ec.breed

Class BufferedBreedingPipeline

java.lang.Object

ec.BreedingSource

ec.BreedingPipeline

ec.breed.BufferedBreedingPipeline

All Implemented Interfaces:

Prototype, Setup, SteadyStateBSourceForm, RandomChoiceChooserD, Serializable, Cloneable

public class BufferedBreedingPipeline
extends BreedingPipeline

If empty, a BufferedBreedingPipeline makes a request of exactly num-inds individuals from a single child source; it then uses these individuals to fill requests (returning min each time), until the buffer is emptied, at which time it grabs exactly num-inds more individuals, and so on.

What is this useful for? Well, let's say for example that you want to cross over two individuals, then cross them over again. You'd like to hook up two CrossoverPipelines in series. Unfortunately, CrossoverPipeline takes two sources; even if you set them to the same source, it requests one individual from the first source and then one from the second, where what you really want is for it to request two individuals from a single source (the other CrossoverPipeline).

The solution to this is to hook a CrossoverPipeline as the source to a BufferedBreedingPipeline of buffer-size 2 (or some multiple of 2 actually). Then the BufferedBreedingPipeline is set as both sources to another CrossoverPipeline.

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

Number of Sources
1

Parameters

base.num-inds int >= 1

(the buffer size)

Default Base
breed.buffered

Version:

1.0

Author:

Sean Luke

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
Individual[]	buffer
int	currentSize
static int	INDS_PRODUCED
static int	NUM_SOURCES
static String	P_BUFFERED
static String	P_BUFSIZE

Fields inherited from class ec.BreedingPipeline

DYNAMIC_SOURCES, likelihood, mybase, P_LIKELIHOOD, P_NUMSOURCES, P_SOURCE, sources, V_SAME

Fields inherited from class ec.BreedingSource

NO_PROBABILITY, P_PROB, probability

Constructor Summary

Constructors

Constructor and Description
BufferedBreedingPipeline()

Method Summary

Methods

Modifier and Type	Method and Description
Parameter	defaultBase() Returns the default base for this prototype.
int	numSources() Returns the number of sources to this pipeline.
void	prepareToProduce(EvolutionState state, int subpopulation, int thread) Called before produce(...), usually once a generation, or maybe only once if you're doing steady-state evolution, to let the breeding source "warm up" prior to producing.
int	produce(int min, int max, int start, int subpopulation, Individual[] inds, EvolutionState state, int thread) Produces n individuals from the given subpopulation and puts them into inds[start...start+n-1], where n = Min(Max(q,min),max), where q is the "typical" number of individuals the BreedingSource produces in one shot, and returns n.
void	setup(EvolutionState state, Parameter base) Sets up the BreedingPipeline.
int	typicalIndsProduced() Returns the "typical" number of individuals produced -- by default this is the minimum typical number of individuals produced by any children sources of the pipeline.

Methods inherited from class ec.BreedingPipeline

clone, finishProducing, individualReplaced, maxChildProduction, minChildProduction, preparePipeline, produces, reproduce, sourcesAreProperForm

Methods inherited from class ec.BreedingSource

getProbability, pickRandom, setProbability, setupProbabilities

Methods inherited from class java.lang.Object

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

Field Detail

P_BUFSIZE

public static final String P_BUFSIZE

See Also:

Constant Field Values

P_BUFFERED

public static final String P_BUFFERED

See Also:

Constant Field Values

INDS_PRODUCED

public static final int INDS_PRODUCED

See Also:

Constant Field Values

NUM_SOURCES

public static final int NUM_SOURCES

See Also:

Constant Field Values

buffer

public Individual[] buffer

currentSize

public int currentSize

Constructor Detail

BufferedBreedingPipeline

public BufferedBreedingPipeline()

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(...).

numSources

public int numSources()

Description copied from class: BreedingPipeline

Returns the number of sources to this pipeline. Called during BreedingPipeline's setup. Be sure to return a value > 0, or DYNAMIC_SOURCES which indicates that setup should check the parameter file for the parameter "num-sources" to make its determination.

Specified by:

numSources in class BreedingPipeline

typicalIndsProduced

public int typicalIndsProduced()

Description copied from class: BreedingPipeline

Returns the "typical" number of individuals produced -- by default this is the minimum typical number of individuals produced by any children sources of the pipeline. If you'd prefer something different, override this method.

Overrides:

typicalIndsProduced in class BreedingPipeline

setup

public void setup(EvolutionState state,
         Parameter base)

Description copied from class: BreedingSource

Sets up the BreedingPipeline. You can use state.output.error here because the top-level caller promises to call exitIfErrors() after calling setup. Note that probability might get modified again by an external source if it doesn't normalize right.

The most common modification is to normalize it with some other set of probabilities, then set all of them up in increasing summation; this allows the use of the fast static BreedingSource-picking utility method, BreedingSource.pickRandom(...). In order to use this method, for example, if four breeding source probabilities are {0.3, 0.2, 0.1, 0.4}, then they should get normalized and summed by the outside owners as: {0.3, 0.5, 0.6, 1.0}.

Specified by:

setup in interface Prototype

Specified by:

setup in interface Setup

Overrides:

setup in class BreedingPipeline

See Also:

Prototype.setup(EvolutionState,Parameter)

prepareToProduce

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

Description copied from class: BreedingSource

Called before produce(...), usually once a generation, or maybe only once if you're doing steady-state evolution, to let the breeding source "warm up" prior to producing. Individuals should be produced from old individuals in positions [start...start+length] in the subpopulation only. May be called again to reset the BreedingSource for a whole 'nuther subpopulation.

Overrides:

prepareToProduce in class BreedingPipeline

produce

public int produce(int min,
          int max,
          int start,
          int subpopulation,
          Individual[] inds,
          EvolutionState state,
          int thread)

Description copied from class: BreedingSource

Produces n individuals from the given subpopulation and puts them into inds[start...start+n-1], where n = Min(Max(q,min),max), where q is the "typical" number of individuals the BreedingSource produces in one shot, and returns n. max must be >= min, and min must be >= 1. For example, crossover might typically produce two individuals, tournament selection might typically produce a single individual, etc.

Specified by:

produce in class BreedingSource