https://github.com/stdlib-js/math-base-special-cabs
Compute an absolute value of a complex number.
https://github.com/stdlib-js/math-base-special-cabs
abs absolute cabs cmplx complex distance javascript magnitude math mathematics modulus node node-js nodejs number stdlib
Last synced: 27 days ago
JSON representation
Compute an absolute value of a complex number.
- Host: GitHub
- URL: https://github.com/stdlib-js/math-base-special-cabs
- Owner: stdlib-js
- License: apache-2.0
- Created: 2021-06-14T16:47:01.000Z (almost 4 years ago)
- Default Branch: main
- Last Pushed: 2025-04-01T06:11:48.000Z (about 1 month ago)
- Last Synced: 2025-04-01T06:31:39.423Z (about 1 month ago)
- Topics: abs, absolute, cabs, cmplx, complex, distance, javascript, magnitude, math, mathematics, modulus, node, node-js, nodejs, number, stdlib
- Language: Python
- Homepage: https://github.com/stdlib-js/stdlib
- Size: 453 KB
- Stars: 2
- 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
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README
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# cabs
[![NPM version][npm-image]][npm-url] [![Build Status][test-image]][test-url] [![Coverage Status][coverage-image]][coverage-url]
> Compute the [absolute value][absolute-value] of a double-precision [complex][@stdlib/complex/float64/ctor] floating-point number.
The [absolute value][absolute-value] of a [complex][@stdlib/complex/float64/ctor] number is defined as
```math
|a + bi| = \sqrt{a^2 + b^2}
```
which corresponds to the length of a vector from the origin to a complex value plotted in the complex plane.
## Installation
```bash
npm install @stdlib/math-base-special-cabs
```
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 cabs = require( '@stdlib/math-base-special-cabs' );
```
#### cabs( z )
Computes an [absolute value][absolute-value] of a double-precision [complex][@stdlib/complex/float64/ctor] floating-point number.
```javascript
var Complex128 = require( '@stdlib/complex-float64-ctor' );
var y = cabs( new Complex128( 5.0, 3.0 ) );
// returns ~5.83
```
## Examples
```javascript
var Complex128 = require( '@stdlib/complex-float64-ctor' );
var discreteUniform = require( '@stdlib/random-base-discrete-uniform' );
var cabs = require( '@stdlib/math-base-special-cabs' );
var z;
var i;
for ( i = 0; i < 100; i++ ) {
z = new Complex128( discreteUniform( -50, 50 ), discreteUniform( -50, 50 ) );
console.log( 'cabs(%s) = %d', z.toString(), cabs( z ) );
}
```
* * *
## C APIs
### Usage
```c
#include "stdlib/math/base/special/cabs.h"
```
#### stdlib_base_cabs( z )
Computes the [absolute value][absolute-value] of a double-precision complex floating-point number.
```c
#include "stdlib/complex/float64/ctor.h"
stdlib_complex128_t z = stdlib_complex128( 5.0, 3.0 );
double y = stdlib_base_cabs( z );
// returns ~5.83
```
The function accepts the following arguments:
- **z**: `[in] stdlib_complex128_t` input value.
```c
double stdlib_base_cabs( const stdlib_complex128_t complex z );
```
### Examples
```c
#include "stdlib/math/base/special/cabs.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 )
};
stdlib_complex128_t v;
double re;
double im;
double y;
int i;
for ( i = 0; i < 4; i++ ) {
v = x[ i ];
y = stdlib_base_cabs( v );
stdlib_complex128_reim( v, &re, &im );
printf( "f(%lf + %lf) = %lf\n", re, im, y );
}
}
```
* * *
## See Also
- [`@stdlib/math-base/special/cabs2`][@stdlib/math/base/special/cabs2]: compute the squared absolute value of a double-precision complex floating-point number.
- [`@stdlib/math-base/special/abs`][@stdlib/math/base/special/abs]: compute the absolute value of a double-precision floating-point number.
* * *
## 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-cabs.svg
[npm-url]: https://npmjs.org/package/@stdlib/math-base-special-cabs
[test-image]: https://github.com/stdlib-js/math-base-special-cabs/actions/workflows/test.yml/badge.svg?branch=main
[test-url]: https://github.com/stdlib-js/math-base-special-cabs/actions/workflows/test.yml?query=branch:main
[coverage-image]: https://img.shields.io/codecov/c/github/stdlib-js/math-base-special-cabs/main.svg
[coverage-url]: https://codecov.io/github/stdlib-js/math-base-special-cabs?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-cabs/tree/deno
[deno-readme]: https://github.com/stdlib-js/math-base-special-cabs/blob/deno/README.md
[umd-url]: https://github.com/stdlib-js/math-base-special-cabs/tree/umd
[umd-readme]: https://github.com/stdlib-js/math-base-special-cabs/blob/umd/README.md
[esm-url]: https://github.com/stdlib-js/math-base-special-cabs/tree/esm
[esm-readme]: https://github.com/stdlib-js/math-base-special-cabs/blob/esm/README.md
[branches-url]: https://github.com/stdlib-js/math-base-special-cabs/blob/main/branches.md
[stdlib-license]: https://raw.githubusercontent.com/stdlib-js/math-base-special-cabs/main/LICENSE
[absolute-value]: https://en.wikipedia.org/wiki/Absolute_value
[@stdlib/complex/float64/ctor]: https://github.com/stdlib-js/complex-float64-ctor
[@stdlib/math/base/special/cabs2]: https://github.com/stdlib-js/math-base-special-cabs2
[@stdlib/math/base/special/abs]: https://github.com/stdlib-js/math-base-special-abs