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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.descriptive;
18  
19  /**
20   * Configuration for computation of statistics.
21   *
22   * <p>This class is immutable.
23   *
24   * @since 1.1
25   */
26  public final class StatisticsConfiguration {
27      /** Default instance. */
28      private static final StatisticsConfiguration DEFAULT = new StatisticsConfiguration(false);
29  
30      /** Flag to control if the statistic is biased, or should use a bias correction. */
31      private final boolean biased;
32  
33      /**
34       * Create an instance.
35       *
36       * @param biased Biased option.
37       */
38      private StatisticsConfiguration(boolean biased) {
39          this.biased = biased;
40      }
41  
42      /**
43       * Return an instance using the default options.
44       *
45       * <ul>
46       *  <li>{@linkplain #isBiased() Biased = false}
47       * </ul>
48       *
49       * @return default instance
50       */
51      public static StatisticsConfiguration withDefaults() {
52          return DEFAULT;
53      }
54  
55      /**
56       * Return an instance with the configured biased option.
57       *
58       * <p>The correction of bias in a statistic is implementation dependent.
59       * If set to {@code true} then bias correction will be disabled.
60       *
61       * <p>This option is used by:
62       * <ul>
63       *  <li>{@link StandardDeviation}
64       *  <li>{@link Variance}
65       *  <li>{@link Skewness}
66       *  <li>{@link Kurtosis}
67       * </ul>
68       *
69       * @param v Value.
70       * @return an instance
71       */
72      public StatisticsConfiguration withBiased(boolean v) {
73          return new StatisticsConfiguration(v);
74      }
75  
76      /**
77       * Checks if the calculation of the statistic is biased. If {@code false} the calculation
78       * should use a bias correction.
79       *
80       * @return true if biased
81       */
82      public boolean isBiased() {
83          return biased;
84      }
85  }