# @stdlib/math-base-special-fast-abs

0.3.0 • Public • Published

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# Absolute Value

Compute an absolute value.

The absolute value is defined as

## Installation

`npm install @stdlib/math-base-special-fast-abs`

## Usage

`var abs = require( '@stdlib/math-base-special-fast-abs' );`

#### abs( x )

Computes an absolute value.

```var v = abs( -1.0 );
// returns 1.0

v = abs( 2.0 );
// returns 2.0

v = abs( 0.0 );
// returns 0.0

v = abs( NaN );
// returns NaN```

## Notes

• This implementation is not IEEE 754 compliant. If provided `-0`, the function returns `-0`.

```var v = abs( -0.0 );
// returns -0.0```

## Examples

```var randu = require( '@stdlib/random-base-randu' );
var round = require( '@stdlib/math-base-special-round' );
var abs = require( '@stdlib/math-base-special-fast-abs' );

var rand;
var i;

for ( i = 0; i < 100; i++ ) {
rand = round( randu() * 100.0 ) - 50.0;
console.log( 'abs(%d) = %d', rand, abs( rand ) );
}```

## C APIs

### Usage

`#include "stdlib/math/base/special/fast/abs.h"`

#### stdlib_base_fast_abs( x )

Computes the absolute value of a double-precision floating-point number.

```double y = stdlib_base_fats_abs( -5.0 );
// returns 5.0```

The function accepts the following arguments:

• x: `[in] double` input value.
`double stdlib_base_fast_abs( const double x );`

### Examples

```#include "stdlib/math/base/special/fast/abs.h"
#include <stdio.h>

int main( void ) {
const double x[] = { 3.14, -3.14, 0.0, 0.0/0.0 };

double y;
int i;
for ( i = 0; i < 4; i++ ) {
y = stdlib_base_fast_abs( x[ i ] );
printf( "|%lf| = %lf\n", x[ i ], y );
}
}```

## Notice

This package is part of stdlib, a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.

For more information on the project, filing bug reports and feature requests, and guidance on how to develop stdlib, see the main project repository.

## Package Sidebar

### Install

`npm i @stdlib/math-base-special-fast-abs`

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