Module org.cicirello.chips_n_salsa
Package org.cicirello.search.operators.bits

Class KPointCrossover

java.lang.Object
org.cicirello.search.operators.bits.KPointCrossover
All Implemented Interfaces:
Splittable<CrossoverOperator<BitVector>>, CrossoverOperator<BitVector>
public final class KPointCrossover extends Object implements CrossoverOperator<BitVector>
Implementation of K-point crossover, a classic crossover operator for BitVectors. K-point crossover is a generalization of two-point crossover. In a K-point crossover, K random cross points are chosen uniformly along the length of the bit vector parents. Both parents are cut at the K cross points, breaking the parents into multiple segments. The bits within every other segment are then swapped between the two parents to form the two children.

  • Constructor Details

    • KPointCrossover

      public KPointCrossover(int k)
      Constructs a K-point crossover operator.
      Parameters:
      k - The number of cross points, which must be at least 1. Although, if you want only a single cross point, you should instead use SinglePointCrossover; and likewise, if you only want 2 cross points, you should instead use TwoPointCrossover.
      Throws:
      IllegalArgumentException - if k is less than 1

  • Method Details

    • cross

      public void cross(BitVector c1, BitVector c2)
      Performs a crossover for an evolutionary algorithm, such that crossover forms two children from two parents. Implementations of this method modify the parameters, transforming the parents into the children.
      Specified by:
      cross in interface CrossoverOperator<BitVector>
      Parameters:
      c1 - A candidate solution subject to the crossover. This method changes the state of c1.
      c2 - A candidate solution subject to the crossover. This method changes the state of c2.
      Throws:
      IllegalArgumentException - if c1.length() is not equal to c2.length()
      IllegalArgumentException - if c1.length() is less than k.

    • split

      public KPointCrossover 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 Splittable<CrossoverOperator<BitVector>>
      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.