# @stdlib/math-base-special-exp

> Natural exponential function.

Latest version **0.2.5** (published 2026-02-08) · Apache-2.0 license · 0 weekly downloads

## Install

```sh
npm install @stdlib/math-base-special-exp
pnpm add @stdlib/math-base-special-exp
yarn add @stdlib/math-base-special-exp
bun add @stdlib/math-base-special-exp
```

## Health

**Score 50/100 (C)** — status: stable.

Positive: has types; no vulnerabilities.

Warnings: low downloads; no esm support; pre 1.0.

## Facts

| | |
|---|---|
| Version | 0.2.5 |
| Published | 2026-02-08 |
| First published | 2021-06-15 |
| Weekly downloads | 0 |
| License | Apache-2.0 |
| TypeScript types | bundled |
| Module format | CommonJS |
| Node | >=0.10.0 |
| Dependencies | 7 |
| Unpacked size | 68.8 KB |
| Known vulnerabilities | 0 |
| Install scripts | no |
| GitHub stars | 1 |
| Author | The Stdlib Authors |
| Maintainers | stdlib-bot, kgryte, planeshifter, rreusser |
| Keywords | stdlib, stdmath, mathematics, math, special, function, math.exp, exp, natural, exponential, euler, power, number |

## Links

- npm: https://www.npmjs.com/package/@stdlib/math-base-special-exp
- Repository: https://github.com/stdlib-js/math-base-special-exp
- Homepage: https://stdlib.io
- Issues: https://github.com/stdlib-js/stdlib/issues
- Funding: https://opencollective.com/stdlib
- npm.io page: https://npm.io/package/@stdlib/math-base-special-exp

## Dependencies (7)

- [@stdlib/math-base-napi-unary](https://npm.io/package/@stdlib/math-base-napi-unary.md) ^0.2.7
- [@stdlib/constants-float64-ninf](https://npm.io/package/@stdlib/constants-float64-ninf.md) ^0.2.3
- [@stdlib/constants-float64-pinf](https://npm.io/package/@stdlib/constants-float64-pinf.md) ^0.2.3
- [@stdlib/utils-library-manifest](https://npm.io/package/@stdlib/utils-library-manifest.md) ^0.2.4
- [@stdlib/math-base-assert-is-nan](https://npm.io/package/@stdlib/math-base-assert-is-nan.md) ^0.2.3
- [@stdlib/math-base-special-ldexp](https://npm.io/package/@stdlib/math-base-special-ldexp.md) ^0.2.4
- [@stdlib/math-base-special-trunc](https://npm.io/package/@stdlib/math-base-special-trunc.md) ^0.2.3

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## Recent versions

- 0.2.5 (latest) — 2026-02-08
- 0.2.4 — 2024-07-28
- 0.2.3 — 2024-04-04
- 0.2.2 — 2024-02-25
- 0.2.1 — 2024-02-24
- 0.2.0 — 2024-02-14
- 0.1.0 — 2023-09-24
- 0.0.6 — 2022-02-16
- 0.0.5 — 2021-08-23
- 0.0.4 — 2021-07-07
- 0.0.3 — 2021-06-27
- 0.0.2 — 2021-06-16
- 0.0.1 — 2021-06-15

## README

<!--

@license Apache-2.0

Copyright (c) 2022 The Stdlib Authors.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

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distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
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<details>
  <summary>
    About stdlib...
  </summary>
  <p>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.</p>
  <p>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.</p>
  <p>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.</p>
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</details>

# exp

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

> Natural [exponential function][exponential-function].

<section class="intro">

The natural [exponential function][exponential-function] is defined as

<!-- <equation class="equation" label="eq:natural_exponential_function" align="center" raw="y = e^x" alt="Natural exponential function definition"> -->

<div class="equation" align="center" data-raw-text="y = e^x" data-equation="eq:natural_exponential_function">
    <img src="https://cdn.jsdelivr.net/gh/stdlib-js/stdlib@117273e7c4f27b0835723c2940d9675af0e14cb7/lib/node_modules/@stdlib/math/base/special/exp/docs/img/equation_natural_exponential_function.svg" alt="Natural exponential function definition">
    <br>
</div>

<!-- </equation> -->

where `e` is [Euler's][@stdlib/constants/float64/e] number.

</section>

<!-- /.intro -->

<section class="installation">

## Installation

```bash
npm install @stdlib/math-base-special-exp
```

</section>

<section class="usage">

## Usage

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

#### exp( x )

Evaluates the natural [exponential function][exponential-function].

```javascript
var v = exp( 4.0 );
// returns ~54.5982

v = exp( -9.0 );
// returns ~1.234e-4

v = exp( 0.0 );
// returns 1.0

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

</section>

<!-- /.usage -->

<section class="examples">

## Examples

<!-- eslint no-undef: "error" -->

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

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

logEachMap( 'e^%0.4f = %0.4f', x, exp );
```

</section>

<!-- /.examples -->

<!-- C interface documentation. -->

* * *

<section class="c">

## C APIs

<!-- Section to include introductory text. Make sure to keep an empty line after the intro `section` element and another before the `/section` close. -->

<section class="intro">

</section>

<!-- /.intro -->

<!-- C usage documentation. -->

<section class="usage">

### Usage

```c
#include "stdlib/math/base/special/exp.h"
```

#### stdlib_base_exp( x )

Evaluates the natural [exponential function][exponential-function].

```c
double out = stdlib_base_exp( 4.0 );
// returns ~54.5982

out = stdlib_base_exp( -9.0 );
// returns ~1.234e-4
```

The function accepts the following arguments:

-   **x**: `[in] double` input value.

```c
double stdlib_base_exp( const double x );
```

</section>

<!-- /.usage -->

<!-- C API usage notes. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->

<section class="notes">

</section>

<!-- /.notes -->

<!-- C API usage examples. -->

<section class="examples">

### Examples

```c
#include "stdlib/math/base/special/exp.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;
        v = stdlib_base_exp( x );
        printf( "e^%lf = %lf\n", x, v );
    }
}
```

</section>

<!-- /.examples -->

</section>

<!-- /.c -->

<!-- Section for related `stdlib` packages. Do not manually edit this section, as it is automatically populated. -->

<section class="related">

* * *

## See Also

-   <span class="package-name">[`@stdlib/math-base/special/exp10`][@stdlib/math/base/special/exp10]</span><span class="delimiter">: </span><span class="description">base 10 exponential function.</span>
-   <span class="package-name">[`@stdlib/math-base/special/exp2`][@stdlib/math/base/special/exp2]</span><span class="delimiter">: </span><span class="description">base 2 exponential function.</span>
-   <span class="package-name">[`@stdlib/math-base/special/expm1`][@stdlib/math/base/special/expm1]</span><span class="delimiter">: </span><span class="description">compute exp(x) - 1.</span>
-   <span class="package-name">[`@stdlib/math-base/special/ln`][@stdlib/math/base/special/ln]</span><span class="delimiter">: </span><span class="description">evaluate the natural logarithm of a double-precision floating-point number.</span>

</section>

<!-- /.related -->

<!-- Section for all links. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->


<section class="main-repo" >

* * *

## 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 &copy; 2016-2026. The Stdlib [Authors][stdlib-authors].

</section>

<!-- /.stdlib -->

<!-- Section for all links. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->

<section class="links">

[npm-image]: http://img.shields.io/npm/v/@stdlib/math-base-special-exp.svg
[npm-url]: https://npmjs.org/package/@stdlib/math-base-special-exp

[test-image]: https://github.com/stdlib-js/math-base-special-exp/actions/workflows/test.yml/badge.svg?branch=v0.2.5
[test-url]: https://github.com/stdlib-js/math-base-special-exp/actions/workflows/test.yml?query=branch:v0.2.5

[coverage-image]: https://img.shields.io/codecov/c/github/stdlib-js/math-base-special-exp/main.svg
[coverage-url]: https://codecov.io/github/stdlib-js/math-base-special-exp?branch=main

<!--

[dependencies-image]: https://img.shields.io/david/stdlib-js/math-base-special-exp.svg
[dependencies-url]: https://david-dm.org/stdlib-js/math-base-special-exp/main

-->

[chat-image]: https://img.shields.io/badge/zulip-join_chat-brightgreen.svg
[chat-url]: https://stdlib.zulipchat.com

[stdlib]: https://github.com/stdlib-js/stdlib

[stdlib-authors]: https://github.com/stdlib-js/stdlib/graphs/contributors

[umd]: https://github.com/umdjs/umd
[es-module]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Modules

[deno-url]: https://github.com/stdlib-js/math-base-special-exp/tree/deno
[deno-readme]: https://github.com/stdlib-js/math-base-special-exp/blob/deno/README.md
[umd-url]: https://github.com/stdlib-js/math-base-special-exp/tree/umd
[umd-readme]: https://github.com/stdlib-js/math-base-special-exp/blob/umd/README.md
[esm-url]: https://github.com/stdlib-js/math-base-special-exp/tree/esm
[esm-readme]: https://github.com/stdlib-js/math-base-special-exp/blob/esm/README.md
[branches-url]: https://github.com/stdlib-js/math-base-special-exp/blob/main/branches.md

[exponential-function]: https://en.wikipedia.org/wiki/Exponential_function

[@stdlib/constants/float64/e]: https://www.npmjs.com/package/@stdlib/constants-float64-e

<!-- <related-links> -->

[@stdlib/math/base/special/exp10]: https://www.npmjs.com/package/@stdlib/math-base-special-exp10

[@stdlib/math/base/special/exp2]: https://www.npmjs.com/package/@stdlib/math-base-special-exp2

[@stdlib/math/base/special/expm1]: https://www.npmjs.com/package/@stdlib/math-base-special-expm1

[@stdlib/math/base/special/ln]: https://www.npmjs.com/package/@stdlib/math-base-special-ln

<!-- </related-links> -->

</section>

<!-- /.links -->

---
_Source: https://npm.io/package/@stdlib/math-base-special-exp · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._