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: 811685 $ $Date: 2009-09-05 13:36:48 -0400 (Sat, 05 Sep 2009) $
029     * @since 2.0
030     */
031    public class RealPointValuePair implements Serializable {
032    
033        /** Serializable version identifier. */
034        private static final long serialVersionUID = 1003888396256744753L;
035    
036        /** Point coordinates. */
037        private final double[] point;
038    
039        /** Value of the objective function at the point. */
040        private final double value;
041    
042        /** Build a point/objective function value pair.
043         * @param point point coordinates (the built instance will store
044         * a copy of the array, not the array passed as argument)
045         * @param value value of an objective function at the point
046         */
047        public RealPointValuePair(final double[] point, final double value) {
048            this.point = point.clone();
049            this.value  = value;
050        }
051    
052        /** Build a point/objective function value pair.
053         * @param point point coordinates (the built instance will store
054         * a copy of the array, not the array passed as argument)
055         * @param value value of an objective function at the point
056         * @param copyArray if true, the input array will be copied, otherwise
057         * it will be referenced
058         */
059        public RealPointValuePair(final double[] point, final double value,
060                                    final boolean copyArray) {
061            this.point = copyArray ? point.clone() : point;
062            this.value  = value;
063        }
064    
065        /** Get the point.
066         * @return a copy of the stored point
067         */
068        public double[] getPoint() {
069            return point.clone();
070        }
071    
072        /** Get a reference to the point.
073         * <p>This method is provided as a convenience to avoid copying
074         * the array, the elements of the array should <em>not</em> be modified.</p>
075         * @return a reference to the internal array storing the point
076         */
077        public double[] getPointRef() {
078            return point;
079        }
080    
081        /** Get the value of the objective function.
082         * @return the stored value of the objective function
083         */
084        public double getValue() {
085            return value;
086        }
087    
088    }