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

0.3.0 • Public • Published

We believe in a future in which the web is a preferred environment for numerical computation. To help realize this future, we've built stdlib. stdlib is a standard library, with an emphasis on numerical and scientific computation, written in JavaScript (and C) for execution in browsers and in Node.js.

The library is fully decomposable, being architected in such a way that you can swap out and mix and match APIs and functionality to cater to your exact preferences and use cases.

When you use stdlib, you can be absolutely certain that you are using the most thorough, rigorous, well-written, studied, documented, tested, measured, and high-quality code out there.

To join us in bringing numerical computing to the web, get started by checking us out on GitHub, and please consider financially supporting stdlib. We greatly appreciate your continued support!

# acosh

Compute the hyperbolic arccosine of a number.

## Installation

npm install @stdlib/math-base-special-fast-acosh

## Usage

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

#### acosh( x )

Computes the hyperbolic arccosine of a number (in radians).

var v = acosh( 1.0 );
// returns 0.0

v = acosh( 2.0 );
// returns ~1.317

v = acosh( 0.5 );
// returns NaN

The domain of x is restricted to [1,+infinity). If x < 1, the function will return NaN.

var v = acosh( 0.0 );
// returns NaN

## Notes

• For large x, the function will overflow.

var v = acosh( 1.0e308 );
// returns Infinity
// (expected 709.889355822726)

## Examples

var linspace = require( '@stdlib/array-base-linspace' );
var acosh = require( '@stdlib/math-base-special-fast-acosh' );

var x = linspace( 1.0, 5.0, 103 );

var i;
for ( i = 0; i < x.length; i++ ) {
console.log( acosh( x[ i ] ) );
}

## C APIs

### Usage

#include "stdlib/math/base/special/fast/acosh.h"

#### stdlib_base_fast_acosh( x )

Computes the hyperbolic arccosine of a double-precision floating-point number.

double out = stdlib_base_fast_acosh( 1.0 );
// returns 0.0

out = stdlib_base_fast_acosh( 2.0 );
// returns ~1.317

The function accepts the following arguments:

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

### Examples

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

int main( void ) {
const double x[] = { 1.0, 1.45, 1.89, 2.33, 2.78, 3.22, 3.66, 4.11, 4.55, 5.0 };

double v;
int i;
for ( i = 0; i < 10; i++ ) {
v = stdlib_base_fast_acosh( x[ i ] );
printf( "acosh(%lf) = %lf\n", x[ i ], v );
}
}

## 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-acosh

stdlib.io

18

0.3.0

Apache-2.0

33.8 kB

16