Class GeneticAlgorithm


  • public class GeneticAlgorithm
    extends java.lang.Object
    Implementation of a genetic algorithm. All factors that govern the operation of the algorithm can be configured for a specific problem.
    Since:
    2.0
    • Field Detail

      • randomGenerator

        private static RandomGenerator randomGenerator
        Static random number generator shared by GA implementation classes. Set the randomGenerator seed to get reproducible results. Use setRandomGenerator(RandomGenerator) to supply an alternative to the default JDK-provided PRNG.
      • crossoverPolicy

        private final CrossoverPolicy crossoverPolicy
        the crossover policy used by the algorithm.
      • crossoverRate

        private final double crossoverRate
        the rate of crossover for the algorithm.
      • mutationPolicy

        private final MutationPolicy mutationPolicy
        the mutation policy used by the algorithm.
      • mutationRate

        private final double mutationRate
        the rate of mutation for the algorithm.
      • selectionPolicy

        private final SelectionPolicy selectionPolicy
        the selection policy used by the algorithm.
      • generationsEvolved

        private int generationsEvolved
        the number of generations evolved to reach StoppingCondition in the last run.
    • Method Detail

      • setRandomGenerator

        public static void setRandomGenerator​(RandomGenerator random)
        Set the (static) random generator.
        Parameters:
        random - random generator
      • getRandomGenerator

        public static RandomGenerator getRandomGenerator()
        Returns the (static) random generator.
        Returns:
        the static random generator shared by GA implementation classes
      • evolve

        public Population evolve​(Population initial,
                                 StoppingCondition condition)
        Evolve the given population. Evolution stops when the stopping condition is satisfied. Updates the generationsEvolved property with the number of generations evolved before the StoppingCondition is satisfied.
        Parameters:
        initial - the initial, seed population.
        condition - the stopping condition used to stop evolution.
        Returns:
        the population that satisfies the stopping condition.
      • nextGeneration

        public Population nextGeneration​(Population current)
        Evolve the given population into the next generation.

        1. Get nextGeneration population to fill from current generation, using its nextGeneration method
        2. Loop until new generation is filled:
        3. Return nextGeneration
        Parameters:
        current - the current population.
        Returns:
        the population for the next generation.
      • getCrossoverPolicy

        public CrossoverPolicy getCrossoverPolicy()
        Returns the crossover policy.
        Returns:
        crossover policy
      • getCrossoverRate

        public double getCrossoverRate()
        Returns the crossover rate.
        Returns:
        crossover rate
      • getMutationPolicy

        public MutationPolicy getMutationPolicy()
        Returns the mutation policy.
        Returns:
        mutation policy
      • getMutationRate

        public double getMutationRate()
        Returns the mutation rate.
        Returns:
        mutation rate
      • getSelectionPolicy

        public SelectionPolicy getSelectionPolicy()
        Returns the selection policy.
        Returns:
        selection policy
      • getGenerationsEvolved

        public int getGenerationsEvolved()
        Returns the number of generations evolved to reach StoppingCondition in the last run.
        Returns:
        number of generations evolved
        Since:
        2.1