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.math4.legacy.stat.descriptive;
18
19 import org.apache.commons.math4.legacy.exception.MathIllegalArgumentException;
20 import org.apache.commons.math4.legacy.exception.NotPositiveException;
21 import org.apache.commons.math4.legacy.exception.NullArgumentException;
22 import org.apache.commons.math4.legacy.exception.NumberIsTooLargeException;
23 import org.apache.commons.math4.legacy.exception.util.LocalizedFormats;
24 import org.apache.commons.math4.legacy.core.MathArrays;
25
26 /**
27 * Abstract base class for implementations of the {@link UnivariateStatistic} interface.
28 * <p>
29 * Provides a default implementation of <code>evaluate(double[]),</code>
30 * delegating to <code>evaluate(double[], int, int)</code> in the natural way.
31 */
32 public abstract class AbstractUnivariateStatistic
33 implements UnivariateStatistic {
34
35 /** Stored data. */
36 private double[] storedData;
37
38 /**
39 * {@inheritDoc}
40 */
41 @Override
42 public double evaluate(final double[] values) throws MathIllegalArgumentException {
43 MathArrays.verifyValues(values, 0, 0);
44 return evaluate(values, 0, values.length);
45 }
46
47 /**
48 * {@inheritDoc}
49 */
50 @Override
51 public abstract double evaluate(double[] values, int begin, int length)
52 throws MathIllegalArgumentException;
53
54 /**
55 * {@inheritDoc}
56 */
57 @Override
58 public abstract UnivariateStatistic copy();
59
60 /**
61 * Set the data array.
62 * <p>
63 * The stored value is a copy of the parameter array, not the array itself.
64 * </p>
65 * @param values data array to store (may be null to remove stored data)
66 * @see #evaluate()
67 */
68 public void setData(final double[] values) {
69 storedData = (values == null) ? null : values.clone();
70 }
71
72 /**
73 * Get a copy of the stored data array.
74 * @return copy of the stored data array (may be null)
75 */
76 public double[] getData() {
77 return (storedData == null) ? null : storedData.clone();
78 }
79
80 /**
81 * Get a reference to the stored data array.
82 * @return reference to the stored data array (may be null)
83 */
84 protected double[] getDataRef() {
85 return storedData;
86 }
87
88 /**
89 * Set the data array. The input array is copied, not referenced.
90 *
91 * @param values data array to store
92 * @param begin the index of the first element to include
93 * @param length the number of elements to include
94 * @throws MathIllegalArgumentException if values is null or the indices
95 * are not valid
96 * @see #evaluate()
97 */
98 public void setData(final double[] values, final int begin, final int length)
99 throws MathIllegalArgumentException {
100 if (values == null) {
101 throw new NullArgumentException(LocalizedFormats.INPUT_ARRAY);
102 }
103
104 if (begin < 0) {
105 throw new NotPositiveException(LocalizedFormats.START_POSITION, begin);
106 }
107
108 if (length < 0) {
109 throw new NotPositiveException(LocalizedFormats.LENGTH, length);
110 }
111
112 if (begin + length > values.length) {
113 throw new NumberIsTooLargeException(LocalizedFormats.SUBARRAY_ENDS_AFTER_ARRAY_END,
114 begin + length, values.length, true);
115 }
116 storedData = new double[length];
117 System.arraycopy(values, begin, storedData, 0, length);
118 }
119
120 /**
121 * Returns the result of evaluating the statistic over the stored data.
122 * <p>
123 * The stored array is the one which was set by previous calls to {@link #setData(double[])}.
124 * </p>
125 * @return the value of the statistic applied to the stored data
126 * @throws MathIllegalArgumentException if the stored data array is null
127 */
128 public double evaluate() throws MathIllegalArgumentException {
129 return evaluate(storedData);
130 }
131 }