jenes.algorithms

Class IslandGA<T extends Chromosome>

java.lang.Object

jenes.GeneticAlgorithm<T>

jenes.algorithms.IslandGA<T>

public class IslandGA<T extends Chromosome>
extends GeneticAlgorithm<T>

IslandGA implements a niche based algorithm

Since:

2.0

Version:

2.0

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	IslandGA.Graph The Graph represent the paths between islands in the algorithm landscape
static class	IslandGA.ReplacementStrategy The elitism strategy enumeration

Nested classes/interfaces inherited from class jenes.GeneticAlgorithm

GeneticAlgorithm.ElitismStrategy, GeneticAlgorithm.ResizeStrategy, GeneticAlgorithm.Statistics

Field Summary

Fields

Modifier and Type	Field and Description
static IslandGA.Graph	DEFAULT_GEOGRAPHY The default topology connecting islands
static int	DEFAULT_MIGRATION The default migration rate between islands
static int	DEFAULT_NICHES The default number of niches
static IslandGA.ReplacementStrategy	DEFAULT_REPLACEMENT The default replacement strategy

Fields inherited from class jenes.GeneticAlgorithm

algorithmListeners, body, DEFAULT_GENERATION_LIMIT, DEFAULT_HISTORY_SIZE, elitism, elitismStrategy, fullEvaluationForced, generation, generationLimit, generationListeners, initialPopulation, MAX_HISTORY_SIZE, MIN_HISTORY_SIZE, random, randomization, resizeStrategy, statistics

Constructor Summary

Constructors

Constructor and Description
IslandGA(Fitness fitness) Creates a IslandGA instance
IslandGA(Fitness fitness, Population<T> population) Creates a IslandGA instance
IslandGA(Fitness fitness, Population<T> population, int genlimit) Creates a IslandGA instance
IslandGA(Fitness fitness, Population<T> population, int genlimit, int niches) Creates a IslandGA instance
IslandGA(Fitness fitness, Population<T> population, int genlimit, int niches, GeneticAlgorithm<T> algo) Creates a IslandGA instance with an empty fitness
IslandGA(Fitness fitness, Population<T> population, int genlimit, int niches, GeneticAlgorithm<T> algo, int migration) Creates a IslandGA instance with an empty fitness
IslandGA(Fitness fitness, Population<T> population, int genlimit, int niches, GeneticAlgorithm<T> algo, int migration, IslandGA.Graph geography) Creates a IslandGA instance
IslandGA(Fitness fitness, Population<T> population, int genlimit, int niches, GeneticAlgorithm<T> algo, int migration, IslandGA.Graph geography, IslandGA.ReplacementStrategy rp) Creates a IslandGA instance
IslandGA(Fitness fitness, Population<T> population, int genlimit, int niches, int migration) Creates a IslandGA instance
IslandGA(Fitness fitness, Population<T> population, int genlimit, int niches, int migration, IslandGA.Graph geography) Creates a IslandGA instance
IslandGA(Fitness fitness, Population<T> population, int genlimit, int niches, int migration, IslandGA.Graph geography, IslandGA.ReplacementStrategy rp) Creates a IslandGA instance

Method Summary

Methods

Modifier and Type	Method and Description
GeneticAlgorithm<T>[]	getAllIslands() Gets the list of algorithms used for the different islands
IslandGA.Graph	getGeography() Return the topology connecting islands
int	getMigration() Returns the migration rate
int	getNiches() Returns the number of niches
IslandGA.ReplacementStrategy	getReplacement() Returns the replacement strategy
protected void	migrate(Population<T>[] branches) Performs migration of individuals between islands
protected void	populateNiches() Distributes individuals among islands by setting their speciem
void	setAllIslands(GeneticAlgorithm<T> algo) Sets the algorithm for all islands
void	setBiggerIsBetter(boolean flag) Sets the algorithm's body objective to maximize (true) or minimize (false) the individual fitness.
void	setElitism(int elitism) Sets the elitism for all the islands
void	setGeography(IslandGA.Graph geography) Sets the topology
void	setIsland(int i, GeneticAlgorithm<T> algo) Sets the algorithm for a specific island
void	setMigration(int migration) Sets the migration rate
void	setNiches(int niches) Sets the number of niches
void	setReplacement(IslandGA.ReplacementStrategy replacement) Sets the replacement stategy

Methods inherited from class jenes.GeneticAlgorithm

addAlgorithmEventListener, addGenerationEventListener, addStage, applyElitism, end, evaluateIndividual, evaluatePopulation, evaluatePopulation, evolve, evolve, evolve, getBody, getCurrentPopulation, getElitism, getElitismStrategy, getFitness, getGeneration, getGenerationLimit, getHistoryAt, getHistorySize, getInitialPopulation, getLastPopulation, getNextPopulation, getPool, getRandomization, getResizeStrategy, getRunner, getStatistics, isBiggerBetter, isFitnessChanged, isFullEvaluationForced, onGeneration, onInit, onStart, onStop, randomizeIndividual, randomizePopulation, removeAlgorithmEventListener, removeGenerationEventListener, setElitismStrategy, setFitness, setFullEvaluationForced, setGenerationLimit, setHistorySize, setRandomization, setRandomization, setRandomSeed, setResizeStrategy, setRunner, start, stop, toString, updateStatistics

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

DEFAULT_NICHES

public static final int DEFAULT_NICHES

The default number of niches

See Also:

Constant Field Values

DEFAULT_MIGRATION

public static final int DEFAULT_MIGRATION

The default migration rate between islands

See Also:

Constant Field Values

DEFAULT_GEOGRAPHY

public static final IslandGA.Graph DEFAULT_GEOGRAPHY

The default topology connecting islands

DEFAULT_REPLACEMENT

public static final IslandGA.ReplacementStrategy DEFAULT_REPLACEMENT

The default replacement strategy

Constructor Detail

IslandGA

public IslandGA(Fitness fitness)

Creates a IslandGA instance

Parameters:

fitness -

IslandGA

public IslandGA(Fitness fitness,
        Population<T> population)

Creates a IslandGA instance

Parameters:

fitness - the fitness object

population - initial population

genlimit - the generation limit

niches - the number of niches

migration - the migration rate

geography - topology connecting islands

rp - replacement strategy

IslandGA

public IslandGA(Fitness fitness,
        Population<T> population,
        int genlimit)

Creates a IslandGA instance

Parameters:

fitness - the fitness object

population - initial population

genlimit - the generation limit

IslandGA

public IslandGA(Fitness fitness,
        Population<T> population,
        int genlimit,
        int niches)

Creates a IslandGA instance

Parameters:

fitness - the fitness object

population - initial population

genlimit - the generation limit

niches - the number of niches

IslandGA

public IslandGA(Fitness fitness,
        Population<T> population,
        int genlimit,
        int niches,
        int migration)

Creates a IslandGA instance

Parameters:

fitness - the fitness object

population - initial population

genlimit - the generation limit

niches - the number of niches

migration - the migration rate

IslandGA

public IslandGA(Fitness fitness,
        Population<T> population,
        int genlimit,
        int niches,
        int migration,
        IslandGA.Graph geography)

Creates a IslandGA instance

Parameters:

fitness - the fitness object

population - initial population

genlimit - the generation limit

niches - the number of niches

migration - the migration rate

geography - topology connecting islands

IslandGA

public IslandGA(Fitness fitness,
        Population<T> population,
        int genlimit,
        int niches,
        int migration,
        IslandGA.Graph geography,
        IslandGA.ReplacementStrategy rp)

Creates a IslandGA instance

Parameters:

fitness - the fitness object

population - initial population

genlimit - the generation limit

niches - the number of niches

migration - the migration rate

geography - topology connecting islands

rp - replacement strategy

IslandGA

public IslandGA(Fitness fitness,
        Population<T> population,
        int genlimit,
        int niches,
        GeneticAlgorithm<T> algo)

Creates a IslandGA instance with an empty fitness

Parameters:

fitness - the fitness object

population - initial population

genlimit - the generation limit

niches - the number of niches

algo - the algorithm to be used for all niches

IslandGA

public IslandGA(Fitness fitness,
        Population<T> population,
        int genlimit,
        int niches,
        GeneticAlgorithm<T> algo,
        int migration)

Creates a IslandGA instance with an empty fitness

Parameters:

fitness - the fitness object

population - initial population

genlimit - the generation limit

niches - the number of niches

algo - the algorithm to be used for all niches

migration - the migration rate

IslandGA

public IslandGA(Fitness fitness,
        Population<T> population,
        int genlimit,
        int niches,
        GeneticAlgorithm<T> algo,
        int migration,
        IslandGA.Graph geography)

Creates a IslandGA instance

Parameters:

fitness - the fitness object

population - initial population

genlimit - the generation limit

niches - the number of niches

algo - the algorithm to be used for all niches

migration - the migration rate

geography - topology connecting islands

IslandGA

public IslandGA(Fitness fitness,
        Population<T> population,
        int genlimit,
        int niches,
        GeneticAlgorithm<T> algo,
        int migration,
        IslandGA.Graph geography,
        IslandGA.ReplacementStrategy rp)

Creates a IslandGA instance

Parameters:

fitness - the fitness object

population - initial population

genlimit - the generation limit

niches - the number of niches

algo - the algorithm to be used for all niches

migration - the migration rate

geography - topology connecting islands

rp - replacement strategy

Method Detail

setElitism

public void setElitism(int elitism)

Sets the elitism for all the islands

Overrides:

setElitism in class GeneticAlgorithm<T extends Chromosome>

Parameters:

elitism -

setIsland

public void setIsland(int i,
             GeneticAlgorithm<T> algo)

Sets the algorithm for a specific island

Parameters:

i - island index

algo - algorithm

setAllIslands

public void setAllIslands(GeneticAlgorithm<T> algo)

Sets the algorithm for all islands

Parameters:

algo - algorithm

getAllIslands

public GeneticAlgorithm<T>[] getAllIslands()

Gets the list of algorithms used for the different islands

Returns:

populateNiches

protected void populateNiches()

Distributes individuals among islands by setting their speciem

migrate

protected void migrate(Population<T>[] branches)

Performs migration of individuals between islands

Parameters:

branches -

getGeography

public final IslandGA.Graph getGeography()

Return the topology connecting islands

Returns:

setGeography

public void setGeography(IslandGA.Graph geography)

Sets the topology

Parameters:

geography -

getMigration

public final int getMigration()

Returns the migration rate

Returns:

rate

setMigration

public void setMigration(int migration)

Sets the migration rate

Parameters:

migration -

getNiches

public final int getNiches()

Returns the number of niches

Returns:

setNiches

public void setNiches(int niches)

Sets the number of niches

Parameters:

niches -

getReplacement

public final IslandGA.ReplacementStrategy getReplacement()

Returns the replacement strategy

Returns:

setReplacement

public void setReplacement(IslandGA.ReplacementStrategy replacement)

Sets the replacement stategy

Parameters:

replacement -

setBiggerIsBetter

public void setBiggerIsBetter(boolean flag)

Description copied from class: GeneticAlgorithm

Sets the algorithm's body objective to maximize (true) or minimize (false) the individual fitness. All stages belonging to the body sequence are recursevely set according to the flag.

Overrides:

setBiggerIsBetter in class GeneticAlgorithm<T extends Chromosome>

Parameters:

flag - true to set the body to maximize the fitness, false to minimize