@stdlib/math-base-special-fast-atanh NPM

atanh

$NPM version$ $Build Status$ $Coverage Status$

Compute the hyperbolic arctangent of a number.

Installation

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

Usage

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

atanh( x )

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

var v = atanh( 0.0 );
// returns 0.0

v = atanh( -0.0 );
// returns -0.0

v = atanh( 0.5 );
// returns ~0.549

v = atanh( 0.9 );
// returns ~1.472

v = atanh( 1.0 );
// returns Infinity

v = atanh( -1.0 );
// returns -Infinity

The domain of x is restricted to [-1,1]. If |x| > 1, the function returns NaN.

var v = atanh( -3.14 );
// returns NaN

Notes

For small x, the function will underflow.

var v = atanh( 1.0e-17 );
// returns 0.0
// (expected 1.0e-17)

Examples

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

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

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

C APIs

Usage

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

stdlib_base_fast_atanh( x )

Computes the hyperbolic arctangent of a double-precision floating-point number (in radians).

double out = stdlib_base_fast_atanh( 0.0 );
// returns 0.0

out = stdlib_base_fast_atanh( -0.0 );
// returns -0.0

The function accepts the following arguments:

x: [in] double input value.

double stdlib_base_fast_atanh( const double x );

Examples

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

int main( void ) {
    const double x[] = { -1.0, -0.78, -0.56, -0.33, -0.11, 0.11, 0.33, 0.56, 0.78, 1.0 };

    double v;
    int i;
    for ( i = 0; i < 10; i++ ) {
        v = stdlib_base_fast_atanh( x[ i ] );
        printf( "atanh(%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.