[petsc-users] Step size setting in TS
Matthew Knepley
knepley at gmail.com
Sun May 7 09:52:24 CDT 2023
On Sun, May 7, 2023 at 10:43 AM Tang, Qi <tangqi at msu.edu> wrote:
> Agree. Not sure adapt_type cfl is what we want.
>
> For fully implicit, we normally increase the time step by certain percent
> when it successfully solves the problem for n time steps. While if it
> fails, we reduce time step by half and re-solve. Can we achieve something
> similar using TS adapt?
>
You can certainly write your own adaptor.I do this in TS ex53 since it has
an impulsive start, and to be accurate, I need
a first timestep that is very small and consistently so. Also the DSP is a
PID controller, so it is doing something morally similar.
Thanks,
Matt
> Qi
>
> On May 6, 2023, at 7:35 PM, Matthew Knepley <knepley at gmail.com> wrote:
>
>
> On Sat, May 6, 2023 at 7:25 PM Jorti, Zakariae via petsc-users <
> petsc-users at mcs.anl.gov> wrote:
>
>> Hello,
>>
>>
>> I have a time-dependent model that I solve using TSSolve.
>>
>> And I am trying to adaptively change the step size (dt).
>>
>> I found that there are some TSAdapt schemes already available.
>>
>> I have tried TSADAPTBASIC and TSADAPTCFL.
>>
>> The former runs without any problems, whereas the latter yields the
>> following error:
>> "
>> [0]PETSC ERROR: --------------------- Error Message
>> --------------------------------------------------------------
>> [0]PETSC ERROR: No support for this operation for this object type
>> [0]PETSC ERROR: Step rejection not implemented. The CFL implementation is
>> incomplete/unusable
>> "
>>
>>
>> How/where the step rejection should be implemented? Are there any
>> examples available?
>>
>
> I would not recommend CFL, which is partially implemented at best. The DSP
> adaptivity is great. There is a recent paper by
> David Ketcheson, Lisandro Dalcin, Matteo Parsani, and collaborators which
> shows that you can set this up to completely
> handle complicated flows, and it is much better than a simple CFL
> condition.
>
> Thanks,
>
> Matt
>
>
>> Besides, I was also attempting to change the step size through the
>> monitor:
>>
>>
>> "
>> SNES snes;
>> TSGetSNES(ts, & snes);
>> SNESConvergedReason reason = SNES_CONVERGED_ITERATING;
>> PetscCall(SNESGetConvergedReason(snes, &reason));
>>
>> if(reason < 0){
>> TSSetTimeStep(ts,28618.7);
>> }
>> else{
>> TSSetTimeStep(ts,57237.4);
>> }
>> "
>>
>> But when I try this solution, the TSStep seems to diverge even though the
>> SNES solver converges (see log file below).
>> Am I doing something wrong here by changing the value of the step size
>> inside the monitor?
>>
>>
>> Thank you.
>>
>> Best,
>>
>>
>> Zakariae
>>
>>
>>
>>
>>
>>
>>
>> -----------------------------------------------------------------
>>
>> Timestep 0: step size = 57237.4, time = 0.,
>> 0 SNES Function norm 2.854104379157e-02
>> 0 KSP Residual norm 2.854104379157e-02
>> 1 KSP Residual norm 8.393431982129e-04
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 0 KSP Residual norm 1.985106864162e-01
>> 1 KSP Residual norm 2.509248490095e-04
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 1 SNES Function norm 1.985106864162e-01
>> 0 KSP Residual norm 1.985106864162e-01
>> 1 KSP Residual norm 2.739697200542e-04
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 0 KSP Residual norm 1.885623182909e-01
>> 1 KSP Residual norm 8.784869181255e-04
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 0 KSP Residual norm 1.664114929279e-01
>> 1 KSP Residual norm 2.277701872167e-04
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 2 SNES Function norm 1.664114929279e-01
>> 0 KSP Residual norm 1.664114929279e-01
>> 1 KSP Residual norm 2.062369048201e-04
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 0 KSP Residual norm 6.155996487462e-02
>> 1 KSP Residual norm 8.830688649637e-05
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 3 SNES Function norm 6.155996487462e-02
>> 0 KSP Residual norm 6.155996487462e-02
>> 1 KSP Residual norm 6.231091742747e-05
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 0 KSP Residual norm 1.828806540636e-02
>> 1 KSP Residual norm 3.623270770725e-05
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 4 SNES Function norm 1.828806540636e-02
>> 0 KSP Residual norm 1.828806540636e-02
>> 1 KSP Residual norm 7.390325185746e-05
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 0 KSP Residual norm 1.659571588896e-02
>> 1 KSP Residual norm 5.280284947190e-05
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 5 SNES Function norm 1.659571588896e-02
>> 0 KSP Residual norm 1.659571588896e-02
>> 1 KSP Residual norm 8.311611006756e-05
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 0 KSP Residual norm 1.475636107890e-02
>> 1 KSP Residual norm 1.890387034462e-04
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 0 KSP Residual norm 1.635129206894e-02
>> 1 KSP Residual norm 8.192897103059e-05
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 6 SNES Function norm 1.635129206894e-02
>> 0 KSP Residual norm 1.635129206894e-02
>> 1 KSP Residual norm 9.049749505225e-04
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 0 KSP Residual norm 1.634946381608e-02
>> 1 KSP Residual norm 9.038879304284e-04
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 0 KSP Residual norm 1.635085731721e-02
>> 1 KSP Residual norm 9.050535714933e-04
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 7 SNES Function norm 1.635085731721e-02
>> 0 KSP Residual norm 1.635085731721e-02
>> 1 KSP Residual norm 1.248783858778e-03
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 0 KSP Residual norm 1.635003937816e-02
>> 1 KSP Residual norm 1.248746884526e-03
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 8 SNES Function norm 1.635003937816e-02
>> 0 KSP Residual norm 1.635003937816e-02
>> 1 KSP Residual norm 1.631242803481e-02
>> 2 KSP Residual norm 1.551854905139e-02
>> 3 KSP Residual norm 7.586491369138e-03
>> 4 KSP Residual norm 2.304721992110e-04
>> Linear solve converged due to CONVERGED_RTOL iterations 4
>> 0 KSP Residual norm 1.635003936717e-02
>> 1 KSP Residual norm 1.631242801091e-02
>> 2 KSP Residual norm 1.551784322549e-02
>> 3 KSP Residual norm 7.706018759197e-03
>> 4 KSP Residual norm 2.652435205967e-04
>> Linear solve converged due to CONVERGED_RTOL iterations 4
>> 9 SNES Function norm 1.282692400720e+06
>> Nonlinear solve did not converge due to DIVERGED_DTOL iterations 9
>> 0 SNES Function norm 2.854104379157e-02
>> 0 KSP Residual norm 2.854104379157e-02
>> 1 KSP Residual norm 5.698410682663e-04
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 0 KSP Residual norm 8.618385788411e-02
>> 1 KSP Residual norm 9.179214337527e-05
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 1 SNES Function norm 8.618385788411e-02
>> 0 KSP Residual norm 8.618385788411e-02
>> 1 KSP Residual norm 9.659611612697e-05
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 0 KSP Residual norm 2.763975792565e-02
>> 1 KSP Residual norm 2.674728432525e-05
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 2 SNES Function norm 2.763975792565e-02
>> 0 KSP Residual norm 2.763975792565e-02
>> 1 KSP Residual norm 1.836844517206e-05
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 0 KSP Residual norm 2.773540750989e-03
>> 1 KSP Residual norm 1.340353004310e-05
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 3 SNES Function norm 2.773540750989e-03
>> 0 KSP Residual norm 2.773540750989e-03
>> 1 KSP Residual norm 5.382019472069e-06
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 0 KSP Residual norm 3.441017533038e-04
>> 1 KSP Residual norm 5.218147408275e-07
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 4 SNES Function norm 3.441017533038e-04
>> 0 KSP Residual norm 3.441017533038e-04
>> 1 KSP Residual norm 4.811955757758e-07
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 0 KSP Residual norm 3.991606932979e-06
>> 1 KSP Residual norm 8.670005394864e-09
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 5 SNES Function norm 3.991606932979e-06
>> 0 KSP Residual norm 3.991606932979e-06
>> 1 KSP Residual norm 8.920137762569e-09
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 0 KSP Residual norm 7.982782045945e-10
>> 1 KSP Residual norm 3.185856555648e-12
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 6 SNES Function norm 7.982782045945e-10
>> Nonlinear solve converged due to CONVERGED_FNORM_RELATIVE iterations 6
>> 0 SNES Function norm 3.475518085003e-04
>> 0 KSP Residual norm 3.475518085003e-04
>> 1 KSP Residual norm 2.328087365783e-04
>> 2 KSP Residual norm 5.062641920970e-09
>> Linear solve converged due to CONVERGED_RTOL iterations 2
>> 0 KSP Residual norm 3.256441726122e-02
>> 1 KSP Residual norm 8.957860841275e-05
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 1 SNES Function norm 3.256441726122e-02
>> 0 KSP Residual norm 3.256441726122e-02
>> 1 KSP Residual norm 5.886144296665e-05
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 0 KSP Residual norm 4.876417342600e-03
>> 1 KSP Residual norm 5.064113356579e-06
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 2 SNES Function norm 4.876417342600e-03
>> 0 KSP Residual norm 4.876417342600e-03
>> 1 KSP Residual norm 7.010281488349e-06
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 0 KSP Residual norm 6.144574635801e-04
>> 1 KSP Residual norm 9.768499579865e-07
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 3 SNES Function norm 6.144574635801e-04
>> 0 KSP Residual norm 6.144574635801e-04
>> 1 KSP Residual norm 8.324370478600e-07
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 0 KSP Residual norm 8.721913471286e-06
>> 1 KSP Residual norm 1.370545428753e-08
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 4 SNES Function norm 8.721913471286e-06
>> 0 KSP Residual norm 8.721913471286e-06
>> 1 KSP Residual norm 1.353680905072e-08
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 0 KSP Residual norm 3.399977638261e-09
>> 1 KSP Residual norm 5.989016835446e-12
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 5 SNES Function norm 3.399977638261e-09
>> Nonlinear solve converged due to CONVERGED_FNORM_RELATIVE iterations 5
>> 0 SNES Function norm 2.854104379157e-02
>> 0 KSP Residual norm 2.854104379157e-02
>> 1 KSP Residual norm 1.733028652796e-04
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 0 KSP Residual norm 7.490800616133e-03
>> 1 KSP Residual norm 8.231034393757e-06
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 1 SNES Function norm 7.490800616133e-03
>> 0 KSP Residual norm 7.490800616133e-03
>> 1 KSP Residual norm 8.349300836114e-06
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 0 KSP Residual norm 1.394207859364e-04
>> 1 KSP Residual norm 5.991798196295e-08
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 2 SNES Function norm 1.394207859364e-04
>> 0 KSP Residual norm 1.394207859364e-04
>> 1 KSP Residual norm 5.941984242417e-08
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 0 KSP Residual norm 2.985895331367e-08
>> 1 KSP Residual norm 1.522240176483e-11
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 3 SNES Function norm 2.985895331367e-08
>> Nonlinear solve converged due to CONVERGED_FNORM_RELATIVE iterations 3
>> 0 SNES Function norm 1.026110861069e-03
>> 0 KSP Residual norm 1.026110861069e-03
>> 1 KSP Residual norm 1.768297003974e-04
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 0 KSP Residual norm 7.742520550463e-03
>> 1 KSP Residual norm 4.379214132544e-06
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 1 SNES Function norm 7.742520550463e-03
>> 0 KSP Residual norm 7.742520550463e-03
>> 1 KSP Residual norm 4.526371657285e-06
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 0 KSP Residual norm 2.574467856482e-05
>> 1 KSP Residual norm 2.285626422848e-08
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 2 SNES Function norm 2.574467856482e-05
>> 0 KSP Residual norm 2.574467856482e-05
>> 1 KSP Residual norm 2.274220735999e-08
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 0 KSP Residual norm 4.797870687759e-09
>> 1 KSP Residual norm 2.841037171618e-12
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 3 SNES Function norm 4.797870687759e-09
>> Nonlinear solve converged due to CONVERGED_FNORM_RELATIVE iterations 3
>> 0 SNES Function norm 2.854104379157e-02
>> 0 KSP Residual norm 2.854104379157e-02
>> 1 KSP Residual norm 5.979305049211e-05
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 0 KSP Residual norm 8.195748548281e-04
>> 1 KSP Residual norm 1.017772307359e-06
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 1 SNES Function norm 8.195748548281e-04
>> 0 KSP Residual norm 8.195748548281e-04
>> 1 KSP Residual norm 1.026961867317e-06
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 0 KSP Residual norm 1.717269750886e-06
>> 1 KSP Residual norm 4.675717893044e-10
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 2 SNES Function norm 1.717269750886e-06
>> Nonlinear solve converged due to CONVERGED_FNORM_RELATIVE iterations 2
>> 0 SNES Function norm 1.325295461903e-03
>> 0 KSP Residual norm 1.325295461903e-03
>> 1 KSP Residual norm 7.421950279125e-05
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 0 KSP Residual norm 1.330639207844e-03
>> 1 KSP Residual norm 3.764830059967e-07
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 1 SNES Function norm 1.330639207844e-03
>> 0 KSP Residual norm 1.330639207844e-03
>> 1 KSP Residual norm 3.764587772248e-07
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 0 KSP Residual norm 2.146996236879e-07
>> 1 KSP Residual norm 1.459926588396e-10
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 2 SNES Function norm 2.146996236879e-07
>> 0 KSP Residual norm 2.146996236879e-07
>> 1 KSP Residual norm 1.470407475325e-10
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 0 KSP Residual norm 2.171052440924e-11
>> 1 KSP Residual norm 1.397958787200e-15
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 3 SNES Function norm 2.171052440924e-11
>> Nonlinear solve converged due to CONVERGED_FNORM_RELATIVE iterations 3
>> 0 SNES Function norm 2.854104379157e-02
>> 0 KSP Residual norm 2.854104379157e-02
>> 1 KSP Residual norm 3.067250018894e-05
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 0 KSP Residual norm 1.608120509564e-04
>> 1 KSP Residual norm 2.171575389779e-07
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 1 SNES Function norm 1.608120509564e-04
>> 0 KSP Residual norm 1.608120509564e-04
>> 1 KSP Residual norm 2.240227170220e-07
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 0 KSP Residual norm 9.106906778906e-08
>> 1 KSP Residual norm 1.799636201836e-11
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 2 SNES Function norm 9.106906778906e-08
>> Nonlinear solve converged due to CONVERGED_FNORM_RELATIVE iterations 2
>> 0 SNES Function norm 1.418151440967e-03
>> 0 KSP Residual norm 1.418151440967e-03
>> 1 KSP Residual norm 3.515151918636e-05
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 0 KSP Residual norm 2.938727941997e-04
>> 1 KSP Residual norm 6.040565904176e-08
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 1 SNES Function norm 2.938727941997e-04
>> 0 KSP Residual norm 2.938727941997e-04
>> 1 KSP Residual norm 6.089297895562e-08
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 0 KSP Residual norm 1.093551284505e-08
>> 1 KSP Residual norm 2.891462873664e-12
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 2 SNES Function norm 1.093551284505e-08
>> Nonlinear solve converged due to CONVERGED_FNORM_RELATIVE iterations 2
>> 0 SNES Function norm 2.854104379157e-02
>> 0 KSP Residual norm 2.854104379157e-02
>> 1 KSP Residual norm 2.050867218313e-05
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 0 KSP Residual norm 3.054570961709e-05
>> 1 KSP Residual norm 4.596885059357e-08
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 1 SNES Function norm 3.054570961709e-05
>> 0 KSP Residual norm 3.054570961709e-05
>> 1 KSP Residual norm 4.828909801995e-08
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 0 KSP Residual norm 1.248104282690e-08
>> 1 KSP Residual norm 8.831951540120e-13
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 2 SNES Function norm 1.248104282690e-08
>> Nonlinear solve converged due to CONVERGED_FNORM_RELATIVE iterations 2
>> 0 SNES Function norm 1.460190420374e-03
>> 0 KSP Residual norm 1.460190420374e-03
>> 1 KSP Residual norm 1.580519450452e-05
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 0 KSP Residual norm 5.884986293527e-05
>> 1 KSP Residual norm 9.020937669734e-09
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 1 SNES Function norm 5.884986293527e-05
>> 0 KSP Residual norm 5.884986293527e-05
>> 1 KSP Residual norm 9.054367061995e-09
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 0 KSP Residual norm 1.698647259662e-09
>> 1 KSP Residual norm 1.767366286599e-13
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 2 SNES Function norm 1.698647259662e-09
>> Nonlinear solve converged due to CONVERGED_FNORM_RELATIVE iterations 2
>> 0 SNES Function norm 2.854104379157e-02
>> 0 KSP Residual norm 2.854104379157e-02
>> 1 KSP Residual norm 1.834492501580e-05
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 0 KSP Residual norm 5.663374849972e-06
>> 1 KSP Residual norm 9.752865227095e-09
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 1 SNES Function norm 5.663374849972e-06
>> 0 KSP Residual norm 5.663374849972e-06
>> 1 KSP Residual norm 1.014567990183e-08
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 0 KSP Residual norm 2.600155584863e-09
>> 1 KSP Residual norm 8.580477366667e-14
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 2 SNES Function norm 2.600155584863e-09
>> Nonlinear solve converged due to CONVERGED_FNORM_RELATIVE iterations 2
>> 0 SNES Function norm 1.479145244919e-03
>> 0 KSP Residual norm 1.479145244919e-03
>> 1 KSP Residual norm 6.804553002336e-06
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 0 KSP Residual norm 1.118291636442e-05
>> 1 KSP Residual norm 1.397149309582e-09
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 1 SNES Function norm 1.118291636442e-05
>> 0 KSP Residual norm 1.118291636442e-05
>> 1 KSP Residual norm 1.386385106529e-09
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 0 KSP Residual norm 2.800461695540e-10
>> 1 KSP Residual norm 3.217319587127e-14
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 2 SNES Function norm 2.800461695540e-10
>> Nonlinear solve converged due to CONVERGED_FNORM_RELATIVE iterations 2
>> 0 SNES Function norm 2.854104379157e-02
>> 0 KSP Residual norm 2.854104379157e-02
>> 1 KSP Residual norm 1.776151497065e-05
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 0 KSP Residual norm 1.076105708636e-06
>> 1 KSP Residual norm 2.155085223926e-09
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 1 SNES Function norm 1.076105708636e-06
>> Nonlinear solve converged due to CONVERGED_FNORM_RELATIVE iterations 1
>> 0 SNES Function norm 1.489507915803e-03
>> 0 KSP Residual norm 1.489507915803e-03
>> 1 KSP Residual norm 2.921538148329e-06
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 0 KSP Residual norm 2.172405782412e-06
>> 1 KSP Residual norm 2.719699969205e-10
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 1 SNES Function norm 2.172405782412e-06
>> 0 KSP Residual norm 2.172405782412e-06
>> 1 KSP Residual norm 2.731813669182e-10
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 0 KSP Residual norm 5.323734019212e-11
>> 1 KSP Residual norm 6.095298326433e-15
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 2 SNES Function norm 5.323734019212e-11
>> Nonlinear solve converged due to CONVERGED_FNORM_RELATIVE iterations 2
>> 0 SNES Function norm 2.854104379157e-02
>> 0 KSP Residual norm 2.854104379157e-02
>> 1 KSP Residual norm 1.746846293829e-05
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 0 KSP Residual norm 2.376406135686e-07
>> 1 KSP Residual norm 5.310287317591e-10
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 1 SNES Function norm 2.376406135686e-07
>> Nonlinear solve converged due to CONVERGED_FNORM_RELATIVE iterations 1
>> 0 SNES Function norm 1.497239199277e-03
>> 0 KSP Residual norm 1.497239199277e-03
>> 1 KSP Residual norm 1.251830706962e-06
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 0 KSP Residual norm 5.023668872625e-07
>> 1 KSP Residual norm 7.656373075632e-11
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 1 SNES Function norm 5.023668872625e-07
>> 0 KSP Residual norm 5.023668872625e-07
>> 1 KSP Residual norm 7.473091471413e-11
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 0 KSP Residual norm 2.003331377435e-11
>> 1 KSP Residual norm 1.347408932811e-15
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 2 SNES Function norm 2.003331377435e-11
>> Nonlinear solve converged due to CONVERGED_FNORM_RELATIVE iterations 2
>> 0 SNES Function norm 2.854104379157e-02
>> 0 KSP Residual norm 2.854104379157e-02
>> 1 KSP Residual norm 1.757419385096e-05
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 0 KSP Residual norm 7.310279661922e-08
>> 1 KSP Residual norm 1.417918576189e-10
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 1 SNES Function norm 7.310279661922e-08
>> Nonlinear solve converged due to CONVERGED_FNORM_RELATIVE iterations 1
>> 0 SNES Function norm 1.503392083665e-03
>> 0 KSP Residual norm 1.503392083665e-03
>> 1 KSP Residual norm 5.327548050375e-07
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 0 KSP Residual norm 1.611770751552e-07
>> 1 KSP Residual norm 2.611036263545e-11
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 1 SNES Function norm 1.611770751552e-07
>> 0 KSP Residual norm 1.611770751552e-07
>> 1 KSP Residual norm 2.607692240234e-11
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 0 KSP Residual norm 1.627978707015e-11
>> 1 KSP Residual norm 4.254078683385e-16
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 2 SNES Function norm 1.627978707015e-11
>> Nonlinear solve converged due to CONVERGED_FNORM_RELATIVE iterations 2
>> 0 SNES Function norm 2.854104379157e-02
>> 0 KSP Residual norm 2.854104379157e-02
>> 1 KSP Residual norm 1.747957348554e-05
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 0 KSP Residual norm 2.999731614900e-08
>> 1 KSP Residual norm 3.643836796648e-11
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 1 SNES Function norm 2.999731614900e-08
>> Nonlinear solve converged due to CONVERGED_FNORM_RELATIVE iterations 1
>> 0 SNES Function norm 1.507740473908e-03
>> 0 KSP Residual norm 1.507740473908e-03
>> 1 KSP Residual norm 2.263876724496e-07
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 0 KSP Residual norm 6.390049329095e-08
>> 1 KSP Residual norm 9.745723464126e-12
>> Linear solve converged due to CONVERGED_RTOL iterations 1
>> 1 SNES Function norm 6.390049329095e-08
>> Nonlinear solve converged due to CONVERGED_FNORM_RELATIVE iterations 1
>> [0]PETSC ERROR: --------------------- Error Message
>> --------------------------------------------------------------
>> [0]PETSC ERROR: TSStep has failed due to DIVERGED_STEP_REJECTED
>>
>>
>>
>>
>
> --
> 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
>
> https://www.cse.buffalo.edu/~knepley/
> <https://urldefense.com/v3/__http://www.cse.buffalo.edu/*knepley/__;fg!!HXCxUKc!36H7a5ZKd2HKi7feEpZgwmCpDoWsW4ZpI6xR5Ve1MWqB5XcmPQVKEmPgqG1IOzSfEcBlgPaPbSPFLg$>
>
>
--
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
https://www.cse.buffalo.edu/~knepley/ <http://www.cse.buffalo.edu/~knepley/>
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