Compute the angle in the plane (in radians) between the positive x-axis and the ray from (0,0) to the point (x,y).
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> Compute the angle in the plane (in radians) between the positive x-axis and the ray from (0,0) to the point (x,y).
``bash`
npm install @stdlib/math-base-special-atan2
`javascript`
var atan2 = require( '@stdlib/math-base-special-atan2' );
#### atan2( 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).
`javascript
var v = atan2( 2.0, 2.0 ); // => atan(1.0)
// returns ~0.785
v = atan2( 6.0, 2.0 ); // => atan(3.0)
// returns ~1.249
v = atan2( -1.0, -1.0 ); // => atan(1.0) - π
// returns ~-2.356
v = atan2( 3.0, 0.0 ); // => π/2
// returns ~1.571
v = atan2( -2.0, 0.0 ); // => -π/2
// returns ~-1.571
v = atan2( 0.0, 0.0 );
// returns 0.0
v = atan2( 3.0, NaN );
// returns NaN
`
`javascript
var uniform = require( '@stdlib/random-array-uniform' );
var logEachMap = require( '@stdlib/console-log-each-map' );
var atan2 = require( '@stdlib/math-base-special-atan2' );
var opts = {
'dtype': 'float64'
};
var x = uniform( 100, 0.0, 100.0, opts );
var y = uniform( 100, 0.0, 100.0, opts );
logEachMap( 'atan2(%0.4f,%0.4f) = %0.4f', y, x, atan2 );
`
*
`c`
#include "stdlib/math/base/special/atan2.h"
#### stdlib_base_atan2( 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).
`c
double out = stdlib_base_atan2( 2.0, 2.0 );
// returns ~0.785
out = stdlib_base_atan2( 6.0, 2.0 );
// returns ~1.249
`
The function accepts the following arguments:
- y: [in] double - y coordinate.[in] double
- x: - x coordinate.
`c`
double stdlib_base_atan2( const double y, const double x );
`c
#include "stdlib/math/base/special/atan2.h"
#include
#include
int main( void ) {
double y;
double x;
double v;
int i;
for ( i = 0; i < 100; i++ ) {
y = ( ( (double)rand() / (double)RAND_MAX ) * 100.0 );
x = ( ( (double)rand() / (double)RAND_MAX ) * 100.0 );
v = stdlib_base_atan2( y, x );
printf( "atan2(%lf, %lf) = %lf\n", y, x, v );
}
return 0;
}
`
*
- [@stdlib/math-base/special/atan][@stdlib/math/base/special/atan]: compute the arctangent of a double-precision floating-point number.
*
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].
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---
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