npm package: @stdlib/math-base-special-sincospi
Description: Simultaneously compute the sine and cosine of a number times π.
Author: The Stdlib Authors
Latest version: 0.3.1

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# sincospi

[![NPM version][npm-image]][npm-url] [![Build Status][test-image]][test-url] [![Coverage Status][coverage-image]][coverage-url] <!-- [![dependencies][dependencies-image]][dependencies-url] -->

> Simultaneously compute the [sine][@stdlib/math/base/special/sin] and [cosine][@stdlib/math/base/special/cos] of a number times [π][@stdlib/constants/float64/pi].

<section class="installation">

## Installation

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

</section>

<section class="usage">

## Usage

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

#### sincospi( x )

Simultaneously computes the [sine][@stdlib/math/base/special/sin] and [cosine][@stdlib/math/base/special/cos] of a `number` times [π][@stdlib/constants/float64/pi] more accurately than `sincos(pi*x)`, especially for large `x`.

```javascript
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][@stdlib/math/base/special/sin] and [cosine][@stdlib/math/base/special/cos] of a `number` times [π][@stdlib/constants/float64/pi] more accurately than `sincos(pi*x)`, especially for large `x`, and assigns results to a provided output array.

```javascript
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
```

</section>

<!-- /.usage -->

<section class="examples">

## Examples

<!-- eslint no-undef: "error" -->

```javascript
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 ] ) );
}
```

</section>

<!-- /.examples -->

<!-- C interface documentation. -->

* * *

<section class="c">

## C APIs

<!-- Section to include introductory text. Make sure to keep an empty line after the intro `section` element and another before the `/section` close. -->

<section class="intro">

</section>

<!-- /.intro -->

<!-- C usage documentation. -->

<section class="usage">

### Usage

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

#### stdlib_base_sincospi( x, &sine, &cosine )

Simultaneously computes the [sine][@stdlib/math/base/special/sin] and [cosine][@stdlib/math/base/special/cos] of a `number` times [π][@stdlib/constants/float64/pi] more accurately than `sincos(pi*x)`, especially for large `x`.

```c
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.

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

</section>

<!-- /.usage -->

<!-- C API usage notes. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->

<section class="notes">

</section>

<!-- /.notes -->

<!-- C API usage examples. -->

<section class="examples">

### Examples

```c
#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 );
    }
}
```

</section>

<!-- /.examples -->

</section>

<!-- /.c -->

<!-- Section for related `stdlib` packages. Do not manually edit this section, as it is automatically populated. -->

<section class="related">

* * *

## See Also

-   <span class="package-name">[`@stdlib/math-base/special/cospi`][@stdlib/math/base/special/cospi]</span><span class="delimiter">: </span><span class="description">compute cos(πx).</span>
-   <span class="package-name">[`@stdlib/math-base/special/sincos`][@stdlib/math/base/special/sincos]</span><span class="delimiter">: </span><span class="description">simultaneously compute the sine and cosine of an angle measured in radians.</span>
-   <span class="package-name">[`@stdlib/math-base/special/sinpi`][@stdlib/math/base/special/sinpi]</span><span class="delimiter">: </span><span class="description">compute sin(πx).</span>

</section>

<!-- /.related -->

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<section class="main-repo" >

* * *

## Notice

This package is part of [stdlib][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][stdlib], see the main project [repository][stdlib].

#### Community

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---

## License

See [LICENSE][stdlib-license].


## Copyright

Copyright &copy; 2016-2026. The Stdlib [Authors][stdlib-authors].

</section>

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[@stdlib/math/base/special/sin]: https://www.npmjs.com/package/@stdlib/math-base-special-sin

[@stdlib/math/base/special/cos]: https://www.npmjs.com/package/@stdlib/math-base-special-cos

[@stdlib/constants/float64/pi]: https://www.npmjs.com/package/@stdlib/constants-float64-pi

<!-- <related-links> -->

[@stdlib/math/base/special/cospi]: https://www.npmjs.com/package/@stdlib/math-base-special-cospi

[@stdlib/math/base/special/sincos]: https://www.npmjs.com/package/@stdlib/math-base-special-sincos

[@stdlib/math/base/special/sinpi]: https://www.npmjs.com/package/@stdlib/math-base-special-sinpi

<!-- </related-links> -->

</section>

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