1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.commons.statistics.inference;
18
19 /**
20 * Represents an alternative hypothesis for a hypothesis test.
21 *
22 * @see <a href="https://en.wikipedia.org/wiki/Alternative_hypothesis">Alternative hypothesis (Wikipedia)</a>
23 * @since 1.1
24 */
25 public enum AlternativeHypothesis {
26 /**
27 * Represents a two-sided test.
28 * <ul>
29 * <li>Null hypothesis (H<sub>0</sub>): {@code p = p0}
30 * <li>Alternative hypothesis (H<sub>1</sub>): {@code p != p0}
31 * </ul>
32 */
33 TWO_SIDED,
34
35 /**
36 * Represents a right-sided test.
37 * <ul>
38 * <li>Null hypothesis (H<sub>0</sub>): {@code p <= p0}
39 * <li>Alternative hypothesis (H<sub>1</sub>): {@code p > p0}
40 * </ul>
41 */
42 GREATER_THAN,
43
44 /**
45 * Represents a left-sided test.
46 * <ul>
47 * <li>Null hypothesis (H<sub>0</sub>): {@code p >= p0}
48 * <li>Alternative hypothesis (H<sub>1</sub>): {@code p < p0}
49 * </ul>
50 */
51 LESS_THAN
52 }