wrote:

> On Wed, Dec 14, 2011 at 12:45 PM, Mark F. Adams <mark.adams at columbia.edu> wrote:
> I have a nonlinear problem and am finding the the convergence test for the interior PETSc linear solver is apparently testing against the norm of the first linear solve (see appended).  This is clearly not what anyone would want, is this the intended semantics?  Is there perhaps a method to reset rtol?
> 
> -snes_view -ksp_view?
> 
>   Matt
>  
> Mark
> 
> Picard iteration 0 max(resid) = 781020
>  0 KSP Residual norm 2.499264167662e+07
>  1 KSP Residual norm 6.330915810095e+06
>  2 KSP Residual norm 1.856999435466e+06
>  3 KSP Residual norm 3.967325725053e+05
>  4 KSP Residual norm 9.037332775808e+04
>  5 KSP Residual norm 1.826960320400e+04
> Linear solve converged due to CONVERGED_RTOL iterations 5
> Picard iteration 1 max(resid) = 727577 ------- Rate = 1.07345
>  0 KSP Residual norm 6.885328126772e+06
>  1 KSP Residual norm 2.150319244570e+06
>  2 KSP Residual norm 2.297759417371e+05
>  3 KSP Residual norm 3.321819214451e+04
>  4 KSP Residual norm 4.155970071625e+03
> Linear solve converged due to CONVERGED_RTOL iterations 4
> Picard iteration 2 max(resid) = 486788 ------- Rate = 1.49465
>  0 KSP Residual norm 2.987417661953e+06
>  1 KSP Residual norm 5.046119985008e+05
>  2 KSP Residual norm 3.882757664605e+04
>  3 KSP Residual norm 4.106091678345e+03
> Linear solve converged due to CONVERGED_RTOL iterations 3
> Picard iteration 3 max(resid) = 137348 ------- Rate = 3.54418
>  0 KSP Residual norm 7.285359985607e+05
>  1 KSP Residual norm 9.132700545850e+04
>  2 KSP Residual norm 6.834608381922e+03
> Linear solve converged due to CONVERGED_RTOL iterations 2
> Picard iteration 4 max(resid) = 25082.7 ------- Rate = 5.47582
>  0 KSP Residual norm 1.207523847817e+05
>  1 KSP Residual norm 1.286174706329e+04
> Linear solve converged due to CONVERGED_RTOL iterations 1
> Picard iteration 5 max(resid) = 5723.21 ------- Rate = 4.38264
>  0 KSP Residual norm 2.211945822133e+04
> Linear solve converged due to CONVERGED_RTOL iterations 0
> 
> 
> 
> 
> -- 
> What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead.
> -- Norbert Wiener

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-dev/attachments/20111214/22da4021/attachment.html>
-------------- next part --------------
An embedded and charset-unspecified text was scrubbed...
Name: out.txt
URL: <http://lists.mcs.anl.gov/pipermail/petsc-dev/attachments/20111214/22da4021/attachment.txt>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-dev/attachments/20111214/22da4021/attachment-0001.html>