001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.commons.statistics.inference;
018
019/**
020 * Contains the result of a test for significance.
021 *
022 * @since 1.1
023 */
024public interface SignificanceResult {
025    /**
026     * Returns the test statistic.
027     *
028     * @return the statistic
029     */
030    double getStatistic();
031
032    /**
033     * Returns the test statistic p-value.
034     *
035     * <p>The number returned is the smallest significance level at which one can
036     * reject the null hypothesis.
037     *
038     * @return the p-value
039     */
040    double getPValue();
041
042    /**
043     * Returns true iff the null hypothesis can be rejected with {@code 100 * (1 - alpha)}
044     * percent confidence.
045     *
046     * <p>The default implementation uses {@code p < alpha}.
047     *
048     * @param alpha Significance level of the test.
049     * @return true iff null hypothesis can be rejected with confidence {@code 1 - alpha}
050     * @throws IllegalArgumentException if {@code alpha} is not in the range {@code (0, 0.5]}.
051     */
052    default boolean reject(double alpha) {
053        Arguments.checkSignificance(alpha);
054        return getPValue() < alpha;
055    }
056}