1 /*
2 * Copyright 2003-2004 The Apache Software Foundation.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16 package org.apache.commons.math.distribution;
17
18
19 /***
20 * Base interface for discrete distributions.
21 *
22 * @version $Revision: 1.17 $ $Date: 2004/11/07 03:32:48 $
23 */
24 public interface DiscreteDistribution extends Distribution {
25 /***
26 * For a random variable X whose values are distributed according
27 * to this distribution, this method returns P(X = x). In other words, this
28 * method represents the probability mass function, or PMF for the distribution.
29 *
30 * @param x the value at which the probability mass function is evaluated.
31 * @return the value of the probability mass function at x
32 */
33 double probability(double x);
34 }