jenes.stage.operator.common

Class TopScaling<T extends Chromosome>

java.lang.Object

jenes.stage.AbstractStage<T>

jenes.stage.operator.Operator<T>

jenes.stage.operator.Scaling<T>

jenes.stage.operator.common.TopScaling<T>

public class TopScaling<T extends Chromosome>
extends Scaling<T>

This operator performs fitness top-scaling. Given f, a fraction of individuals. Best individuals are given a score 1/m*n, where n is the number of individuals. Alternatively, a number q of individuals can be provided, instead of fraction f. The others are given 0.

TopScaling is compatible with multi-objective optimization.

Since:

2.0

Version:

2.0

Nested Class Summary

Nested classes/interfaces inherited from class jenes.stage.operator.Operator

Operator.Statistics

Field Summary

Fields

Modifier and Type	Field and Description
static double	DEFAULT_FRACTION The defaulf fraction

Fields inherited from class jenes.stage.operator.Operator

random, statistics

Fields inherited from class jenes.stage.AbstractStage

biggerIsBetter, fitness, ga

Constructor Summary

Constructors

Constructor and Description
TopScaling() Creates an instance with default fraction
TopScaling(double f) Creates an instance with the given fraction
TopScaling(int q) Creates an instance with the given quantity of individuals

Method Summary

Methods

Modifier and Type	Method and Description
double	getFraction() Returns the fraction
int	getQuantity() Return the number of top individuals to consider
void	scale(Population<T> pop) Method used to scale the fitness of indivduals belonging to given Population
void	setFraction(double f) Sets the fraction of individuals to consider.
void	setQuantity(int q) Sets the number of top individuals to consider.

Methods inherited from class jenes.stage.operator.Scaling

process

Methods inherited from class jenes.stage.operator.Operator

getStatistics, updateStatistics

Methods inherited from class jenes.stage.AbstractStage

dispose, getFitness, init, isBiggerBetter, isFitnessChanged, setBiggerIsBetter, setBiggerIsBetter, setFitness, setFitness

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_FRACTION

public static double DEFAULT_FRACTION

The defaulf fraction

Constructor Detail

TopScaling

public TopScaling()

Creates an instance with default fraction

TopScaling

public TopScaling(double f)

Creates an instance with the given fraction

Parameters:

f - fraction between 0 (0%) and 1 (i.e. 100%).

TopScaling

public TopScaling(int q)

Creates an instance with the given quantity of individuals

Parameters:

q - quantity of top individuals

Method Detail

getFraction

public final double getFraction()

Returns the fraction

Returns:

setFraction

public final void setFraction(double f)

Sets the fraction of individuals to consider. The value provided as input is trimmed between 0 and 1.

Parameters:

f - the fraction

getQuantity

public final int getQuantity()

Return the number of top individuals to consider

Returns:

quantity

setQuantity

public final void setQuantity(int q)

Sets the number of top individuals to consider.

Parameters:

q - quantity

scale

public void scale(Population<T> pop)

Description copied from class: Scaling

Method used to scale the fitness of indivduals belonging to given Population

Specified by:

scale in class Scaling<T extends Chromosome>

Parameters:

pop - population of individuals to scale