| 
 | 1 | +<!--  | 
 | 2 | +
  | 
 | 3 | +@license Apache-2.0  | 
 | 4 | +
  | 
 | 5 | +Copyright (c) 2024 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 | +# ahavercosf  | 
 | 22 | + | 
 | 23 | +> Compute the [inverse half-value versed cosine][archavercosine] of a single-precision floating point number.  | 
 | 24 | +
  | 
 | 25 | +<section class="intro">  | 
 | 26 | + | 
 | 27 | +The [inverse half-value versed cosine][archavercosine] is defined as  | 
 | 28 | + | 
 | 29 | +<!-- <equation class="equation" label="eq:archavercosine" align="center" raw="\operatorname{ahavercos}(\theta) = 2 \cdot \arccos(\sqrt{\theta})" alt="Inverse half-value versed cosine."> -->  | 
 | 30 | + | 
 | 31 | +```math  | 
 | 32 | +\mathop{\mathrm{ahavercos}}(\theta) = 2 \cdot \arccos(\sqrt{\theta})  | 
 | 33 | +```  | 
 | 34 | + | 
 | 35 | +<!-- <div class="equation" align="center" data-raw-text="\operatorname{ahavercos}(\theta) = 2 \cdot \arccos(\sqrt{\theta})" data-equation="eq:archavercosine">  | 
 | 36 | +    <img src="https://cdn.jsdelivr.net/gh/stdlib-js/stdlib@bb29798906e119fcb2af99e94b60407a270c9b32/lib/node_modules/@stdlib/math/base/special/ahavercos/docs/img/equation_archavercosine.svg" alt="Inverse half-value versed cosine.">  | 
 | 37 | +    <br>  | 
 | 38 | +</div> -->  | 
 | 39 | + | 
 | 40 | +<!-- </equation> -->  | 
 | 41 | + | 
 | 42 | +</section>  | 
 | 43 | + | 
 | 44 | +<!-- /.intro -->  | 
 | 45 | + | 
 | 46 | +<section class="usage">  | 
 | 47 | + | 
 | 48 | +## Usage  | 
 | 49 | + | 
 | 50 | +```javascript  | 
 | 51 | +var ahavercosf = require( '@stdlib/math/base/special/ahavercosf' );  | 
 | 52 | +```  | 
 | 53 | + | 
 | 54 | +#### ahavercosf( x )  | 
 | 55 | + | 
 | 56 | +Computes the [inverse half-value versed cosine][archavercosine] of a single-precision floating point number (in radians).  | 
 | 57 | + | 
 | 58 | +```javascript  | 
 | 59 | +var v = ahavercosf( 0.0 );  | 
 | 60 | +// returns ~3.1416  | 
 | 61 | + | 
 | 62 | +v = ahavercosf( 1.0 );  | 
 | 63 | +// returns 0.0  | 
 | 64 | + | 
 | 65 | +v = ahavercosf( 0.5 );  | 
 | 66 | +// returns ~1.5708  | 
 | 67 | +```  | 
 | 68 | + | 
 | 69 | +If `x < 0`, `x > 1`, or `x` is `NaN`, the function returns `NaN`.  | 
 | 70 | + | 
 | 71 | +```javascript  | 
 | 72 | +var v = ahavercosf( 1.5 );  | 
 | 73 | +// returns NaN  | 
 | 74 | + | 
 | 75 | +v = ahavercosf( -3.14 );  | 
 | 76 | +// returns NaN  | 
 | 77 | + | 
 | 78 | +v = ahavercosf( NaN );  | 
 | 79 | +// returns NaN  | 
 | 80 | +```  | 
 | 81 | + | 
 | 82 | +</section>  | 
 | 83 | + | 
 | 84 | +<!-- /.usage -->  | 
 | 85 | + | 
 | 86 | +<section class="examples">  | 
 | 87 | + | 
 | 88 | +## Examples  | 
 | 89 | + | 
 | 90 | +<!-- eslint no-undef: "error" -->  | 
 | 91 | + | 
 | 92 | +```javascript  | 
 | 93 | +var linspace = require( '@stdlib/array/base/linspace' );  | 
 | 94 | +var ahavercosf = require( '@stdlib/math/base/special/ahavercosf' );  | 
 | 95 | + | 
 | 96 | +var x = linspace( 0.0, 1.0, 100 );  | 
 | 97 | + | 
 | 98 | +var i;  | 
 | 99 | +for ( i = 0; i < x.length; i++ ) {  | 
 | 100 | +    console.log( ahavercosf( x[ i ] ) );  | 
 | 101 | +}  | 
 | 102 | +```  | 
 | 103 | + | 
 | 104 | +</section>  | 
 | 105 | + | 
 | 106 | +<!-- /.examples -->  | 
 | 107 | + | 
 | 108 | +<!-- C interface documentation. -->  | 
 | 109 | + | 
 | 110 | +* * *  | 
 | 111 | + | 
 | 112 | +<section class="c">  | 
 | 113 | + | 
 | 114 | +## C APIs  | 
 | 115 | + | 
 | 116 | +<!-- Section to include introductory text. Make sure to keep an empty line after the intro `section` element and another before the `/section` close. -->  | 
 | 117 | + | 
 | 118 | +<section class="intro">  | 
 | 119 | + | 
 | 120 | +</section>  | 
 | 121 | + | 
 | 122 | +<!-- /.intro -->  | 
 | 123 | + | 
 | 124 | +<!-- C usage documentation. -->  | 
 | 125 | + | 
 | 126 | +<section class="usage">  | 
 | 127 | + | 
 | 128 | +### Usage  | 
 | 129 | + | 
 | 130 | +```c  | 
 | 131 | +#include "stdlib/math/base/special/ahavercosf.h"  | 
 | 132 | +```  | 
 | 133 | + | 
 | 134 | +#### stdlib_base_ahavercosf( x )  | 
 | 135 | + | 
 | 136 | +Computes the [inverse half-value versed cosine][archavercosine] of a single-precision floating-point number (in radians).  | 
 | 137 | + | 
 | 138 | +```c  | 
 | 139 | +float out = stdlib_base_ahavercosf( 0.0f );  | 
 | 140 | +// returns ~3.1416f  | 
 | 141 | +```  | 
 | 142 | + | 
 | 143 | +If `x < 0`, `x > 1`, or `x` is `NaN`, the function returns `NaN`.  | 
 | 144 | + | 
 | 145 | +```c  | 
 | 146 | +float out = stdlib_base_ahavercosf( -3.14f );  | 
 | 147 | +// returns NaN  | 
 | 148 | +```  | 
 | 149 | + | 
 | 150 | +The function accepts the following arguments:  | 
 | 151 | + | 
 | 152 | +-   **x**: `[in] float` input value.  | 
 | 153 | + | 
 | 154 | +```c  | 
 | 155 | +float stdlib_base_ahavercosf( const float x );  | 
 | 156 | +```  | 
 | 157 | +
  | 
 | 158 | +</section>  | 
 | 159 | +
  | 
 | 160 | +<!-- /.usage -->  | 
 | 161 | +
  | 
 | 162 | +<!-- C API usage notes. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->  | 
 | 163 | +
  | 
 | 164 | +<section class="notes">  | 
 | 165 | +
  | 
 | 166 | +</section>  | 
 | 167 | +
  | 
 | 168 | +<!-- /.notes -->  | 
 | 169 | +
  | 
 | 170 | +<!-- C API usage examples. -->  | 
 | 171 | +
  | 
 | 172 | +<section class="examples">  | 
 | 173 | +
  | 
 | 174 | +### Examples  | 
 | 175 | +
  | 
 | 176 | +```c  | 
 | 177 | +#include "stdlib/math/base/special/ahavercosf.h"  | 
 | 178 | +#include <stdio.h>  | 
 | 179 | +
  | 
 | 180 | +int main( void ) {  | 
 | 181 | +    const float x[] = { -2.0f, -1.6f, -1.2f, -0.8f, -0.4f, 0.4f, 0.8f, 1.2f, 1.6f, 2.0f };  | 
 | 182 | +      | 
 | 183 | +    float v;  | 
 | 184 | +    int i;  | 
 | 185 | +    for ( i = 0; i < 10; i++ ) {  | 
 | 186 | +        v = stdlib_base_ahavercosf( x[ i ] );  | 
 | 187 | +        printf( "ahavercosf(%f) = %f\n", x[ i ], v );  | 
 | 188 | +    }  | 
 | 189 | +}  | 
 | 190 | +```  | 
 | 191 | + | 
 | 192 | +</section>  | 
 | 193 | + | 
 | 194 | +<!-- /.examples -->  | 
 | 195 | + | 
 | 196 | +</section>  | 
 | 197 | + | 
 | 198 | +<!-- /.c -->  | 
 | 199 | + | 
 | 200 | +<!-- Section for related `stdlib` packages. Do not manually edit this section, as it is automatically populated. -->  | 
 | 201 | + | 
 | 202 | +<section class="related">  | 
 | 203 | + | 
 | 204 | +</section>  | 
 | 205 | + | 
 | 206 | +<!-- /.related -->  | 
 | 207 | + | 
 | 208 | +<!-- Section for all links. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->  | 
 | 209 | + | 
 | 210 | +<section class="links">  | 
 | 211 | + | 
 | 212 | +[archavercosine]: https://en.wikipedia.org/wiki/Versine  | 
 | 213 | + | 
 | 214 | +<!-- <related-links> -->  | 
 | 215 | + | 
 | 216 | +<!-- </related-links> -->  | 
 | 217 | + | 
 | 218 | +</section>  | 
 | 219 | + | 
 | 220 | +<!-- /.links -->  | 
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