/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.commons.math.distribution;

import org.apache.commons.math.MathException;

/**
 * Computes the cumulative, inverse cumulative and density functions for the
 * beta distribuiton.
 *
 * @see <a href=
 *      "http://en.wikipedia.org/wiki/Beta_distribution">Beta_distribution</a>
 * @version $Revision$ $Date$
 * @since 2.0
 */
public interface BetaDistribution extends ContinuousDistribution, HasDensity<Double> {
	/**
	 * Modify the shape parameter, alpha.
	 * 
	 * @param alpha
	 *            the new shape parameter.
	 */
	void setAlpha(double alpha);

	/**
	 * Access the shape parameter, alpha
	 * 
	 * @return alpha.
	 */
	double getAlpha();

	/**
	 * Modify the shape parameter, beta.
	 * 
	 * @param beta
	 *            the new scale parameter.
	 */
	void setBeta(double beta);

	/**
	 * Access the shape parameter, beta
	 * 
	 * @return beta.
	 */
	double getBeta();

	/**
	 * Return the probability density for a particular point.
	 * 
	 * @param x
	 *            The point at which the density should be computed.
	 * @return The pdf at point x.
	 * @exception MathException
	 *                if probability density cannot be computed
	 */
	double density(Double x) throws MathException;

}
