001 /* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017 package org.apache.commons.math.distribution; 018 019 /** 020 * The Gamma Distribution. 021 * 022 * <p> 023 * References: 024 * <ul> 025 * <li><a href="http://mathworld.wolfram.com/GammaDistribution.html"> 026 * Gamma Distribution</a></li> 027 * </ul> 028 * </p> 029 * 030 * @version $Revision: 693598 $ $Date: 2008-09-09 16:37:08 -0400 (Tue, 09 Sep 2008) $ 031 */ 032 public interface GammaDistribution extends ContinuousDistribution, HasDensity<Double> { 033 /** 034 * Modify the shape parameter, alpha. 035 * @param alpha the new shape parameter. 036 */ 037 void setAlpha(double alpha); 038 039 /** 040 * Access the shape parameter, alpha 041 * @return alpha. 042 */ 043 double getAlpha(); 044 045 /** 046 * Modify the scale parameter, beta. 047 * @param beta the new scale parameter. 048 */ 049 void setBeta(double beta); 050 051 /** 052 * Access the scale parameter, beta 053 * @return beta. 054 */ 055 double getBeta(); 056 057 /** 058 * Return the probability density for a particular point. 059 * @param x The point at which the density should be computed. 060 * @return The pdf at point x. 061 */ 062 double density(Double x); 063 }