<div class="gmail_quote">On Fri, Nov 11, 2011 at 08:29, Juha Jäykkä <span dir="ltr"><<a href="mailto:juhaj@iki.fi">juhaj@iki.fi</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<div id=":1tb">Right. I just may need them for my boundary conditions: they depend on time<br>
derivatives, i.e. change in value of something between time steps. It may be<br>
necessary to compute those values separately for each substep, but I am not<br>
sure yet. I am just making sure I have easy access to them - from your answer<br>
it looks like I need to hard code them.</div></blockquote></div><br><div>We pass in the time of the stage when your RHSFunction is called. If you haven't eliminated boundary conditions, your system is likely differential-algebraic, in which case you can use the IFunction interface with an implicit or IMEX method (e.g. TSARKIMEX, TSROSW). This has been improved in petsc-dev, so consider using it if you want the latest adaptivity and IMEX features.</div>