Hi Ian, Sorry, there isn't any way to do this as an implicit command in FiPy, whether as a simple reset during sweeping or as a fully implicit constraint in the equations. Of course, you can always try these techniques explicitly in the Python code or in the design of the equations. I agree that It would be nice to have a one sided constraint syntactically in FiPy, but I'm not sure how best to make that work internally.
Cheers, Daniel On Tue, Aug 2, 2016 at 10:46 AM, Campbell, Ian <[email protected]> wrote: > Hi All, > > > > I would like to prevent the CellVariables I am solving for from ever > reaching physically-meaningless and incorrect values, such as concentrations > becoming negative. Is there a way to do this? > > > > The most natural place I could think of it being is an argument in > CellVariable declaration, such as “phi = CellVariable(mesh = mesh2d, value = > phi_0, upperlimit = 10**7, lowerlimit = 0)”. However, I haven’t found such > an option there or in any of the FiPy documentation. > > > > With best regards, > > > > - Ian > > > _______________________________________________ > fipy mailing list > [email protected] > http://www.ctcms.nist.gov/fipy > [ NIST internal ONLY: https://email.nist.gov/mailman/listinfo/fipy ] > -- Daniel Wheeler _______________________________________________ fipy mailing list [email protected] http://www.ctcms.nist.gov/fipy [ NIST internal ONLY: https://email.nist.gov/mailman/listinfo/fipy ]
