https://github.com/stdlib-js/math-base-ops-cneg
Negate a complex number.
https://github.com/stdlib-js/math-base-ops-cneg
cmplx complex javascript math mathematics neg negate negation negative node node-js nodejs number stdlib
Last synced: 7 months ago
JSON representation
Negate a complex number.
- Host: GitHub
- URL: https://github.com/stdlib-js/math-base-ops-cneg
- Owner: stdlib-js
- License: apache-2.0
- Created: 2021-06-08T13:46:20.000Z (over 4 years ago)
- Default Branch: main
- Last Pushed: 2025-02-02T15:27:11.000Z (12 months ago)
- Last Synced: 2025-04-12T16:16:01.300Z (10 months ago)
- Topics: cmplx, complex, javascript, math, mathematics, neg, negate, negation, negative, node, node-js, nodejs, number, stdlib
- Language: JavaScript
- Homepage: https://github.com/stdlib-js/stdlib
- Size: 521 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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# cneg
[![NPM version][npm-image]][npm-url] [![Build Status][test-image]][test-url] [![Coverage Status][coverage-image]][coverage-url]
> Negate a double-precision complex floating-point number.
## Installation
```bash
npm install @stdlib/math-base-ops-cneg
```
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 cneg = require( '@stdlib/math-base-ops-cneg' );
```
#### cneg( z )
Negates a double-precision complex floating-point number.
```javascript
var Complex128 = require( '@stdlib/complex-float64-ctor' );
var real = require( '@stdlib/complex-float64-real' );
var imag = require( '@stdlib/complex-float64-imag' );
var z = new Complex128( -4.2, 5.5 );
var out = cneg( z );
// returns
var re = real( out );
// returns 4.2
var im = imag( out );
// returns -5.5
z = new Complex128( 0.0, 0.0 );
out = cneg( z );
// returns
re = real( out );
// returns -0.0
im = imag( out );
// returns -0.0
z = new Complex128( NaN, NaN );
out = cneg( z );
// returns
re = real( out );
// returns NaN
im = imag( out );
// returns NaN
```
## Examples
```javascript
var Complex128 = require( '@stdlib/complex-float64-ctor' );
var discreteUniform = require( '@stdlib/random-base-discrete-uniform' );
var cneg = require( '@stdlib/math-base-ops-cneg' );
function randomComplex() {
var re = discreteUniform( -50, 50 );
var im = discreteUniform( -50, 50 );
return new Complex128( re, im );
}
var z;
var o;
var i;
for ( i = 0; i < 100; i++ ) {
z = randomComplex();
o = cneg( z );
console.log( 'negate(%s) = %s', z.toString(), o.toString() );
}
```
* * *
## C APIs
### Usage
```c
#include "stdlib/math/base/ops/cneg.h"
```
#### stdlib_base_cneg( z )
Negates 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( 3.0, -2.0 );
stdlib_complex128_t out = stdlib_base_cneg( z );
double re = stdlib_complex128_real( out );
// returns -3.0
double im = stdlib_complex128_imag( out );
// returns 2.0
```
The function accepts the following arguments:
- **z**: `[in] stdlib_complex128_t` input value.
```c
stdlib_complex128_t stdlib_base_cneg( const stdlib_complex128_t z );
```
### Examples
```c
#include "stdlib/math/base/ops/cneg.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, 1.5 ),
stdlib_complex128( -3.14, 1.5 ),
stdlib_complex128( 0.0, -0.0 ),
stdlib_complex128( 0.0/0.0, 0.0/0.0 )
};
stdlib_complex128_t v;
stdlib_complex128_t y;
double re;
double im;
int i;
for ( i = 0; i < 4; i++ ) {
v = x[ i ];
stdlib_complex128_reim( v, &re, &im );
printf( "z = %lf + %lfi\n", re, im );
y = stdlib_base_cneg( v );
stdlib_complex128_reim( y, &re, &im );
printf( "cneg(z) = %lf + %lfi\n", re, im );
}
}
```
* * *
## See Also
- [`@stdlib/math-base/special/cabs`][@stdlib/math/base/special/cabs]: compute the absolute value of a double-precision complex 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-ops-cneg.svg
[npm-url]: https://npmjs.org/package/@stdlib/math-base-ops-cneg
[test-image]: https://github.com/stdlib-js/math-base-ops-cneg/actions/workflows/test.yml/badge.svg?branch=main
[test-url]: https://github.com/stdlib-js/math-base-ops-cneg/actions/workflows/test.yml?query=branch:main
[coverage-image]: https://img.shields.io/codecov/c/github/stdlib-js/math-base-ops-cneg/main.svg
[coverage-url]: https://codecov.io/github/stdlib-js/math-base-ops-cneg?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-ops-cneg/tree/deno
[deno-readme]: https://github.com/stdlib-js/math-base-ops-cneg/blob/deno/README.md
[umd-url]: https://github.com/stdlib-js/math-base-ops-cneg/tree/umd
[umd-readme]: https://github.com/stdlib-js/math-base-ops-cneg/blob/umd/README.md
[esm-url]: https://github.com/stdlib-js/math-base-ops-cneg/tree/esm
[esm-readme]: https://github.com/stdlib-js/math-base-ops-cneg/blob/esm/README.md
[branches-url]: https://github.com/stdlib-js/math-base-ops-cneg/blob/main/branches.md
[stdlib-license]: https://raw.githubusercontent.com/stdlib-js/math-base-ops-cneg/main/LICENSE
[@stdlib/math/base/special/cabs]: https://github.com/stdlib-js/math-base-special-cabs