[petsc-users] TSSetIJacobian is never called

[Matthew Knepley]

On Mon, Oct 27, 2014 at 1:02 PM, Sharp Stone <thronesf at gmail.com> wrote:

> Hi Matt,
>
> Thank you for your reply and sorry for the confusion.
>
> No. What I was trying to say is my code has never called the
> TSSetIJacobian() routine. I don't know why this happens, and how to resolve
> this either.
>

If your code has not called TSSetIJacobian(), I can only assume it is
because you did not put it in. However, in
the code fragment you sent, it was definitely there.

  Thanks,

    Matt


> Thank you in advance!
>
> On Mon, Oct 27, 2014 at 1:57 PM, Matthew Knepley <knepley at gmail.com>
> wrote:
>
>> On Mon, Oct 27, 2014 at 12:52 PM, Sharp Stone <thronesf at gmail.com> wrote:
>>
>>> Dear All,
>>>
>>> I'm using the TS theta solver for backward Euler method. But I found
>>> that the TSSetIJacobian() routine has never been called. I did the code
>>> just following what the example does: src/ts/examples/tutorials/ex17. I can
>>> run the example without errors. But when I run my code, it won't be as good
>>> as the example as stated above. I also attached the piece of my setups to
>>> this email.
>>>
>>> How could I fix this problem? Thank you in advance!
>>>
>>
>> I cannot understand the paragraph above.
>>
>>   1) TS ex17 does call TSSetIJacobian(), unless you choose a matrix-free
>> version. You seem to imply above that it does not.
>>
>>   2) Do you mean that you do not call it? You do not have too, since you
>> can use the finite difference approximations offered by SNES
>>
>>   Thanks,
>>
>>     Matt
>>
>>
>>>
>>>     TSCreate(PETSC_COMM_WORLD, &ts);
>>>     TSSetProblemType(ts, TS_NONLINEAR);
>>>     TSSetType(ts, TSTHETA);
>>>     TSThetaSetTheta(ts, 1.0);
>>>     TSSetIFunction(ts, NULL, FormIFunction, &appctx);
>>>     DMSetMatType(da, MATAIJ);
>>>     DMCreateMatrix(da, &J);
>>>     TSSetDM(ts, da);
>>>     TSSetIJacobian(ts, J, J, FormIJacobian, &appctx);
>>>     TSSetDuration(ts, timeStepsMax, Tend);
>>>     // Evaluate initial conditions
>>>     FormInitialSolution(&appctx);
>>>     TSSetSolution(ts, solution);
>>>     dt = 1.0;
>>>     TSSetInitialTimeStep(ts, 0.0, dt);
>>>     TSSolve(ts, solution);
>>>
>>> --
>>> Best regards,
>>>
>>> Feng
>>>
>>
>>
>>
>> --
>> 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
>>
>
>
>
> --
> Best regards,
>
> Feng
>



-- 
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
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