cospif

Compute the cosine of a number times π.

Installation

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

Usage

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

cospif( x )

Computes cos(πx) in single-precision floating-point format more accurately than cos(pi*x), especially for large x.

var y = cospif( 0.0 );
// returns 1.0

y = cospif( 0.5 );
// returns 0.0

y = cospif( 0.1 );
// returns ~0.951

y = cospif( NaN );
// returns NaN

Examples

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

var opts = {
    'dtype': 'float32'
};
var x = uniform( 100, -100.0, 100.0, opts );

logEachMap( 'cos( π * %0.4f ) = %0.4f', x, cospif );

C APIs

Usage

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

stdlib_base_cospif( x )

Computes cos(πx) in single-precision floating-point format more accurately than cos(pi*x), especially for large x.

float out = stdlib_base_cospif( 0.5f );
// returns 0.0f

The function accepts the following arguments:

• x: [in] float input value.

float stdlib_base_cospif( const float x );

Examples

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

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

    float y;
    int i;
    for ( i = 0; i < 5; i++ ) {
        y = stdlib_base_cospif( x[ i ] );
        printf( "cos( π * %f ) = %f\n", x[ i ], y );
    }
}

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

License

See LICENSE.

Copyright

Copyright © 2016-2026. The Stdlib Authors.