@stdlib/math-base-special-atan

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atan

Compute the arctangent of a double-precision floating-point number.

Installation

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

Usage

var atan = require( '@stdlib/math-base-special-atan' );

atan( x )

Computes the arctangent of a double-precision floating-point number.

var v = atan( 0.0 );
// returns ~0.0

v = atan( -3.141592653589793/2.0 );
// returns ~-1.004

v = atan( 3.141592653589793/2.0 );
// returns ~1.004

v = atan( NaN );
// returns NaN

Examples

var uniform = require( '@stdlib/random-array-uniform' );
var logEachMap = require( '@stdlib/console-log-each-map' );
var atan = require( '@stdlib/math-base-special-atan' );

var x = uniform( 100, -1000.0, 1000.0, {
    'dtype': 'float64'
});

logEachMap( 'atan(%0.4f) = %0.4f', x, atan );

C APIs

Usage

#include "stdlib/math/base/special/atan.h"

stdlib_base_atan( x )

Computes the arctangent of a double-precision floating-point number.

double out = stdlib_base_atan( 0.0 );
// returns ~0.0

out = stdlib_base_atan( -3.141592653589793/2.0 );
// returns ~-1.004

The function accepts the following arguments:

• x: [in] double input value.

double stdlib_base_atan( const double x );

Examples

#include "stdlib/math/base/special/atan.h"
#include <stdio.h>

int main( void ) {
    const double x[] = { -1000.0, -777.78, -555.56, -333.33, -111.11,  111.11, 333.33,  555.56, 777.78, 1000.0 };
    double v;
    int i;

    for ( i = 0; i < 10; i++ ) {
        v = stdlib_base_atan( x[ i ] );
        printf( "atan(%lf) = %lf\n", x[ i ], v );
    }
}

See Also

• @stdlib/math-base/special/acos: compute the arccosine of a double-precision floating-point number.
• @stdlib/math-base/special/asin: compute the arcsine of a double-precision floating-point number.
• @stdlib/math-base/special/atanh: compute the hyperbolic arctangent of a double-precision floating-point number.

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.

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Copyright

Copyright © 2016-2026. The Stdlib Authors.