Package org.apache.commons.math3.genetics

Class Chromosome

java.lang.Object
org.apache.commons.math3.genetics.Chromosome
All Implemented Interfaces:
Comparable<Chromosome>, Fitness
Direct Known Subclasses:
AbstractListChromosome
public abstract class Chromosome extends Object implements Comparable<Chromosome>, Fitness
Individual in a population. Chromosomes are compared based on their fitness.

The chromosomes are IMMUTABLE, and so their fitness is also immutable and therefore it can be cached.

Since:
2.0

  • Constructor Details

    • Chromosome

      public Chromosome()

  • Method Details

    • getFitness

      public double getFitness()
      Access the fitness of this chromosome. The bigger the fitness, the better the chromosome.

      Computation of fitness is usually very time-consuming task, therefore the fitness is cached.

      Returns:
      the fitness

    • compareTo

      public int compareTo(Chromosome another)
      Compares two chromosomes based on their fitness. The bigger the fitness, the better the chromosome.
      Specified by:
      compareTo in interface Comparable<Chromosome>
      Parameters:
      another - another chromosome to compare
      Returns:
      • -1 if another is better than this
      • 1 if another is worse than this
      • 0 if the two chromosomes have the same fitness

    • isSame

      protected boolean isSame(Chromosome another)
      Returns true iff another has the same representation and therefore the same fitness. By default, it returns false -- override it in your implementation if you need it.
      Parameters:
      another - chromosome to compare
      Returns:
      true if another is equivalent to this chromosome

    • findSameChromosome

      protected Chromosome findSameChromosome(Population population)
      Searches the population for another chromosome with the same representation. If such chromosome is found, it is returned, if no such chromosome exists, returns null.
      Parameters:
      population - Population to search
      Returns:
      Chromosome with the same representation, or null if no such chromosome exists.

    • searchForFitnessUpdate

      public void searchForFitnessUpdate(Population population)
      Searches the population for a chromosome representing the same solution, and if it finds one, updates the fitness to its value.
      Parameters:
      population - Population to search