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    import org.apache.commons.math.analysis.MultivariateRealFunction;
023    
024    /** 
025     * This class holds a point and the value of an objective function at this point.
026     * <p>This is a simple immutable container.</p>
027     * @see VectorialPointValuePair
028     * @see MultivariateRealFunction
029     * @version $Revision: 799857 $ $Date: 2009-08-01 09:07:12 -0400 (Sat, 01 Aug 2009) $
030     * @since 2.0
031     */
032    public class RealPointValuePair implements Serializable {
033    
034        /** Serializable version identifier. */
035        private static final long serialVersionUID = 1003888396256744753L;
036    
037        /** Point coordinates. */
038        private final double[] point;
039    
040        /** Value of the objective function at the point. */
041        private final double value;
042    
043        /** Build a point/objective function value pair.
044         * @param point point coordinates (the built instance will store
045         * a copy of the array, not the array passed as argument)
046         * @param value value of an objective function at the point
047         */
048        public RealPointValuePair(final double[] point, final double value) {
049            this.point = point.clone();
050            this.value  = value;
051        }
052    
053        /** Build a point/objective function value pair.
054         * @param point point coordinates (the built instance will store
055         * a copy of the array, not the array passed as argument)
056         * @param value value of an objective function at the point
057         * @param copyArray if true, the input array will be copied, otherwise
058         * it will be referenced
059         */
060        public RealPointValuePair(final double[] point, final double value,
061                                    final boolean copyArray) {
062            this.point = copyArray ? point.clone() : 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.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    
089    }