[petsc-users] Modification to ex11.c

[Mark Adams]

Just to be clear, you seem to be suggesting adding an interface for this
and/or code to clone?

On Fri, Apr 17, 2020 at 11:08 AM Matthew Knepley <knepley at gmail.com> wrote:

> On Fri, Apr 17, 2020 at 10:58 AM Mark Adams <mfadams at lbl.gov> wrote:
>
>> Line 1528 of dmplexsnes.c ?
>>
>
> Yes. This is where we add in u_t, so it would make sense to also add in
> the source term here. If it were a function of t, s(t), you would
> just add vol*s(t).
>
>   Thanks,
>
>     Matt
>
>
>> On Fri, Apr 17, 2020 at 10:41 AM Matthew Knepley <knepley at gmail.com>
>> wrote:
>>
>>> Tried it again and works for me.
>>>
>>>    Matt
>>>
>>> On Fri, Apr 17, 2020 at 10:39 AM Mark Adams <mfadams at lbl.gov> wrote:
>>>
>>>> Matt, that kink seems messed up.
>>>>
>>>> On Fri, Apr 17, 2020 at 9:18 AM Matthew Knepley <knepley at gmail.com>
>>>> wrote:
>>>>
>>>>> Mark is right, you could just add in a source term for each cell this
>>>>> way.
>>>>>
>>>>> If you really wanted a lower level interface, it would go here I think:
>>>>>
>>>>>
>>>>> https://gitlab.com/petsc/petsc/-/blob/master/src/snes/utils/dmplexsnes.c#L1528
>>>>>
>>>>> What would you want the interface to look like?
>>>>>
>>>>>   Thanks,
>>>>>
>>>>>     Matt
>>>>>
>>>>> On Fri, Apr 17, 2020 at 7:55 AM Mark Adams <mfadams at lbl.gov> wrote:
>>>>>
>>>>>> You can write your own DMPlexTSComputeRHSFunctionFVM method like this
>>>>>> and give that to the dm.
>>>>>>
>>>>>> PetscErrorCode foo(DM dm, PetscReal time, Vec locX, Vec F, void *user)
>>>>>> {
>>>>>>   PetscErrorCode ierr;
>>>>>>   PetscFunctionBegin;
>>>>>>   ierr = DMPlexTSComputeRHSFunctionFVM(dm, time, locX, F, user);CHKERRQ(ierr);
>>>>>> ...
>>>>>>
>>>>>>   PetscFunctionReturn(0);
>>>>>> }
>>>>>>
>>>>>>
>>>>>> On Fri, Apr 17, 2020 at 5:28 AM MUKKUND SUNJII <
>>>>>> mukkundsunjii at gmail.com> wrote:
>>>>>>
>>>>>>> Greetings,
>>>>>>>
>>>>>>> I had been working on ts/tutorials/ex11.c as part of my master’s
>>>>>>> thesis.
>>>>>>>
>>>>>>> In ex11.c, there is a 2D Shallow Water Model. I want to modify the
>>>>>>> model by adding a source term to the model. This source term would factor
>>>>>>> in the effects of bathymetry or bed elevation in addition to water height.
>>>>>>>
>>>>>>> I know how I will be able to achieve this if just use
>>>>>>> TSSetRHSFunction(). However ex11.c makes use of the Riemann Solver for the
>>>>>>> computation fluxes at the interfaces (therefore, it uses
>>>>>>> DMTSSetRHSFunctionLocal(dm, DMPlexTSComputeRHSFunctionFVM, user) ).
>>>>>>>
>>>>>>> Is there a routine that allows me to *add* a source term *for every
>>>>>>> cell* to the RHS function?
>>>>>>>
>>>>>>> Thank you in advance!
>>>>>>>
>>>>>>> Regards,
>>>>>>>
>>>>>>> Mukkund
>>>>>>>
>>>>>>
>>>>>
>>>>> --
>>>>> 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
>>>>>
>>>>> https://www.cse.buffalo.edu/~knepley/
>>>>> <http://www.cse.buffalo.edu/~knepley/>
>>>>>
>>>>
>>>
>>> --
>>> 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
>>>
>>> https://www.cse.buffalo.edu/~knepley/
>>> <http://www.cse.buffalo.edu/~knepley/>
>>>
>>
>
> --
> 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
>
> https://www.cse.buffalo.edu/~knepley/
> <http://www.cse.buffalo.edu/~knepley/>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20200417/d2f10070/attachment.html>