[petsc-users] TS problem: runge-kutta gives 0 step-length

[Matthew Knepley]

On Tue, Apr 12, 2011 at 5:02 AM, Juha Jäykkä <juhaj at iki.fi> wrote:

> Hi list!
>
> I have a small problem with running a TS program with -ts_type runge-kutta.
> It
> keeps telling me
>
> Very small steps: 0.000000
>
> from the very beginning and never gets anywhere. The programs works fine
> for
> other TS types (well, at least euler, beuler, cn and gl).
>
> I am out of ideas as to why this happens. I even checked the RK source
> code.
> Any ideas?
>

Yes, the debugger to look at what happens when it chooses the new timestep.
This
is dependent on parameters you pass in (rk->maxerror, rk->p, ts->max_time).

    Matt


> Cheers,
> Juha
>



-- 
What most experimenters take for granted before they begin their experiments
is infinitely more interesting than any results to which their experiments
lead.
-- Norbert Wiener
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