README.md (2154B)
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 # Probability Mass Function 22 23 > [Degenerate distribution][degenerate-distribution] [probability mass function][pmf] (PMF). 24 25 <section class="intro"> 26 27 </section> 28 29 <!-- /.intro --> 30 31 <section class="usage"> 32 33 ## Usage 34 35 ```javascript 36 var pmf = require( '@stdlib/stats/base/dists/degenerate/pmf' ); 37 ``` 38 39 #### pmf( x, mu ) 40 41 Evaluates the [PMF][pmf] of a [degenerate distribution][degenerate-distribution] centered at `mu`. 42 43 ```javascript 44 var y = pmf( 2.0, 8.0 ); 45 // returns 0.0 46 47 y = pmf( 8.0, 8.0 ); 48 // returns 1.0 49 ``` 50 51 #### pmf.factory( mu ) 52 53 Returns a function for evaluating the [PMF][pmf] of a [degenerate distribution][degenerate-distribution] centered at `mu`. 54 55 ```javascript 56 var mypmf = pmf.factory( 10.0 ); 57 58 var y = mypmf( 10.0 ); 59 // returns 1.0 60 61 y = mypmf( 5.0 ); 62 // returns 0.0 63 64 y = mypmf( 12.0 ); 65 // returns 0.0 66 ``` 67 68 </section> 69 70 <!-- /.usage --> 71 72 <section class="examples"> 73 74 ## Examples 75 76 <!-- eslint no-undef: "error" --> 77 78 ```javascript 79 var randu = require( '@stdlib/random/base/randu' ); 80 var round = require( '@stdlib/math/base/special/round' ); 81 var pmf = require( '@stdlib/stats/base/dists/degenerate/pmf' ); 82 83 var mu; 84 var x; 85 var y; 86 var i; 87 88 for ( i = 0; i < 100; i++ ) { 89 x = round( randu()*5.0 ); 90 mu = round( randu()*5.0 ); 91 y = pmf( x, mu ); 92 console.log( 'x: %d, µ: %d, P(X=x;µ): %d', x, mu, y ); 93 } 94 ``` 95 96 </section> 97 98 <!-- /.examples --> 99 100 <section class="links"> 101 102 [pmf]: https://en.wikipedia.org/wiki/Probability_mass_function 103 104 [degenerate-distribution]: https://en.wikipedia.org/wiki/Degenerate_distribution 105 106 </section> 107 108 <!-- /.links -->