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Diffstat (limited to 'src/main/java/org/apache/commons/math/distribution/Distribution.java')
| -rw-r--r-- | src/main/java/org/apache/commons/math/distribution/Distribution.java | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/src/main/java/org/apache/commons/math/distribution/Distribution.java b/src/main/java/org/apache/commons/math/distribution/Distribution.java new file mode 100644 index 0000000..221aeb7 --- /dev/null +++ b/src/main/java/org/apache/commons/math/distribution/Distribution.java @@ -0,0 +1,56 @@ +/* + * 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; + +import org.apache.commons.math.MathException; + +/** + * Base interface for probability distributions. + * + * @version $Revision: 1054524 $ $Date: 2011-01-03 05:59:18 +0100 (lun. 03 janv. 2011) $ + */ +public interface 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 (cumulative) distribution function, or + * CDF, for this distribution. + * + * @param x the value at which the distribution function is evaluated. + * @return the probability that a random variable with this + * distribution takes a value less than or equal to <code>x</code> + * @throws MathException if the cumulative probability can not be + * computed due to convergence or other numerical errors. + */ + double cumulativeProbability(double x) throws MathException; + + /** + * For a random variable X whose values are distributed according + * to this distribution, this method returns P(x0 ≤ X ≤ x1). + * + * @param x0 the (inclusive) lower bound + * @param x1 the (inclusive) upper bound + * @return the probability that a random variable with this distribution + * will take a value between <code>x0</code> and <code>x1</code>, + * including the endpoints + * @throws MathException if the cumulative probability can not be + * computed due to convergence or other numerical errors. + * @throws IllegalArgumentException if <code>x0 > x1</code> + */ + double cumulativeProbability(double x0, double x1) throws MathException; + +} |