https://github.com/stdlib-js/math-base-special-cpolar
Compute the absolute value and the phase of a complex number.
https://github.com/stdlib-js/math-base-special-cpolar
abs absolute angle arg argument cabs carg cphase distance javascript magnitude math mathematics modulus node node-js nodejs phase polar stdlib
Last synced: 12 days ago
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Compute the absolute value and the phase of a complex number.
- Host: GitHub
- URL: https://github.com/stdlib-js/math-base-special-cpolar
- Owner: stdlib-js
- License: apache-2.0
- Created: 2021-06-15T17:44:50.000Z (over 4 years ago)
- Default Branch: main
- Last Pushed: 2025-07-22T03:41:22.000Z (4 months ago)
- Last Synced: 2025-10-23T16:23:51.668Z (14 days ago)
- Topics: abs, absolute, angle, arg, argument, cabs, carg, cphase, distance, javascript, magnitude, math, mathematics, modulus, node, node-js, nodejs, phase, polar, stdlib
- Language: Python
- Homepage: https://github.com/stdlib-js/stdlib
- Size: 772 KB
- Stars: 3
- Watchers: 2
- 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
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README
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# cpolar
[![NPM version][npm-image]][npm-url] [![Build Status][test-image]][test-url] [![Coverage Status][coverage-image]][coverage-url]
> Compute the [absolute value][@stdlib/math/base/special/cabs] and [phase][@stdlib/math/base/special/cphase] of a double-precision complex floating-point number.
## Installation
```bash
npm install @stdlib/math-base-special-cpolar
```
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 cpolar = require( '@stdlib/math-base-special-cpolar' );
```
#### cpolar( z )
Computes the [absolute value][@stdlib/math/base/special/cabs] and [phase][@stdlib/math/base/special/cphase] of a double-precision complex floating-point number.
```javascript
var Complex128 = require( '@stdlib/complex-float64-ctor' );
var o = cpolar( new Complex128( 5.0, 3.0 ) );
// returns [ ~5.83, ~0.5404 ]
```
#### cpolar.assign( z, out, stride, offset )
Computes the [absolute value][@stdlib/math/base/special/cabs] and [phase][@stdlib/math/base/special/cphase] of a double-precision complex floating-point number and assigns results to a provided output array.
```javascript
var Complex128 = require( '@stdlib/complex-float64-ctor' );
var Float64Array = require( '@stdlib/array-float64' );
var out = new Float64Array( 2 );
var v = cpolar.assign( new Complex128( 5.0, 3.0 ), out, 1, 0 );
// returns [ ~5.83, ~0.5404 ]
var bool = ( v === out );
// returns true
```
## Examples
```javascript
var Complex128 = require( '@stdlib/complex-float64-ctor' );
var randu = require( '@stdlib/random-base-randu' );
var round = require( '@stdlib/math-base-special-round' );
var cpolar = require( '@stdlib/math-base-special-cpolar' );
var re;
var im;
var z;
var o;
var i;
for ( i = 0; i < 100; i++ ) {
re = round( randu()*100.0 ) - 50.0;
im = round( randu()*100.0 ) - 50.0;
z = new Complex128( re, im );
o = cpolar( z );
z = z.toString();
console.log( 'abs(%s) = %d. arg(%s) = %d', z, o[0], z, o[1] );
}
```
* * *
## C APIs
### Usage
```c
#include "stdlib/math/base/special/cpolar.h"
```
#### stdlib_base_cpolar( z, cabs, cphase )
Computes the [absolute value][@stdlib/math/base/special/cabs] and [phase][@stdlib/math/base/special/cphase] of a double-precision complex floating-point number.
```c
#include "stdlib/complex/float64/ctor.h"
#include "stdlib/complex/float64/real.h"
#include "stdlib/complex/float64/imag.h"
stdlib_complex128_t z = stdlib_complex128( 5.0, 3.0 );
double cabs;
double cphase;
stdlib_base_cpolar( z, &cabs, &cphase );
```
The function accepts the following arguments:
- **z**: `[in] stdlib_complex128_t` input value.
- **cabs**: `[out] double*` destination for the absolute value.
- **cphase**: `[out] double*` destination for the phase value in radians.
```c
void stdlib_base_cpolar( const stdlib_complex128_t z, double *cabs, double *cphase );
```
### Examples
```c
#include "stdlib/math/base/special/cpolar.h"
#include "stdlib/complex/float64/ctor.h"
#include "stdlib/complex/float64/reim.h"
#include
int main( void ) {
const stdlib_complex128_t x[] = {
stdlib_complex128( 3.14, 1.0 ),
stdlib_complex128( -3.14, -1.0 ),
stdlib_complex128( 0.0, 0.0 ),
stdlib_complex128( 0.0/0.0, 0.0/0.0 )
};
double cphase;
double cabs;
double re;
double im;
int i;
for ( i = 0; i < 4; i++ ) {
stdlib_base_cpolar( x[i], &cabs, &cphase );
stdlib_complex128_reim( x[i], &re, &im );
printf( "cpolar(%lf + %lfi) => cabs: %lf, cphase: %lf\n", re, im, cabs, cphase );
}
}
```
* * *
## See Also
- [`@stdlib/math-base/special/cabs`][@stdlib/math/base/special/cabs]: compute the absolute value of a double-precision complex floating-point number.
- [`@stdlib/math-base/special/cphase`][@stdlib/math/base/special/cphase]: compute the argument of a double-precision complex floating-point number in radians.
* * *
## 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]
---
## License
See [LICENSE][stdlib-license].
## Copyright
Copyright © 2016-2025. The Stdlib [Authors][stdlib-authors].
[npm-image]: http://img.shields.io/npm/v/@stdlib/math-base-special-cpolar.svg
[npm-url]: https://npmjs.org/package/@stdlib/math-base-special-cpolar
[test-image]: https://github.com/stdlib-js/math-base-special-cpolar/actions/workflows/test.yml/badge.svg?branch=main
[test-url]: https://github.com/stdlib-js/math-base-special-cpolar/actions/workflows/test.yml?query=branch:main
[coverage-image]: https://img.shields.io/codecov/c/github/stdlib-js/math-base-special-cpolar/main.svg
[coverage-url]: https://codecov.io/github/stdlib-js/math-base-special-cpolar?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-cpolar/tree/deno
[deno-readme]: https://github.com/stdlib-js/math-base-special-cpolar/blob/deno/README.md
[umd-url]: https://github.com/stdlib-js/math-base-special-cpolar/tree/umd
[umd-readme]: https://github.com/stdlib-js/math-base-special-cpolar/blob/umd/README.md
[esm-url]: https://github.com/stdlib-js/math-base-special-cpolar/tree/esm
[esm-readme]: https://github.com/stdlib-js/math-base-special-cpolar/blob/esm/README.md
[branches-url]: https://github.com/stdlib-js/math-base-special-cpolar/blob/main/branches.md
[stdlib-license]: https://raw.githubusercontent.com/stdlib-js/math-base-special-cpolar/main/LICENSE
[@stdlib/math/base/special/cabs]: https://github.com/stdlib-js/math-base-special-cabs
[@stdlib/math/base/special/cphase]: https://github.com/stdlib-js/math-base-special-cphase