[petsc-dev] Fwd: Is there any example that allows time-integration provided by users

[Jed Brown]

Yes, but even more than linear fieldsplit, there are _many_ variations,
involving nonlinear change of basis and various types of elimination. I
worry that it may be even more complicated and harder to use.


On Thu, Dec 13, 2012 at 9:15 AM, Barry Smith <bsmith at mcs.anl.gov> wrote:

>
>   We could possibly provide the equivalent of PCFieldSplit for nonlinear
> problems?  These could be accelerated via the various non-linear
> accelerates or even via matrix-free Newton?
>
>
>    Barry
>
>
> Begin forwarded message:
>
> *From: *Jed Brown <jedbrown at mcs.anl.gov>
> *Subject: **Re: Is there any example that allows time-integration
> provided by users*
> *Date: *December 13, 2012 11:06:29 AM CST
> *To: *Lulu Liu <lulu.liu at kaust.edu.sa>, Barry Smith <bsmith at mcs.anl.gov>
>
> It sounds like you want to do classical operator splitting (which is
> notoriously inaccurate). The literature on these methods is rife with
> special-purpose band-aids that I'd rather not try to support all of in
> PETSc.
>
> My preference would be to write your method as an ARKIMEX, with "trivial"
> implicit part on the "part" of the equation that you wanted to treat
> explicitly, or if you wanted to solve both implicitly (but decoupled) then
> do the appropriate incomplete solve. Can you be more specific about what
> problem you want to solve?
>
>
> On Wed, Dec 12, 2012 at 7:42 AM, Lulu Liu <lulu.liu at kaust.edu.sa> wrote:
>
>> There is two equations in my system, and I want solve the first one, and
>> then solve the second equation. Is there any example that allows me to
>> solve equations one by one?
>>
>>
>> I want to solve nonlinear system on every time level, but it is feasible
>> if I could provide the time discretization schemes by myself. Is there any
>> example about this?
>>
>> Thank you!
>>
>> --
>>  Best wishes,
>> Lulu Liu
>> Applied Mathematics and Computational Science
>> King Abdullah University of Science and Technology
>> Tel：＋966－0544701599
>>
>>
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>
>
>
>
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