View Javadoc

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  
18  package org.apache.commons.math.optimization;
19  
20  import java.io.Serializable;
21  
22  import org.apache.commons.math.analysis.MultivariateRealFunction;
23  
24  /** 
25   * This class holds a point and the value of an objective function at this point.
26   * <p>This is a simple immutable container.</p>
27   * @see VectorialPointValuePair
28   * @see MultivariateRealFunction
29   * @version $Revision: 799857 $ $Date: 2009-08-01 09:07:12 -0400 (Sat, 01 Aug 2009) $
30   * @since 2.0
31   */
32  public class RealPointValuePair implements Serializable {
33  
34      /** Serializable version identifier. */
35      private static final long serialVersionUID = 1003888396256744753L;
36  
37      /** Point coordinates. */
38      private final double[] point;
39  
40      /** Value of the objective function at the point. */
41      private final double value;
42  
43      /** Build a point/objective function value pair.
44       * @param point point coordinates (the built instance will store
45       * a copy of the array, not the array passed as argument)
46       * @param value value of an objective function at the point
47       */
48      public RealPointValuePair(final double[] point, final double value) {
49          this.point = point.clone();
50          this.value  = value;
51      }
52  
53      /** Build a point/objective function value pair.
54       * @param point point coordinates (the built instance will store
55       * a copy of the array, not the array passed as argument)
56       * @param value value of an objective function at the point
57       * @param copyArray if true, the input array will be copied, otherwise
58       * it will be referenced
59       */
60      public RealPointValuePair(final double[] point, final double value,
61                                  final boolean copyArray) {
62          this.point = copyArray ? point.clone() : point;
63          this.value  = value;
64      }
65  
66      /** Get the point.
67       * @return a copy of the stored point
68       */
69      public double[] getPoint() {
70          return point.clone();
71      }
72  
73      /** Get a reference to the point.
74       * <p>This method is provided as a convenience to avoid copying
75       * the array, the elements of the array should <em>not</em> be modified.</p>
76       * @return a reference to the internal array storing the point
77       */
78      public double[] getPointRef() {
79          return point;
80      }
81  
82      /** Get the value of the objective function.
83       * @return the stored value of the objective function
84       */
85      public double getValue() {
86          return value;
87      }
88  
89  }