[petsc-users] Change SNES/TS setting from inside context

[Jed Brown]

On Thu, Oct 27, 2011 at 06:44, behzad baghapour
<behzad.baghapour at gmail.com>wrote:

> 2- page 120 of PETSc manual (TS): "For location-dependent
> pseudo-timestepping, the interface function has not yet been created."
> Is there any way to control time-step locally? (This is due to variable
> time updating usually needed in PDE solution)
>

The documentation needs to be updated. Use TSSetIJacobian() and regard the
"shift" as a maximum shift (corresponds to minimum time step). If you have a
cell in which you want to take a 10x longer time step, then use shift/10 in
that cell. Note that you can use steady-state constraints on some fields.
For example, src/ts/examples/tutorials/ex26.c (in petsc-dev) uses no shift
for the velocity components (enforces incompressibility in
velocity-vorticity form).
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20111027/ad64d360/attachment.htm>