[petsc-users] TSBDF prr-load higher order solution

[Jed Brown]

Can you restart using small low-order steps?

Hong, does (or should) your trajectory stuff support an exact checkpointing scheme for BDF?

I think we could add an interface to access the stored steps, but there are few things other than checkpointing that would make sense mathematically. Would you be up for making a merge request to add TSBDFGetStepVecs(TS ts, PetscInt *num_steps, const PetscReal **times, const Vec *vecs) and the respective setter? 

Alfredo J Duarte Gomez <aduarteg at utexas.edu> writes:

> Good morning PETSC team,
>
> I am currently using a TSBDF object, which is working very well.
>
> However, I am running into trouble restarting higher order BDF methods.
>
> My problem is highly nonlinear, and when restarted for higher order BDF
> methods (using the TSBDF_Restart function), wiggles appear in a specific
> region of the solution.
>
> Is there any way I can initialize the higher order BDF restart loading
> previous solutions from a data file? I took a look at the code, but there
> is no obvious way to do this.
>
> Thanks,
>
> -Alfredo
>
> -- 
> Alfredo Duarte
> Graduate Research Assistant
> The University of Texas at Austin