Package ec.select

Class FitProportionateSelection

java.lang.Object

ec.BreedingSource

ec.SelectionMethod

ec.select.FitProportionateSelection

All Implemented Interfaces:

Prototype, Setup, RandomChoiceChooserD, Serializable, Cloneable

Direct Known Subclasses:

BoltzmannSelection, SigmaScalingSelection

public class FitProportionateSelection
extends SelectionMethod

Picks individuals in a population in direct proportion to their fitnesses as returned by their fitness() methods. This is expensive to set up and bring down, so it's not appropriate for steady-state evolution. If you're not familiar with the relative advantages of selection methods and just want a good one, use TournamentSelection instead. Not appropriate for multiobjective fitnesses.

Note: Fitnesses must be non-negative. 0 is assumed to be the worst fitness.

Typical Number of Individuals Produced Per produce(...) call
Always 1.

Default Base
select.fitness-proportionate

See Also:

• Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
double[]	fitnesses	Normalized, totalized fitnesses for the population
static final String	P_FITNESSPROPORTIONATE	Default base

Fields inherited from class ec.SelectionMethod

INDS_PRODUCED, KEY_PARENTS

Fields inherited from class ec.BreedingSource

NO_PROBABILITY, P_PROB, probability

Constructor Summary

Constructors

Constructor	Description
FitProportionateSelection()

Method Summary

Modifier and Type	Method	Description
Parameter	defaultBase()	Returns the default base for this prototype.
void	finishProducing(EvolutionState s, int subpopulation, int thread)	A default version of finishProducing, which does nothing.
void	prepareToProduce(EvolutionState s, int subpopulation, int thread)	A default version of prepareToProduce which does nothing.
int	produce(int subpopulation, EvolutionState state, int thread)	An alternative form of "produce" special to Selection Methods; selects an individual from the given subpopulation and returns its position in that subpopulation.

Methods inherited from class ec.SelectionMethod

produce, produces, produceWithoutCloning, typicalIndsProduced

Methods inherited from class ec.BreedingSource

clone, fillStubs, getProbability, pickRandom, preparePipeline, setProbability, setup, setupProbabilities

Methods inherited from class java.lang.Object

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

Field Details

P_FITNESSPROPORTIONATE

public static final String P_FITNESSPROPORTIONATE

Default base

See Also:

• Constant Field Values

fitnesses

public double[] fitnesses

Normalized, totalized fitnesses for the population

Constructor Details

FitProportionateSelection

public FitProportionateSelection()

Method Details

defaultBase

public Parameter defaultBase()

Description copied from interface: Prototype

Returns the default base for this prototype. This should generally be implemented by building off of the static base() method on the DefaultsForm object for the prototype's package. This should be callable during setup(...).

prepareToProduce

public void prepareToProduce(EvolutionState s,
 int subpopulation,
 int thread)

Description copied from class: SelectionMethod

A default version of prepareToProduce which does nothing.

Overrides:

prepareToProduce in class SelectionMethod

produce

public int produce(int subpopulation,
 EvolutionState state,
 int thread)

Description copied from class: SelectionMethod

An alternative form of "produce" special to Selection Methods; selects an individual from the given subpopulation and returns its position in that subpopulation.

Specified by:

produce in class SelectionMethod

finishProducing

public void finishProducing(EvolutionState s,
 int subpopulation,
 int thread)

Description copied from class: SelectionMethod

A default version of finishProducing, which does nothing.

Overrides:

finishProducing in class SelectionMethod