Tracking variables while solving

[martinsgronli]

Hi

I am solving the heat equation with temperature dependent coefficients, such as rho and c.
term_1 = f"3 * laplace(T)"
eq = PDE({"T": f"({term_1}) / ({rho} * {c})"}, bc = [bc_x_left, bc_x_right])
res = eq.solve(field, t_end, dt, tracker = self.storage.tracker(dt))

E.g. rho = "200 - T" such that rho will be changed as the simulation runs. It will also vary in space since temperature varies in space.

Is there a way to track the value of such coefficients in order to plot them afterwards? I need to verify that their values are actually correct.

[david-zwicker]

You can't directly track internal variables, but you could use a DataTracker to track arbitrary data. I realize that it might be very useful to have an option to storage tracker, which allows to transform fields and calculated derived quantities. I'll think about it.

[david-zwicker]

I updated the master branch of py-pde, which now contains a transformation argument when you initialize the tracker. In your case, you should be able to use

def transform(field, t):
    return FieldCollection([field, 200 - field])

term_1 = f"3 * laplace(T)" 
eq = PDE({"T": f"({term_1}) / ({rho} * {c})"}, bc = [bc_x_left, bc_x_right])
res = eq.solve(field, t_end, dt, tracker = self.storage.tracker(dt, transformation=transform)) 

[martinsgronli]

Thank you very much!