cmul.js (1272B)
1 /** 2 * @license Apache-2.0 3 * 4 * Copyright (c) 2018 The Stdlib Authors. 5 * 6 * Licensed under the Apache License, Version 2.0 (the "License"); 7 * you may not use this file except in compliance with the License. 8 * You may obtain a copy of the License at 9 * 10 * http://www.apache.org/licenses/LICENSE-2.0 11 * 12 * Unless required by applicable law or agreed to in writing, software 13 * distributed under the License is distributed on an "AS IS" BASIS, 14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 15 * See the License for the specific language governing permissions and 16 * limitations under the License. 17 */ 18 19 'use strict'; 20 21 // MAIN // 22 23 /** 24 * Multiplies two complex numbers. 25 * 26 * @private 27 * @param {(Array|TypedArray|Object)} out - output array 28 * @param {number} re1 - real component 29 * @param {number} im1 - imaginary component 30 * @param {number} re2 - real component 31 * @param {number} im2 - imaginary component 32 * @returns {(Array|TypedArray|Object)} real and imaginary components 33 * 34 * @example 35 * var out = new Array( 2 ); 36 * var v = cmul( out, 5.0, 3.0, -2.0, 1.0 ); 37 * // returns [ -13.0, -1.0 ] 38 */ 39 function cmul( out, re1, im1, re2, im2 ) { 40 out[ 0 ] = (re1*re2) - (im1*im2); 41 out[ 1 ] = (re1*im2) + (im1*re2); 42 return out; 43 } 44 45 46 // EXPORTS // 47 48 module.exports = cmul;