org.apache.commons.math3.genetics

Class ElitisticListPopulation

java.lang.Object

org.apache.commons.math3.genetics.ListPopulation

org.apache.commons.math3.genetics.ElitisticListPopulation

All Implemented Interfaces:

java.lang.Iterable<Chromosome>, Population

public class ElitisticListPopulation
extends ListPopulation

Population of chromosomes which uses elitism (certain percentage of the best chromosomes is directly copied to the next generation).

Since:

2.0

Constructor Summary

Constructors

Constructor and Description
ElitisticListPopulation(int populationLimit, double elitismRate) Creates a new ElitisticListPopulation instance and initializes its inner chromosome list.
ElitisticListPopulation(java.util.List<Chromosome> chromosomes, int populationLimit, double elitismRate) Creates a new ElitisticListPopulation instance.

Method Summary

Modifier and Type	Method and Description
double	getElitismRate() Access the elitism rate.
Population	nextGeneration() Start the population for the next generation.
void	setElitismRate(double elitismRate) Sets the elitism rate, i.e.

Methods inherited from class org.apache.commons.math3.genetics.ListPopulation

addChromosome, addChromosomes, getChromosomes, getFittestChromosome, getPopulationLimit, getPopulationSize, iterator, setChromosomes, setPopulationLimit, toString

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Constructor Detail

ElitisticListPopulation

public ElitisticListPopulation(java.util.List<Chromosome> chromosomes,
                               int populationLimit,
                               double elitismRate)
                        throws NullArgumentException,
                               NotPositiveException,
                               NumberIsTooLargeException,
                               OutOfRangeException

Creates a new ElitisticListPopulation instance.

Parameters:

chromosomes - list of chromosomes in the population

populationLimit - maximal size of the population

elitismRate - how many best chromosomes will be directly transferred to the next generation [in %]

Throws:

NullArgumentException - if the list of chromosomes is null

NotPositiveException - if the population limit is not a positive number (< 1)

NumberIsTooLargeException - if the list of chromosomes exceeds the population limit

OutOfRangeException - if the elitism rate is outside the [0, 1] range

ElitisticListPopulation

public ElitisticListPopulation(int populationLimit,
                               double elitismRate)
                        throws NotPositiveException,
                               OutOfRangeException

Creates a new ElitisticListPopulation instance and initializes its inner chromosome list.

Parameters:

populationLimit - maximal size of the population

elitismRate - how many best chromosomes will be directly transferred to the next generation [in %]

Throws:

NotPositiveException - if the population limit is not a positive number (< 1)

OutOfRangeException - if the elitism rate is outside the [0, 1] range

Method Detail

nextGeneration

public Population nextGeneration()

Start the population for the next generation. The elitismRate percents of the best chromosomes are directly copied to the next generation.

Returns:

the beginnings of the next generation.

setElitismRate

public void setElitismRate(double elitismRate)
                    throws OutOfRangeException

Sets the elitism rate, i.e. how many best chromosomes will be directly transferred to the next generation [in %].

Parameters:

elitismRate - how many best chromosomes will be directly transferred to the next generation [in %]

Throws:

OutOfRangeException - if the elitism rate is outside the [0, 1] range

getElitismRate

public double getElitismRate()

Access the elitism rate.

Returns:

the elitism rate