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https://github.com/stdlib-js/math-base-special-rempio2
Compute `x - nπ/2 = r`.
https://github.com/stdlib-js/math-base-special-rempio2
division javascript math mathematics node node-js nodejs pi pio2 precision remainder stdlib
Last synced: about 2 months ago
JSON representation
Compute `x - nπ/2 = r`.
- Host: GitHub
- URL: https://github.com/stdlib-js/math-base-special-rempio2
- Owner: stdlib-js
- License: apache-2.0
- Created: 2021-06-15T17:05:37.000Z (over 3 years ago)
- Default Branch: main
- Last Pushed: 2024-09-08T19:20:32.000Z (4 months ago)
- Last Synced: 2024-09-08T20:49:50.293Z (4 months ago)
- Topics: division, javascript, math, mathematics, node, node-js, nodejs, pi, pio2, precision, remainder, stdlib
- Language: JavaScript
- Homepage: https://github.com/stdlib-js/stdlib
- Size: 866 KB
- Stars: 1
- Watchers: 3
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- Contributing: CONTRIBUTING.md
- License: LICENSE
- Code of conduct: CODE_OF_CONDUCT.md
- Citation: CITATION.cff
- Security: SECURITY.md
Awesome Lists containing this project
README
About stdlib...
We believe in a future in which the web is a preferred environment for numerical computation. To help realize this future, we've built stdlib. stdlib is a standard library, with an emphasis on numerical and scientific computation, written in JavaScript (and C) for execution in browsers and in Node.js.
The library is fully decomposable, being architected in such a way that you can swap out and mix and match APIs and functionality to cater to your exact preferences and use cases.
When you use stdlib, you can be absolutely certain that you are using the most thorough, rigorous, well-written, studied, documented, tested, measured, and high-quality code out there.
To join us in bringing numerical computing to the web, get started by checking us out on GitHub, and please consider financially supporting stdlib. We greatly appreciate your continued support!
# rempio2
[![NPM version][npm-image]][npm-url] [![Build Status][test-image]][test-url] [![Coverage Status][coverage-image]][coverage-url]
> Compute `x - nπ/2 = r`.
## Installation
```bash
npm install @stdlib/math-base-special-rempio2
```
Alternatively,
- To load the package in a website via a `script` tag without installation and bundlers, use the [ES Module][es-module] available on the [`esm`][esm-url] branch (see [README][esm-readme]).
- If you are using Deno, visit the [`deno`][deno-url] branch (see [README][deno-readme] for usage intructions).
- For use in Observable, or in browser/node environments, use the [Universal Module Definition (UMD)][umd] build available on the [`umd`][umd-url] branch (see [README][umd-readme]).
The [branches.md][branches-url] 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
```javascript
var rempio2 = require( '@stdlib/math-base-special-rempio2' );
```
#### rempio2( x, y )
Computes `x - nπ/2 = r`.
```javascript
var y = [ 0.0, 0.0 ];
var n = rempio2( 128.0, y );
// returns 81
var y1 = y[ 0 ];
// returns ~0.765
var y2 = y[ 1 ];
// returns ~3.618e-17
```
When `x` is `NaN` or infinite, the function returns `0` and sets the elements of `y` to `NaN`.
```javascript
var y = [ 0.0, 0.0 ];
var n = rempio2( NaN, y );
// returns 0
var y1 = y[ 0 ];
// returns NaN
var y2 = y[ 1 ];
// returns NaN
y = [ 0.0, 0.0 ];
n = rempio2( Infinity, y );
// returns 0
y1 = y[ 0 ];
// returns NaN
y2 = y[ 1 ];
// returns NaN
```
## Notes
- The function returns `n` and stores the remainder `r` as two numbers in `y`, such that `y[0]+y[1] = r`.
- For input values larger than `2^20*π/2` in magnitude, the function **only** returns the last three binary digits of `n` and not the full result.
## Examples
```javascript
var linspace = require( '@stdlib/array-base-linspace' );
var rempio2 = require( '@stdlib/math-base-special-rempio2' );
var x = linspace( 0.0, 100.0, 100 );
var y = [ 0.0, 0.0 ];
var n;
var i;
for ( i = 0; i < x.length; i++ ) {
n = rempio2( x[ i ], y );
console.log( '%d - %dπ/2 = %d + %d', x[ i ], n, y[ 0 ], y[ 1 ] );
}
```
* * *
## C APIs
### Usage
```c
#include "stdlib/math/base/special/rempio2.h"
```
#### stdlib_base_rempio2( x, &rem1, &rem2 )
Computes `x - nπ/2 = r`.
```c
#include
double rem1;
double rem2;
int32_t n = stdlib_base_rempio2( 4.0, &rem1, &rem2 );
```
The function accepts the following arguments:
- **x**: `[in] double` input value.
- **rem1**: `[out] double*` destination for first remainder number.
- **rem2**: `[out] double*` destination for second remainder number.
```c
int32_t stdlib_base_rempio2( const double x, double *rem1, double *rem2 );
```
### Notes
- The function returns `n` and stores the remainder `r` as two numbers in `rem1` and `rem2`, respectively, such that `rem1+rem2 = r`.
### Examples
```c
#include "stdlib/math/base/special/rempio2.h"
#include
#include
#include
int main( void ) {
const double x[] = { 0.0, 1.0, 4.0, 128.0 };
double rem1;
double rem2;
int32_t n;
int i;
for ( i = 0; i < 4; i++ ) {
n = stdlib_base_rempio2( x[ i ], &rem1, &rem2 );
printf( "%lf - %"PRId32"π/2 = %lf + %lf\n", x[ i ], n, rem1, rem2 );
}
}
```
* * *
## 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
[![Chat][chat-image]][chat-url]
---
## Copyright
Copyright © 2016-2024. The Stdlib [Authors][stdlib-authors].
[npm-image]: http://img.shields.io/npm/v/@stdlib/math-base-special-rempio2.svg
[npm-url]: https://npmjs.org/package/@stdlib/math-base-special-rempio2
[test-image]: https://github.com/stdlib-js/math-base-special-rempio2/actions/workflows/test.yml/badge.svg?branch=main
[test-url]: https://github.com/stdlib-js/math-base-special-rempio2/actions/workflows/test.yml?query=branch:main
[coverage-image]: https://img.shields.io/codecov/c/github/stdlib-js/math-base-special-rempio2/main.svg
[coverage-url]: https://codecov.io/github/stdlib-js/math-base-special-rempio2?branch=main
[chat-image]: https://img.shields.io/gitter/room/stdlib-js/stdlib.svg
[chat-url]: https://app.gitter.im/#/room/#stdlib-js_stdlib:gitter.im
[stdlib]: https://github.com/stdlib-js/stdlib
[stdlib-authors]: https://github.com/stdlib-js/stdlib/graphs/contributors
[umd]: https://github.com/umdjs/umd
[es-module]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Modules
[deno-url]: https://github.com/stdlib-js/math-base-special-rempio2/tree/deno
[deno-readme]: https://github.com/stdlib-js/math-base-special-rempio2/blob/deno/README.md
[umd-url]: https://github.com/stdlib-js/math-base-special-rempio2/tree/umd
[umd-readme]: https://github.com/stdlib-js/math-base-special-rempio2/blob/umd/README.md
[esm-url]: https://github.com/stdlib-js/math-base-special-rempio2/tree/esm
[esm-readme]: https://github.com/stdlib-js/math-base-special-rempio2/blob/esm/README.md
[branches-url]: https://github.com/stdlib-js/math-base-special-rempio2/blob/main/branches.md