ec.select
Class FitProportionateSelection

java.lang.Object
  extended by ec.BreedingSource
      extended by ec.SelectionMethod
          extended by ec.select.FitProportionateSelection
All Implemented Interfaces:
Prototype, Setup, RandomChoiceChooser, java.io.Serializable, java.lang.Cloneable

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

Version:
1.0
Author:
Sean Luke
See Also:
Serialized Form

Field Summary
static java.lang.String P_FITNESSPROPORTIONATE
          Default base
 float[] sortedFit
          Sorted, normalized, totalized fitnesses for the population
 
Fields inherited from class ec.SelectionMethod
INDS_PRODUCED
 
Fields inherited from class ec.BreedingSource
CHECKBOUNDARY, DEFAULT_PRODUCED, NO_PROBABILITY, P_PROB, probability, UNUSED
 
Constructor Summary
FitProportionateSelection()
           
 
Method Summary
 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
preparePipeline, produce, produces, typicalIndsProduced
 
Methods inherited from class ec.BreedingSource
clone, getProbability, pickRandom, setProbability, setup, setupProbabilities
 
Methods inherited from class java.lang.Object
equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

P_FITNESSPROPORTIONATE

public static final java.lang.String P_FITNESSPROPORTIONATE
Default base

See Also:
Constant Field Values

sortedFit

public float[] sortedFit
Sorted, normalized, totalized fitnesses for the population

Constructor Detail

FitProportionateSelection

public FitProportionateSelection()
Method Detail

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