main.js (1353B)
1 /** 2 * @license Apache-2.0 3 * 4 * Copyright (c) 2020 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 isnanf = require( './../../../../base/assert/is-nanf' ); 24 25 26 // MAIN // 27 28 /** 29 * Evaluates the signum function for a single-precision floating-point number. 30 * 31 * @param {number} x - input value 32 * @returns {number} function value 33 * 34 * @example 35 * var sign = signumf( -5.0 ); 36 * // returns -1.0 37 * 38 * @example 39 * var sign = signumf( 5.0 ); 40 * // returns 1.0 41 * 42 * @example 43 * var sign = signumf( -0.0 ); 44 * // returns -0.0 45 * 46 * @example 47 * var sign = signumf( 0.0 ); 48 * // returns 0.0 49 * 50 * @example 51 * var sign = signumf( NaN ); 52 * // returns NaN 53 */ 54 function signumf( x ) { 55 if ( x === 0.0 || isnanf( x ) ) { 56 return x; // addresses both +-0 57 } 58 return ( x < 0.0 ) ? -1.0 : 1.0; 59 } 60 61 62 // EXPORTS // 63 64 module.exports = signumf;