org.jenetics.engine

Class Engine.Builder<G extends Gene<?,G>,C extends Comparable<? super C>>

java.lang.Object

org.jenetics.engine.Engine.Builder<G,C>

All Implemented Interfaces:

Copyable<Engine.Builder<G,C>>

Enclosing class:

Engine<G extends Gene<?,G>,C extends Comparable<? super C>>

public static final class Engine.Builder<G extends Gene<?,G>,C extends Comparable<? super C>>
extends Object
implements Copyable<Engine.Builder<G,C>>

Builder class for building GA Engine instances.

Since:

3.0

Version:

3.8

Author:

Franz Wilhelmstötter

See Also:

Engine

Method Summary

Modifier and Type	Method and Description
Engine.Builder<G,C>	alterers(Alterer<G,C> first, Alterer<G,C>... rest) The alterers used for alter the offspring population.
Engine<G,C>	build() Builds an new Engine instance from the set properties.
Engine.Builder<G,C>	clock(Clock clock) The clock used for calculating the execution durations.
Engine.Builder<G,C>	copy() Create a new builder, with the current configuration.
Engine.Builder<G,C>	executor(Executor executor) The executor used by the engine.
Engine.Builder<G,C>	fitnessFunction(Function<? super Genotype<G>,? extends C> function) Set the fitness function of the evolution Engine.
Engine.Builder<G,C>	fitnessScaler(Function<? super C,? extends C> scaler) Set the fitness scaler of the evolution Engine.
Engine.Builder<G,C>	genotypeFactory(Factory<Genotype<G>> genotypeFactory) The genotype factory used for creating new individuals.
Engine.Builder<G,C>	genotypeValidator(Predicate<? super Genotype<G>> validator) The genotype validator used for detecting invalid individuals.
Alterer<G,C>	getAlterers() Return the used Alterer of the GA.
Clock	getClock() Return the Clock the engine is using for measuring the execution time.
Executor	getExecutor() Return the Executor the engine is using for executing the evolution steps.
Function<? super Genotype<G>,? extends C>	getFitnessFunction() Return the fitness function of the GA engine.
Function<? super C,? extends C>	getFitnessScaler() Return the fitness scaler of the GA engine.
Factory<Genotype<G>>	getGenotypeFactory() Return the used genotype Factory of the GA.
int	getIndividualCreationRetries() Return the maximal number of attempt before the Engine gives up creating a valid individual (Phenotype).
long	getMaximalPhenotypeAge() Return the maximal allowed phenotype age.
double	getOffspringFraction() Return the offspring fraction.
Selector<G,C>	getOffspringSelector() Return the used offspring Selector of the GA.
Optimize	getOptimize() Return the optimization strategy.
int	getPopulationSize() Return the number of individuals of a population.
Selector<G,C>	getSurvivorsSelector() Return the used survivor Selector of the GA.
Engine.Builder<G,C>	individualCreationRetries(int retries) The maximal number of attempt before the Engine gives up creating a valid individual (Phenotype).
Engine.Builder<G,C>	maximalPhenotypeAge(long age) The maximal allowed age of a phenotype.
Engine.Builder<G,C>	maximizing() Set to a fitness maximizing strategy.
Engine.Builder<G,C>	minimizing() Set to a fitness minimizing strategy.
Engine.Builder<G,C>	offspringFraction(double fraction) The offspring fraction.
Engine.Builder<G,C>	offspringSelector(Selector<G,C> selector) The selector used for selecting the offspring population.
Engine.Builder<G,C>	offspringSize(int size) The number of offspring individuals.
Engine.Builder<G,C>	optimize(Optimize optimize) The optimization strategy used by the engine.
Engine.Builder<G,C>	phenotypeValidator(Predicate<? super Phenotype<G,C>> validator) The phenotype validator used for detecting invalid individuals.
Engine.Builder<G,C>	populationSize(int size) The number of individuals which form the population.
Engine.Builder<G,C>	selector(Selector<G,C> selector) The selector used for selecting the survivors and offspring population.
Engine.Builder<G,C>	survivorsFraction(double fraction) The survivors fraction.
Engine.Builder<G,C>	survivorsSelector(Selector<G,C> selector) The selector used for selecting the survivors population.
Engine.Builder<G,C>	survivorsSize(int size) The number of survivors.

Methods inherited from class java.lang.Object

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

Method Detail

fitnessFunction

public Engine.Builder<G,C> fitnessFunction(Function<? super Genotype<G>,? extends C> function)

Set the fitness function of the evolution Engine.

Parameters:

function - the fitness function to use in the GA Engine

Returns:

this builder, for command chaining

fitnessScaler

public Engine.Builder<G,C> fitnessScaler(Function<? super C,? extends C> scaler)

Set the fitness scaler of the evolution Engine. Default value is set to the identity function.

Parameters:

scaler - the fitness scale to use in the GA Engine

Returns:

this builder, for command chaining

genotypeFactory

public Engine.Builder<G,C> genotypeFactory(Factory<Genotype<G>> genotypeFactory)

The genotype factory used for creating new individuals.

Parameters:

genotypeFactory - the genotype factory for creating new individuals.

Returns:

this builder, for command chaining

offspringSelector

public Engine.Builder<G,C> offspringSelector(Selector<G,C> selector)

The selector used for selecting the offspring population. Default values is set to TournamentSelector<>(3).

Parameters:

selector - used for selecting the offspring population

Returns:

this builder, for command chaining

survivorsSelector

public Engine.Builder<G,C> survivorsSelector(Selector<G,C> selector)

The selector used for selecting the survivors population. Default values is set to TournamentSelector<>(3).

Parameters:

selector - used for selecting survivors population

Returns:

this builder, for command chaining

selector

public Engine.Builder<G,C> selector(Selector<G,C> selector)

The selector used for selecting the survivors and offspring population. Default values is set to TournamentSelector<>(3).

Parameters:

selector - used for selecting survivors and offspring population

Returns:

this builder, for command chaining

alterers

@SafeVarargs
public final Engine.Builder<G,C> alterers(Alterer<G,C> first,
                                                       Alterer<G,C>... rest)

The alterers used for alter the offspring population. Default values is set to new SinglePointCrossover<>(0.2) followed by new Mutator<>(0.15).

Parameters:

first - the first alterer used for alter the offspring population

rest - the rest of the alterers used for alter the offspring population

Returns:

this builder, for command chaining

Throws:

NullPointerException - if one of the alterers is null.

phenotypeValidator

public Engine.Builder<G,C> phenotypeValidator(Predicate<? super Phenotype<G,C>> validator)

The phenotype validator used for detecting invalid individuals. Alternatively it is also possible to set the genotype validator with genotypeFactory(Factory), which will replace any previously set phenotype validators.

Default value is set to Phenotype::isValid.

Parameters:

validator - the validator used for validating the individuals (phenotypes).

Returns:

this builder, for command chaining

Throws:

NullPointerException - if the validator is null.

Since:

3.1

See Also:

genotypeValidator(Predicate)

genotypeValidator

public Engine.Builder<G,C> genotypeValidator(Predicate<? super Genotype<G>> validator)

The genotype validator used for detecting invalid individuals. Alternatively it is also possible to set the phenotype validator with phenotypeValidator(Predicate), which will replace any previously set genotype validators.

Default value is set to Genotype::isValid.

Parameters:

validator - the validator used for validating the individuals (genotypes).

Returns:

this builder, for command chaining

Throws:

NullPointerException - if the validator is null.

Since:

3.1

See Also:

phenotypeValidator(Predicate)

optimize

public Engine.Builder<G,C> optimize(Optimize optimize)

The optimization strategy used by the engine. Default values is set to Optimize.MAXIMUM.

Parameters:

optimize - the optimization strategy used by the engine

Returns:

this builder, for command chaining

maximizing

public Engine.Builder<G,C> maximizing()

Set to a fitness maximizing strategy.

Returns:

this builder, for command chaining

Since:

3.4

minimizing

public Engine.Builder<G,C> minimizing()

Set to a fitness minimizing strategy.

Returns:

this builder, for command chaining

Since:

3.4

offspringFraction

public Engine.Builder<G,C> offspringFraction(double fraction)

The offspring fraction. Default values is set to 0.6. This method call is equivalent to survivorsFraction(1 - offspringFraction) and will override any previously set survivors-fraction.

Parameters:

fraction - the offspring fraction

Returns:

this builder, for command chaining

Throws:

IllegalArgumentException - if the fraction is not within the range [0, 1].

See Also:

survivorsFraction(double)

survivorsFraction

public Engine.Builder<G,C> survivorsFraction(double fraction)

The survivors fraction. Default values is set to 0.4. This method call is equivalent to offspringFraction(1 - survivorsFraction) and will override any previously set offspring-fraction.

Parameters:

fraction - the survivors fraction

Returns:

this builder, for command chaining

Throws:

IllegalArgumentException - if the fraction is not within the range [0, 1].

Since:

3.8

See Also:

offspringFraction(double)

offspringSize

public Engine.Builder<G,C> offspringSize(int size)

The number of offspring individuals.

Parameters:

size - the number of offspring individuals.

Returns:

this builder, for command chaining

Throws:

IllegalArgumentException - if the size is not within the range [0, population-size].

Since:

3.8

survivorsSize

public Engine.Builder<G,C> survivorsSize(int size)

The number of survivors.

Parameters:

size - the number of survivors.

Returns:

this builder, for command chaining

Throws:

IllegalArgumentException - if the size is not within the range [0, population-size].

Since:

3.8

populationSize

public Engine.Builder<G,C> populationSize(int size)

The number of individuals which form the population. Default values is set to 50.

Parameters:

size - the number of individuals of a population

Returns:

this builder, for command chaining

Throws:

IllegalArgumentException - if size < 1

maximalPhenotypeAge

public Engine.Builder<G,C> maximalPhenotypeAge(long age)

The maximal allowed age of a phenotype. Default values is set to 70.

Parameters:

age - the maximal phenotype age

Returns:

this builder, for command chaining

Throws:

IllegalArgumentException - if age < 1

executor

public Engine.Builder<G,C> executor(Executor executor)

The executor used by the engine.

Parameters:

executor - the executor used by the engine

Returns:

this builder, for command chaining

clock

public Engine.Builder<G,C> clock(Clock clock)

The clock used for calculating the execution durations.

Parameters:

clock - the clock used for calculating the execution durations

Returns:

this builder, for command chaining

individualCreationRetries

public Engine.Builder<G,C> individualCreationRetries(int retries)

The maximal number of attempt before the Engine gives up creating a valid individual (Phenotype). Default values is set to 10.

Parameters:

retries - the maximal retry count

Returns:

this builder, for command chaining

Throws:

IllegalArgumentException - if the given retry count is smaller than zero.

Since:

3.1

build

public Engine<G,C> build()

Builds an new Engine instance from the set properties.

Returns:

an new Engine instance from the set properties

getAlterers

public Alterer<G,C> getAlterers()

Return the used Alterer of the GA.

Returns:

the used Alterer of the GA.

getClock

public Clock getClock()

Return the Clock the engine is using for measuring the execution time.

Returns:

the clock used for measuring the execution time

Since:

3.1

getExecutor

public Executor getExecutor()

Return the Executor the engine is using for executing the evolution steps.

Returns:

the executor used for performing the evolution steps

Since:

3.1

getFitnessFunction

public Function<? super Genotype<G>,? extends C> getFitnessFunction()

Return the fitness function of the GA engine.

Returns:

the fitness function

Since:

3.1

getFitnessScaler

public Function<? super C,? extends C> getFitnessScaler()

Return the fitness scaler of the GA engine.

Returns:

the fitness scaler

Since:

3.1

getGenotypeFactory

public Factory<Genotype<G>> getGenotypeFactory()

Return the used genotype Factory of the GA. The genotype factory is used for creating the initial population and new, random individuals when needed (as replacement for invalid and/or died genotypes).

Returns:

the used genotype Factory of the GA.

Since:

3.1

getMaximalPhenotypeAge

public long getMaximalPhenotypeAge()

Return the maximal allowed phenotype age.

Returns:

the maximal allowed phenotype age

Since:

3.1

getOffspringFraction

public double getOffspringFraction()

Return the offspring fraction.

Returns:

the offspring fraction.

getOffspringSelector

public Selector<G,C> getOffspringSelector()

Return the used offspring Selector of the GA.

Returns:

the used offspring Selector of the GA.

Since:

3.1

getSurvivorsSelector

public Selector<G,C> getSurvivorsSelector()

Return the used survivor Selector of the GA.

Returns:

the used survivor Selector of the GA.

Since:

3.1

getOptimize

public Optimize getOptimize()

Return the optimization strategy.

Returns:

the optimization strategy

Since:

3.1

getPopulationSize

public int getPopulationSize()

Return the number of individuals of a population.

Returns:

the number of individuals of a population

Since:

3.1

getIndividualCreationRetries

public int getIndividualCreationRetries()

Return the maximal number of attempt before the Engine gives up creating a valid individual (Phenotype).

Returns:

the maximal number of Phenotype creation attempts

Since:

3.1

copy

public Engine.Builder<G,C> copy()

Create a new builder, with the current configuration.

Specified by:

copy in interface Copyable<Engine.Builder<G extends Gene<?,G>,C extends Comparable<? super C>>>

Returns:

a new builder, with the current configuration

Since:

3.1