[petsc-users] strange TS adaptivity behavior

[Jed Brown]

Mark Adams <mfadams at lbl.gov> writes:

> On Mon, Apr 6, 2020 at 3:47 PM Jed Brown <jed at jedbrown.org> wrote:
>
>> This typically happens when your model is discontinuous or you activate
>> some fast transitien.  You have a really aggressive lower bound on your
>> time step so its hard to tell here.
>>
>
> The time step goes down to like 1e-3.
> I am suspecting that my source term needs to be smoother and am working on
> that now.
> It is disconcerting that the truncation error goes up as the time stp is
> reduced, but in this example it does start to go down again.

If you increase resolution at differentiating a discontinuity, you'd
expect to become more and more confident that the error is large.