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 [00:10<?, ?it/s]
  0%|          | 0.1/10000.0 [00:15<425:48:24, 153.29s/it]
  0%|          | 0.2/10000.0 [00:15<212:54:19, 76.65s/it]
  0%|          | 0.3/10000.0 [00:15<141:56:12, 51.10s/it]
  0%|          | 12.8/10000.0 [00:15<3:19:21,  1.20s/it]
  4%|▎         | 354.9/10000.0 [00:15<06:57, 23.10it/s]
  4%|▎         | 354.9/10000.0 [00:15<06:59, 23.01it/s]
  4%|▎         | 354.9/10000.0 [00:15<06:59, 23.01it/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()