001 /*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 * http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017
018 package org.apache.commons.math.optimization;
019
020 import java.io.Serializable;
021
022
023 /**
024 * This class holds a point and the value of an objective function at this point.
025 * <p>This is a simple immutable container.</p>
026 * @see VectorialPointValuePair
027 * @see org.apache.commons.math.analysis.MultivariateRealFunction
028 * @version $Revision: 980981 $ $Date: 2010-07-31 00:03:04 +0200 (sam. 31 juil. 2010) $
029 * @since 2.0
030 */
031 public class RealPointValuePair implements Serializable {
032 /** Serializable version identifier. */
033 private static final long serialVersionUID = 1003888396256744753L;
034
035 /** Point coordinates. */
036 private final double[] point;
037
038 /** Value of the objective function at the point. */
039 private final double value;
040
041 /** Build a point/objective function value pair.
042 * @param point point coordinates (the built instance will store
043 * a copy of the array, not the array passed as argument)
044 * @param value value of an objective function at the point
045 */
046 public RealPointValuePair(final double[] point, final double value) {
047 this.point = (point == null) ? null : point.clone();
048 this.value = value;
049 }
050
051 /** Build a point/objective function value pair.
052 * @param point point coordinates (the built instance will store
053 * a copy of the array, not the array passed as argument)
054 * @param value value of an objective function at the point
055 * @param copyArray if true, the input array will be copied, otherwise
056 * it will be referenced
057 */
058 public RealPointValuePair(final double[] point, final double value,
059 final boolean copyArray) {
060 this.point = copyArray ?
061 ((point == null) ? null : point.clone()) :
062 point;
063 this.value = value;
064 }
065
066 /** Get the point.
067 * @return a copy of the stored point
068 */
069 public double[] getPoint() {
070 return (point == null) ? null : point.clone();
071 }
072
073 /** Get a reference to the point.
074 * <p>This method is provided as a convenience to avoid copying
075 * the array, the elements of the array should <em>not</em> be modified.</p>
076 * @return a reference to the internal array storing the point
077 */
078 public double[] getPointRef() {
079 return point;
080 }
081
082 /** Get the value of the objective function.
083 * @return the stored value of the objective function
084 */
085 public double getValue() {
086 return value;
087 }
088 }