| /* |
| * 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.arrays; |
| |
| import org.junit.jupiter.api.Assertions; |
| import org.junit.jupiter.api.Test; |
| |
| /** |
| * Test cases for the {@link CosAngle} class. |
| */ |
| public class CosAngleTest { |
| |
| @Test |
| public void testCosAngle2D() { |
| double expected; |
| |
| final double[] v1 = {1, 0}; |
| expected = 1; |
| Assertions.assertEquals(expected, CosAngle.value(v1, v1), 0d); |
| |
| final double[] v2 = {0, 1}; |
| expected = 0; |
| Assertions.assertEquals(expected, CosAngle.value(v1, v2), 0d); |
| |
| final double[] v3 = {7, 7}; |
| expected = Math.sqrt(2) / 2; |
| Assertions.assertEquals(expected, CosAngle.value(v1, v3), 1e-15); |
| Assertions.assertEquals(expected, CosAngle.value(v3, v2), 1e-15); |
| |
| final double[] v4 = {-5, 0}; |
| expected = -1; |
| Assertions.assertEquals(expected, CosAngle.value(v1, v4), 0); |
| |
| final double[] v5 = {-100, 100}; |
| expected = 0; |
| Assertions.assertEquals(expected, CosAngle.value(v3, v5), 0); |
| } |
| |
| @Test |
| public void testCosAngle3D() { |
| double expected; |
| |
| final double[] v1 = {1, 1, 0}; |
| expected = 1; |
| Assertions.assertEquals(expected, CosAngle.value(v1, v1), 1e-15); |
| |
| final double[] v2 = {1, 1, 1}; |
| expected = Math.sqrt(2) / Math.sqrt(3); |
| Assertions.assertEquals(expected, CosAngle.value(v1, v2), 1e-15); |
| } |
| |
| @Test |
| public void testCosAngleExtreme() { |
| double expected; |
| |
| final double tiny = 1e-200; |
| final double[] v1 = {tiny, tiny}; |
| final double big = 1e200; |
| final double[] v2 = {-big, -big}; |
| expected = -1; |
| Assertions.assertEquals(expected, CosAngle.value(v1, v2), 1e-15); |
| |
| final double[] v3 = {big, -big}; |
| expected = 0; |
| Assertions.assertEquals(expected, CosAngle.value(v1, v3), 1e-15); |
| } |
| |
| @Test |
| public void testCosAngle_dimensionMismatch() { |
| final double[] a = {1.0}; |
| final double[] b = {1.0, 2.0}; |
| |
| Assertions.assertThrows(IllegalArgumentException.class, () -> { |
| CosAngle.value(a, b); |
| }); |
| } |
| } |