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
18 package org.apache.commons.math.estimation;
19
20 /**
21 * This interface represents an estimation problem.
22 *
23 * <p>This interface should be implemented by all real estimation
24 * problems before they can be handled by the estimators through the
25 * {@link Estimator#estimate Estimator.estimate} method.</p>
26 *
27 * <p>An estimation problem, as seen by a solver is a set of
28 * parameters and a set of measurements. The parameters are adjusted
29 * during the estimation through the {@link #getUnboundParameters
30 * getUnboundParameters} and {@link EstimatedParameter#setEstimate
31 * EstimatedParameter.setEstimate} methods. The measurements both have
32 * a measured value which is generally fixed at construction and a
33 * theoretical value which depends on the model and hence varies as
34 * the parameters are adjusted. The purpose of the solver is to reduce
35 * the residual between these values, it can retrieve the measurements
36 * through the {@link #getMeasurements getMeasurements} method.</p>
37 *
38 * @see Estimator
39 * @see WeightedMeasurement
40 *
41 * @version $Revision: 620312 $ $Date: 2008-02-10 12:28:59 -0700 (Sun, 10 Feb 2008) $
42 * @since 1.2
43 *
44 */
45
46 public interface EstimationProblem {
47 /**
48 * Get the measurements of an estimation problem.
49 * @return measurements
50 */
51 public WeightedMeasurement[] getMeasurements();
52
53 /**
54 * Get the unbound parameters of the problem.
55 * @return unbound parameters
56 */
57 public EstimatedParameter[] getUnboundParameters();
58
59 /**
60 * Get all the parameters of the problem.
61 * @return parameters
62 */
63 public EstimatedParameter[] getAllParameters();
64
65 }