[petsc-users] Any TSGL examples, or higher order BDFs?

[Mark Lohry]

Thanks Jed. I'm not terribly familiar with those mixed implicit/explicit 
methods; are they appropriate for fully implicit solutions by just 
setting the explicit part to 0? (I realize that's more a math question 
than a petsc one)

-Mark


On 04/24/2015 11:20 AM, Jed Brown wrote:
> Mark Lohry <mlohry at princeton.edu> writes:
>
>> I'd like to use a 3rd+ order BDF with TS, which appears to only have 1st
>> order (backward euler/TSBEULER), and then the bindings to SUNDIALS.
> What about TSARKIMEX, TSROSW, and TSEIMEX?  These are really the methods
> we recommend.
>
>> I'd like to avoid SUNDIALS as it looks like it forces the use of it's
>> own non-linear solvers.
> Yeah.
>
>> Am I correct in thinking the preferred way to construct a BDF with TS is
>> to use TSGL? Are there any examples of TSGL in use? I'm not seeing any
>> in the docs.
> You can use -ts_type gl, but I haven't worked with those methods in a
> long time and they have not been robust in practice.  I recommend using
> ROSW as a default.