Class NPointCrossover<T>

  • Type Parameters:
    T - generic type of the AbstractListChromosomes for crossover
    All Implemented Interfaces:
    CrossoverPolicy

    public class NPointCrossover<T>
    extends java.lang.Object
    implements CrossoverPolicy
    N-point crossover policy. For each iteration a random crossover point is selected and the first part from each parent is copied to the corresponding child, and the second parts are copied crosswise. Example (2-point crossover):
     -C- denotes a crossover point
               -C-       -C-                         -C-        -C-
     p1 = (1 0  | 1 0 0 1 | 0 1 1)    X    p2 = (0 1  | 1 0 1 0  | 1 1 1)
          \----/ \-------/ \-----/              \----/ \--------/ \-----/
            ||      (*)       ||                  ||      (**)       ||
            VV      (**)      VV                  VV      (*)        VV
          /----\ /--------\ /-----\             /----\ /--------\ /-----\
     c1 = (1 0  | 1 0 1 0  | 0 1 1)    X   c2 = (0 1  | 1 0 0 1  | 0 1 1)
     
    This policy works only on AbstractListChromosome, and therefore it is parameterized by T. Moreover, the chromosomes must have same lengths.
    Since:
    3.1
    • Field Detail

      • crossoverPoints

        private final int crossoverPoints
        The number of crossover points.
    • Constructor Detail

      • NPointCrossover

        public NPointCrossover​(int crossoverPoints)
                        throws NotStrictlyPositiveException
        Creates a new NPointCrossover policy using the given number of points.

        Note: the number of crossover points must be < chromosome length - 1. This condition can only be checked at runtime, as the chromosome length is not known in advance.

        Parameters:
        crossoverPoints - the number of crossover points
        Throws:
        NotStrictlyPositiveException - if the number of crossoverPoints is not strictly positive