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 * https://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
18 /*
19 * This is not the original file distributed by the Apache Software Foundation
20 * It has been modified by the Hipparchus project
21 */
22
23 package org.hipparchus.stat.ranking;
24
25 /**
26 * Strategies for handling NaN values in rank transformations.
27 * <ul>
28 * <li>MINIMAL - NaNs are treated as minimal in the ordering, equivalent to
29 * (that is, tied with) <code>Double.NEGATIVE_INFINITY</code>.</li>
30 * <li>MAXIMAL - NaNs are treated as maximal in the ordering, equivalent to
31 * <code>Double.POSITIVE_INFINITY</code></li>
32 * <li>REMOVED - NaNs are removed before the rank transform is applied</li>
33 * <li>FIXED - NaNs are left "in place," that is the rank transformation is
34 * applied to the other elements in the input array, but the NaN elements
35 * are returned unchanged.</li>
36 * <li>FAILED - If any NaN is encountered in the input array, an appropriate
37 * exception is thrown</li>
38 * </ul>
39 *
40 */
41 public enum NaNStrategy {
42
43 /** NaNs are considered minimal in the ordering */
44 MINIMAL,
45
46 /** NaNs are considered maximal in the ordering */
47 MAXIMAL,
48
49 /** NaNs are removed before computing ranks */
50 REMOVED,
51
52 /** NaNs are left in place */
53 FIXED,
54
55 /** NaNs result in an exception */
56 FAILED
57 }