[petsc-users] monitoring the convergence of fieldsplit 0 and 1

[Barry Smith]

   Chris,

     It appears you should call PCFieldSplitGetSubKSP() and then get the information you want out of the individual KSPs. If this doesn't work please let us know.

   Barry

> On Apr 10, 2015, at 6:48 AM, Klaij, Christiaan <C.Klaij at marin.nl> wrote:
> 
> A question when using PCFieldSplit: for each linear iteration of
> the system, how many iterations for fielsplit 0 and 1?
> 
> One way to find out is to run with -ksp_monitor,
> -fieldsplit_0_ksp_monitor and -fieldsplit_0_ksp_monitor. This
> gives the complete convergence history.
> 
> Another way, suggested by Matt, is to use -ksp_monitor,
> -fieldsplit_0_ksp_converged_reason and
> -fieldsplit_1_ksp_converged_reason. This gives only the totals
> for fieldsplit 0 and 1 (but without saying for which one).
> 
> Both ways require to somehow process the output, which is a bit
> inconvenient. Could KSPGetResidualHistory perhaps return (some)
> information on the subsystems' convergence for processing inside
> the code?
> 
> Chris
> 
> 
> dr. ir. Christiaan Klaij
> CFD Researcher
> Research & Development
> E mailto:C.Klaij at marin.nl
> T +31 317 49 33 44
> 
> 
> MARIN
> 2, Haagsteeg, P.O. Box 28, 6700 AA Wageningen, The Netherlands
> T +31 317 49 39 11, F +31 317 49 32 45, I www.marin.nl
>