atan

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

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

var x = linspace( -1000.0, 1000.0, 100 );

var i;
for ( i = 0; i < x.length; i++ ) {
    console.log( atan( x[ i ] ) );
}

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 );
    }
}