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.math4.legacy.fitting;
18
19 import org.apache.commons.math4.legacy.analysis.polynomials.PolynomialFunction;
20
21 /**
22 * Fits points to a {@link
23 * org.apache.commons.math4.legacy.analysis.polynomials.PolynomialFunction.Parametric polynomial}
24 * function.
25 * <br>
26 * The size of the {@link #withStartPoint(double[]) initial guess} array defines the
27 * degree of the polynomial to be fitted.
28 * They must be sorted in increasing order of the polynomial's degree.
29 * The optimal values of the coefficients will be returned in the same order.
30 *
31 * @since 3.3
32 */
33 public final class PolynomialCurveFitter extends SimpleCurveFitter {
34 /** Parametric function to be fitted. */
35 private static final PolynomialFunction.Parametric FUNCTION = new PolynomialFunction.Parametric();
36
37 /**
38 * Constructor used by the factory methods.
39 *
40 * @param initialGuess Initial guess.
41 * @param maxIter Maximum number of iterations of the optimization algorithm.
42 */
43 private PolynomialCurveFitter(double[] initialGuess,
44 int maxIter) {
45 super(FUNCTION, initialGuess, null, maxIter);
46 }
47
48 /**
49 * Creates a default curve fitter.
50 * Zero will be used as initial guess for the coefficients, and the maximum
51 * number of iterations of the optimization algorithm is set to
52 * {@link Integer#MAX_VALUE}.
53 *
54 * @param degree Degree of the polynomial to be fitted.
55 * @return a curve fitter.
56 *
57 * @see #withStartPoint(double[])
58 * @see #withMaxIterations(int)
59 */
60 public static PolynomialCurveFitter create(int degree) {
61 return new PolynomialCurveFitter(new double[degree + 1], Integer.MAX_VALUE);
62 }
63 }