[petsc-users] Automatic Differentiation

[Matthew Knepley]

On Tue, Jun 2, 2015 at 4:05 PM, Harshad Sahasrabudhe <hsahasra at purdue.edu>
wrote:

> I haven't tried the FD Jacobian. How do I enable that? I have been
> providing the Jacobian.
>

Just do not provide the Jacobian. It will turn on.

  Thanks,

     Matt


> On Tue, Jun 2, 2015 at 4:59 PM, Matthew Knepley <knepley at gmail.com> wrote:
>
>> On Tue, Jun 2, 2015 at 3:55 PM, Harshad Sahasrabudhe <hsahasra at purdue.edu
>> > wrote:
>>
>>> Hi,
>>>
>>> Does PETSc have automatic differentiation capability? I'm solving an
>>> elliptic non-linear equation in which calculating the correct Jacobian is
>>> extremely demanding. The system doesn't converge with an approximate
>>> Jacobian. Is there any SNES solver I should try which doesn't use a
>>> Jacobian?
>>>
>>
>> Do you mean it does not converge with the default FD Jacobian?
>>
>>   Matt
>>
>>
>>> Thanks,
>>> Harshad
>>>
>>
>>
>>
>> --
>> 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
>>
>
>


-- 
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
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20150602/e90e39fd/attachment.html>