001/* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017package org.apache.commons.numbers.arrays; 018 019/** 020 * Computes the cosine of the angle between two vectors. 021 */ 022public final class CosAngle { 023 024 /** Private constructor. */ 025 private CosAngle() { 026 // intentionally empty. 027 } 028 029 /** 030 * Computes the cosine of the angle between {@code v1} and {@code v2}. 031 * 032 * @param v1 Cartesian coordinates of the first vector. 033 * @param v2 Cartesian coordinates of the second vector. 034 * @return the cosine of the angle between the vectors. 035 * @throws IllegalArgumentException if the sizes of the input arrays are different 036 */ 037 public static double value(double[] v1, 038 double[] v2) { 039 return LinearCombination.value(v1, v2) / SafeNorm.value(v1) / SafeNorm.value(v2); 040 } 041} 042