selectfitnessrange.java

遗传算法源代码,实现了选择操作、交叉操作和变异操作

/*--- formatted by Jindent 2.1, (www.c-lab.de/~jindent) ---*/

/**
 * SelectLeastFitness Class
 *
 * location: net.openai.ai.ga.selection.common.SelectLeastFitness
 *
 */
package net.openai.ai.ga.selection.common;

import net.openai.ai.ga.selection.*;
import net.openai.ai.ga.population.*;
import net.openai.ai.ga.cell.*;

import java.util.Iterator;

/**
 * <code>SelectFitnessRange</code> is a <code>SelectionAlgorithm</code>
 * that will return a portion of the passed <code>Population</code> that
 * have a fitness in the given range.
 *
 * @author	Jared Grubb
 * @version	%I%, %G%
 * @since	JDK1.3
 */
public class SelectFitnessRange implements SelectionAlgorithm {
    private double lowerBound, upperBound;
    private boolean lowerExclusive, upperExclusive;

    /**
     * Creates a new <code>SelectFitnessRange</code> object for choosing
     * the <code>Cell</code>s out of the specified <code>Population</code> who
     * have a fitness in the specified range, inclusive. (Equilivant to
     * <code>SelectFitnessRange(lowerBound, false, upperBound, false)</code>).
     *
     * @param lowerBound the lower bound of the fitness range to allow, inclusive
     * @param upperBound the upper bound of the fitness range to allow, inclusive
     * @throws <code>ArithmeticException</code> on lowerBound>upperBound
     */
    public SelectFitnessRange(double lowerBound, double upperBound) {
        this(lowerBound, false, upperBound, false);
    }

    /**
     * Creates a new <code>SelectFitnessRange</code> object for choosing
     * the <code>Cell</code>s out of the specified <code>Population</code> who
     * have a fitness in the specified range, specified with whether each
     * bound is treated inclusive or exclusive.
     *
     * @param lowerBound the lower bound of the fitness range to allow
     * @param lowerExclusive <code>false</code> lowerBound is inclusive
     *                       <code>true</code> lowerBound is exclusive
     * @param upperBound the upper bound of the fitness range to allow
     * @param upperExclusive <code>false</code> upperBound is inclusive
     *                       <code>true</code> upperrBound is exclusive
     * @throws <code>ArithmeticException</code> on lowerBound>upperBound
     */
    public SelectFitnessRange(double lowerBound, boolean lowerExclusive,
                              double upperBound, boolean upperExclusive) {
        if (lowerBound>upperBound)
            throw new ArithmeticException(
                "SelectFitnessRange: lowerBound exceed upperBound, "+lowerBound+">"+upperBound);
        this.lowerBound = lowerBound;
        this.lowerExclusive = lowerExclusive;
        this.upperBound = upperBound;
        this.upperExclusive = upperExclusive;
    }

    /**
     * Chooses the <code>Cell</code>s in the specified <code>Population</code>
     * with fitness in a given range. There is no limit to the number of
     * members returned; it is possible that no cells are returned (when none
     * meet the range requirements) or that all the cells are returned (when
     * they all meet the requirements).
     *
     * @param pop  the <code>Population</code> to choose from
     * @return a selected <code>Population</code> in arbitrary order
     */
    public Population selectFromPopulation(Population pop) {
        Population output = new Population();

        Cell tempCell;
        double tempFitness;

        for(Iterator i=pop.getCellIterator(); i.hasNext(); ) {
            tempCell = (Cell) i.next();
            tempFitness = tempCell.getFitness();

            if (tempFitness>this.upperBound || tempFitness<this.lowerBound)
                continue;

            if (lowerExclusive && tempFitness==this.lowerBound)
                continue;
            if (upperExclusive && tempFitness==this.upperBound)
                continue;

            output.addCell(tempCell);
        }

        return output;
    }
}



/*--- formatting done in "Sun Java Convention" style on 12-28-2000 ---*/