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.*;
9 public class MathUtilTest {
11 public static final double EPS = 0.00000000001;
14 public void miscMathTest() {
16 assertEquals(PI*PI, MathUtil.pow2(PI), EPS);
17 assertEquals(PI*PI*PI, MathUtil.pow3(PI), EPS);
18 assertEquals(PI*PI*PI*PI, MathUtil.pow4(PI), EPS);
20 assertEquals(1.0, MathUtil.clamp(0.9999, 1.0, 2.0));
21 assertEquals(1.23, MathUtil.clamp(1.23, 1.0, 2.0));
22 assertEquals(2.0, MathUtil.clamp(2 + EPS/100, 1.0, 2.0));
24 assertEquals(1.0f, MathUtil.clamp(0.9999f, 1.0f, 2.0f));
25 assertEquals(1.23f, MathUtil.clamp(1.23f, 1.0f, 2.0f));
26 assertEquals(2.0f, MathUtil.clamp(2.0001f, 1.0f, 2.0f));
28 assertEquals(1, MathUtil.clamp(-3, 1, 5));
29 assertEquals(3, MathUtil.clamp(3, 1, 5));
30 assertEquals(5, MathUtil.clamp(6, 1, 5));
32 assertEquals(-1.0, MathUtil.sign(Double.NEGATIVE_INFINITY));
33 assertEquals(-1.0, MathUtil.sign(-100));
34 assertEquals(-1.0, MathUtil.sign(Math.nextAfter(0.0, -1.0)));
35 assertEquals( 1.0, MathUtil.sign(Math.nextUp(0.0)));
36 assertEquals( 1.0, MathUtil.sign(100));
37 assertEquals( 1.0, MathUtil.sign(Double.POSITIVE_INFINITY));
41 public void hypotTest() {
43 for (int i=0; i<10000; i++) {
44 double x = Math.random()*100 - 50;
45 double y = Math.random()*i - i/2;
46 double z = Math.hypot(x, y);
47 assertEquals(z, MathUtil.hypot(x, y), EPS);
53 public void reduceTest() {
55 for (int i=-1000; i<1000; i++) {
56 double angle = Math.random() * 2*PI;
57 double shift = angle + i*2*PI;
58 assertEquals(angle, MathUtil.reduce360(shift), EPS);
61 for (int i=-1000; i<1000; i++) {
62 double angle = Math.random() * 2*PI - PI;
63 double shift = angle + i*2*PI;
64 assertEquals(angle, MathUtil.reduce180(shift), EPS);
70 public void minmaxTest() {
71 assertEquals(1.0, MathUtil.min(1.0, Math.nextUp(1.0)));
72 assertEquals(1.0, MathUtil.min(1.0, Double.POSITIVE_INFINITY));
73 assertEquals(1.0, MathUtil.min(NaN, 1.0));
74 assertEquals(1.0, MathUtil.min(1.0, NaN));
75 assertEquals(NaN, MathUtil.min(NaN, NaN));
77 assertEquals(Math.nextUp(1.0), MathUtil.max(1.0, Math.nextUp(1.0)));
78 assertEquals(Double.POSITIVE_INFINITY, MathUtil.max(1.0, Double.POSITIVE_INFINITY));
79 assertEquals(1.0, MathUtil.max(NaN, 1.0));
80 assertEquals(1.0, MathUtil.max(1.0, NaN));
81 assertEquals(NaN, MathUtil.max(NaN, NaN));
83 assertEquals(1.0, MathUtil.min(1.0, 2.0, 3.0));
84 assertEquals(1.0, MathUtil.min(1.0, NaN, NaN));
85 assertEquals(1.0, MathUtil.min(NaN, 1.0, NaN));
86 assertEquals(1.0, MathUtil.min(NaN, NaN, 1.0));
87 assertEquals(1.0, MathUtil.min(2.0, NaN, 1.0));
88 assertEquals(1.0, MathUtil.min(1.0, 2.0, NaN));
89 assertEquals(1.0, MathUtil.min(NaN, 2.0, 1.0));
91 assertEquals(3.0, MathUtil.max(1.0, 3.0, 2.0));
92 assertEquals(1.0, MathUtil.max(1.0, NaN, NaN));
93 assertEquals(1.0, MathUtil.max(NaN, 1.0, NaN));
94 assertEquals(1.0, MathUtil.max(NaN, NaN, 1.0));
95 assertEquals(2.0, MathUtil.max(2.0, NaN, 1.0));
96 assertEquals(2.0, MathUtil.max(1.0, 2.0, NaN));
97 assertEquals(2.0, MathUtil.max(NaN, 2.0, 1.0));
101 public void mapTest() {
102 assertEquals(1.0, MathUtil.map(1.0, 0.0, 5.0, -1.0, 9.0), EPS);
103 assertEquals(7.0, MathUtil.map(1.0, 5.0, 0.0, -1.0, 9.0), EPS);
104 assertEquals(7.0, MathUtil.map(1.0, 0.0, 5.0, 9.0, -1.0), EPS);
105 assertEquals(6.0, MathUtil.map(6.0, 0.0, 5.0, Math.nextUp(6.0), 6.0), EPS);
106 assertEquals(6.0, MathUtil.map(6.0, 0.0, 0.0, Math.nextUp(6.0), 6.0), EPS);
108 MathUtil.map(6.0, 1.0, Math.nextUp(1.0), 1.0, 2.0);
109 fail("Should not be reached.");
110 } catch (IllegalArgumentException normal) { }
112 assertEquals(7.0, MathUtil.map(Math.nextUp(1.0), 0.0, 5.0, 9.0, -1.0), EPS);
117 public void equalsTest() {
118 assertTrue(MathUtil.equals(1.0, 1.0 + MathUtil.EPSILON/3));
119 assertFalse(MathUtil.equals(1.0, 1.0 + MathUtil.EPSILON*2));
120 assertTrue(MathUtil.equals(-1.0, -1.0 + MathUtil.EPSILON/3));
121 assertFalse(MathUtil.equals(-1.0, -1.0 + MathUtil.EPSILON*2));
123 for (double zero: new double[] { 0.0, MathUtil.EPSILON/10, -MathUtil.EPSILON/10 }) {
125 assertTrue(MathUtil.equals(zero, MathUtil.EPSILON/3));
126 assertTrue(MathUtil.equals(zero, -MathUtil.EPSILON/3));
127 assertFalse(MathUtil.equals(zero, MathUtil.EPSILON*2));
128 assertFalse(MathUtil.equals(zero, -MathUtil.EPSILON*2));
130 assertTrue(MathUtil.equals(MathUtil.EPSILON/3, zero));
131 assertTrue(MathUtil.equals(-MathUtil.EPSILON/3, zero));
132 assertFalse(MathUtil.equals(MathUtil.EPSILON*2, zero));
133 assertFalse(MathUtil.equals(-MathUtil.EPSILON*2, zero));
137 for (double value: new double[] { PI*1e20, -PI*1e20 }) {
138 assertTrue("value=" + value, MathUtil.equals(value, value + 1));
139 assertTrue("value=" + value, MathUtil.equals(value, Math.nextUp(value)));
140 assertTrue("value=" + value, MathUtil.equals(value, value * (1+MathUtil.EPSILON)));
143 assertFalse(MathUtil.equals(NaN, 0.0));
144 assertFalse(MathUtil.equals(0.0, NaN));
145 assertFalse(MathUtil.equals(NaN, NaN));