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 */
017package org.apache.commons.math4.optim;
018
019import java.io.Serializable;
020
021import org.apache.commons.math4.util.Pair;
022
023/**
024 * This class holds a point and the vectorial value of an objective function at
025 * that point.
026 *
027 * @see PointValuePair
028 * @see org.apache.commons.math4.analysis.MultivariateVectorFunction
029 * @since 3.0
030 */
031public 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        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}