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https://github.com/stdlib-js/math-base-special-cflipsign

Return a complex number with the same magnitude as `z` and the sign of `y*z`.
https://github.com/stdlib-js/math-base-special-cflipsign

cmplx complex flipsign javascript math mathematics node node-js nodejs number stdlib

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Return a complex number with the same magnitude as `z` and the sign of `y*z`.

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# cflipsign



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



> Return a double-precision complex floating-point number with the same magnitude as `z` and the sign of `y*z`.



## Installation



```bash

npm install @stdlib/math-base-special-cflipsign

```



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 cflipsign = require( '@stdlib/math-base-special-cflipsign' );

```



#### cflipsign( z, y )



Returns a double-precision complex floating-point number with the same magnitude as `z` and the sign of `y*z`.



```javascript

var Complex128 = require( '@stdlib/complex-float64-ctor' );

var real = require( '@stdlib/complex-float64-real' );

var imag = require( '@stdlib/complex-float64-imag' );



var v = cflipsign( new Complex128( -4.2, 5.5 ), -1.0 );

// returns 



var re = real( v );

// returns 4.2



var im = imag( v );

// returns -5.5

```



## Examples



```javascript

var uniform = require( '@stdlib/random-base-uniform' ).factory;

var Complex128 = require( '@stdlib/complex-float64-ctor' );

var cflipsign = require( '@stdlib/math-base-special-cflipsign' );



var rand = uniform( -50.0, 50.0 );



var z;

var y;

var i;

for ( i = 0; i < 100; i++ ) {

    z = new Complex128( rand(), rand() );

    y = rand();

    console.log( 'cflipsign(%s, %d) = %s', z, y, cflipsign( z, y ) );

}

```



* * *



## C APIs



### Usage



```c

#include "stdlib/math/base/special/cflipsign.h"

```



#### stdlib_base_cflipsign( z, y )



Returns a double-precision complex floating-point number with the same magnitude as `z` and the sign of `y*z`.



```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( 2.5, -1.5 );



stdlib_complex128_t out = stdlib_base_cflipsign( z, -1.0 );



double re = stdlib_complex128_real( out );

// returns -2.5



double im = stdlib_complex128_imag( out );

// returns 1.5

```



The function accepts the following arguments:



-   **z**: `[in] stdlib_complex128_t` input value.

-   **y**: `[in] double` number from which to derive the sign.



```c

stdlib_complex128_t stdlib_base_cflipsign( const stdlib_complex128_t z, const double y );

```



### Examples



```c

#include "stdlib/math/base/special/cflipsign.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 re1;

    double im1;

    double re2;

    double im2;

    int i;

    for ( i = 0; i < 4; i++ ) {

        v = x[ i ];

        y = stdlib_base_cflipsign( v, -1.0 );

        stdlib_complex128_reim( v, &re1, &im1 );

        stdlib_complex128_reim( y, &re2, &im2 );

        printf( "cflipsign(%lf + %lfi, %lf) = %lf + %lfi\n", re1, im1, -1.0, re2, im2 );

}

```



* * *



## See Also



-   [`@stdlib/math-base/ops/cneg`][@stdlib/math/base/ops/cneg]: negate a double-precision complex floating-point number.

-   [`@stdlib/math-base/special/csignum`][@stdlib/math/base/special/csignum]: evaluate the signum function 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 © 2016-2024. The Stdlib [Authors][stdlib-authors].



[npm-image]: http://img.shields.io/npm/v/@stdlib/math-base-special-cflipsign.svg

[npm-url]: https://npmjs.org/package/@stdlib/math-base-special-cflipsign



[test-image]: https://github.com/stdlib-js/math-base-special-cflipsign/actions/workflows/test.yml/badge.svg?branch=main

[test-url]: https://github.com/stdlib-js/math-base-special-cflipsign/actions/workflows/test.yml?query=branch:main



[coverage-image]: https://img.shields.io/codecov/c/github/stdlib-js/math-base-special-cflipsign/main.svg

[coverage-url]: https://codecov.io/github/stdlib-js/math-base-special-cflipsign?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-cflipsign/tree/deno

[deno-readme]: https://github.com/stdlib-js/math-base-special-cflipsign/blob/deno/README.md

[umd-url]: https://github.com/stdlib-js/math-base-special-cflipsign/tree/umd

[umd-readme]: https://github.com/stdlib-js/math-base-special-cflipsign/blob/umd/README.md

[esm-url]: https://github.com/stdlib-js/math-base-special-cflipsign/tree/esm

[esm-readme]: https://github.com/stdlib-js/math-base-special-cflipsign/blob/esm/README.md

[branches-url]: https://github.com/stdlib-js/math-base-special-cflipsign/blob/main/branches.md



[stdlib-license]: https://raw.githubusercontent.com/stdlib-js/math-base-special-cflipsign/main/LICENSE



[@stdlib/math/base/ops/cneg]: https://github.com/stdlib-js/math-base-ops-cneg



[@stdlib/math/base/special/csignum]: https://github.com/stdlib-js/math-base-special-csignum