<div class="gmail_quote">On Thu, Oct 27, 2011 at 06:44, behzad baghapour <span dir="ltr"><<a href="mailto:behzad.baghapour@gmail.com">behzad.baghapour@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<div id=":29k">2- page 120 of PETSc manual (TS): "For location-dependent pseudo-timestepping, the interface function has not yet been created."<br>
Is there any way to control time-step locally? (This is due to variable time updating usually needed in PDE solution)<br></div></blockquote></div><br><div>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).</div>