ec.breed
Class BufferedBreedingPipeline

java.lang.Object
  extended by ec.BreedingSource
      extended by ec.BreedingPipeline
          extended by ec.breed.BufferedBreedingPipeline
All Implemented Interfaces:
Prototype, Setup, SteadyStateBSourceForm, RandomChoiceChooser, java.io.Serializable, java.lang.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
 Individual[] buffer
           
 int currentSize
           
static int INDS_PRODUCED
           
static int NUM_SOURCES
           
static java.lang.String P_BUFFERED
           
static java.lang.String P_BUFSIZE
           
 
Fields inherited from class ec.BreedingPipeline
DYNAMIC_SOURCES, mybase, P_NUMSOURCES, P_SOURCE, sources, V_SAME
 
Fields inherited from class ec.BreedingSource
CHECKBOUNDARY, DEFAULT_PRODUCED, NO_PROBABILITY, P_PROB, probability, UNUSED
 
Constructor Summary
BufferedBreedingPipeline()
           
 
Method Summary
 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, 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 java.lang.String P_BUFSIZE
See Also:
Constant Field Values

P_BUFFERED

public static final java.lang.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