Class IteratedLocalSearch

pyvrp/IteratedLocalSearch.py:48–197

Creates an IteratedLocalSearch instance. Parameters ---------- data The problem data instance. penalty_manager Penalty manager to use. rng Random number generator. search_method Search method to use. initial_solution Initial s

class IteratedLocalSearch:
    """
    Creates an IteratedLocalSearch instance.

    Parameters
    ----------
    data
        The problem data instance.
    penalty_manager
        Penalty manager to use.
    rng
        Random number generator.
    search_method
        Search method to use.
    initial_solution
        Initial solution to start the search with.
    params
        Iterated local search parameters to use. If not provided, a default
        will be used.
    """

    def __init__(
        self,
        data: ProblemData,
        penalty_manager: PenaltyManager,
        rng: RandomNumberGenerator,
        search_method: SearchMethod,
        initial_solution: Solution,
        params: IteratedLocalSearchParams = IteratedLocalSearchParams(),
    ):
        self._data = data
        self._pm = penalty_manager
        self._rng = rng
        self._search = search_method
        self._init = initial_solution
        self._params = params

    def run(
        self,
        stop: StoppingCriterion,
        collect_stats: bool = True,
        display: bool = False,
        display_interval: float = 5.0,
    ) -> Result:
        """
        Runs the iterated local search algorithm with the provided stopping
        criterion. The algorithm uses late acceptance hill-climbing as the
        acceptance criterion; see [1]_ for details.

        Parameters
        ----------
        stop
            Stopping criterion to use. The algorithm runs until the first time
            the stopping criterion returns ``True``.
        collect_stats
            Whether to collect statistics about the solver's progress. Default
            ``True``.
        display