ec.steadystate

Class SteadyStateBreeder

java.lang.Object

ec.Breeder

ec.simple.SimpleBreeder

ec.steadystate.SteadyStateBreeder

All Implemented Interfaces:

Setup, Singleton, Serializable

public class SteadyStateBreeder
extends SimpleBreeder

This subclass of Breeder performs the evaluation portion of Steady-State Evolution and (in distributed form) Asynchronous Evolution. The procedure is as follows. We begin with an empty Population and one by one create new Indivdiuals and send them off to be evaluated. In basic Steady-State Evolution the individuals are immediately evaluated and we wait for them; but in Asynchronous Evolution the individuals are evaluated for however long it takes and we don't wait for them to finish. When individuals return they are added to the Population until it is full. No duplicate individuals are allowed.

At this point the system switches to its "steady state": individuals are bred from the population one by one, and sent off to be evaluated. Once again, in basic Steady-State Evolution the individuals are immediately evaluated and we wait for them; but in Asynchronous Evolution the individuals are evaluated for however long it takes and we don't wait for them to finish. When an individual returns, we mark an individual in the Population for death, then replace it with the new returning individual. Note that during the steady-state, Asynchronous Evolution could be still sending back some "new" individuals created during the initialization phase, not "bred" individuals.

The determination of how an individual is marked for death is done by the SteadyStateBreeder. This is a SelectionMethod. Note that this SelectionMethod probably should not be selecting for the "fittest" individuals, but rather for either random individuals (the standard approach) or for "bad" individuals.

Parameters

deselector classname, inherits and != ec.SelectionMethod

(The SelectionMethod used to pick individuals for death)

Version:

1.0

Author:

Sean Luke

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
(package private) BreedingPipeline[]	bp If st.firstTimeAround, this acts exactly like SimpleBreeder.
(package private) SelectionMethod[]	deselectors Loaded during the first iteration of breedPopulation
static String	P_DESELECTOR
private static long	serialVersionUID

Fields inherited from class ec.simple.SimpleBreeder

backupPopulation, clonePipelineAndPopulation, elite, eliteFrac, NOT_SET, P_CLONE_PIPELINE_AND_POPULATION, P_ELITE, P_ELITE_FRAC, P_REEVALUATE_ELITES, P_SEQUENTIAL_BREEDING, pool, reevaluateElites, sequentialBreeding

Constructor Summary

Constructors

Constructor and Description
SteadyStateBreeder() Do we allow duplicates?

Method Summary

Methods

Modifier and Type	Method and Description
Individual	breedIndividual(EvolutionState state, int subpop, int thread)
void	finishPipelines(EvolutionState state)
void	individualReplaced(SteadyStateEvolutionState state, int subpopulation, int thread, int individual) Called whenever individuals have been replaced by new individuals in the population.
void	prepareToBreed(EvolutionState state, int thread)
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.
void	sourcesAreProperForm(SteadyStateEvolutionState state, BreedingPipeline[] breedingPipelines) Called to check to see if the breeding sources are correct -- if you use this method, you must call state.output.exitIfErrors() immediately afterwards.

Methods inherited from class ec.simple.SimpleBreeder

breedPopChunk, breedPopulation, computeSubpopulationLength, loadElites, numElites, shouldBreedSubpop, unmarkElitesEvaluated, usingElitism

Methods inherited from class java.lang.Object

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

Field Detail

serialVersionUID

private static final long serialVersionUID

See Also:

Constant Field Values

bp

BreedingPipeline[] bp

If st.firstTimeAround, this acts exactly like SimpleBreeder. Else, it only breeds one new individual per subpopulation, to place in position 0 of the subpopulation.

P_DESELECTOR

public static final String P_DESELECTOR

See Also:

Constant Field Values

deselectors

SelectionMethod[] deselectors

Loaded during the first iteration of breedPopulation

Constructor Detail

SteadyStateBreeder

public SteadyStateBreeder()

Do we allow duplicates?

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.

Specified by:

setup in interface Setup

Overrides:

setup in class SimpleBreeder

sourcesAreProperForm

public void sourcesAreProperForm(SteadyStateEvolutionState state,
                        BreedingPipeline[] breedingPipelines)

Called to check to see if the breeding sources are correct -- if you use this method, you must call state.output.exitIfErrors() immediately afterwards.

individualReplaced

public void individualReplaced(SteadyStateEvolutionState state,
                      int subpopulation,
                      int thread,
                      int individual)

Called whenever individuals have been replaced by new individuals in the population.

finishPipelines

public void finishPipelines(EvolutionState state)

prepareToBreed

public void prepareToBreed(EvolutionState state,
                  int thread)

breedIndividual

public Individual breedIndividual(EvolutionState state,
                         int subpop,
                         int thread)