jasima.core.random.continuous.DblDistribution.java Source code

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Here is the source code for jasima.core.random.continuous.DblDistribution.java

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/*******************************************************************************
 * This file is part of jasima, v1.3, the Java simulator for manufacturing and 
 * logistics.
 *  
 * Copyright (c) 2015       jasima solutions UG
 * Copyright (c) 2010-2015 Torsten Hildebrandt and jasima contributors
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *******************************************************************************/
package jasima.core.random.continuous;

import jasima.core.util.Pair;

import java.util.Random;

import org.apache.commons.math3.distribution.RealDistribution;

/**
 * Returns an arbitrarily distributed random number stream. Its distribution is
 * determined by an arbitrary {@link RealDistribution} object from the Apache
 * Commons Math library. This class is usually not used directly but through its
 * various sub-classes implementing particular distributions and exposing their
 * parameters as Java Bean properties.
 * 
 * @author Torsten Hildebrandt
 * @version 
 *          "$Id$"
 */
public class DblDistribution extends DblStream {

    private static final long serialVersionUID = -157283852135250753L;

    private RealDistribution distribution;

    public DblDistribution() {
        this(null, null, null);
    }

    public DblDistribution(RealDistribution distribution) {
        this(null, null, distribution);
    }

    public DblDistribution(Random random, RealDistribution distribution) {
        this(random, null, distribution);
    }

    public DblDistribution(String name, RealDistribution distribution) {
        this(null, name, distribution);
    }

    public DblDistribution(Random random, String name, RealDistribution distribution) {
        super();
        setRndGen(random);
        setDistribution(distribution);
        setName(name);
    }

    public RealDistribution getDistribution() {
        return distribution;
    }

    /**
     * Sets the continuous distribution to use.
     */
    protected void setDistribution(RealDistribution distribution) {
        this.distribution = distribution;
    }

    @Override
    public double nextDbl() {
        return distribution.inverseCumulativeProbability(rndGen.nextDouble());
    }

    @Override
    public double getNumericalMean() {
        if (distribution == null) {
            return Double.NaN;
        } else {
            return distribution.getNumericalMean();
        }
    }

    @Override
    public Pair<Double, Double> getValueRange() {
        if (distribution == null)
            return null;
        return new Pair<Double, Double>(distribution.getSupportLowerBound(), distribution.getSupportUpperBound());
    }

    @Override
    public String toString() {
        return "DblDistribution(" + String.valueOf(distribution) + ')';
    }

}