npm package: @stdlib/math-base-special-atan2f
Description: Compute the angle in the plane (in radians) between the positive x-axis and the ray from (0,0) to the point (x,y) as a single-precision floating-point number.
Author: The Stdlib Authors
Latest version: 0.1.1

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# atan2f

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

> Compute the angle in the plane (in radians) between the positive x-axis and the ray from `(0,0)` to the point `(x,y)` as a single-precision floating-point number.

<section class="installation">

## Installation

```bash
npm install @stdlib/math-base-special-atan2f
```

</section>

<section class="usage">

## Usage

```javascript
var atan2f = require( '@stdlib/math-base-special-atan2f' );
```

#### atan2f( y, x )

Computes the angle in the plane (in radians) between the positive x-axis and the ray from `(0,0)` to the point `(x,y)` as a single-precision floating-point number.

```javascript
var v = atan2f( 2.0, 2.0 ); // => atanf( 1.0 )
// returns ~0.785

v = atan2f( 6.0, 2.0 ); // => atanf( 3.0 )
// returns ~1.249

v = atan2f( -1.0, -1.0 ); // => atanf( 1.0 ) - π
// returns ~-2.356

v = atan2f( 3.0, 0.0 ); // => π/2
// returns ~1.571

v = atan2f( -2.0, 0.0 ); // => -π/2
// returns ~-1.571

v = atan2f( 0.0, 0.0 );
// returns 0.0

v = atan2f( 3.0, 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 atan2f = require( '@stdlib/math-base-special-atan2f' );

var opts = {
    'dtype': 'float32'
};
var x = uniform( 100, 0.0, 100.0, opts );
var y = uniform( 100, 0.0, 100.0, opts );

logEachMap( 'atan2f(%0.4f,%0.4f) = %0.4f', y, x, atan2f );
```

</section>

<!-- /.examples -->

<!-- C interface documentation. -->

* * *

<section class="c">

## C APIs

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<section class="intro">

</section>

<!-- /.intro -->

<!-- C usage documentation. -->

<section class="usage">

### Usage

```c
#include "stdlib/math/base/special/atan2f.h"
```

#### stdlib_base_atan2f( y, x )

Computes the angle in the plane (in radians) between the positive x-axis and the ray from `(0,0)` to the point `(x,y)` as a single-precision floating-point number.

```c
float out = stdlib_base_atan2f( 2.0f, 2.0f );
// returns ~0.785f

out = stdlib_base_atan2f( 6.0f, 2.0f );
// returns ~1.249f
```

The function accepts the following arguments:

-   **y**: `[in] float` `y` coordinate.
-   **x**: `[in] float` `x` coordinate.

```c
float stdlib_base_atan2f( const float y, const float 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/atan2f.h"
#include <stdlib.h>
#include <stdio.h>

int main( void ) {
    float y;
    float x;
    float v;
    int i;

    for ( i = 0; i < 100; i++ ) {
        y = ( ( (float)rand() / (float)RAND_MAX ) * 100.0f );
        x = ( ( (float)rand() / (float)RAND_MAX ) * 100.0f );
        v = stdlib_base_atan2f( y, x );
        printf( "atan2f(%f, %f) = %f\n", y, x, v );
    }
    return 0;
}
```

</section>

<!-- /.examples -->

</section>

<!-- /.c -->

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<section class="related">

</section>

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<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>

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