Function test_solve_custom_params

tests/test_solve.py:89–106

Tests that solving an instance with custom solver parameters works as expected by checking how solutions are accepted.

(rc208)

def test_solve_custom_params(rc208):
    """
    Tests that solving an instance with custom solver parameters works as
    expected by checking how solutions are accepted.
    """

    def monotonically_decreasing(arr) -> np.bool_:
        return np.all(np.diff(arr) <= 0)

    # Configure ILS to only accept improving solutions by setting
    # ``history_length=1``.
    params = SolveParams(IteratedLocalSearchParams(history_length=1))
    res = solve(rc208, stop=MaxIterations(20), params=params)

    # The current costs should now be monotonically decreasing. The first datum
    # is skipped because it's an empty initial solution with penalised cost 0.
    costs = [datum.current_cost for datum in res.stats.data[1:]]
    assert_(monotonically_decreasing(costs))