I don't believe there's anything you can do with the solver to enforce this constraint, but you can just manually "fix" the concentration in your sweep/solve loop. This is how the "double obstacle potential" (infinite energy barrier at zero concentration) is algorithmically implemented in my field.
> On Nov 17, 2016, at 11:23 AM, Korevaar, Martin <[email protected]> > wrote: > > However, due to some numerical inaccuracies, c_f sometimes becomes smaller > than zero and solutions fail. Is it possible to put a constraint on the > values of c_f so that the solver will only return solutions that comply to > this constraint? _______________________________________________ fipy mailing list [email protected] http://www.ctcms.nist.gov/fipy [ NIST internal ONLY: https://email.nist.gov/mailman/listinfo/fipy ]
