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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.math3.optim;
18  
19  import java.io.Serializable;
20  import org.apache.commons.math3.util.Pair;
21  
22  /**
23   * This class holds a point and the vectorial value of an objective function at
24   * that point.
25   *
26   * @see PointValuePair
27   * @see org.apache.commons.math3.analysis.MultivariateVectorFunction
28   * @version $Id: PointVectorValuePair.java 1435539 2013-01-19 13:27:24Z tn $
29   * @since 3.0
30   */
31  public class PointVectorValuePair extends Pair<double[], double[]> implements Serializable {
32      /** Serializable UID. */
33      private static final long serialVersionUID = 20120513L;
34  
35      /**
36       * Builds a point/objective function value pair.
37       *
38       * @param point Point coordinates. This instance will store
39       * a copy of the array, not the array passed as argument.
40       * @param value Value of the objective function at the point.
41       */
42      public PointVectorValuePair(final double[] point,
43                                  final double[] value) {
44          this(point, value, true);
45      }
46  
47      /**
48       * Build a point/objective function value pair.
49       *
50       * @param point Point coordinates.
51       * @param value Value of the objective function at the point.
52       * @param copyArray if {@code true}, the input arrays will be copied,
53       * otherwise they will be referenced.
54       */
55      public PointVectorValuePair(final double[] point,
56                                  final double[] value,
57                                  final boolean copyArray) {
58          super(copyArray ?
59                ((point == null) ? null :
60                 point.clone()) :
61                point,
62                copyArray ?
63                ((value == null) ? null :
64                 value.clone()) :
65                value);
66      }
67  
68      /**
69       * Gets the point.
70       *
71       * @return a copy of the stored point.
72       */
73      public double[] getPoint() {
74          final double[] p = getKey();
75          return p == null ? null : p.clone();
76      }
77  
78      /**
79       * Gets a reference to the point.
80       *
81       * @return a reference to the internal array storing the point.
82       */
83      public double[] getPointRef() {
84          return getKey();
85      }
86  
87      /**
88       * Gets the value of the objective function.
89       *
90       * @return a copy of the stored value of the objective function.
91       */
92      @Override
93      public double[] getValue() {
94          final double[] v = super.getValue();
95          return v == null ? null : v.clone();
96      }
97  
98      /**
99       * Gets a reference to the value of the objective function.
100      *
101      * @return a reference to the internal array storing the value of
102      * the objective function.
103      */
104     public double[] getValueRef() {
105         return super.getValue();
106     }
107 
108     /**
109      * Replace the instance with a data transfer object for serialization.
110      * @return data transfer object that will be serialized
111      */
112     private Object writeReplace() {
113         return new DataTransferObject(getKey(), getValue());
114     }
115 
116     /** Internal class used only for serialization. */
117     private static class DataTransferObject implements Serializable {
118         /** Serializable UID. */
119         private static final long serialVersionUID = 20120513L;
120         /**
121          * Point coordinates.
122          * @Serial
123          */
124         private final double[] point;
125         /**
126          * Value of the objective function at the point.
127          * @Serial
128          */
129         private final double[] value;
130 
131         /** Simple constructor.
132          * @param point Point coordinates.
133          * @param value Value of the objective function at the point.
134          */
135         public DataTransferObject(final double[] point, final double[] value) {
136             this.point = point.clone();
137             this.value = value.clone();
138         }
139 
140         /** Replace the deserialized data transfer object with a {@link PointValuePair}.
141          * @return replacement {@link PointValuePair}
142          */
143         private Object readResolve() {
144             return new PointVectorValuePair(point, value, false);
145         }
146     }
147 }