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 * https://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 /*
19 * This is not the original file distributed by the Apache Software Foundation
20 * It has been modified by the Hipparchus project
21 */
22 package org.hipparchus.analysis;
23
24 import org.hipparchus.analysis.function.Sinc;
25
26 /**
27 * Auxiliary class for testing optimizers.
28 *
29 */
30 public class SumSincFunction implements MultivariateFunction {
31 private static final UnivariateFunction sinc = new Sinc();
32
33 /**
34 * Factor that will multiply each term of the sum.
35 */
36 private final double factor;
37
38 /**
39 * @param factor Factor that will multiply each term of the sum.
40 */
41 public SumSincFunction(double factor) {
42 this.factor = factor;
43 }
44
45 /**
46 * @param point Argument.
47 * @return the value of this function at point {@code x}.
48 */
49 @Override
50 public double value(double[] point) {
51 double sum = 0;
52 for (int i = 0, max = point.length; i < max; i++) {
53 final double x = point[i];
54 final double v = sinc.value(x);
55 sum += v;
56 }
57 return factor * sum;
58 }
59
60 }