/*
 * 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;


/**
 * Base interface for discrete distributions.
 *
 * @version $Revision: 480440 $ $Date: 2006-11-29 00:14:12 -0700 (Wed, 29 Nov 2006) $
 */
public interface DiscreteDistribution extends Distribution {
    /**
     * For a random variable X whose values are distributed according
     * to this distribution, this method returns P(X = x). In other words, this
     * method represents the probability mass function, or PMF for the distribution.
     * 
     * @param x the value at which the probability mass function is evaluated.
     * @return the value of the probability mass function at x
     */
    double probability(double x);
}