[petsc-users] SNESSetJacobian and TSSetRHSJacobian

[Zou (Non-US), Ling]

Thank you Peter.

Can I simply ignore this step:

TSSetRHSJacobian(ts, J, J, SNESDefaultComputeJacobian, PETSC_NULL);


And get the SNES context from TS, then set the Jacobian option this way:

SNES snes;

TSGetSNES(ts, &snes);

SNESSetJacobian(snes, J, J, SNESDefaultComputeJacobian, PETSC_NULL);


(Guess my last email didn't work well)


Ling



On Wed, May 22, 2013 at 3:17 PM, Peter Brune <prbrune at gmail.com> wrote:

> This may be done with the command-line option:
>
> -snes_fd
>
> - Peter
>
>
> On Wed, May 22, 2013 at 4:03 PM, Zou (Non-US), Ling <ling.zou at inl.gov>wrote:
>
>> Hi All,
>>
>> In 'SNESSetJacobian' I could pass 'SNESDefaultComputeJacobian' to let
>> PETSc do the finite differencing for me to calculate Jacobian, i.e.,
>>
>> SNESSetJacobian(snes, J, J, SNESDefaultComputeJacobian, PETSC_NULL);
>>
>>
>> In TSSetRHSJacobian, this options seems to be invalid, i.e., it requires
>> a function to evaluate the Jacobian, i.e.,
>>
>>
>> TSSetRHSJacobian(ts, J, J, FormRHSJacobian, PETSC_NULL);
>>
>>
>> Is it possible that TS could also use PETSc finite differencing Jacobian
>> as SNES does?
>>
>>
>> Best,
>>
>>
>> Ling
>>
>
>
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