npm package: @stdlib/complex-float64-real
Description: Return the real component of a double-precision complex floating-point number.
Author: The Stdlib Authors
Latest version: 0.1.2

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<details>
  <summary>
    About stdlib...
  </summary>
  <p>We believe in a future in which the web is a preferred environment for numerical computation. To help realize this future, we've built stdlib. stdlib is a standard library, with an emphasis on numerical and scientific computation, written in JavaScript (and C) for execution in browsers and in Node.js.</p>
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</details>

# real

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

> Return the real component of a double-precision complex floating-point number.

<!-- Section to include introductory text. Make sure to keep an empty line after the intro `section` element and another before the `/section` close. -->

<section class="intro">

</section>

<!-- /.intro -->

<!-- Package usage documentation. -->

<section class="installation">

## Installation

```bash
npm install @stdlib/complex-float64-real
```

</section>

<section class="usage">

## Usage

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

#### real( z )

Returns the **real** component of a double-precision complex floating-point number.

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

var z = new Complex128( 5.0, 3.0 );
var re = real( z );
// returns 5.0
```

</section>

<!-- /.usage -->

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

<section class="notes">

</section>

<!-- /.notes -->

<!-- Package usage examples. -->

<section class="examples">

## Examples

<!-- eslint-disable max-len -->

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

```javascript
var Complex128 = require( '@stdlib/complex-float64-ctor' );
var discreteUniform = require( '@stdlib/random-base-discrete-uniform' );
var filledarrayBy = require( '@stdlib/array-filled-by' );
var real = require( '@stdlib/complex-float64-real' );

function random() {
    return new Complex128( discreteUniform( -10, 10 ), discreteUniform( -10, 10 ) ); // eslint-disable-line max-len
}

// Generate an array of random complex numbers:
var x = filledarrayBy( 100, 'complex128', random );
// returns <Complex128Array>

// Retrieve the real component of each complex number...
var z;
var i;
for ( i = 0; i < x.length; i++ ) {
    z = x.get( i );
    console.log( 'real(%s) = %d', z.toString(), real( z ) );
}
```

</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/real.h"
```

#### stdlib_complex128_real( z )

Returns the real component of a double-precision complex floating-point number.

```c
#include "stdlib/complex/float64/ctor.h"

stdlib_complex128_t z = stdlib_complex128( 5.0, 2.0 );

// ...

double re = stdlib_complex128_real( z );
// returns 5.0
```

The function accepts the following arguments:

-   **z**: `[in] stdlib_complex128_t` double-precision complex floating-point number.

```c
double stdlib_complex128_real( const stdlib_complex128_t z );
```

</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/complex/float64/real.h"
#include "stdlib/complex/float64/ctor.h"
#include <stdio.h>

int main( void ) {
    const stdlib_complex128_t x[] = {
        stdlib_complex128( 5.0, 2.0 ),
        stdlib_complex128( -2.0, 1.0 ),
        stdlib_complex128( 0.0, -0.0 ),
        stdlib_complex128( 0.0/0.0, 0.0/0.0 )
    };

    int i;
    for ( i = 0; i < 4; i++ ) {
        printf( "real(v) = %lf\n", stdlib_complex128_real( x[ i ] ) );
    }
}
```

</section>

<!-- /.examples -->

</section>

<!-- /.c -->

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<section class="references">

</section>

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<section class="related">

* * *

## See Also

-   <span class="package-name">[`@stdlib/complex-float64/imag`][@stdlib/complex/float64/imag]</span><span class="delimiter">: </span><span class="description">return the imaginary component of a double-precision complex floating-point number.</span>
-   <span class="package-name">[`@stdlib/complex-float64/reim`][@stdlib/complex/float64/reim]</span><span class="delimiter">: </span><span class="description">return the real and imaginary components of a double-precision complex floating-point number.</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

[![Chat][chat-image]][chat-url]

---

## License

See [LICENSE][stdlib-license].


## Copyright

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

</section>

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<!-- <related-links> -->

[@stdlib/complex/float64/imag]: https://www.npmjs.com/package/@stdlib/complex-float64-imag

[@stdlib/complex/float64/reim]: https://www.npmjs.com/package/@stdlib/complex-float64-reim

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