org.drugis.addis.entities.relativeeffect.GaussianBase.java Source code

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Here is the source code for org.drugis.addis.entities.relativeeffect.GaussianBase.java

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/*
 * This file is part of ADDIS (Aggregate Data Drug Information System).
 * ADDIS is distributed from http://drugis.org/.
 * Copyright  2009 Gert van Valkenhoef, Tommi Tervonen.
 * Copyright  2010 Gert van Valkenhoef, Tommi Tervonen, Tijs Zwinkels,
 * Maarten Jacobs, Hanno Koeslag, Florin Schimbinschi, Ahmad Kamal, Daniel
 * Reid.
 * Copyright  2011 Gert van Valkenhoef, Ahmad Kamal, Daniel Reid, Florin
 * Schimbinschi.
 * Copyright  2012 Gert van Valkenhoef, Daniel Reid, Jol Kuiper, Wouter
 * Reckman.
 * Copyright  2013 Gert van Valkenhoef, Jol Kuiper.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package org.drugis.addis.entities.relativeeffect;

import org.apache.commons.math3.distribution.NormalDistribution;
import org.drugis.common.beans.AbstractObservable;

public abstract class GaussianBase extends AbstractObservable implements Distribution {
    private double d_mu;
    private double d_sigma;
    private NormalDistribution d_dist;

    public GaussianBase(double mu, double sigma) {
        if (Double.isNaN(mu))
            throw new IllegalArgumentException("mu may not be NaN");
        if (Double.isNaN(sigma))
            throw new IllegalArgumentException("sigma may not be NaN");
        if (sigma < 0.0)
            throw new IllegalArgumentException("sigma must be >= 0.0");
        d_mu = mu;
        d_sigma = sigma;
        if (getSigma() != 0.0) {
            d_dist = new NormalDistribution(d_mu, d_sigma);
        }
    }

    protected double calculateQuantile(double p) {
        if (getSigma() == 0.0) {
            return getMu();
        }
        return d_dist.inverseCumulativeProbability(p);
    }

    protected double calculateCumulativeProbability(double x) {
        return d_dist.cumulativeProbability(x);
    }

    public double getSigma() {
        return d_sigma;
    }

    public double getMu() {
        return d_mu;
    }

    public GaussianBase plus(GaussianBase other) {
        if (!canEqual(other))
            throw new IllegalArgumentException("Cannot add together " + getClass().getSimpleName() + " and "
                    + other.getClass().getSimpleName());
        return newInstance(getMu() + other.getMu(),
                Math.sqrt(getSigma() * getSigma() + other.getSigma() * other.getSigma()));
    }

    protected abstract GaussianBase newInstance(double mu, double sigma);

    abstract protected boolean canEqual(GaussianBase other);

    @Override
    public boolean equals(Object obj) {
        if (obj instanceof GaussianBase) {
            GaussianBase other = (GaussianBase) obj;
            return canEqual(other) && d_mu == other.d_mu && d_sigma == other.d_sigma;
        }
        return false;
    }

    @Override
    public int hashCode() {
        return ((Double) d_mu).hashCode() + 31 * ((Double) d_sigma).hashCode();
    }

    @Override
    public String toString() {
        return getClass().getSimpleName() + "(mu=" + getMu() + ", sigma=" + getSigma() + ")";
    }
}