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 package org.hipparchus.fitting;
23
24 import java.util.List;
25 import java.util.ArrayList;
26 import java.io.Serializable;
27
28 /**
29 * Simple container for weighted observed points used
30 * in {@link AbstractCurveFitter curve fitting} algorithms.
31 *
32 */
33 public class WeightedObservedPoints implements Serializable {
34
35 /** Serializable version id. */
36 private static final long serialVersionUID = 20130813L;
37
38 /** Observed points. */
39 private final List<WeightedObservedPoint> observations;
40
41 /** Simple constructor.
42 * @since 3.0
43 */
44 public WeightedObservedPoints() {
45 this.observations = new ArrayList<>();
46 }
47
48 /**
49 * Adds a point to the sample.
50 * Calling this method is equivalent to calling
51 * {@code add(1.0, x, y)}.
52 *
53 * @param x Abscissa of the point.
54 * @param y Observed value at {@code x}. After fitting we should
55 * have {@code f(x)} as close as possible to this value.
56 *
57 * @see #add(double, double, double)
58 * @see #add(WeightedObservedPoint)
59 * @see #toList()
60 */
61 public void add(double x, double y) {
62 add(1d, x, y);
63 }
64
65 /**
66 * Adds a point to the sample.
67 *
68 * @param weight Weight of the observed point.
69 * @param x Abscissa of the point.
70 * @param y Observed value at {@code x}. After fitting we should
71 * have {@code f(x)} as close as possible to this value.
72 *
73 * @see #add(double, double)
74 * @see #add(WeightedObservedPoint)
75 * @see #toList()
76 */
77 public void add(double weight, double x, double y) {
78 observations.add(new WeightedObservedPoint(weight, x, y));
79 }
80
81 /**
82 * Adds a point to the sample.
83 *
84 * @param observed Observed point to add.
85 *
86 * @see #add(double, double)
87 * @see #add(double, double, double)
88 * @see #toList()
89 */
90 public void add(WeightedObservedPoint observed) {
91 observations.add(observed);
92 }
93
94 /**
95 * Gets a <em>snapshot</em> of the observed points.
96 * The list of stored points is copied in order to ensure that
97 * modification of the returned instance does not affect this
98 * container.
99 * Conversely, further modification of this container (through
100 * the {@code add} or {@code clear} methods) will not affect the
101 * returned list.
102 *
103 * @return the observed points, in the order they were added to this
104 * container.
105 *
106 * @see #add(double, double)
107 * @see #add(double, double, double)
108 * @see #add(WeightedObservedPoint)
109 */
110 public List<WeightedObservedPoint> toList() {
111 // The copy is necessary to ensure thread-safety because of the
112 // "clear" method (which otherwise would be able to empty the
113 // list of points while it is being used by another thread).
114 return new ArrayList<WeightedObservedPoint>(observations);
115 }
116
117 /**
118 * Removes all observations from this container.
119 */
120 public void clear() {
121 observations.clear();
122 }
123 }