atan2f

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.

Installation

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

Usage

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.

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

Examples

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 APIs

Usage

#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.

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.

float stdlib_base_atan2f( const float y, const float x );

Examples

#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;
}

Notice

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

Community

Copyright

Copyright © 2016-2026. The Stdlib Authors.