org.jgap.impl

Class BestChromosomesSelector

java.lang.Object

org.jgap.NaturalSelector

org.jgap.NaturalSelectorExt

org.jgap.impl.BestChromosomesSelector

All Implemented Interfaces:

java.io.Serializable, java.lang.Cloneable, Configurable, INaturalSelector, ICloneable

public class BestChromosomesSelector
extends NaturalSelectorExt
implements ICloneable

Implementation of a NaturalSelector that takes the top n chromosomes into the next generation. n can be specified. Which chromosomes are the best is decided by evaluating their fitness value.

Since:

1.1

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class org.jgap.NaturalSelector

NaturalSelector.AgeFitnessValueComparator, NaturalSelector.FitnessAgeValueComparator, NaturalSelector.FitnessValueComparator

Constructor Summary

Constructors

Constructor and Description
BestChromosomesSelector() Default constructor.
BestChromosomesSelector(Configuration a_config) Using original rate of 1.0
BestChromosomesSelector(Configuration a_config, double a_originalRate)

Method Summary

Modifier and Type	Method and Description
java.lang.Object	clone()
void	empty() Empties out the working pool of Chromosomes.
boolean	equals(java.lang.Object a_o)
double	getOriginalRate()
boolean	returnsUniqueChromosomes()
void	selectChromosomes(int a_howManyToSelect, Population a_to_pop) Selects a given number of chromosomes from the pool that will move on to the next generation population.
void	setOriginalRate(double a_originalRate) Setting this parameter controls how many chromosomes of the original population will be considered for selection to the next population.

Methods inherited from class org.jgap.NaturalSelectorExt

getDoubletteChromosomesAllowed, select, setDoubletteChromosomesAllowed

Methods inherited from class org.jgap.NaturalSelector

getConfiguration

Methods inherited from class java.lang.Object

getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

BestChromosomesSelector

public BestChromosomesSelector()
                        throws InvalidConfigurationException

Default constructor. Attention: The configuration used is the one set with the static method Genotype.setConfiguration.

Throws:

InvalidConfigurationException

Since:

1.1

BestChromosomesSelector

public BestChromosomesSelector(Configuration a_config)
                        throws InvalidConfigurationException

Using original rate of 1.0

Parameters:

a_config - the configuration to use

Throws:

InvalidConfigurationException

Since:

3.0

BestChromosomesSelector

public BestChromosomesSelector(Configuration a_config,
                               double a_originalRate)
                        throws InvalidConfigurationException

Throws:

InvalidConfigurationException

Method Detail

selectChromosomes

public void selectChromosomes(int a_howManyToSelect,
                              Population a_to_pop)

Selects a given number of chromosomes from the pool that will move on to the next generation population. This selection will be guided by the fitness values. The chromosomes with the best fitness value win.

Parameters:

a_to_pop - the population the chromosomes will be added to

a_howManyToSelect - the number of chromosomes to select

Since:

1.1

empty

public void empty()

Empties out the working pool of Chromosomes.

Specified by:

empty in interface INaturalSelector

Since:

1.1

returnsUniqueChromosomes

public boolean returnsUniqueChromosomes()

Specified by:

returnsUniqueChromosomes in interface INaturalSelector

Returns:

always true as no Chromosome can be returnd multiple times

Since:

2.0

setOriginalRate

public void setOriginalRate(double a_originalRate)

Setting this parameter controls how many chromosomes of the original population will be considered for selection to the next population. If the value is 1 then the whole original population is considered, if it is 0.5 only half of the chromosomes are considered. If doublettes are allowed, then a number of chromosomes missing (number of to be selected minus number selected) will be added.

Parameters:

a_originalRate - the rate of how many of the original chromosomes will be selected according to BestChromosomeSelector's strategy. The rest (non-original) of the chromosomes is added as duplicates

Since:

2.0

getOriginalRate

public double getOriginalRate()

Returns:

see setOriginalRate

Since:

2.0

equals

public boolean equals(java.lang.Object a_o)

Overrides:

equals in class NaturalSelectorExt

Parameters:

a_o - the object to compare

Returns:

true: compared object is seen as equal to current instance

clone

public java.lang.Object clone()

Specified by:

clone in interface ICloneable

Overrides:

clone in class java.lang.Object

Returns:

clone of the current object instance