ec.vector.breed
Class VectorCrossoverPipeline

java.lang.Object
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  +--ec.BreedingSource
        |
        +--ec.BreedingPipeline
              |
              +--ec.vector.breed.VectorCrossoverPipeline
All Implemented Interfaces:
java.lang.Cloneable, Prototype, RandomChoiceChooser, java.io.Serializable, Setup, SteadyStateBSourceForm

public class VectorCrossoverPipeline
extends BreedingPipeline

VectorCrossoverPipeline is a BreedingPipeline which implements a simple default crossover for VectorIndividuals. Normally it takes two individuals and returns two crossed-over child individuals. Optionally, it can take two individuals, cross them over, but throw away the second child (a one-child crossover). VectorCrossoverPipeline works by calling defaultCrossover(...) on the first parent individual.

Typical Number of Individuals Produced Per produce(...) call
2 * minimum typical number of individuals produced by each source, unless tossSecondParent is set, in which case it's simply the minimum typical number.

Number of Sources
2

Parameters
base.toss
bool = true or false (default)/td>
(after crossing over with the first new individual, should its second sibling individual be thrown away instead of adding it to the population?)

Default Base
vector.xover

See Also:
Serialized Form

Field Summary
static int NUM_SOURCES
           
static java.lang.String P_CROSSOVER
           
static java.lang.String P_TOSS
           
 boolean tossSecondParent
          Should the pipeline discard the second parent after crossing over?
 
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
VectorCrossoverPipeline()
           
 
Method Summary
 Parameter defaultBase()
          Returns the default base for this prototype.
 int numSources()
          Returns 2
 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.
 java.lang.Object protoClone()
          Creates a new individual cloned from a prototype, and suitable to begin use in its own evolutionary context.
 void setup(EvolutionState state, Parameter base)
          Sets up the BreedingPipeline.
 int typicalIndsProduced()
          Returns 2 * minimum number of typical individuals produced by any sources, else 1* minimum number if tossSecondParent is true.
 
Methods inherited from class ec.BreedingPipeline
individualReplaced, maxChildProduction, minChildProduction, preparePipeline, prepareToProduce, produces, sourcesAreProperForm
 
Methods inherited from class ec.BreedingSource
getProbability, pickRandom, protoCloneSimple, setProbability, setupProbabilities
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

P_TOSS

public static final java.lang.String P_TOSS

P_CROSSOVER

public static final java.lang.String P_CROSSOVER

NUM_SOURCES

public static final int NUM_SOURCES

tossSecondParent

public boolean tossSecondParent
Should the pipeline discard the second parent after crossing over?
Constructor Detail

VectorCrossoverPipeline

public VectorCrossoverPipeline()
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()
Returns 2
Overrides:
numSources in class BreedingPipeline

protoClone

public java.lang.Object protoClone()
                            throws java.lang.CloneNotSupportedException
Description copied from interface: Prototype
Creates a new individual cloned from a prototype, and suitable to begin use in its own evolutionary context.

The question here is whether or not this means to perform a "deep" or "light" ("shallow") clone, or something in-between. You may need to deep-clone parts of your object rather than simply copying their references, depending on the situation:

Implementations.

If you know that your superclasses will never change their protoClone() implementations, you might try inlining them in your overridden protoClone() method. But this is dangerous (though it yields a small net increase).

In general, you want to keep your deep cloning to an absolute minimum, so that you don't have to call protoClone() but one time.

The approach taken here is the fastest that I am aware of while still permitting objects to be specified at runtime from a parameter file. It would be faster to use the "new" operator; but that would require hard-coding that we can't do. Although using java.lang.Object.clone() entails an extra layer that deals with stripping away the "protected" keyword and also wrapping the exception handling (which is a BIG hit, about three times as slow as using "new"), it's still MUCH faster than using java.lang.Class.newInstance(), and also much faster than rolling our own Clone() method.

Overrides:
protoClone 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}.

Overrides:
setup in class BreedingPipeline
Following copied from class: ec.BreedingSource
See Also:
Prototype.setup(EvolutionState,Parameter)

typicalIndsProduced

public int typicalIndsProduced()
Returns 2 * minimum number of typical individuals produced by any sources, else 1* minimum number if tossSecondParent is true.
Overrides:
typicalIndsProduced in class BreedingPipeline

produce

public int produce(int min,
                   int max,
                   int start,
                   int subpopulation,
                   Individual[] inds,
                   EvolutionState state,
                   int thread)
            throws java.lang.CloneNotSupportedException
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.
Overrides:
produce in class BreedingSource