kurtosis.js (1433B)
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( '@stdlib/math/base/assert/is-nan' ); 24 25 26 // MAIN // 27 28 /** 29 * Returns the excess kurtosis of a uniform distribution. 30 * 31 * @param {number} a - minimum support 32 * @param {number} b - maximum support 33 * @returns {number} excess kurtosis 34 * 35 * @example 36 * var v = kurtosis( 0.0, 1.0 ); 37 * // returns -1.2 38 * 39 * @example 40 * var v = kurtosis( 4.0, 12.0 ); 41 * // returns -1.2 42 * 43 * @example 44 * var v = kurtosis( -4.0, 4.0 ); 45 * // returns -1.2 46 * 47 * @example 48 * var v = kurtosis( 1.0, -0.1 ); 49 * // returns NaN 50 * 51 * @example 52 * var v = kurtosis( 2.0, NaN ); 53 * // returns NaN 54 * 55 * @example 56 * var v = kurtosis( NaN, 2.0 ); 57 * // returns NaN 58 */ 59 function kurtosis( a, b ) { 60 if ( 61 isnan( a ) || 62 isnan( b ) || 63 a >= b 64 ) { 65 return NaN; 66 } 67 return -1.2; 68 } 69 70 71 // EXPORTS // 72 73 module.exports = kurtosis;