org.apache.commons.math3.genetics
Class GeneticAlgorithm

java.lang.Object
  extended by org.apache.commons.math3.genetics.GeneticAlgorithm

public class GeneticAlgorithm
extends 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
Version:
$Id: GeneticAlgorithm.java 1416643 2012-12-03 19:37:14Z tn $

Constructor Summary
GeneticAlgorithm(CrossoverPolicy crossoverPolicy, double crossoverRate, MutationPolicy mutationPolicy, double mutationRate, SelectionPolicy selectionPolicy)
          Create a new genetic algorithm.
 
Method Summary
 Population evolve(Population initial, StoppingCondition condition)
          Evolve the given population.
 CrossoverPolicy getCrossoverPolicy()
          Returns the crossover policy.
 double getCrossoverRate()
          Returns the crossover rate.
 int getGenerationsEvolved()
          Returns the number of generations evolved to reach StoppingCondition in the last run.
 MutationPolicy getMutationPolicy()
          Returns the mutation policy.
 double getMutationRate()
          Returns the mutation rate.
static RandomGenerator getRandomGenerator()
          Returns the (static) random generator.
 SelectionPolicy getSelectionPolicy()
          Returns the selection policy.
 Population nextGeneration(Population current)
          Evolve the given population into the next generation.
static void setRandomGenerator(RandomGenerator random)
          Set the (static) random generator.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

GeneticAlgorithm

public GeneticAlgorithm(CrossoverPolicy crossoverPolicy,
                        double crossoverRate,
                        MutationPolicy mutationPolicy,
                        double mutationRate,
                        SelectionPolicy selectionPolicy)
                 throws OutOfRangeException
Create a new genetic algorithm.

Parameters:
crossoverPolicy - The CrossoverPolicy
crossoverRate - The crossover rate as a percentage (0-1 inclusive)
mutationPolicy - The MutationPolicy
mutationRate - The mutation rate as a percentage (0-1 inclusive)
selectionPolicy - The SelectionPolicy
Throws:
OutOfRangeException - if the crossover or mutation rate is outside the [0, 1] range
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


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