2.4.1 Post-step hook function

Demonstrate the simple hook function in PDE, which is called after each time step and may modify the state and abort the simulation.

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from pde import PDE, ScalarField, UnitGrid


def post_step_hook(state_data, t):
    """Helper function called after every time step."""
    state_data[24:40, 24:40] = 1  # set central region to given value

    if t > 1e3:
        raise StopIteration  # abort simulation at given time

    return state_data


eq = PDE({"c": "laplace(c)"}, post_step_hook=post_step_hook)
state = ScalarField(UnitGrid([64, 64]))
result = eq.solve(state, dt=0.1, t_range=1e4)
result.plot()