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sincospi

Simultaneously compute the sine and cosine of a number times π.

Installation

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

Alternatively,

• To load the package in a website via a script tag without installation and bundlers, use the ES Module available on the esm branch (see README).
• If you are using Deno, visit the deno branch (see README for usage intructions).
• For use in Observable, or in browser/node environments, use the Universal Module Definition (UMD) build available on the umd branch (see README).

The branches.md file summarizes the available branches and displays a diagram illustrating their relationships.

To view installation and usage instructions specific to each branch build, be sure to explicitly navigate to the respective README files on each branch, as linked to above.

Usage

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

sincospi( x )

Simultaneously computes the sine and cosine of a number times π more accurately than sincos(pi*x), especially for large x.

var v = sincospi( 0.0 );
// returns [ 0.0, 1.0 ]

v = sincospi( 0.5 );
// returns [ 1.0, 0.0 ]

v = sincospi( 0.1 );
// returns [ ~0.309, ~0.951 ]

v = sincospi( NaN );
// returns [ NaN, NaN ]

sincospi( x, out, stride, offset )

Simultaneously computes the sine and cosine of a number times π more accurately than sincos(pi*x), especially for large x, and assigns results to a provided output array.

var Float64Array = require( '@stdlib/array-float64' );

var out = new Float64Array( 2 );

var v = sincospi.assign( 0.0, out, 1, 0 );
// returns <Float64Array>[ 0.0, 1.0 ]

var bool = ( v === out );
// returns true

Examples

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

var x = linspace( 0.0, 2.0, 101 );

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

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C APIs

Usage

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

stdlib_base_sincospi( x, &sine, &cosine )

Simultaneously computes the sine and cosine of a number times π more accurately than sincos(pi*x), especially for large x.

double cosine;
double sine;

stdlib_base_sincospi( 4.0, &sine, &cosine );

The function accepts the following arguments:

• x: [in] double input value.
• sine: [out] double* destination for the sine.
• cosine: [out] double* destination for the cosine.

void stdlib_base_sincospi( const double x, double *sine, double *cosine );

Examples

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

int main( void ) {
    const double x[] = { 0.0, 1.57, 3.14, 6.28 };

    double cosine;
    double sine;
    int i;
    for ( i = 0; i < 4; i++ ) {
        stdlib_base_sincospi( x[ i ], &sine, &cosine );
        printf( "x: %lf => sine: %lf, cosine: %lf\n", x[ i ], sine, cosine );
    }
}

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See Also

• @stdlib/math-base/special/cospi: compute cos(πx).
• @stdlib/math-base/special/sincos: simultaneously compute the sine and cosine of a number.
• @stdlib/math-base/special/sinpi: compute sin(πx).

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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

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License

See LICENSE.

Copyright

Copyright © 2016-2024. The Stdlib Authors.