1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.commons.math.distribution;
18
19
20 /**
21 * Base interface for discrete distributions.
22 *
23 * @version $Revision: 480440 $ $Date: 2006-11-29 00:14:12 -0700 (Wed, 29 Nov 2006) $
24 */
25 public interface DiscreteDistribution extends Distribution {
26 /**
27 * For a random variable X whose values are distributed according
28 * to this distribution, this method returns P(X = x). In other words, this
29 * method represents the probability mass function, or PMF for the distribution.
30 *
31 * @param x the value at which the probability mass function is evaluated.
32 * @return the value of the probability mass function at x
33 */
34 double probability(double x);
35 }