Interface SingleSolutionMetaheuristic<T extends Copyable<T>>

Type Parameters:
T - The type of object under optimization.
All Superinterfaces:
Metaheuristic<T>, ReoptimizableMetaheuristic<T>, Splittable<TrackableSearch<T>>, TrackableSearch<T>
All Known Implementing Classes:
OnePlusOneEvolutionaryAlgorithm, OnePlusOneGeneticAlgorithm, SimulatedAnnealing
public interface SingleSolutionMetaheuristic<T extends Copyable<T>> extends ReoptimizableMetaheuristic<T>
This interface defines the required methods for implementations of single-solution metaheuristics, i.e., metaheuristics such as simulated annealing that operate one a single candidate solution (as compared to population-based metaheuristics such as genetic algorithms. It is also specifically focused on metaheuristics for which the maximum run length can be specified.

  • Method Details

    • optimize

      SolutionCostPair<T> optimize(int runLength, T start)
      Executes a run of the metaheuristic beginning at a specified starting solution. If this method is called multiple times, each call begins by reinitializing the metaheuristic's control parameters. as if it was a fresh run.

      Implementing classes should provide more specific documentation of this method to define in particular what run length means in the context of the given metaheuristic. It is also recommended that implementing classes rename the runLength parameter to be a more meaningful name within the context of that metaheuristic.

      Parameters:
      runLength - The length of a run of this metaheuristic.
      start - The desired starting solution.
      Returns:
      The current solution at the end of this run and its cost, which may or may not be the best of run solution, and which may or may not be the same as the solution contained in this metaheuristic's ProgressTracker, which contains the best of all runs. Returns null if the run did not execute, such as if the ProgressTracker already contains the theoretical best solution.

    • split

      SingleSolutionMetaheuristic<T> split()
      Description copied from interface: Splittable
      Generates a functionally identical copy of this object, for use in multithreaded implementations of search algorithms. The state of the object that is returned may or may not be identical to that of the original. Thus, this is a distinct concept from the functionality of the Copyable interface. Classes that implement this interface must ensure that the object returned performs the same functionality, and that it does not share any state data that would be either unsafe or inefficient for concurrent access by multiple threads. The split method is allowed to simply return the this reference, provided that it is both safe and efficient for multiple threads to share a single copy of the Splittable object. The intention is to provide a multithreaded search with the capability to provide spawned threads with their own distinct search operators. Such multithreaded algorithms can call the split method for each thread it spawns to generate a functionally identical copy of the operator, but with independent state.
      Specified by:
      split in interface Metaheuristic<T extends Copyable<T>>
      Specified by:
      split in interface ReoptimizableMetaheuristic<T extends Copyable<T>>
      Specified by:
      split in interface Splittable<T extends Copyable<T>>
      Returns:
      A functionally identical copy of the object, or a reference to this if it is both safe and efficient for multiple threads to share a single instance of this Splittable object.