[petsc-users] Question about Pseudo Time Stepping

[Barry Smith]

  What code are you running? So we can run a reproducer.


> On Aug 26, 2025, at 4:21 AM, Aldo Bonfiglioli <aldo.bonfiglioli at unibas.it> wrote:
> 
> Hi there,
> 
> I am using -ts_type pseudo to find steady solutions of the Euler/NS PDEs.
> 
> It looks like FormRHSFunction is called twice with the exactly same value of the dependent variable (u)
> 
> before invoking TSRHSJacobianFn and then solving the linear system with KSP (u is then updated)
> 
> 
>> 1 TS dt 0.141197 time 0.141197 
>> Calling FormRHSFunction; ||u|| =    60.489405479528003        463.15635675129079        62.813532026019146        5.9789502719351155     
>> Calling FormRHSFunction; ||u|| =    60.489405479528003        463.15635675129079        62.813532026019146        5.9789502719351155 
>> Calling TSRHSJacobianFn with ||u|| =    60.489405479528003        463.15635675129079        62.813532026019146        5.9789502719351155 
>>      Linear solve converged due to CONVERGED_RTOL iterations 9 
>> Calling FormRHSFunction; ||u|| =    60.489405476878737        463.15635675602186        62.813532031616965        5.9789502710519811 
>> 2 TS dt 0.155917 time 0.297115 
>> Calling FormRHSFunction; ||u|| =    60.489405476878737        463.15635675602186        62.813532031616965        5.9789502710519811 
>> Calling FormRHSFunction; ||u|| =    60.489405476878737        463.15635675602186        62.813532031616965        5.9789502710519811 
>> Calling TSRHSJacobianFn with ||u|| =    60.489405476878737        463.15635675602186        62.813532031616965        5.9789502710519811
>> 
> Why is it so? Am I possibly misusing (or missing) some options?
> 
> My .petscrc file is attached.
> 
> Thank you,
> 
> Aldo
> 
> -- 
> Dr. Aldo Bonfiglioli
> Associate professor of Fluid Mechanics
> Dipartimento di Ingegneria
> Universita' della Basilicata
> V.le dell'Ateneo Lucano, 10 85100 Potenza ITALY
> tel:+39.0971.205203 fax:+39.0971.205215
> web: https://urldefense.us/v3/__http://docenti.unibas.it/site/home/docente.html?m=002423__;!!G_uCfscf7eWS!dbaOWMZSge8uqvR9TNizV3K7TdZt-gKWocxl5mk3p-3muUHHd2_c4QfE4CFLhjnmSJhr_VhecH-vFUZs6mKLlSY$  <https://urldefense.us/v3/__http://docenti.unibas.it/site/home/docente.html?m=002423__;!!G_uCfscf7eWS!ci_aySHdF2Qx_B-37IOzELFDtcQRthJ2NItK-JNbfXB0M2_21B_z97WIfjxZUyKCVRRhd1mzL6b-rnCed_i8LLA56JvFdz7JBrw$><dotpetscrc.txt>

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