[petsc-users] TimeStepper norm problems. EMIL Please read this

[Lisandro Dalcin]

On 24 March 2015 at 18:40, Emil Constantinescu <emconsta at mcs.anl.gov> wrote:
>> Of course, though my B-D is order 2, and as you said, it is the just
>> for the estimator.
>>
>>> if the time step varies wildly (can be easily constrained),
>>> it may create some problems with the estimator.
>>>
>>
>> Indeed, the default clipping 0.1,10 is usually too wide, I usually do
>> -ts_adapt_basic_clip 0.5,2.0
>
>
> The limits are a bit more strict for BDF2, but that's for the worst case and
> no filtering. So that looks good too.

I'm not sure I'm following you 100%. Please note I'm not using BDF2 in
the usual sense, what I do is to compute an A POSTERIORI error
estimator using a BD of order 2 to estimate LTE^{n+1} with the
solution vectors U^{n+1}, U^{n} and U^{n-1}, and this is AFTER
computing U^{n-1}.


-- 
Lisandro Dalcin
============
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