npm package: @stdlib/complex-float64-base-sub
Description: Subtract two double-precision complex floating-point numbers.
Author: The Stdlib Authors
Latest version: 0.1.1

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# csub

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

<section class="intro">

</section>

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<section class="installation">

## Installation

```bash
npm install @stdlib/complex-float64-base-sub
```

</section>

<section class="usage">

## Usage

```javascript
var csub = require( '@stdlib/complex-float64-base-sub' );
```

#### csub( z1, z2 )

Subtracts two double-precision complex floating-point numbers.

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

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

var v = csub( z1, z2 );
// returns <Complex128>[ 7.0, 2.0 ]
```

</section>

<!-- /.usage -->

<section class="examples">

## Examples

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

```javascript
var Complex128Array = require( '@stdlib/array-complex128' );
var discreteUniform = require( '@stdlib/random-array-discrete-uniform' );
var logEachMap = require( '@stdlib/console-log-each-map' );
var csub = require( '@stdlib/complex-float64-base-sub' );

// Generate arrays of random values:
var z1 = new Complex128Array( discreteUniform( 200, -50, 50 ) );
var z2 = new Complex128Array( discreteUniform( 200, -50, 50 ) );

// Perform element-wise subtraction:
logEachMap( '(%s) - (%s) = %s', z1, z2, csub );
```

</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/complex/float64/base/sub.h"
```

#### stdlib_base_complex128_sub( z1, z2 )

Subtracts two double-precision complex floating-point numbers.

```c
#include "stdlib/complex/float64/ctor.h"
#include "stdlib/complex/float64/real.h"
#include "stdlib/complex/float64/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_complex128_sub( z1, z2 );

double re = stdlib_complex128_real( out );
// returns 7.0

double im = stdlib_complex128_imag( out );
// returns 2.0
```

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_complex128_sub( 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>

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

<section class="examples">

### Examples

```c
#include "stdlib/complex/float64/base/sub.h"
#include "stdlib/complex/float64/ctor.h"
#include "stdlib/complex/float64/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_complex128_reim( v, &re, &im );
        printf( "z = %lf + %lfi\n", re, im );

        y = stdlib_base_complex128_sub( v, v );
        stdlib_complex128_reim( y, &re, &im );
        printf( "csub(z, z) = %lf + %lfi\n", re, im );
    }
}
```

</section>

<!-- /.examples -->

</section>

<!-- /.c -->

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<section class="related">

* * *

## See Also

-   <span class="package-name">[`@stdlib/complex-float64/base/add`][@stdlib/complex/float64/base/add]</span><span class="delimiter">: </span><span class="description">add two double-precision complex floating-point numbers.</span>
-   <span class="package-name">[`@stdlib/complex-float64/base/div`][@stdlib/complex/float64/base/div]</span><span class="delimiter">: </span><span class="description">divide two complex numbers.</span>
-   <span class="package-name">[`@stdlib/complex-float64/base/mul`][@stdlib/complex/float64/base/mul]</span><span class="delimiter">: </span><span class="description">multiply two double-precision complex floating-point numbers.</span>

</section>

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* * *

## 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].

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## License

See [LICENSE][stdlib-license].


## Copyright

Copyright &copy; 2016-2026. The Stdlib [Authors][stdlib-authors].

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