README.md

sinpi

Compute the sine of a number times π.

Usage

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

sinpi( x )

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

var y = sinpi( 0.0 );
// returns 0.0

y = sinpi( 0.5 );
// returns 1.0

y = sinpi( 0.9 );
// returns ~0.309

y = sinpi( NaN );
// returns NaN

Examples

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

var opts = {
    'dtype': 'float64'
};
var x = uniform( 100, -100.0, 100.0, opts );

logEachMap( 'sin( π * %0.4f ) = %0.4f', x, sinpi );

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C APIs

Usage

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

stdlib_base_sinpi( x )

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

double y = stdlib_base_sinpi( 0.5 );
// returns 1.0

The function accepts the following arguments:

• x: [in] double input value.

double stdlib_base_sinpi( const double x );

Examples

#include "stdlib/math/base/special/sinpi.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_sinpi( x[ i ] );
        printf( "sinpi(%lf) = %lf\n", x[ i ], y );
    }
}

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See Also

• @stdlib/math/base/special/sin: compute the sine of a number.