Hi Elizabeth, On 8/15/07, Elizabeth Tseng <[EMAIL PROTECTED]> wrote: > > Hi, > I was using the PDE solver with about 10 variables and a system of > equations. I noticed that sometimes, after sweeping, the variable values > become 1.#QNAN. What confuses me even more is that it shows up randomly. > If I re-run the time steps, sometimes it will go all the way to the end > without giving me NANs, and sometimes, after a few time steps, 1.#QNAN > pops up.
Very strange. If you reduce the input file to the simplest form possible that still produces the bug and post it, we could take a look and see if there isn't something that is obviously wrong. > > One of the equations I'm solving is like this: > > eq_C_1b = TransientTerm() == ((k_on_b/epsilon) * Ab * R_1b) - > ImplicitSourceTerm(coeff = k_off_b) \ > - > ImplicitSourceTerm(coeff = k_x_a * R_1a) \ > + k_negx_a * C_1ab > > eq_C_1ab = xxx..... > > Because I'm actually testing different control sets, sometimes, some > variables (ex: C_1ab) and constants (ex: k_x_a) will be purposely set to > 0, but the equations (ex: eq_C1_ab) still gets sweeped and the variable > updated. Could this be the cause? You can set the variable c_1ab to zero and then solve eq_C_1ab for C_1ab. That shouldn't be a problem at all. Likewise setting any coefficient to zero shouldn't be a problem. Cheers > > Thanks, > Elizabeth > > -- Daniel Wheeler
