+package net.sf.openrocket.util;
+
+import static java.lang.Double.NaN;
+import static java.lang.Math.PI;
+import static org.junit.Assert.*;
+
+import org.junit.Test;
+
+public class MathUtilTest {
+
+ public static final double EPS = 0.00000000001;
+
+ @Test
+ public void miscMathTest() {
+
+ assertEquals(PI*PI, MathUtil.pow2(PI), EPS);
+ assertEquals(PI*PI*PI, MathUtil.pow3(PI), EPS);
+ assertEquals(PI*PI*PI*PI, MathUtil.pow4(PI), EPS);
+
+ assertEquals(1.0, MathUtil.clamp(0.9999, 1.0, 2.0));
+ assertEquals(1.23, MathUtil.clamp(1.23, 1.0, 2.0));
+ assertEquals(2.0, MathUtil.clamp(2 + EPS/100, 1.0, 2.0));
+
+ assertEquals(1.0f, MathUtil.clamp(0.9999f, 1.0f, 2.0f));
+ assertEquals(1.23f, MathUtil.clamp(1.23f, 1.0f, 2.0f));
+ assertEquals(2.0f, MathUtil.clamp(2.0001f, 1.0f, 2.0f));
+
+ assertEquals(1, MathUtil.clamp(-3, 1, 5));
+ assertEquals(3, MathUtil.clamp(3, 1, 5));
+ assertEquals(5, MathUtil.clamp(6, 1, 5));
+
+ assertEquals(-1.0, MathUtil.sign(Double.NEGATIVE_INFINITY));
+ assertEquals(-1.0, MathUtil.sign(-100));
+ assertEquals(-1.0, MathUtil.sign(Math.nextAfter(0.0, -1.0)));
+ assertEquals( 1.0, MathUtil.sign(Math.nextUp(0.0)));
+ assertEquals( 1.0, MathUtil.sign(100));
+ assertEquals( 1.0, MathUtil.sign(Double.POSITIVE_INFINITY));
+ }
+
+ @Test
+ public void hypotTest() {
+
+ for (int i=0; i<10000; i++) {
+ double x = Math.random()*100 - 50;
+ double y = Math.random()*i - i/2;
+ double z = Math.hypot(x, y);
+ assertEquals(z, MathUtil.hypot(x, y), EPS);
+ }
+
+ }
+
+ @Test
+ public void reduceTest() {
+
+ for (int i=-1000; i<1000; i++) {
+ double angle = Math.random() * 2*PI;
+ double shift = angle + i*2*PI;
+ assertEquals(angle, MathUtil.reduce360(shift), EPS);
+ }
+
+ for (int i=-1000; i<1000; i++) {
+ double angle = Math.random() * 2*PI - PI;
+ double shift = angle + i*2*PI;
+ assertEquals(angle, MathUtil.reduce180(shift), EPS);
+ }
+
+ }
+
+ @Test
+ public void minmaxTest() {
+ assertEquals(1.0, MathUtil.min(1.0, Math.nextUp(1.0)));
+ assertEquals(1.0, MathUtil.min(1.0, Double.POSITIVE_INFINITY));
+ assertEquals(1.0, MathUtil.min(NaN, 1.0));
+ assertEquals(1.0, MathUtil.min(1.0, NaN));
+ assertEquals(NaN, MathUtil.min(NaN, NaN));
+
+ assertEquals(Math.nextUp(1.0), MathUtil.max(1.0, Math.nextUp(1.0)));
+ assertEquals(Double.POSITIVE_INFINITY, MathUtil.max(1.0, Double.POSITIVE_INFINITY));
+ assertEquals(1.0, MathUtil.max(NaN, 1.0));
+ assertEquals(1.0, MathUtil.max(1.0, NaN));
+ assertEquals(NaN, MathUtil.max(NaN, NaN));
+
+ assertEquals(1.0, MathUtil.min(1.0, 2.0, 3.0));
+ assertEquals(1.0, MathUtil.min(1.0, NaN, NaN));
+ assertEquals(1.0, MathUtil.min(NaN, 1.0, NaN));
+ assertEquals(1.0, MathUtil.min(NaN, NaN, 1.0));
+ assertEquals(1.0, MathUtil.min(2.0, NaN, 1.0));
+ assertEquals(1.0, MathUtil.min(1.0, 2.0, NaN));
+ assertEquals(1.0, MathUtil.min(NaN, 2.0, 1.0));
+
+ assertEquals(3.0, MathUtil.max(1.0, 3.0, 2.0));
+ assertEquals(1.0, MathUtil.max(1.0, NaN, NaN));
+ assertEquals(1.0, MathUtil.max(NaN, 1.0, NaN));
+ assertEquals(1.0, MathUtil.max(NaN, NaN, 1.0));
+ assertEquals(2.0, MathUtil.max(2.0, NaN, 1.0));
+ assertEquals(2.0, MathUtil.max(1.0, 2.0, NaN));
+ assertEquals(2.0, MathUtil.max(NaN, 2.0, 1.0));
+ }
+
+ @Test
+ public void mapTest() {
+ assertEquals(1.0, MathUtil.map(1.0, 0.0, 5.0, -1.0, 9.0), EPS);
+ assertEquals(7.0, MathUtil.map(1.0, 5.0, 0.0, -1.0, 9.0), EPS);
+ assertEquals(7.0, MathUtil.map(1.0, 0.0, 5.0, 9.0, -1.0), EPS);
+ assertEquals(6.0, MathUtil.map(6.0, 0.0, 5.0, Math.nextUp(6.0), 6.0), EPS);
+ assertEquals(6.0, MathUtil.map(6.0, 0.0, 0.0, Math.nextUp(6.0), 6.0), EPS);
+ try {
+ MathUtil.map(6.0, 1.0, Math.nextUp(1.0), 1.0, 2.0);
+ fail("Should not be reached.");
+ } catch (IllegalArgumentException normal) { }
+
+ assertEquals(7.0, MathUtil.map(Math.nextUp(1.0), 0.0, 5.0, 9.0, -1.0), EPS);
+ }
+
+
+ @Test
+ public void equalsTest() {
+ assertTrue(MathUtil.equals(1.0, 1.0 + MathUtil.EPSILON/3));
+ assertFalse(MathUtil.equals(1.0, 1.0 + MathUtil.EPSILON*2));
+ assertTrue(MathUtil.equals(-1.0, -1.0 + MathUtil.EPSILON/3));
+ assertFalse(MathUtil.equals(-1.0, -1.0 + MathUtil.EPSILON*2));
+
+ for (double zero: new double[] { 0.0, MathUtil.EPSILON/10, -MathUtil.EPSILON/10 }) {
+
+ assertTrue(MathUtil.equals(zero, MathUtil.EPSILON/3));
+ assertTrue(MathUtil.equals(zero, -MathUtil.EPSILON/3));
+ assertFalse(MathUtil.equals(zero, MathUtil.EPSILON*2));
+ assertFalse(MathUtil.equals(zero, -MathUtil.EPSILON*2));
+
+ assertTrue(MathUtil.equals(MathUtil.EPSILON/3, zero));
+ assertTrue(MathUtil.equals(-MathUtil.EPSILON/3, zero));
+ assertFalse(MathUtil.equals(MathUtil.EPSILON*2, zero));
+ assertFalse(MathUtil.equals(-MathUtil.EPSILON*2, zero));
+
+ }
+
+ for (double value: new double[] { PI*1e20, -PI*1e20 }) {
+ assertTrue("value=" + value, MathUtil.equals(value, value + 1));
+ assertTrue("value=" + value, MathUtil.equals(value, Math.nextUp(value)));
+ assertTrue("value=" + value, MathUtil.equals(value, value * (1+MathUtil.EPSILON)));
+ }
+
+ assertFalse(MathUtil.equals(NaN, 0.0));
+ assertFalse(MathUtil.equals(0.0, NaN));
+ assertFalse(MathUtil.equals(NaN, NaN));
+ }
+
+}