cospi

Compute the cosine of a number times π.

Usage

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

cospi( x )

Computes cos(πx) more accurately than cos(pi*x), especially for large x.

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

y = cospi( 0.5 );
// returns 0.0

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

y = cospi( NaN );
// returns NaN

Examples

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

var x = linspace( -100.0, 100.0, 100 );

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