commons-numbers-angle/src/test/java/org/apache/commons/numbers/angle/PlaneAngleRadiansTest.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements. See the NOTICE file distributed with this
 * work for additional information regarding copyright ownership. The ASF
 * licenses this file to You under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law
 * or agreed to in writing, software distributed under the License is
 * distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied. See the License for the specific language
 * governing permissions and limitations under the License.
 */
package org.apache.commons.numbers.angle;

import org.junit.Assert;
import org.junit.jupiter.api.Test;

/**
 * Test cases for the {@link PlaneAngleRadians} class.
 */
public class PlaneAngleRadiansTest {
    private static final double TWO_PI = 2 * Math.PI;

    @Test
    public void testNormalize() {
        for (double a = -15.0; a <= 15.0; a += 0.1) {
            for (double b = -15.0; b <= 15.0; b += 0.2) {
                final double c = PlaneAngleRadians.normalize(a, b);
                Assert.assertTrue((b - Math.PI) <= c);
                Assert.assertTrue(c <= (b + Math.PI));
                double twoK = Math.rint((a - c) / Math.PI);
                Assert.assertEquals(c, a - twoK * Math.PI, 1e-14);
            }
        }
    }

    @Test
    public void testNormalizeBetweenMinusPiAndPi1() {
        final double value = 1.25 * TWO_PI;
        final double expected = 0.25 * TWO_PI;
        final double actual = PlaneAngleRadians.normalizeBetweenMinusPiAndPi(value);
        final double tol = Math.ulp(expected);
        Assert.assertEquals(expected, actual, tol);
    }
    @Test
    public void testNormalizeBetweenMinusPiAndPi2() {
        final double value = 0.75 * TWO_PI;
        final double expected = -0.25 * TWO_PI;
        final double actual = PlaneAngleRadians.normalizeBetweenMinusPiAndPi(value);
        final double tol = Math.ulp(expected);
        Assert.assertEquals(expected, actual, tol);
    }
    @Test
    public void testNormalizeBetweenMinusPiAndPi3() {
        final double value = 0.5 * TWO_PI + 1e-10;
        final double expected = -0.5 * TWO_PI + 1e-10;
        final double actual = PlaneAngleRadians.normalizeBetweenMinusPiAndPi(value);
        final double tol = Math.ulp(expected);
        Assert.assertEquals(expected, actual, tol);
    }
    @Test
    public void testNormalizeBetweenMinusPiAndPi4() {
        final double value = 5 * Math.PI / 4;
        final double expected = Math.PI * (1d / 4 - 1);
        final double actual = PlaneAngleRadians.normalizeBetweenMinusPiAndPi(value);
        final double tol = Math.ulp(expected);
        Assert.assertEquals(expected, actual, tol);
    }

    @Test
    public void testNormalizeBetweenMinusPiAndPi_lowerBound() {
        final double value = -Math.PI;
        final double expected = -Math.PI;
        final double actual = PlaneAngleRadians.normalizeBetweenMinusPiAndPi(value);
        final double tol = Math.ulp(expected);
        Assert.assertEquals(expected, actual, tol);
    }
    @Test
    public void testNormalizeBetweenMinusPiAndPi_upperBound() {
        final double value = +Math.PI;
        final double expected = -Math.PI;
        final double actual = PlaneAngleRadians.normalizeBetweenMinusPiAndPi(value);
        final double tol = Math.ulp(expected);
        Assert.assertEquals(expected, actual, tol);
    }

    @Test
    public void testNormalizeBetweenZeroAndTwoPi1() {
        final double value = 1.25 * TWO_PI;
        final double expected = 0.25 * TWO_PI;
        final double actual = PlaneAngleRadians.normalizeBetweenZeroAndTwoPi(value);
        final double tol = Math.ulp(expected);
        Assert.assertEquals(expected, actual, tol);
    }
    @Test
    public void testNormalizeBetweenZeroAndTwoPi2() {
        final double value = 1.75 * TWO_PI;
        final double expected = 0.75 * TWO_PI;
        final double actual = PlaneAngleRadians.normalizeBetweenZeroAndTwoPi(value);
        final double tol = Math.ulp(expected);
        Assert.assertEquals(expected, actual, tol);
    }
    @Test
    public void testNormalizeBetweenZeroAndTwoPi3() {
        final double value = -0.5 * TWO_PI + 1e-10;
        final double expected = 0.5 * TWO_PI + 1e-10;
        final double actual = PlaneAngleRadians.normalizeBetweenZeroAndTwoPi(value);
        final double tol = Math.ulp(expected);
        Assert.assertEquals(expected, actual, tol);
    }
    @Test
    public void testNormalizeBetweenZeroAndTwoPi4() {
        final double value = 9 * Math.PI / 4;
        final double expected = Math.PI / 4;
        final double actual = PlaneAngleRadians.normalizeBetweenZeroAndTwoPi(value);
        final double tol = Math.ulp(expected);
        Assert.assertEquals(expected, actual, tol);
    }

    @Test
    public void testNormalizeBetweenZeroAndTwoPi_lowerBound() {
        final double value = 0.0;
        final double expected = 0.0;
        final double actual = PlaneAngleRadians.normalizeBetweenZeroAndTwoPi(value);
        final double tol = Math.ulp(expected);
        Assert.assertEquals(expected, actual, tol);
    }
    @Test
    public void testNormalizeBetweenZeroAndTwoPi_upperBound() {
        final double value = 2.0 * Math.PI;
        final double expected = 0.0;
        final double actual = PlaneAngleRadians.normalizeBetweenZeroAndTwoPi(value);
        final double tol = Math.ulp(expected);
        Assert.assertEquals(expected, actual, tol);
    }
}