/*
* Distribution.java
*
* Copyright (C) 2002-2006 Alexei Drummond and Andrew Rambaut
*
* This file is part of BEAST.
* See the NOTICE file distributed with this work for additional
* information regarding copyright ownership and licensing.
*
* BEAST is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* BEAST 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with BEAST; if not, write to the
* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301 USA
*/
package math;
/**
* an interface for a distribution.
*
* @author Alexei Drummond
* @author Andrew Rambaut
* @version $Id: Distribution.java,v 1.7 2005/05/24 20:26:00 rambaut Exp $
*/
public interface Distribution {
/**
* probability density function of the distribution
*
* @param x
* argument
* @return pdf value
*/
public double pdf(double x);
/**
* the natural log of the probability density function of the distribution
*
* @param x
* argument
* @return log pdf value
*/
public double logPdf(double x);
/**
* cumulative density function of the distribution
*
* @param x
* argument
* @return cdf value
*/
public double cdf(double x);
/**
* quantile (inverse cumulative density function) of the distribution
*
* @param y
* argument
* @return icdf value
*/
public double quantile(double y);
/**
* mean of the distribution
*
* @return mean
*/
public double mean();
/**
* variance of the distribution
*
* @return variance
*/
public double variance();
/**
* @return a probability density function representing this distribution
*/
public UnivariateFunction getProbabilityDensityFunction();
}