README.md (2270B)
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 # Haversine 22 23 > Compute the half-value [versed sine][versed-sine]. 24 25 <section class="intro"> 26 27 The half-value [versed sine][versed-sine] is defined as 28 29 <!-- <equation class="equation" label="eq:haversine" align="center" raw="\operatorname{haversin}(\theta) = \frac{1 - \cos \theta}{2}" alt="Haversed sine."> --> 30 31 <div class="equation" align="center" data-raw-text="\operatorname{haversin}(\theta) = \frac{1 - \cos \theta}{2}" data-equation="eq:haversine"> 32 <img src="https://cdn.jsdelivr.net/gh/stdlib-js/stdlib@26abdafc2789332d3fcc28c36d4b22669a5fde03/lib/node_modules/@stdlib/math/base/special/haversin/docs/img/equation_haversine.svg" alt="Haversed sine."> 33 <br> 34 </div> 35 36 <!-- </equation> --> 37 38 </section> 39 40 <!-- /.intro --> 41 42 <section class="usage"> 43 44 ## Usage 45 46 ```javascript 47 var haversin = require( '@stdlib/math/base/special/haversin' ); 48 ``` 49 50 #### haversin( x ) 51 52 Computes the half-value [versed sine][versed-sine] (in radians). 53 54 ```javascript 55 var v = haversin( 0.0 ); 56 // returns 0.0 57 58 v = haversin( 3.141592653589793/2.0 ); 59 // returns ~0.5 60 61 v = haversin( -3.141592653589793/6.0 ); 62 // returns ~0.06699 63 ``` 64 65 </section> 66 67 <!-- /.usage --> 68 69 <section class="examples"> 70 71 ## Examples 72 73 <!-- eslint no-undef: "error" --> 74 75 ```javascript 76 var linspace = require( '@stdlib/array/linspace' ); 77 var TWO_PI = require( '@stdlib/constants/float64/two-pi' ); 78 var haversin = require( '@stdlib/math/base/special/haversin' ); 79 80 var x = linspace( 0.0, TWO_PI, 100 ); 81 var i; 82 83 for ( i = 0; i < x.length; i++ ) { 84 console.log( haversin( x[ i ] ) ); 85 } 86 ``` 87 88 </section> 89 90 <!-- /.examples --> 91 92 <section class="links"> 93 94 [versed-sine]: https://en.wikipedia.org/wiki/Versine 95 96 </section> 97 98 <!-- /.links -->