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.

  0%|          | 0/10000.0 [00:00<?, ?it/s]
Initializing:   0%|          | 0/10000.0 [00:00<?, ?it/s]
  0%|          | 0/10000.0 [00:14<?, ?it/s]
  0%|          | 0.1/10000.0 [00:14<397:37:51, 143.15s/it]
  0%|          | 0.2/10000.0 [00:14<198:48:57, 71.58s/it]
  0%|          | 13.5/10000.0 [00:14<2:56:30,  1.06s/it]
  5%|▍         | 467.8/10000.0 [00:14<04:52, 32.62it/s]
  5%|▍         | 467.8/10000.0 [00:14<04:52, 32.55it/s]
  5%|▍         | 467.8/10000.0 [00:14<04:52, 32.55it/s]

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


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()