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.util.Arrays;
020    
021    /**
022     * Simple optimization constraints: lower and upper bounds.
023     * The valid range of the parameters is an interval that can be infinite
024     * (in one or both directions).
025     * <br/>
026     * Immutable class.
027     *
028     * @version $Id: SimpleBounds.java 1435539 2013-01-19 13:27:24Z tn $
029     * @since 3.1
030     */
031    public class SimpleBounds implements OptimizationData {
032        /** Lower bounds. */
033        private final double[] lower;
034        /** Upper bounds. */
035        private final double[] upper;
036    
037        /**
038         * @param lB Lower bounds.
039         * @param uB Upper bounds.
040         */
041        public SimpleBounds(double[] lB,
042                            double[] uB) {
043            lower = lB.clone();
044            upper = uB.clone();
045        }
046    
047        /**
048         * Gets the lower bounds.
049         *
050         * @return the lower bounds.
051         */
052        public double[] getLower() {
053            return lower.clone();
054        }
055        /**
056         * Gets the upper bounds.
057         *
058         * @return the upper bounds.
059         */
060        public double[] getUpper() {
061            return upper.clone();
062        }
063    
064        /**
065         * Factory method that creates instance of this class that represents
066         * unbounded ranges.
067         *
068         * @param dim Number of parameters.
069         * @return a new instance suitable for passing to an optimizer that
070         * requires bounds specification.
071         */
072        public static SimpleBounds unbounded(int dim) {
073            final double[] lB = new double[dim];
074            Arrays.fill(lB, Double.NEGATIVE_INFINITY);
075            final double[] uB = new double[dim];
076            Arrays.fill(uB, Double.POSITIVE_INFINITY);
077    
078            return new SimpleBounds(lB, uB);
079        }
080    }