ec.pso

Class PSOBreeder

java.lang.Object

ec.Breeder

ec.pso.PSOBreeder

All Implemented Interfaces:

Setup, Singleton, Serializable

public class PSOBreeder
extends Breeder

PSOBreeder is a simple single-threaded Breeder which performs Particle Swarm Optimization using the Particle class as individuals. PSOBreeder relies on a number of parameters which define weights for various vectors computed during Particle Swarm Optimization, plus a few flags:

• Neighborhoods for particles have a size S determined by the parameter neighborhood-size. It's best if S were even.
• Neighborhoods for particles are constructed in one of three ways:
  • random: pick S informants randomly without replacement within the subpopulation, not including the particle itself, once at the beginning of the run.
  • random-each-time: pick S informants randomly without replacement within the subpopulation, not including the particle itself, every single generation.
  • toroidal: pick the floor(S/2) informants to the left of the particle's location within the subpopulation and the ceiling(S/2) informants to the right of the particle's location in the subpopulation, once at the beginning of the run.
• To this you can add the particle itself to the neighborhood, with include-self.
• The basic velocity update equation is VELOCITY <-- (VELOCITY * velocity-coefficent) + (VECTOR-TO-GLOBAL-BEST * global-coefficient) + (VECTOR-TO-NEIGHBORHOOD-BEST * informant-coefficient) + (VECTOR-TO-PERSONAL-BEST * personal-coefficient)
• The basic particle update equation is PARTICLE <-- PARTICLE + VELOCITY

Parameters

base.velocity-coefficient float ≥ 0	(The weight for the velocity)
base.personal-coefficient float ≥ 0	(The weight for the personal-best vector)
base.informant-coefficient float ≥ 0	(The weight for the neighborhood/informant-best vector)
base.global-coefficient float ≥ 0	(The weight for the global-best vector)
base.neighborhood-size int > 0	(The size of the neighborhood of informants, not including the particle)
base.neighborhood-style String, one of: random toroidal random-each-time	(The method of generating the neighborhood of informants, not including the particle)
base.include-self true or false (default)	(Whether to include the particle itself as a member of the neighborhood after building the neighborhood)

Author:

Khaled Ahsan Talukder

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
static int	C_NEIGHBORHOOD_RANDOM
static int	C_NEIGHBORHOOD_RANDOM_EACH_TIME
static int	C_NEIGHBORHOOD_TOROIDAL
double[][]	globalBest
Fitness[]	globalBestFitness
double	globalCoeff
boolean	includeSelf
double	informantCoeff
int	neighborhood
int	neighborhoodSize
static String	P_GLOBAL_COEFFICIENT
static String	P_INCLUDE_SELF
static String	P_INFORMANT_COEFFICIENT
static String	P_NEIGHBORHOOD
static String	P_NEIGHBORHOOD_SIZE
static String	P_PERSONAL_COEFFICIENT
static String	P_VELOCITY_COEFFICIENT
double	personalCoeff
static String	V_NEIGHBORHOOD_RANDOM
static String	V_NEIGHBORHOOD_RANDOM_EACH_TIME
static String	V_NEIGHBORHOOD_TOROIDAL
double	velCoeff

Constructor Summary

Constructors

Constructor and Description
PSOBreeder()

Method Summary

Methods

Modifier and Type	Method and Description
Population	breedPopulation(EvolutionState state) Breeds state.population, returning a new population.
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.

Methods inherited from class java.lang.Object

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

Field Detail

C_NEIGHBORHOOD_RANDOM

public static final int C_NEIGHBORHOOD_RANDOM

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Constant Field Values

C_NEIGHBORHOOD_TOROIDAL

public static final int C_NEIGHBORHOOD_TOROIDAL

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Constant Field Values

C_NEIGHBORHOOD_RANDOM_EACH_TIME

public static final int C_NEIGHBORHOOD_RANDOM_EACH_TIME

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Constant Field Values

P_VELOCITY_COEFFICIENT

public static final String P_VELOCITY_COEFFICIENT

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Constant Field Values

P_PERSONAL_COEFFICIENT

public static final String P_PERSONAL_COEFFICIENT

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Constant Field Values

P_INFORMANT_COEFFICIENT

public static final String P_INFORMANT_COEFFICIENT

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Constant Field Values

P_GLOBAL_COEFFICIENT

public static final String P_GLOBAL_COEFFICIENT

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Constant Field Values

P_INCLUDE_SELF

public static final String P_INCLUDE_SELF

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Constant Field Values

P_NEIGHBORHOOD

public static final String P_NEIGHBORHOOD

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Constant Field Values

P_NEIGHBORHOOD_SIZE

public static final String P_NEIGHBORHOOD_SIZE

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Constant Field Values

V_NEIGHBORHOOD_RANDOM

public static final String V_NEIGHBORHOOD_RANDOM

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Constant Field Values

V_NEIGHBORHOOD_TOROIDAL

public static final String V_NEIGHBORHOOD_TOROIDAL

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Constant Field Values

V_NEIGHBORHOOD_RANDOM_EACH_TIME

public static final String V_NEIGHBORHOOD_RANDOM_EACH_TIME

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Constant Field Values

neighborhood

public int neighborhood

velCoeff

public double velCoeff

personalCoeff

public double personalCoeff

informantCoeff

public double informantCoeff

globalCoeff

public double globalCoeff

neighborhoodSize

public int neighborhoodSize

includeSelf

public boolean includeSelf

globalBest

public double[][] globalBest

globalBestFitness

public Fitness[] globalBestFitness

Constructor Detail

PSOBreeder

public PSOBreeder()

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.

breedPopulation

public Population breedPopulation(EvolutionState state)

Description copied from class: Breeder

Breeds state.population, returning a new population. In general, state.population should not be modified.

Specified by:

breedPopulation in class Breeder