npm package: @stdlib/complex-float32-base-identity
Description: Evaluate the identity function for a single-precision complex floating-point number.
Author: The Stdlib Authors
Latest version: 0.1.1

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# Identity Function

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

> Evaluate the [identity function][identity-function] of a single-precision [complex][@stdlib/complex/float32/ctor] floating-point number.

<section class="intro">

The [identity-function][identity-function] is defined as

<!-- <equation class="equation" label="eq:identity_function" align="center" raw="f(z) = z" alt="Identity function"> -->

<div class="equation" align="center" data-raw-text="f(z) = z" data-equation="eq:identity_function">
    <img src="https://cdn.jsdelivr.net/gh/stdlib-js/stdlib@79c18caa8e6697ecbe8bcf813a8d54a470168a75/lib/node_modules/@stdlib/complex/float32/base/identity/docs/img/equation_identity_function.svg" alt="Identity function">
    <br>
</div>

<!-- </equation> -->

for all `z`.

</section>

<!-- /.intro -->

<section class="installation">

## Installation

```bash
npm install @stdlib/complex-float32-base-identity
```

</section>

<section class="usage">

## Usage

```javascript
var cidentityf = require( '@stdlib/complex-float32-base-identity' );
```

#### cidentityf( z )

Evaluates the [identity function][identity-function] for a single-precision [complex][@stdlib/complex/float32/ctor] floating-point number.

```javascript
var Complex64 = require( '@stdlib/complex-float32-ctor' );

var v = cidentityf( new Complex64( -1.0, 2.0 ) );
// returns <Complex64>[ -1.0, 2.0 ]
```

</section>

<!-- /.usage -->

<section class="examples">

## Examples

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

```javascript
var discreteUniform = require( '@stdlib/random-base-discrete-uniform' );
var Complex64 = require( '@stdlib/complex-float32-ctor' );
var cidentityf = require( '@stdlib/complex-float32-base-identity' );

var z;
var i;
for ( i = 0; i < 100; i++ ) {
    z = new Complex64( discreteUniform( -50, 50 ), discreteUniform( -50, 50 ) );
    console.log( 'identity(%s) = %s', z, cidentityf( z ) );
}
```

</section>

<!-- /.examples -->

<!-- C interface documentation. -->

* * *

<section class="c">

## C APIs

<!-- 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 -->

<!-- C usage documentation. -->

<section class="usage">

### Usage

```c
#include "stdlib/complex/float32/base/identity.h"
```

#### stdlib_base_complex64_identity( z )

Evaluates the identity function for a single-precision complex floating-point number.

```c
#include "stdlib/complex/float32/ctor.h"
#include "stdlib/complex/float32/real.h"
#include "stdlib/complex/float32/imag.h"

stdlib_complex64_t z = stdlib_complex64( 2.0f, 2.0f );
stdlib_complex64_t out = stdlib_base_complex64_identity( z );

float re = stdlib_complex64_real( out );
// returns 2.0f

float im = stdlib_complex64_imag( out );
// returns 2.0f
```

The function accepts the following arguments:

-   **z**: `[in] stdlib_complex64_t` input value.

```c
stdlib_complex64_t stdlib_base_complex64_identity( const stdlib_complex64_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/float32/base/identity.h"
#include "stdlib/complex/float32/ctor.h"
#include "stdlib/complex/float32/reim.h"
#include <stdio.h>

int main( void ) {
    const stdlib_complex64_t x[] = {
        stdlib_complex64( 3.14f, 1.0f ),
        stdlib_complex64( -3.14f, -1.0f ),
        stdlib_complex64( 0.0f, 0.0f ),
        stdlib_complex64( 0.0f/0.0f, 0.0f/0.0f )
    };

    stdlib_complex64_t v;
    stdlib_complex64_t y;
    float re1;
    float im1;
    float re2;
    float im2;
    int i;
    for ( i = 0; i < 4; i++ ) {
        v = x[ i ];
        y = stdlib_base_complex64_identity( v );
        stdlib_complex64_reim( v, &re1, &im1 );
        stdlib_complex64_reim( y, &re2, &im2 );
        printf( "cidentity(%f + %fi) = %f + %fi\n", re1, im1, re2, im2 );
    }
}
```

</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/complex-float64/base/identity`][@stdlib/complex/float64/base/identity]</span><span class="delimiter">: </span><span class="description">evaluate the identity function for a double-precision complex floating-point number.</span>
-   <span class="package-name">[`@stdlib/number-float32/base/identity`][@stdlib/number/float32/base/identity]</span><span class="delimiter">: </span><span class="description">evaluate the identity function for a single-precision 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>

<!-- /.stdlib -->

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[umd]: https://github.com/umdjs/umd
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[deno-url]: https://github.com/stdlib-js/complex-float32-base-identity/tree/deno
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[stdlib-license]: https://raw.githubusercontent.com/stdlib-js/complex-float32-base-identity/main/LICENSE

[identity-function]: https://en.wikipedia.org/wiki/Identity_function

[@stdlib/complex/float32/ctor]: https://www.npmjs.com/package/@stdlib/complex-float32-ctor

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

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

[@stdlib/number/float32/base/identity]: https://www.npmjs.com/package/@stdlib/number-float32-base-identity

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

</section>

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