time-to-botec/js/node_modules/@stdlib/math/base/special/labs/README.md

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@license Apache-2.0
Copyright (c) 2018 The Stdlib Authors.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
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# Absolute Value
> Compute an [absolute value][absolute-value] of a signed 32-bit integer.
<section class="intro">
The [absolute value][absolute-value] is defined as
<!-- <equation class="equation" label="eq:absolute_value" align="center" raw="|x| = \begin{cases} x & \textrm{if}\ x \geq 0 \\ -x & \textrm{if}\ x < 0\end{cases}" alt="Absolute value"> -->
<div class="equation" align="center" data-raw-text="|x| = \begin{cases} x &amp; \textrm{if}\ x \geq 0 \\ -x &amp; \textrm{if}\ x &lt; 0\end{cases}" data-equation="eq:absolute_value">
<img src="https://cdn.jsdelivr.net/gh/stdlib-js/stdlib@dc413bd931fa2ac3d9d19d2cb44a08dbd5a3e9ad/lib/node_modules/@stdlib/math/base/special/labs/docs/img/equation_absolute_value.svg" alt="Absolute value">
<br>
</div>
<!-- </equation> -->
</section>
<!-- /.intro -->
<section class="usage">
## Usage
```javascript
var labs = require( '@stdlib/math/base/special/labs' );
```
#### labs( x )
Computes an [absolute value][absolute-value] of a signed 32-bit integer.
```javascript
var v = labs( -1|0 );
// returns 1
v = labs( 2|0 );
// returns 2
v = labs( 0|0 );
// returns 0
```
</section>
<!-- /.usage -->
<!-- Package usage notes. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->
<section class="notes">
## Notes
- The implementation assumes two's complement.
- In two's complement systems, the absolute value of the minimum signed 32-bit integer is out-of-range. The absolute value for the minimum signed 32-bit integer is thus undefined.
```javascript
// -2^31
var x = -2147483648|0;
var v = labs( x );
// returns -2147483648
```
</section>
<!-- /.notes -->
<section class="examples">
## Examples
<!-- eslint no-undef: "error" -->
```javascript
var randu = require( '@stdlib/random/base/randu' );
var round = require( '@stdlib/math/base/special/round' );
var labs = require( '@stdlib/math/base/special/labs' );
var x;
var i;
for ( i = 0; i < 100; i++ ) {
x = round( randu() * 100.0 ) - 50;
console.log( 'abs(%d) = %d', x, labs( x|0 ) );
}
```
</section>
<!-- /.examples -->
<!-- C interface documentation. -->
* * *
<section class="c">
## C APIs
<!-- Section to include introductory text. Make sure to keep an empty line after the intro `section` element and another before the `/section` close. -->
<section class="intro">
</section>
<!-- /.intro -->
<!-- C usage documentation. -->
<section class="usage">
### Usage
```c
#include "stdlib/math/base/special/labs.h"
```
#### stdlib_base_labs( x )
Computes the absolute value of a signed 32-bit integer in two's complement format.
```c
#include <stdint.h>
int32_t y = stdlib_base_labs( -5 );
// returns 5
```
The function accepts the following arguments:
- **x**: `[in] int32_t` input value.
```c
int32_t stdlib_base_labs( const int32_t x );
```
</section>
<!-- /.usage -->
<!-- C API usage notes. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->
<section class="notes">
</section>
<!-- /.notes -->
<!-- C API usage examples. -->
<section class="examples">
### Examples
```c
#include "stdlib/math/base/special/labs.h"
#include <stdint.h>
#include <stdio.h>
int main() {
int32_t x[] = { 3, -3, 0, -10 };
int32_t y;
int i;
for ( i = 0; i < 4; i++ ) {
y = stdlib_base_labs( x[ i ] );
printf( "|%i| = %i\n", x[ i ], y );
}
}
```
</section>
<!-- /.examples -->
</section>
<!-- /.c -->
<section class="links">
[absolute-value]: https://en.wikipedia.org/wiki/Absolute_value
</section>
<!-- /.links -->