[firedrake] NonlinearVariationalSolver

[Anna Kalogirou]

Hello,

Can someone of you please check the way I use NonlinearVariationalSolver 
in the code attached? The code runs but the result is a bit odd. In 
addition, in the screen it writes

pyop2:INFO Solving linear variational problem...

and I am suspecting it might be solving the corresponding linear problem 
instead of the nonlinear one.

Thank you very much.

Best, Anna.



On 11/11/14 12:31, Lawrence Mitchell wrote:
> Hi Anna,
>
> On 10/11/14 20:25, Lawrence Mitchell wrote:
>> Hi Anna,
>>
>> On 10 Nov 2014, at 19:39, Anna Kalogirou <a.kalogirou at leeds.ac.uk>
>> wrote:
>>
>>> Hi Lawrence,
>>>
>>> Does it matter that I am solving a linear problem with the
>>> nonlinear solver? I am just trying to reproduce the linear one that
>>> works first, before introducing the nonlinear terms. I tried also
>>> adding the parameter {'snes_type': 'ksponly'} and the code works,
>>> but the result is not as good.
>>>
>>> Do you have any idea what might be happening?
>>>
>>> P.S. The linear code can be found attached.
>>
>> Thanks, I think I have found the problem, it is not in your code.
>> The problem appears to be a subtle issue in which we interact with
>> PETSc, which means that it is not computing the initial residual
>> correctly.  I will prepare a fix tomorrow and let you know when
>> things are fixed.
> I've now fixed the problem.  If you reinstall PyOP2 (I guess with pip,
> if you followed the website instructions) your nonlinear problem should
> now run fine.
>
> Let us know if you have any problems.
>
> Cheers,
>
> Lawrence

-- 
  
  Dr Anna Kalogirou
  Research Fellow
  School of Mathematics
  University of Leeds

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