JavaScript asinh

Returns the inverse hyperbolic sine of the number, i.e. the value whose hyperbolic sine is number

1
2
3
4
56
7
8
9
10

function asinh (arg) {
    // Returns the inverse hyperbolic sine of the number, i.e. the value whose hyperbolic sine is number  
    // 
    // version: 1109.2015
    // discuss at: http://phpjs.org/functions/asinh    // +   original by: Onno Marsman
    // *     example 1: asinh(8723321.4);
    // *     returns 1: 16.67465779841863
    return Math.log(arg + Math.sqrt(arg * arg + 1));
}

Examples

Running

1

asinh(8723321.4);

Should return

1

16.67465779841863

Dependencies

No dependencies, you can use this function standalone.

Open syntax issues

php.js uses JsLint to help us keep our code consistent and prevent some common bugs.

Eventually we want all code to pass or at least take into consideration most fixes suggested by JsLint, following this JsLint configuration we’ve decided on.

Authors

Thanks to the following developers, you get to have asinh goodness in JavaScript.

• Onno Marsman ( original )

Comments

Add Comment

Name

Email

Website

Title

Content

Use:

[CODE]
your_stuff('here');
[/CODE]

for proper code formatting
By submitting code here you are allowing us to use it in php.js hence dual licensing it under the MIT and GPL licenses

Mike Speciner
20 Jul '11

  This does not work for negative arg. It also suffers from poor precision for |arg| << 1.

To fix the first problem, try
return Math.log(Math.abs(arg) + Math.sqrt(arg * arg + 1))*(arg<0?-1:1);

The second problem is much harder to fix; best might be a rational function approximation for small args.
If there were a builtin function log1p(x) := log(1+x), and similarly
expm1(x) := exp(x)-1, things would be much simpler for all the hyperbolic functions and their inverses.

Contribute a New function