1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.commons.math3.optim.nonlinear.scalar;
18
19 import org.apache.commons.math3.analysis.MultivariateFunction;
20 import org.apache.commons.math3.optim.BaseMultivariateOptimizer;
21 import org.apache.commons.math3.optim.OptimizationData;
22 import org.apache.commons.math3.optim.ConvergenceChecker;
23 import org.apache.commons.math3.optim.PointValuePair;
24 import org.apache.commons.math3.exception.TooManyEvaluationsException;
25
26 /**
27 * Base class for a multivariate scalar function optimizer.
28 *
29 * @since 3.1
30 */
31 public abstract class MultivariateOptimizer
32 extends BaseMultivariateOptimizer<PointValuePair> {
33 /** Objective function. */
34 private MultivariateFunction function;
35 /** Type of optimization. */
36 private GoalType goal;
37
38 /**
39 * @param checker Convergence checker.
40 */
41 protected MultivariateOptimizer(ConvergenceChecker<PointValuePair> checker) {
42 super(checker);
43 }
44
45 /**
46 * {@inheritDoc}
47 *
48 * @param optData Optimization data. In addition to those documented in
49 * {@link BaseMultivariateOptimizer#parseOptimizationData(OptimizationData[])
50 * BaseMultivariateOptimizer}, this method will register the following data:
51 * <ul>
52 * <li>{@link ObjectiveFunction}</li>
53 * <li>{@link GoalType}</li>
54 * </ul>
55 * @return {@inheritDoc}
56 * @throws TooManyEvaluationsException if the maximal number of
57 * evaluations is exceeded.
58 */
59 @Override
60 public PointValuePair optimize(OptimizationData... optData)
61 throws TooManyEvaluationsException {
62 // Set up base class and perform computation.
63 return super.optimize(optData);
64 }
65
66 /**
67 * Scans the list of (required and optional) optimization data that
68 * characterize the problem.
69 *
70 * @param optData Optimization data.
71 * The following data will be looked for:
72 * <ul>
73 * <li>{@link ObjectiveFunction}</li>
74 * <li>{@link GoalType}</li>
75 * </ul>
76 */
77 @Override
78 protected void parseOptimizationData(OptimizationData... optData) {
79 // Allow base class to register its own data.
80 super.parseOptimizationData(optData);
81
82 // The existing values (as set by the previous call) are reused if
83 // not provided in the argument list.
84 for (OptimizationData data : optData) {
85 if (data instanceof GoalType) {
86 goal = (GoalType) data;
87 continue;
88 }
89 if (data instanceof ObjectiveFunction) {
90 function = ((ObjectiveFunction) data).getObjectiveFunction();
91 continue;
92 }
93 }
94 }
95
96 /**
97 * @return the optimization type.
98 */
99 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 public double computeObjectiveValue(double[] params) {
114 super.incrementEvaluationCount();
115 return function.value(params);
116 }
117 }