1 package net.sf.openrocket.util;
3 import static java.lang.Double.NaN;
4 import static java.lang.Math.PI;
5 import static org.junit.Assert.*;
7 import java.util.ArrayList;
10 import org.junit.Test;
12 public class MathUtilTest {
14 public static final double EPS = 0.00000000001;
18 public void rangeTest() {
21 a = MathUtil.range(0, 10, 2);
22 assertEquals(0, a[0], 0);
23 assertEquals(10, a[5], 0);
24 assertEquals(6, a.length, 0);
26 a = MathUtil.range(1, 2, 2);
27 assertEquals(1, a[0], 0);
28 assertEquals(1, a.length, 0);
34 public void miscMathTest() {
36 assertEquals(PI * PI, MathUtil.pow2(PI), EPS);
37 assertEquals(PI * PI * PI, MathUtil.pow3(PI), EPS);
38 assertEquals(PI * PI * PI * PI, MathUtil.pow4(PI), EPS);
40 assertEquals(1.0, MathUtil.clamp(0.9999, 1.0, 2.0), 0);
41 assertEquals(1.23, MathUtil.clamp(1.23, 1.0, 2.0), 0);
42 assertEquals(2.0, MathUtil.clamp(2 + EPS / 100, 1.0, 2.0), 0);
44 assertEquals(1.0f, MathUtil.clamp(0.9999f, 1.0f, 2.0f), 0);
45 assertEquals(1.23f, MathUtil.clamp(1.23f, 1.0f, 2.0f), 0);
46 assertEquals(2.0f, MathUtil.clamp(2.0001f, 1.0f, 2.0f), 0);
48 assertEquals(1, MathUtil.clamp(-3, 1, 5));
49 assertEquals(3, MathUtil.clamp(3, 1, 5));
50 assertEquals(5, MathUtil.clamp(6, 1, 5));
52 assertEquals(-1.0, MathUtil.sign(Double.NEGATIVE_INFINITY), EPS);
53 assertEquals(-1.0, MathUtil.sign(-100), EPS);
54 assertEquals(-1.0, MathUtil.sign(Math.nextAfter(0.0, -1.0)), EPS);
55 assertEquals(1.0, MathUtil.sign(Math.nextUp(0.0)), EPS);
56 assertEquals(1.0, MathUtil.sign(100), EPS);
57 assertEquals(1.0, MathUtil.sign(Double.POSITIVE_INFINITY), EPS);
61 public void hypotTest() {
63 for (int i = 0; i < 10000; i++) {
64 double x = Math.random() * 100 - 50;
65 double y = Math.random() * i - i / 2;
66 double z = Math.hypot(x, y);
67 assertEquals(z, MathUtil.hypot(x, y), EPS);
73 public void reduceTest() {
75 for (int i = -1000; i < 1000; i++) {
76 double angle = Math.random() * 2 * PI;
77 double shift = angle + i * 2 * PI;
78 assertEquals(angle, MathUtil.reduce360(shift), EPS);
81 for (int i = -1000; i < 1000; i++) {
82 double angle = Math.random() * 2 * PI - PI;
83 double shift = angle + i * 2 * PI;
84 assertEquals(angle, MathUtil.reduce180(shift), EPS);
90 public void minmaxTest() {
91 assertEquals(1.0, MathUtil.min(1.0, Math.nextUp(1.0)), 0);
92 assertEquals(1.0, MathUtil.min(1.0, Double.POSITIVE_INFINITY), 0);
93 assertEquals(1.0, MathUtil.min(NaN, 1.0), 0);
94 assertEquals(1.0, MathUtil.min(1.0, NaN), 0);
95 assertEquals(NaN, MathUtil.min(NaN, NaN), 0);
97 assertEquals(Math.nextUp(1.0), MathUtil.max(1.0, Math.nextUp(1.0)), 0);
98 assertEquals(Double.POSITIVE_INFINITY, MathUtil.max(1.0, Double.POSITIVE_INFINITY), 0);
99 assertEquals(1.0, MathUtil.max(NaN, 1.0), 0);
100 assertEquals(1.0, MathUtil.max(1.0, NaN), 0);
101 assertEquals(NaN, MathUtil.max(NaN, NaN), 0);
103 assertEquals(1.0, MathUtil.min(1.0, 2.0, 3.0), 0);
104 assertEquals(1.0, MathUtil.min(1.0, NaN, NaN), 0);
105 assertEquals(1.0, MathUtil.min(NaN, 1.0, NaN), 0);
106 assertEquals(1.0, MathUtil.min(NaN, NaN, 1.0), 0);
107 assertEquals(1.0, MathUtil.min(2.0, NaN, 1.0), 0);
108 assertEquals(1.0, MathUtil.min(1.0, 2.0, NaN), 0);
109 assertEquals(1.0, MathUtil.min(NaN, 2.0, 1.0), 0);
111 assertEquals(3.0, MathUtil.max(1.0, 3.0, 2.0), 0);
112 assertEquals(1.0, MathUtil.max(1.0, NaN, NaN), 0);
113 assertEquals(1.0, MathUtil.max(NaN, 1.0, NaN), 0);
114 assertEquals(1.0, MathUtil.max(NaN, NaN, 1.0), 0);
115 assertEquals(2.0, MathUtil.max(2.0, NaN, 1.0), 0);
116 assertEquals(2.0, MathUtil.max(1.0, 2.0, NaN), 0);
117 assertEquals(2.0, MathUtil.max(NaN, 2.0, 1.0), 0);
119 assertEquals(1.0, MathUtil.min(1.0, 2.0, 3.0, 4.0), 0);
120 assertEquals(1.0, MathUtil.min(1.0, NaN, NaN, NaN), 0);
121 assertEquals(1.0, MathUtil.min(NaN, 1.0, NaN, NaN), 0);
122 assertEquals(1.0, MathUtil.min(NaN, NaN, 1.0, NaN), 0);
123 assertEquals(1.0, MathUtil.min(2.0, NaN, 1.0, NaN), 0);
124 assertEquals(1.0, MathUtil.min(2.0, NaN, NaN, 1.0), 0);
125 assertEquals(1.0, MathUtil.min(1.0, 2.0, NaN, 3.0), 0);
126 assertEquals(1.0, MathUtil.min(NaN, 2.0, 3.0, 1.0), 0);
131 public void mapTest() {
132 assertEquals(1.0, MathUtil.map(1.0, 0.0, 5.0, -1.0, 9.0), EPS);
133 assertEquals(7.0, MathUtil.map(1.0, 5.0, 0.0, -1.0, 9.0), EPS);
134 assertEquals(7.0, MathUtil.map(1.0, 0.0, 5.0, 9.0, -1.0), EPS);
135 assertEquals(6.0, MathUtil.map(6.0, 0.0, 5.0, Math.nextUp(6.0), 6.0), EPS);
136 assertEquals(6.0, MathUtil.map(6.0, 0.0, 0.0, Math.nextUp(6.0), 6.0), EPS);
138 MathUtil.map(6.0, 1.0, Math.nextUp(1.0), 1.0, 2.0);
139 fail("Should not be reached.");
140 } catch (IllegalArgumentException normal) {
143 assertEquals(7.0, MathUtil.map(Math.nextUp(1.0), 0.0, 5.0, 9.0, -1.0), EPS);
148 public void mapCoordinateTest() {
149 assertEquals(new Coordinate(0.8, 2.0, 1.6, 4.0),
150 MathUtil.map(1.0, 0.0, 5.0, new Coordinate(0, 1, 2, 3), new Coordinate(4, 6, 0, 8)));
155 public void equalsTest() {
156 assertTrue(MathUtil.equals(1.0, 1.0 + MathUtil.EPSILON / 3));
157 assertFalse(MathUtil.equals(1.0, 1.0 + MathUtil.EPSILON * 2));
158 assertTrue(MathUtil.equals(-1.0, -1.0 + MathUtil.EPSILON / 3));
159 assertFalse(MathUtil.equals(-1.0, -1.0 + MathUtil.EPSILON * 2));
161 for (double zero : new double[] { 0.0, MathUtil.EPSILON / 10, -MathUtil.EPSILON / 10 }) {
163 assertTrue(MathUtil.equals(zero, MathUtil.EPSILON / 3));
164 assertTrue(MathUtil.equals(zero, -MathUtil.EPSILON / 3));
165 assertFalse(MathUtil.equals(zero, MathUtil.EPSILON * 2));
166 assertFalse(MathUtil.equals(zero, -MathUtil.EPSILON * 2));
168 assertTrue(MathUtil.equals(MathUtil.EPSILON / 3, zero));
169 assertTrue(MathUtil.equals(-MathUtil.EPSILON / 3, zero));
170 assertFalse(MathUtil.equals(MathUtil.EPSILON * 2, zero));
171 assertFalse(MathUtil.equals(-MathUtil.EPSILON * 2, zero));
175 for (double value : new double[] { PI * 1e20, -PI * 1e20 }) {
176 assertTrue("value=" + value, MathUtil.equals(value, value + 1));
177 assertTrue("value=" + value, MathUtil.equals(value, Math.nextUp(value)));
178 assertTrue("value=" + value, MathUtil.equals(value, value * (1 + MathUtil.EPSILON)));
181 assertFalse(MathUtil.equals(NaN, 0.0));
182 assertFalse(MathUtil.equals(0.0, NaN));
183 assertFalse(MathUtil.equals(NaN, NaN));
187 public void testAverageStddev() {
188 List<Integer> ints = new ArrayList<Integer>();
189 List<Double> doubles = new ArrayList<Double>();
203 assertEquals(4.75, MathUtil.average(ints), EPS);
204 assertEquals(1.707825127659933, MathUtil.stddev(ints), EPS);
205 assertEquals(4.771666666666667, MathUtil.average(doubles), EPS);
206 assertEquals(2.024454659078999, MathUtil.stddev(doubles), EPS);
210 public void testMedian() {
211 List<Integer> ints = new ArrayList<Integer>();
212 List<Double> doubles = new ArrayList<Double>();
226 assertEquals(4.5, MathUtil.median(ints), EPS);
227 assertEquals(4.415, MathUtil.median(doubles), EPS);
232 assertEquals(5, MathUtil.median(ints), EPS);
233 assertEquals(5.43, MathUtil.median(doubles), EPS);
237 public void testInterpolate() {
242 x = new ArrayList<Double>();
243 y = new ArrayList<Double>();
246 v= MathUtil.interpolate(null, y, 0.0);
247 assertEquals("Failed to test for domain null", Double.NaN, v, EPS);
249 v = MathUtil.interpolate(x, y, 0.0);
250 assertEquals("Failed to test for empty domain", Double.NaN, v, EPS);
252 x = new ArrayList<Double>();
254 y = new ArrayList<Double>();
256 v = MathUtil.interpolate(x, null, 0.0);
257 assertEquals("Failed to test for range null", Double.NaN, v, EPS);
259 v = MathUtil.interpolate(x, y, 0.0);
260 assertEquals("Failed to test for empty range", Double.NaN, v, EPS);
262 x = new ArrayList<Double>();
265 y = new ArrayList<Double>();
269 v = MathUtil.interpolate(x,y,0.0);
270 assertEquals("Failed to test t out of domain", Double.NaN, v, EPS);
272 v = MathUtil.interpolate(x,y,5.0);
273 assertEquals("Failed to test t out of domain", Double.NaN, v, EPS);
275 v = MathUtil.interpolate(x,y,1.0);
276 assertEquals("Failed to calculate left endpoint", 15.0, v, EPS);
277 v = MathUtil.interpolate(x,y,2.0);
278 assertEquals("Failed to calculate right endpoint", 17.0, v, EPS);
279 v = MathUtil.interpolate(x,y,1.5);
280 assertEquals("Failed to calculate center", 16.0, v, EPS);
282 x = new ArrayList<Double>();
287 y = new ArrayList<Double>();
292 v = MathUtil.interpolate(x,y,1.5);
293 assertEquals("Failed to calculate center with longer list", 16.0, v, EPS);