main.js (1627B)
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 // MODULES // 22 23 var isnan = require( './../../../../base/assert/is-nan' ); 24 var isInfinite = require( './../../../../base/assert/is-infinite' ); 25 var PINF = require( '@stdlib/constants/float64/pinf' ); 26 var sqrt = require( './../../../../base/special/sqrt' ); 27 28 29 // MAIN // 30 31 /** 32 * Computes the hypotenuse avoiding overflow and underflow. 33 * 34 * @param {number} x - number 35 * @param {number} y - number 36 * @returns {number} hypotenuse 37 * 38 * @example 39 * var h = hypot( -5.0, 12.0 ); 40 * // returns 13.0 41 * 42 * @example 43 * var h = hypot( NaN, 12.0 ); 44 * // returns NaN 45 * 46 * @example 47 * var h = hypot( -0.0, -0.0 ); 48 * // returns 0.0 49 */ 50 function hypot( x, y ) { 51 var tmp; 52 if ( isnan( x ) || isnan( y ) ) { 53 return NaN; 54 } 55 if ( isInfinite( x ) || isInfinite( y ) ) { 56 return PINF; 57 } 58 if ( x < 0.0 ) { 59 x = -x; 60 } 61 if ( y < 0.0 ) { 62 y = -y; 63 } 64 if ( x < y ) { 65 tmp = y; 66 y = x; 67 x = tmp; 68 } 69 if ( x === 0.0 ) { 70 return 0.0; 71 } 72 y /= x; 73 return x * sqrt( 1.0 + (y*y) ); 74 } 75 76 77 // EXPORTS // 78 79 module.exports = hypot;