[petsc-users] Adaptive controllers in TS

[Miguel Angel Salazar de Troya]

That might be a reasonable argument, but I'm not sure. This is one of the
papers that explains it. I'm re-reading to see if I skipped any details:

http://www.sciencedirect.com/science/article/pii/S0377042709006062

Miguel

On Mon, Oct 20, 2014 at 11:42 PM, Jed Brown <jed at jedbrown.org> wrote:

> Miguel Angel Salazar de Troya <salazardetroya at gmail.com> writes:
>
> > Thanks for your response
> >
> > I'm struggling with this problem because the literature is not clear for
> me
> > on how to calculate the discrete adjoint with adaptive time stepping
> > algorithms. They cover the details when automatic differentiation tools
> are
> > used. They mention that because the time step depend on the solution, it
> > also depends on the parameter. Hence, there are terms that represent the
> > derivative of the time step w.r.t. the parameters. What it is confusing
> is
> > that they mention these terms must be removed. I don't understand this.
> I'm
> > planning to hard-code the discrete adjoint problem (and use the TS if
> > possible).
>
> Are they suggesting that the time step sizes for a given run should be
> frozen (at least locally) so that you have consistent gradients for a
> while?
>



-- 
*Miguel Angel Salazar de Troya*
Graduate Research Assistant
Department of Mechanical Science and Engineering
University of Illinois at Urbana-Champaign
(217) 550-2360
salaza11 at illinois.edu
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20141021/90599d44/attachment.html>