[petsc-users] TSSetIJacobian is never called

Matthew Knepley knepley at gmail.com
Mon Oct 27 13:43:14 CDT 2014 

On Mon, Oct 27, 2014 at 1:40 PM, Sharp Stone <thronesf at gmail.com> wrote:

> Hi Matt,
>
> Thank you very much for your reply.
>
> The ts_view output is attached below. I found my code results say "SNES
> has not been set up", and PC "has not been set up". Does this cause the
> problem? If so I do not see example ex17 explicitly set up the snes object?
>

Never ever ever send part of an error message. Send the entire thing copied
from the terminal.


> PS: I don't know why the -ts_view option does not work in my command line,
> so I use TSView() routine just before the TSSolve() routine.
>

Always check the return code from all calls. One of your calls is failing
and you do not notice.

  Matt


>
>
>
> TS output:
>
> TS Object: 1 MPI processes
>   type: theta
>   maximum steps=100000000
>   maximum time=5e-06
>   total number of nonlinear solver iterations=0
>   total number of nonlinear solve failures=0
>   total number of linear solver iterations=0
>   total number of rejected steps=0
>     Theta=1
>     Extrapolation=no
>   SNES Object:   1 MPI processes
>     type: newtonls
>     SNES has not been set up so information may be incomplete
>     maximum iterations=50, maximum function evaluations=10000
>     tolerances: relative=1e-08, absolute=1e-50, solution=1e-08
>     total number of linear solver iterations=0
>     total number of function evaluations=0
>     SNESLineSearch Object:     1 MPI processes
>       type: bt
>         interpolation: cubic
>         alpha=1.000000e-04
>       maxstep=1.000000e+08, minlambda=1.000000e-12
>       tolerances: relative=1.000000e-08, absolute=1.000000e-15,
> lambda=1.000000e-08
>       maximum iterations=40
>     KSP Object:     1 MPI processes
>       type: gmres
>         GMRES: restart=30, using Classical (unmodified) Gram-Schmidt
> Orthogonalization with no iterative refinement
>         GMRES: happy breakdown tolerance 1e-30
>       maximum iterations=10000, initial guess is zero
>       tolerances:  relative=1e-05, absolute=1e-50, divergence=10000
>       left preconditioning
>       using DEFAULT norm type for convergence test
>     PC Object:     1 MPI processes
>       type: ilu
>       PC has not been set up so information may be incomplete
>         ILU: out-of-place factorization
>         0 levels of fill
>         tolerance for zero pivot 2.22045e-14
>         using diagonal shift on blocks to prevent zero pivot [INBLOCKS]
>         matrix ordering: natural
>       linear system matrix = precond matrix:
>       Mat Object:       1 MPI processes
>         type: seqaij
>         rows=20904, cols=20904, bs=4
>         total: nonzeros=410816, allocated nonzeros=410816
>         total number of mallocs used during MatSetValues calls =0
>           using I-node routines: found 5226 nodes, limit used is 5
>
>
>
> On Mon, Oct 27, 2014 at 2:13 PM, Matthew Knepley <knepley at gmail.com>
> wrote:
>
>> On Mon, Oct 27, 2014 at 1:11 PM, Sharp Stone <thronesf at gmail.com> wrote:
>>
>>> Hi Matt,
>>>
>>> Thank you for your reply.
>>>
>>> That's why I am confused and need help. I set printf routines as I run
>>> my code, but it never output it on the screen.
>>>
>>
>> Here is one point of confusion:
>>
>>   1) TSSetIJacobian() sets a callback routine for creating the Jacobian.
>> This was definitely called
>>
>>   2) FormIJacobian() is your function which I assume creates the
>> Jacobian. This is what I think you are saying is not called.
>>
>> Not all TS solvers use a linear solve. Your first step is to run with
>> -ts_view so that we can see what solver is actually being used.
>>
>>    Matt
>>
>>
>>> Thanks!
>>>
>>> On Mon, Oct 27, 2014 at 2:05 PM, Matthew Knepley <knepley at gmail.com>
>>> wrote:
>>>
>>>> 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
>>>>
>>>
>>>
>>>
>>> --
>>> 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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