ec.simple
Class SimpleBreeder

java.lang.Object
  ec.Breeder
      ec.simple.SimpleBreeder

All Implemented Interfaces:

Setup, Singleton, java.io.Serializable

Direct Known Subclasses:

NSGA2Breeder, SpatialBreeder, SPEA2Breeder, SteadyStateBreeder

public class SimpleBreeder
extends Breeder

Breeds each subpopulation separately, with no inter-population exchange, and using a generational approach. A SimpleBreeder may have multiple threads; it divvys up a subpopulation into chunks and hands one chunk to each thread to populate. One array of BreedingPipelines is obtained from a population's Species for each operating breeding thread. Prior to breeding a subpopulation, a SimpleBreeder may first fill part of the new subpopulation up with the best n individuals from the old subpopulation. By default, n is 0 for each subpopulation (that is, this "elitism" is not done). The elitist step is performed by a single thread.

Parameters

base.elite.i int >= 0 (default=0)	(the number of elitist individuals for subpopulation i)
base.reevalate-elites.i boolean (default = false)	(should we reevaluate the elites of subpopulation i each generation?)

See Also:

Serialized Form

Field Summary

int[]	elite An array[subpop] of the number of elites to keep for that subpopulation
static java.lang.String	P_ELITE
static java.lang.String	P_REEVALUATE_ELITES
boolean[]	reevaluateElites

Constructor Summary

SimpleBreeder()

Method Summary

protected void	breedPopChunk(Population newpop, EvolutionState state, int[] numinds, int[] from, int threadnum) A private helper function for breedPopulation which breeds a chunk of individuals in a subpopulation for a given thread.
Population	breedPopulation(EvolutionState state) A simple breeder that doesn't attempt to do any cross- population breeding.
int	computeSubpopulationLength(Population newpop, int subpopulation) Elites are often stored in the top part of the subpopulation; this function returns what part of the subpopulation contains individuals to replace with newly-bred ones (up to but not including the elites).
protected void	loadElites(EvolutionState state, Population newpop) A private helper function for breedPopulation which loads elites into a subpopulation.
void	setup(EvolutionState state, Parameter base) Sets up the object by reading it from the parameters stored in state, built off of the parameter base base.
protected void	unmarkElitesEvaluated(Population newpop)

Methods inherited from class java.lang.Object

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

Field Detail

P_ELITE

public static final java.lang.String P_ELITE

See Also:

Constant Field Values

P_REEVALUATE_ELITES

public static final java.lang.String P_REEVALUATE_ELITES

See Also:

Constant Field Values

elite

public int[] elite

An array[subpop] of the number of elites to keep for that subpopulation

reevaluateElites

public boolean[] reevaluateElites

Constructor Detail

SimpleBreeder

public SimpleBreeder()

Method Detail

setup

public void setup(EvolutionState state,
                  Parameter base)

Description copied from interface: Setup

Sets up the object by reading it from the parameters stored in state, built off of the parameter base base. If an ancestor implements this method, be sure to call super.setup(state,base); before you do anything else.

computeSubpopulationLength

public int computeSubpopulationLength(Population newpop,
                                      int subpopulation)

Elites are often stored in the top part of the subpopulation; this function returns what part of the subpopulation contains individuals to replace with newly-bred ones (up to but not including the elites).

breedPopulation

public Population breedPopulation(EvolutionState state)

A simple breeder that doesn't attempt to do any cross- population breeding. Basically it applies pipelines, one per thread, to various subchunks of a new population.

Specified by:

breedPopulation in class Breeder

breedPopChunk

protected void breedPopChunk(Population newpop,
                             EvolutionState state,
                             int[] numinds,
                             int[] from,
                             int threadnum)

A private helper function for breedPopulation which breeds a chunk of individuals in a subpopulation for a given thread. Although this method is declared public (for the benefit of a private helper class in this file), you should not call it.

unmarkElitesEvaluated

protected void unmarkElitesEvaluated(Population newpop)

loadElites

protected void loadElites(EvolutionState state,
                          Population newpop)

A private helper function for breedPopulation which loads elites into a subpopulation.