About stdlib…

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!

exp2

[![NPM version][npm-image]][npm-url] [![Build Status][test-image]][test-url] [![Coverage Status][coverage-image]][coverage-url]

Base 2 [exponential function][exponential-function].

## Installation

bash
npm install @stdlib/math-base-special-exp2

Alternatively,

- To load the package in a website via a script tag without installation and bundlers, use the [ES Module][es-module] available on the [esm][esm-url] branch (see [README][esm-readme]).
- If you are using Deno, visit the [deno][deno-url] branch (see [README][deno-readme] for usage intructions).
- For use in Observable, or in browser/node environments, use the [Universal Module Definition (UMD)][umd] build available on the [umd][umd-url] branch (see [README][umd-readme]).

The [branches.md][branches-url] file summarizes the available branches and displays a diagram illustrating their relationships.

To view installation and usage instructions specific to each branch build, be sure to explicitly navigate to the respective README files on each branch, as linked to above.

## Usage

javascript
var exp2 = require( '@stdlib/math-base-special-exp2' );

#### exp2( x )

Evaluates the base 2 [exponential function][exponential-function].

javascript
var v = exp2( 3.0 );
// returns 8.0

v = exp2( -9.0 );
// returns ~0.002

v = exp2( 0.0 );
// returns 1.0

v = exp2( NaN );
// returns NaN

## Examples

javascript
var uniform = require( '@stdlib/random-array-uniform' );
var logEachMap = require( '@stdlib/console-log-each-map' );
var exp2 = require( '@stdlib/math-base-special-exp2' );

var opts = {
    'dtype': 'float64'
};
var x = uniform( 100, -50.0, 50.0, opts );

logEachMap( '2^%0.4f = %0.4f', x, exp2 );

## C APIs

### Usage

c
#include "stdlib/math/base/special/exp2.h"

#### stdlib_base_exp2( x )

Evaluates the base 2 [exponential function][exponential-function].

c
double out = stdlib_base_exp2( 3.0 );
// returns 8.0

out = stdlib_base_exp2( -9.0 );
// returns ~0.002

The function accepts the following arguments:

- x: [in] double input value.

c
double stdlib_base_exp2( const double x );

### Examples

c
#include "stdlib/math/base/special/exp2.h"
#include <stdlib.h>
#include <stdio.h>

int main( void ) {
    double x;
    double v;
    int i;

    for ( i = 0; i < 100; i++ ) {
        x = ( ( (double)rand() / (double)RAND_MAX ) * 100.0 ) - 50.0;
        v = stdlib_base_exp2( x );
        printf( "2^%lf = %lf\n", x, v );
    }
}

*

## Notice

This package is part of [stdlib][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][stdlib], see the main project [repository][stdlib].

#### Community

[![Chat][chat-image]][chat-url]

—-

## Copyright

Copyright © 2016-2025. The Stdlib [Authors][stdlib-authors].