| /* |
| * 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.math4.legacy.stat.interval; |
| |
| import org.apache.commons.math4.legacy.exception.MathIllegalArgumentException; |
| import org.apache.commons.math4.legacy.exception.util.LocalizedFormats; |
| |
| /** |
| * Represents an interval estimate of a population parameter. |
| * |
| * @since 3.3 |
| */ |
| public class ConfidenceInterval { |
| |
| /** Lower endpoint of the interval. */ |
| private double lowerBound; |
| |
| /** Upper endpoint of the interval. */ |
| private double upperBound; |
| |
| /** |
| * The asserted probability that the interval contains the population. |
| * parameter |
| */ |
| private double confidenceLevel; |
| |
| /** |
| * Create a confidence interval with the given bounds and confidence level. |
| * <p> |
| * Preconditions: |
| * <ul> |
| * <li>{@code lower} must be strictly less than {@code upper}</li> |
| * <li>{@code confidenceLevel} must be strictly between 0 and 1 (exclusive)</li> |
| * </ul> |
| * |
| * @param lowerBound lower endpoint of the interval |
| * @param upperBound upper endpoint of the interval |
| * @param confidenceLevel coverage probability |
| * @throws MathIllegalArgumentException if the preconditions are not met |
| */ |
| public ConfidenceInterval(double lowerBound, double upperBound, double confidenceLevel) { |
| checkParameters(lowerBound, upperBound, confidenceLevel); |
| this.lowerBound = lowerBound; |
| this.upperBound = upperBound; |
| this.confidenceLevel = confidenceLevel; |
| } |
| |
| /** |
| * @return the lower endpoint of the interval |
| */ |
| public double getLowerBound() { |
| return lowerBound; |
| } |
| |
| /** |
| * @return the upper endpoint of the interval |
| */ |
| public double getUpperBound() { |
| return upperBound; |
| } |
| |
| /** |
| * @return the asserted probability that the interval contains the |
| * population parameter |
| */ |
| public double getConfidenceLevel() { |
| return confidenceLevel; |
| } |
| |
| /** |
| * @return String representation of the confidence interval |
| */ |
| @Override |
| public String toString() { |
| return "[" + lowerBound + ";" + upperBound + "] (confidence level:" + confidenceLevel + ")"; |
| } |
| |
| /** |
| * Verifies that (lower, upper) is a valid non-empty interval and confidence |
| * is strictly between 0 and 1. |
| * |
| * @param lower lower endpoint |
| * @param upper upper endpoint |
| * @param confidence confidence level |
| */ |
| private void checkParameters(double lower, double upper, double confidence) { |
| if (lower >= upper) { |
| throw new MathIllegalArgumentException(LocalizedFormats.LOWER_BOUND_NOT_BELOW_UPPER_BOUND, lower, upper); |
| } |
| if (confidence <= 0 || confidence >= 1) { |
| throw new MathIllegalArgumentException(LocalizedFormats.OUT_OF_BOUNDS_CONFIDENCE_LEVEL, confidence, 0, 1); |
| } |
| } |
| } |