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    }