org.apache.commons.math.distribution.AbstractDistribution Maven / Gradle / Ivy
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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;
import java.io.Serializable;
import org.apache.commons.math.MathException;
import org.apache.commons.math.MathRuntimeException;
import org.apache.commons.math.exception.util.LocalizedFormats;
/**
* Base class for probability distributions.
*
* @version $Revision: 1054524 $ $Date: 2011-01-03 05:59:18 +0100 (lun. 03 janv. 2011) $
*/
public abstract class AbstractDistribution
implements Distribution, Serializable {
/** Serializable version identifier */
private static final long serialVersionUID = -38038050983108802L;
/**
* Default constructor.
*/
protected AbstractDistribution() {
super();
}
/**
* For a random variable X whose values are distributed according
* to this distribution, this method returns P(x0 ≤ X ≤ x1).
*
* The default implementation uses the identity
*
* P(x0 ≤ X ≤ x1) = P(X ≤ x1) - P(X ≤ x0)
*
* @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 x0 and x1,
* including the endpoints.
* @throws MathException if the cumulative probability can not be
* computed due to convergence or other numerical errors.
* @throws IllegalArgumentException if x0 > x1
*/
public double cumulativeProbability(double x0, double x1)
throws MathException {
if (x0 > x1) {
throw MathRuntimeException.createIllegalArgumentException(
LocalizedFormats.LOWER_ENDPOINT_ABOVE_UPPER_ENDPOINT,
x0, x1);
}
return cumulativeProbability(x1) - cumulativeProbability(x0);
}
}