dlife.ga
Class RouletteWheel

java.lang.Object
  dlife.ga.RouletteWheel

All Implemented Interfaces:

ParentSelector, Serializable

public class RouletteWheel
extends Object
implements ParentSelector

An implementation of weighted roulette wheel selection. Each Individual in the Population is given a slot on a hypothetical roulette wheel. The size of each Individual's slot is proportional to its fitness. The wheel is then spun and the Individual on which it stops is selected as the parent. This ParentSelector only works if all individuals have positive fitness. Use a FitnessScaler in order to work with populations where non-positive fitness values are valid.

Version:

Jan 7, 2007

Author:

Grant Braught, Dickinson College

See Also:

Serialized Form

Constructor Summary

RouletteWheel()

Method Summary

Individual

pickParent(Population pop) Use a weighted roulette wheel technique to select an Individual from the Population.

Methods inherited from class java.lang.Object

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

Constructor Detail

RouletteWheel

public RouletteWheel()

Method Detail

pickParent

public Individual pickParent(Population pop)

Use a weighted roulette wheel technique to select an Individual from the Population.

Specified by:

pickParent in interface ParentSelector

Parameters:

pop - the Population to choose from.

Returns:

the Individual selected to become a Parent.

Throws:

IllegalStateException - if any Individual has negative fitness or if all Individuals have 0 fitness.