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+/*
+ * 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;
+
+/**
+ * The Pascal distribution.  The Pascal distribution is a special case of the
+ * Negative Binomial distribution where the number of successes parameter is an
+ * integer.
+ *
+ * There are various ways to express the probability mass and distribution
+ * functions for the Pascal distribution.  The convention employed by the
+ * library is to express these functions in terms of the number of failures in
+ * a Bernoulli experiment [2].
+ *
+ * <p>
+ * References:
+ * <ol>
+ * <li><a href="http://mathworld.wolfram.com/NegativeBinomialDistribution.html">
+ * Negative Binomial Distribution</a></li>
+ * <oi><a href="http://en.wikipedia.org/wiki/Negative_binomial_distribution#Waiting_time_in_a_Bernoulli_process">Waiting Time in a Bernoulli Process</a></li>
+ * </ul>
+ * </p>
+ *
+ * @version $Revision: 920852 $ $Date: 2010-03-09 13:53:44 +0100 (mar. 09 mars 2010) $
+ * @since 1.2
+ */
+public interface PascalDistribution extends IntegerDistribution {
+    /**
+     * Access the number of successes for this distribution.
+     *
+     * @return the number of successes
+     */
+    int getNumberOfSuccesses();
+
+    /**
+     * Access the probability of success for this distribution.
+     *
+     * @return the probability of success
+     */
+    double getProbabilityOfSuccess();
+
+    /**
+     * Change the number of successes for this distribution.
+     *
+     * @param successes the new number of successes
+     * @deprecated as of v2.1
+     */
+    @Deprecated
+    void setNumberOfSuccesses(int successes);
+
+    /**
+     * Change the probability of success for this distribution.
+     *
+     * @param p the new probability of success
+     * @deprecated as of v2.1
+     */
+    @Deprecated
+    void setProbabilityOfSuccess(double p);
+}