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    package org.apache.commons.math3.optim;
018    
019    import java.io.Serializable;
020    import org.apache.commons.math3.util.Pair;
021    
022    /**
023     * This class holds a point and the vectorial value of an objective function at
024     * that point.
025     *
026     * @see PointValuePair
027     * @see org.apache.commons.math3.analysis.MultivariateVectorFunction
028     * @version $Id: PointVectorValuePair.java 1416643 2012-12-03 19:37:14Z tn $
029     * @since 3.0
030     */
031    public class PointVectorValuePair extends Pair<double[], double[]> implements Serializable {
032        /** Serializable UID. */
033        private static final long serialVersionUID = 20120513L;
034    
035        /**
036         * Builds a point/objective function value pair.
037         *
038         * @param point Point coordinates. This instance will store
039         * a copy of the array, not the array passed as argument.
040         * @param value Value of the objective function at the point.
041         */
042        public PointVectorValuePair(final double[] point,
043                                    final double[] value) {
044            this(point, value, true);
045        }
046    
047        /**
048         * Build a point/objective function value pair.
049         *
050         * @param point Point coordinates.
051         * @param value Value of the objective function at the point.
052         * @param copyArray if {@code true}, the input arrays will be copied,
053         * otherwise they will be referenced.
054         */
055        public PointVectorValuePair(final double[] point,
056                                    final double[] value,
057                                    final boolean copyArray) {
058            super(copyArray ?
059                  ((point == null) ? null :
060                   point.clone()) :
061                  point,
062                  copyArray ?
063                  ((value == null) ? null :
064                   value.clone()) :
065                  value);
066        }
067    
068        /**
069         * Gets the point.
070         *
071         * @return a copy of the stored point.
072         */
073        public double[] getPoint() {
074            final double[] p = getKey();
075            return p == null ? null : p.clone();
076        }
077    
078        /**
079         * Gets a reference to the point.
080         *
081         * @return a reference to the internal array storing the point.
082         */
083        public double[] getPointRef() {
084            return getKey();
085        }
086    
087        /**
088         * Gets the value of the objective function.
089         *
090         * @return a copy of the stored value of the objective function.
091         */
092        @Override
093        public double[] getValue() {
094            final double[] v = super.getValue();
095            return v == null ? null : v.clone();
096        }
097    
098        /**
099         * Gets a reference to the value of the objective function.
100         *
101         * @return a reference to the internal array storing the value of
102         * the objective function.
103         */
104        public double[] getValueRef() {
105            return super.getValue();
106        }
107    
108        /**
109         * Replace the instance with a data transfer object for serialization.
110         * @return data transfer object that will be serialized
111         */
112        private Object writeReplace() {
113            return new DataTransferObject(getKey(), getValue());
114        }
115    
116        /** Internal class used only for serialization. */
117        private static class DataTransferObject implements Serializable {
118            /** Serializable UID. */
119            private static final long serialVersionUID = 20120513L;
120            /**
121             * Point coordinates.
122             * @Serial
123             */
124            private final double[] point;
125            /**
126             * Value of the objective function at the point.
127             * @Serial
128             */
129            private final double[] value;
130    
131            /** Simple constructor.
132             * @param point Point coordinates.
133             * @param value Value of the objective function at the point.
134             */
135            public DataTransferObject(final double[] point, final double[] value) {
136                this.point = point.clone();
137                this.value = value.clone();
138            }
139    
140            /** Replace the deserialized data transfer object with a {@link PointValuePair}.
141             * @return replacement {@link PointValuePair}
142             */
143            private Object readResolve() {
144                return new PointVectorValuePair(point, value, false);
145            }
146        }
147    }