npm package: @stdlib/math-base-ops-cmul
Description: Multiply two double-precision complex floating-point numbers.
Author: The Stdlib Authors
Latest version: 0.2.1

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</details>

# cmul

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> Multiply two double-precision complex floating-point numbers.

<section class="intro">

</section>

<!-- /.intro -->

<section class="installation">

## Installation

```bash
npm install @stdlib/math-base-ops-cmul
```

</section>

<section class="usage">

## Usage

```javascript
var cmul = require( '@stdlib/math-base-ops-cmul' );
```

#### cmul( z1, z2 )

Multiplies two double-precision complex floating-point numbers.

```javascript
var Complex128 = require( '@stdlib/complex-float64' );
var real = require( '@stdlib/complex-real' );
var imag = require( '@stdlib/complex-imag' );

var z1 = new Complex128( 5.0, 3.0 );
var z2 = new Complex128( -2.0, 1.0 );

var v = cmul( z1, z2 );
// returns <Complex128>

var re = real( v );
// returns -13.0

var im = imag( v );
// returns -1.0
```

</section>

<!-- /.usage -->

<section class="examples">

## Examples

<!-- eslint no-undef: "error" -->

```javascript
var Complex128 = require( '@stdlib/complex-float64' );
var discreteUniform = require( '@stdlib/random-base-discrete-uniform' ).factory;
var cmul = require( '@stdlib/math-base-ops-cmul' );

var rand;
var z1;
var z2;
var z3;
var i;

rand = discreteUniform( -50, 50 );
for ( i = 0; i < 100; i++ ) {
    z1 = new Complex128( rand(), rand() );
    z2 = new Complex128( rand(), rand() );
    z3 = cmul( z1, z2 );
    console.log( '(%s) * (%s) = %s', z1.toString(), z2.toString(), z3.toString() );
}
```

</section>

<!-- /.examples -->

<!-- C interface documentation. -->

* * *

<section class="c">

## C APIs

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<section class="intro">

</section>

<!-- /.intro -->

<!-- C usage documentation. -->

<section class="usage">

### Usage

```c
#include "stdlib/math/base/ops/cmul.h"
```

#### stdlib_base_cmul( z1, z2 )

Multiplies two double-precision complex floating-point numbers.

```c
#include "stdlib/complex/float64.h"
#include "stdlib/complex/real.h"
#include "stdlib/complex/imag.h"

stdlib_complex128_t z1 = stdlib_complex128( 5.0, 3.0 );
stdlib_complex128_t z2 = stdlib_complex128( -2.0, 1.0 );

stdlib_complex128_t out = stdlib_base_cmul( z1, z2 );

double re = stdlib_real( out );
// returns -13.0

double im = stdlib_imag( out );
// returns -1.0
```

The function accepts the following arguments:

-   **z1**: `[in] stdlib_complex128_t` input value.
-   **z2**: `[in] stdlib_complex128_t` input value.

```c
stdlib_complex128_t stdlib_base_cmul( const stdlib_complex128_t z1, const stdlib_complex128_t z2 );
```

</section>

<!-- /.usage -->

<!-- C API usage notes. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->

<section class="notes">

</section>

<!-- /.notes -->

<!-- C API usage examples. -->

<section class="examples">

### Examples

```c
#include "stdlib/math/base/ops/cmul.h"
#include "stdlib/complex/float64.h"
#include "stdlib/complex/reim.h"
#include <stdio.h>

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_reim( v, &re, &im );
        printf( "z = %lf + %lfi\n", re, im );

        y = stdlib_base_cmul( v, v );
        stdlib_reim( y, &re, &im );
        printf( "cmul(z, z) = %lf + %lfi\n", re, im );
    }
}
```

</section>

<!-- /.examples -->

</section>

<!-- /.c -->

<!-- Section for related `stdlib` packages. Do not manually edit this section, as it is automatically populated. -->

<section class="related">

* * *

## See Also

-   <span class="package-name">[`@stdlib/math-base/ops/cadd`][@stdlib/math/base/ops/cadd]</span><span class="delimiter">: </span><span class="description">add two double-precision complex floating-point numbers.</span>
-   <span class="package-name">[`@stdlib/math-base/ops/cdiv`][@stdlib/math/base/ops/cdiv]</span><span class="delimiter">: </span><span class="description">divide two complex numbers.</span>
-   <span class="package-name">[`@stdlib/math-base/ops/csub`][@stdlib/math/base/ops/csub]</span><span class="delimiter">: </span><span class="description">subtract two double-precision complex floating-point numbers.</span>

</section>

<!-- /.related -->

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<section class="main-repo" >

* * *

## 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

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---

## License

See [LICENSE][stdlib-license].


## Copyright

Copyright &copy; 2016-2024. The Stdlib [Authors][stdlib-authors].

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[@stdlib/math/base/ops/cadd]: https://www.npmjs.com/package/@stdlib/math-base-ops-cadd

[@stdlib/math/base/ops/cdiv]: https://www.npmjs.com/package/@stdlib/math-base-ops-cdiv

[@stdlib/math/base/ops/csub]: https://www.npmjs.com/package/@stdlib/math-base-ops-csub

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</section>

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