README.md (3724B)
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 # Quantile Function 22 23 > [Bernoulli][bernoulli-distribution] distribution [quantile function][quantile-function]. 24 25 <section class="intro"> 26 27 The [quantile function][quantile-function] for a [Bernoulli][bernoulli-distribution] random variable is 28 29 <!-- <equation class="equation" label="eq:bernoulli_quantile_function" align="center" raw="Q(r;p)=\begin{cases} 0 & \text{if } r \le 1-p \\ 1 & \text{if } r > 1-p \end{cases}" alt="Quantile function for a Bernoulli distribution."> --> 30 31 <div class="equation" align="center" data-raw-text="Q(r;p)=\begin{cases} 0 & \text{if } r \le 1-p \\ 1 & \text{if } r > 1-p \end{cases}" data-equation="eq:bernoulli_quantile_function"> 32 <img src="https://cdn.jsdelivr.net/gh/stdlib-js/stdlib@591cf9d5c3a0cd3c1ceec961e5c49d73a68374cb/lib/node_modules/@stdlib/stats/base/dists/bernoulli/quantile/docs/img/equation_bernoulli_quantile_function.svg" alt="Quantile function for a Bernoulli distribution."> 33 <br> 34 </div> 35 36 <!-- </equation> --> 37 38 for `0 <= r <= 1`, where `p` is the success probability. 39 40 </section> 41 42 <!-- /.intro --> 43 44 <section class="usage"> 45 46 ## Usage 47 48 ```javascript 49 var quantile = require( '@stdlib/stats/base/dists/bernoulli/quantile' ); 50 ``` 51 52 #### quantile( r, p ) 53 54 Evaluates the [quantile function][quantile-function] for a [Bernoulli][bernoulli-distribution] distribution with success probability `p` at a value `r`. 55 56 ```javascript 57 var y = quantile( 0.8, 0.4 ); 58 // returns 1 59 60 y = quantile( 0.5, 0.4 ); 61 // returns 0 62 63 y = quantile( 0.9, 0.1 ); 64 // returns 0 65 ``` 66 67 If provided `r <= 0` or `r >= 0`, the function returns `NaN`. 68 69 ```javascript 70 var y = quantile( 1.9, 0.5 ); 71 // returns NaN 72 73 y = quantile( -0.1, 0.5 ); 74 // returns NaN 75 ``` 76 77 If provided `NaN` as any argument, the function returns `NaN`. 78 79 ```javascript 80 var y = quantile( NaN, 1.0 ); 81 // returns NaN 82 83 y = quantile( 0.0, NaN ); 84 // returns NaN 85 ``` 86 87 If provided a success probability `p` outside the interval `[0,1]`, the function returns `NaN`. 88 89 ```javascript 90 var y = quantile( 0.4, -1.0 ); 91 // returns NaN 92 93 y = quantile( 0.4, 1.5 ); 94 // returns NaN 95 ``` 96 97 #### quantile.factory( p ) 98 99 Returns a function for evaluating the [quantile function][quantile-function] for a [Bernoulli][bernoulli-distribution] distribution with success probability `p`. 100 101 ```javascript 102 var myquantile = quantile.factory( 0.4 ); 103 var y = myquantile( 0.4 ); 104 // returns 0 105 106 y = myquantile( 0.8 ); 107 // returns 1 108 109 y = myquantile( 1.0 ); 110 // returns 1 111 ``` 112 113 </section> 114 115 <!-- /.usage --> 116 117 <section class="examples"> 118 119 ## Examples 120 121 <!-- eslint no-undef: "error" --> 122 123 ```javascript 124 var randu = require( '@stdlib/random/base/randu' ); 125 var quantile = require( '@stdlib/stats/base/dists/bernoulli/quantile' ); 126 127 var p; 128 var r; 129 var y; 130 var i; 131 132 for ( i = 0; i < 10; i++ ) { 133 r = randu(); 134 p = randu(); 135 y = quantile( r, p ); 136 console.log( 'r: %d, p: %d, Q(r;p): %d', r.toFixed( 4 ), p.toFixed( 4 ), y.toFixed( 4 ) ); 137 } 138 ``` 139 140 </section> 141 142 <!-- /.examples --> 143 144 <section class="links"> 145 146 [bernoulli-distribution]: https://en.wikipedia.org/wiki/Bernoulli_distribution 147 148 [quantile-function]: https://en.wikipedia.org/wiki/Quantile_function 149 150 </section> 151 152 <!-- /.links -->