README.md (4039B)
1 <!-- 2 3 @license Apache-2.0 4 5 Copyright (c) 2018 The Stdlib Authors. 6 7 Licensed under the Apache License, Version 2.0 (the "License"); 8 you may not use this file except in compliance with the License. 9 You may obtain a copy of the License at 10 11 http://www.apache.org/licenses/LICENSE-2.0 12 13 Unless required by applicable law or agreed to in writing, software 14 distributed under the License is distributed on an "AS IS" BASIS, 15 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 16 See the License for the specific language governing permissions and 17 limitations under the License. 18 19 --> 20 21 # Skewness 22 23 > [Discrete uniform][discrete-uniform-distribution] distribution [skewness][skewness]. 24 25 <!-- Section to include introductory text. Make sure to keep an empty line after the intro `section` element and another before the `/section` close. --> 26 27 <section class="intro"> 28 29 The [skewness][skewness] for a [discrete uniform][discrete-uniform-distribution] random variable with minimum support `a` and maximum support `b` is 30 31 <!-- <equation class="equation" label="eq:discrete_uniform_skewness" align="center" raw="\operatorname{skew}\left( X \right) = 0" alt="Skewness for a discrete uniform distribution."> --> 32 33 <div class="equation" align="center" data-raw-text="\operatorname{skew}\left( X \right) = 0" data-equation="eq:discrete_uniform_skewness"> 34 <img src="https://cdn.jsdelivr.net/gh/stdlib-js/stdlib@591cf9d5c3a0cd3c1ceec961e5c49d73a68374cb/lib/node_modules/@stdlib/stats/base/dists/discrete-uniform/skewness/docs/img/equation_discrete_uniform_skewness.svg" alt="Skewness for a discrete uniform distribution."> 35 <br> 36 </div> 37 38 <!-- </equation> --> 39 40 </section> 41 42 <!-- /.intro --> 43 44 <!-- Package usage documentation. --> 45 46 <section class="usage"> 47 48 ## Usage 49 50 ```javascript 51 var skewness = require( '@stdlib/stats/base/dists/discrete-uniform/skewness' ); 52 ``` 53 54 #### skewness( a, b ) 55 56 Returns the [skewness][skewness] of a [discrete uniform][discrete-uniform-distribution] distribution with parameters `a` (minimum support) and `b` (maximum support). 57 58 ```javascript 59 var v = skewness( 0, 1 ); 60 // returns 0.0 61 62 v = skewness( 4, 12 ); 63 // returns 0.0 64 65 v = skewness( 2, 8 ); 66 // returns 0.0 67 ``` 68 69 If `a` or `b` is not an integer value, the function returns `NaN`. 70 71 ```javascript 72 var v = skewness( 0.1, 2 ); 73 // returns NaN 74 75 v = skewness( 0, 2.2 ); 76 // returns NaN 77 78 v = skewness( NaN, 2 ); 79 // returns NaN 80 81 v = skewness( 2, NaN ); 82 // returns NaN 83 ``` 84 85 If provided `a > b`, the function returns `NaN`. 86 87 ```javascript 88 var y = skewness( 3, 2 ); 89 // returns NaN 90 91 y = skewness( -1, -2 ); 92 // returns NaN 93 ``` 94 95 </section> 96 97 <!-- /.usage --> 98 99 <!-- Package usage notes. Make sure to keep an empty line after the `section` element and another before the `/section` close. --> 100 101 <section class="notes"> 102 103 </section> 104 105 <!-- /.notes --> 106 107 <!-- Package usage examples. --> 108 109 <section class="examples"> 110 111 ## Examples 112 113 <!-- eslint no-undef: "error" --> 114 115 ```javascript 116 var randint = require( '@stdlib/random/base/discrete-uniform' ); 117 var skewness = require( '@stdlib/stats/base/dists/discrete-uniform/skewness' ); 118 119 var randa = randint.factory( 0, 10 ); 120 var randb = randint.factory(); 121 var a; 122 var b; 123 var v; 124 var i; 125 126 for ( i = 0; i < 10; i++ ) { 127 a = randa(); 128 b = randb( a, a+randa() ); 129 v = skewness( a, b ); 130 console.log( 'a: %d, b: %d, skew(X;a,b): %d', a.toFixed( 4 ), b.toFixed( 4 ), v.toFixed( 4 ) ); 131 } 132 ``` 133 134 </section> 135 136 <!-- /.examples --> 137 138 <!-- Section to include cited references. If references are included, add a horizontal rule *before* the section. Make sure to keep an empty line after the `section` element and another before the `/section` close. --> 139 140 <section class="references"> 141 142 </section> 143 144 <!-- /.references --> 145 146 <!-- Section for all links. Make sure to keep an empty line after the `section` element and another before the `/section` close. --> 147 148 <section class="links"> 149 150 [discrete-uniform-distribution]: https://en.wikipedia.org/wiki/Discrete_uniform_distribution 151 152 [skewness]: https://en.wikipedia.org/wiki/Skewness 153 154 </section> 155 156 <!-- /.links -->