Cosine

Compute the cosine of a number.

Installation

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

Usage

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

cos( x )

Computes the cosine of a number (in radians).

var v = cos( 0.0 );
// returns 1.0

v = cos( 3.141592653589793/4.0 );
// returns ~0.707

v = cos( -3.141592653589793/6.0 );
// returns ~0.866

v = cos( NaN );
// returns NaN

Examples

var linspace = require( '@stdlib/array-base-linspace' );
var TWO_PI = require( '@stdlib/constants-float64-two-pi' );
var cos = require( '@stdlib/math-base-special-cos' );

var x = linspace( 0.0, TWO_PI, 100 );

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

C APIs

Usage

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

stdlib_base_cos( x )

Computes the cosine of a number (in radians).

double out = stdlib_base_cos( 0.0 );
// returns 1.0

out = stdlib_base_cos( 3.141592653589793 / 4.0 );
// returns ~-0.707

The function accepts the following arguments:

• x: [in] double input value.

double stdlib_base_cos( const double x );

Examples

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

int main( void ) {
    const double x[] = { 0.0, 0.523, 0.785, 1.047, 3.14 };

    double y;
    int i;
    for ( i = 0; i < 5; i++ ) {
        y = stdlib_base_cos( x[ i ] );
        printf( "cos(%lf) = %lf\n", x[ i ], y );
    }
}

See Also

• @stdlib/math-base/special/cospi: compute cos(πx).
• @stdlib/math-base/special/cosm1: compute the cosine of a number minus one.
• @stdlib/math-base/special/sin: compute the sine of a number.
• @stdlib/math-base/special/tan: evaluate the tangent of a 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.

Community

Copyright

Copyright © 2016-2024. The Stdlib Authors.