Actually I want to update the domain according to the global CFL number; e.g. dt = CFL * dx / Lambda; separately for each cell ( dx is the dimension of the cell and Lambda is the local maximum eigenvalue of the field )
So, here shift is the maximum time step and I should adjust other cells to this maximum value? Thanks, On Thu, Oct 27, 2011 at 5:49 PM, Jed Brown <jedbrown at mcs.anl.gov> wrote: > 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). > -- ================================== Behzad Baghapour Ph.D. Candidate, Mechecanical Engineering University of Tehran, Tehran, Iran https://sites.google.com/site/behzadbaghapour Fax: 0098-21-88020741 ================================== -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20111027/807b3418/attachment.htm>
