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.nonlinear.scalar;
018
019 import org.apache.commons.math3.analysis.MultivariateFunction;
020 import org.apache.commons.math3.optim.BaseMultivariateOptimizer;
021 import org.apache.commons.math3.optim.OptimizationData;
022 import org.apache.commons.math3.optim.ConvergenceChecker;
023 import org.apache.commons.math3.optim.PointValuePair;
024 import org.apache.commons.math3.exception.TooManyEvaluationsException;
025
026 /**
027 * Base class for a multivariate scalar function optimizer.
028 *
029 * @version $Id$
030 * @since 3.1
031 */
032 public abstract class MultivariateOptimizer
033 extends BaseMultivariateOptimizer<PointValuePair> {
034 /** Objective function. */
035 private MultivariateFunction function;
036 /** Type of optimization. */
037 private GoalType goal;
038
039 /**
040 * @param checker Convergence checker.
041 */
042 protected MultivariateOptimizer(ConvergenceChecker<PointValuePair> checker) {
043 super(checker);
044 }
045
046 /**
047 * {@inheritDoc}
048 *
049 * @param optData Optimization data. The following data will be looked for:
050 * <ul>
051 * <li>{@link org.apache.commons.math3.optim.MaxEval}</li>
052 * <li>{@link org.apache.commons.math3.optim.InitialGuess}</li>
053 * <li>{@link org.apache.commons.math3.optim.SimpleBounds}</li>
054 * <li>{@link ObjectiveFunction}</li>
055 * <li>{@link GoalType}</li>
056 * </ul>
057 * @return {@inheritDoc}
058 * @throws TooManyEvaluationsException if the maximal number of
059 * evaluations is exceeded.
060 */
061 @Override
062 public PointValuePair optimize(OptimizationData... optData)
063 throws TooManyEvaluationsException {
064 // Retrieve settings.
065 parseOptimizationData(optData);
066 // Set up base class and perform computation.
067 return super.optimize(optData);
068 }
069
070 /**
071 * Scans the list of (required and optional) optimization data that
072 * characterize the problem.
073 *
074 * @param optData Optimization data.
075 * The following data will be looked for:
076 * <ul>
077 * <li>{@link ObjectiveFunction}</li>
078 * <li>{@link GoalType}</li>
079 * </ul>
080 */
081 private void parseOptimizationData(OptimizationData... optData) {
082 // The existing values (as set by the previous call) are reused if
083 // not provided in the argument list.
084 for (OptimizationData data : optData) {
085 if (data instanceof GoalType) {
086 goal = (GoalType) data;
087 continue;
088 }
089 if (data instanceof ObjectiveFunction) {
090 function = ((ObjectiveFunction) data).getObjectiveFunction();
091 continue;
092 }
093 }
094 }
095
096 /**
097 * @return the optimization type.
098 */
099 public GoalType getGoalType() {
100 return goal;
101 }
102
103 /**
104 * Computes the objective function value.
105 * This method <em>must</em> be called by subclasses to enforce the
106 * evaluation counter limit.
107 *
108 * @param params Point at which the objective function must be evaluated.
109 * @return the objective function value at the specified point.
110 * @throws TooManyEvaluationsException if the maximal number of
111 * evaluations is exceeded.
112 */
113 protected double computeObjectiveValue(double[] params) {
114 super.incrementEvaluationCount();
115 return function.value(params);
116 }
117 }