npm package: @stdlib/constants-float64-phi
Description: Golden ratio.
Author: The Stdlib Authors
Latest version: 0.2.3

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# PHI

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

> [Golden ratio][phi].

<section class="intro">

The [golden ratio][phi] can be defined algebraically as

<!-- <equation class="equation" label="eq:golden_ratio" align="center" raw="\phi = \frac{1 + \sqrt{5}}{2}" alt="Golden ratio"> -->

<div class="equation" align="center" data-raw-text="\phi = \frac{1 + \sqrt{5}}{2}" data-equation="eq:golden_ratio">
    <img src="https://cdn.jsdelivr.net/gh/stdlib-js/stdlib@5d87cc7cb2c58aeb732872f89562d2c89571cc8a/lib/node_modules/@stdlib/constants/float64/phi/docs/img/equation_golden_ratio.svg" alt="Golden ratio">
    <br>
</div>

<!-- </equation> -->

</section>

<!-- /.intro -->

<section class="installation">

## Installation

```bash
npm install @stdlib/constants-float64-phi
```

</section>

<section class="usage">

## Usage

```javascript
var PHI = require( '@stdlib/constants-float64-phi' );
```

#### PHI

The [golden ratio][phi-value].

```javascript
var bool = ( PHI === 1.618033988749895 );
// returns true
```

</section>

<!-- /.usage -->

<section class="examples">

## Examples

<!-- TODO: better example using Fibonacci(?) -->

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

```javascript
var PHI = require( '@stdlib/constants-float64-phi' );

console.log( PHI );
// => 1.618033988749895
```

</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/constants/float64/phi.h"
```

#### STDLIB_CONSTANT_FLOAT64_PHI

Macro for the [golden ratio][phi-value].

</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">

</section>

<!-- /.examples -->

</section>

<!-- /.c -->

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

<section class="related">

</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]

---

## License

See [LICENSE][stdlib-license].


## Copyright

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

</section>

<!-- /.stdlib -->

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<section class="links">

[npm-image]: http://img.shields.io/npm/v/@stdlib/constants-float64-phi.svg
[npm-url]: https://npmjs.org/package/@stdlib/constants-float64-phi

[test-image]: https://github.com/stdlib-js/constants-float64-phi/actions/workflows/test.yml/badge.svg?branch=v0.2.3
[test-url]: https://github.com/stdlib-js/constants-float64-phi/actions/workflows/test.yml?query=branch:v0.2.3

[coverage-image]: https://img.shields.io/codecov/c/github/stdlib-js/constants-float64-phi/main.svg
[coverage-url]: https://codecov.io/github/stdlib-js/constants-float64-phi?branch=main

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

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[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/constants-float64-phi/tree/deno
[deno-readme]: https://github.com/stdlib-js/constants-float64-phi/blob/deno/README.md
[umd-url]: https://github.com/stdlib-js/constants-float64-phi/tree/umd
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[esm-url]: https://github.com/stdlib-js/constants-float64-phi/tree/esm
[esm-readme]: https://github.com/stdlib-js/constants-float64-phi/blob/esm/README.md
[branches-url]: https://github.com/stdlib-js/constants-float64-phi/blob/main/branches.md

[stdlib-license]: https://raw.githubusercontent.com/stdlib-js/constants-float64-phi/main/LICENSE

[phi]: https://en.wikipedia.org/wiki/Golden_ratio

[phi-value]: http://oeis.org/A001622

</section>

<!-- /.links -->