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.
npm install @stdlib/math-base-special-atan2fWe 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!
About stdlib...
[![NPM version][npm-image]][npm-url] [![Build Status][test-image]][test-url] [![Coverage Status][coverage-image]][coverage-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.
``bash`
npm install @stdlib/math-base-special-atan2f
`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
`
`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 );
`
*
`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.[in] float
- x: x coordinate.
`c`
float stdlib_base_atan2f( const float y, const float x );
`c
#include "stdlib/math/base/special/atan2f.h"
#include
#include
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;
}
`
*
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 © 2016-2026. The Stdlib [Authors][stdlib-authors].
[npm-image]: http://img.shields.io/npm/v/@stdlib/math-base-special-atan2f.svg
[npm-url]: https://npmjs.org/package/@stdlib/math-base-special-atan2f
[test-image]: https://github.com/stdlib-js/math-base-special-atan2f/actions/workflows/test.yml/badge.svg?branch=v0.1.1
[test-url]: https://github.com/stdlib-js/math-base-special-atan2f/actions/workflows/test.yml?query=branch:v0.1.1
[coverage-image]: https://img.shields.io/codecov/c/github/stdlib-js/math-base-special-atan2f/main.svg
[coverage-url]: https://codecov.io/github/stdlib-js/math-base-special-atan2f?branch=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-atan2f/tree/deno
[deno-readme]: https://github.com/stdlib-js/math-base-special-atan2f/blob/deno/README.md
[umd-url]: https://github.com/stdlib-js/math-base-special-atan2f/tree/umd
[umd-readme]: https://github.com/stdlib-js/math-base-special-atan2f/blob/umd/README.md
[esm-url]: https://github.com/stdlib-js/math-base-special-atan2f/tree/esm
[esm-readme]: https://github.com/stdlib-js/math-base-special-atan2f/blob/esm/README.md
[branches-url]: https://github.com/stdlib-js/math-base-special-atan2f/blob/main/branches.md