org.jgap.impl
Class BestChromosomesSelector

java.lang.Object
  org.jgap.NaturalSelector
      org.jgap.impl.BestChromosomesSelector

All Implemented Interfaces:

java.io.Serializable, Configurable, INaturalSelector

public class BestChromosomesSelector
extends NaturalSelector

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.FitnessValueComparator

Constructor Summary

BestChromosomesSelector()
Default constructor.

BestChromosomesSelector(Configuration a_config)
Using original rate of 1.0

BestChromosomesSelector(Configuration a_config, double a_originalRate)

Method Summary

protected void	add(IChromosome a_chromosomeToAdd) Add a Chromosome instance to this selector's working pool of Chromosomes.
void	empty() Empties out the working pool of Chromosomes.
boolean	getDoubletteChromosomesAllowed()
double	getOriginalRate()
boolean	returnsUniqueChromosomes()
void	select(int a_howManyToSelect, Population a_from_pop, Population a_to_pop) Selects a given number of Chromosomes from the pool that will move on to the next generation population.
void	setDoubletteChromosomesAllowed(boolean a_doublettesAllowed) Determines whether doublette chromosomes may be added to the selector or will be ignored.
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.NaturalSelector

getConfiguration

Methods inherited from class java.lang.Object

clone, equals, finalize, 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

add

protected void add(IChromosome a_chromosomeToAdd)

Add a Chromosome instance to this selector's working pool of Chromosomes.

Specified by:

add in class NaturalSelector

Parameters:

a_chromosomeToAdd - the specimen to add to the pool

Since:

1.1

select

public void select(int a_howManyToSelect,
                   Population a_from_pop,
                   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_from_pop - the population the Chromosomes will be selected from

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.

Since:

1.1

setDoubletteChromosomesAllowed

public void setDoubletteChromosomesAllowed(boolean a_doublettesAllowed)

Determines whether doublette chromosomes may be added to the selector or will be ignored.

Parameters:

a_doublettesAllowed - true: doublette chromosomes allowed to be added to the selector. FALSE: doublettes will be ignored and not added

Since:

2.0

getDoubletteChromosomesAllowed

public boolean getDoubletteChromosomesAllowed()

Returns:

true: doublette chromosomes allowed to be added to the selector

Since:

2.0

returnsUniqueChromosomes

public boolean returnsUniqueChromosomes()

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