01 /*
02 * Java Genetic Algorithm Library (jenetics-3.5.0).
03 * Copyright (c) 2007-2016 Franz Wilhelmstötter
04 *
05 * Licensed under the Apache License, Version 2.0 (the "License");
06 * you may not use this file except in compliance with the License.
07 * You may obtain a copy of the License at
08 *
09 * 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 * Author:
18 * Franz Wilhelmstötter (franz.wilhelmstoetter@gmx.at)
19 */
20 package org.jenetics.internal.math;
21
22 import org.jenetics.internal.util.require;
23
24 /**
25 * Some statistical (special) functions.
26 *
27 * @author <a href="mailto:franz.wilhelmstoetter@gmx.at">Franz Wilhelmstötter</a>
28 * @since 1.0
29 * @version 3.0
30 */
31 public final class statistics {
32 private statistics() {require.noInstance();}
33
34 /**
35 * Return the minimum value of the given double array.
36 *
37 * @param values the double array.
38 * @return the minimum value or {@link Double#NaN} if the given array is
39 * empty.
40 * @throws NullPointerException if the given array is {@code null}.
41 */
42 public static double min(final double[] values) {
43 double min = Double.NaN;
44 if (values.length > 0) {
45 min = values[0];
46
47 for (int i = values.length; --i >= 1;) {
48 if (values[i] < min) {
49 min = values[i];
50 }
51 }
52 }
53
54 return min;
55 }
56
57 /**
58 * Return the maximum value of the given double array.
59 *
60 * @param values the double array.
61 * @return the maximum value or {@link Double#NaN} if the given array is
62 * empty.
63 * @throws NullPointerException if the given array is {@code null}.
64 */
65 public static double max(final double[] values) {
66 double max = Double.NaN;
67 if (values.length > 0) {
68 max = values[0];
69
70 for (int i = values.length; --i >= 1;) {
71 if (values[i] > max) {
72 max = values[i];
73 }
74 }
75 }
76
77 return max;
78 }
79
80 /**
81 * Add the values of the given array.
82 *
83 * @param values the values to add.
84 * @return the values sum.
85 * @throws NullPointerException if the values are null;
86 */
87 public static long sum(final long[] values) {
88 long sum = 0;
89 for (int i = values.length; --i >= 0;) {
90 sum += values[i];
91 }
92 return sum;
93 }
94
95 }
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