Reflective boundary conditions

[ghislainp]

Hi,

I've a first order ODE
D [y1, y2] / Dt = f(y1,y2)

and I'd like to constrain y1 = 0.5 * y2 at one boundary. Ideally with a hard constraint. Do you have any suggestion ?

[lululxvi]

Seems not easy to do.

[ghislainp]

In fact, it seems to work, with a soft constraint:

def boundary_condition_bottom_func(x, y, X):
    return y[:, 0] - 0.5 * y[:, 1]

bc_bottom = dde.OperatorBC(geom, boundary_condition_bottom_func, boundary_condition_bottom)

Do you think it is fine ?

[lululxvi]

It is fine.