npm package: @stdlib/math-base-special-cphasef
Description: Compute the argument of a single-precision complex floating-point number in radians.
Author: The Stdlib Authors
Latest version: 0.1.1

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# cphasef

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

> Compute the [argument][complex-number-argument] of a single-precision complex floating-point number in radians.

<section class="intro">

The [argument][complex-number-argument] of a complex number, also known as the **phase**, is the angle of the radius extending from the origin to the complex number plotted in the complex plane and the positive real axis.

</section>

<!-- /.intro -->

<section class="installation">

## Installation

```bash
npm install @stdlib/math-base-special-cphasef
```

</section>

<section class="usage">

## Usage

```javascript
var cphasef = require( '@stdlib/math-base-special-cphasef' );
```

#### cphasef( z )

Computes the [argument][complex-number-argument] of a single-precision complex floating-point number.

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

var phi = cphasef( new Complex64( 5.0, 3.0 ) );
// returns ~0.5404
```

</section>

<!-- /.usage -->

<section class="examples">

## Examples

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

```javascript
var Complex64Array = require( '@stdlib/array-complex64' );
var uniform = require( '@stdlib/random-array-uniform' );
var logEachMap = require( '@stdlib/console-log-each-map' );
var cphasef = require( '@stdlib/math-base-special-cphasef' );

// Create an array of random numbers:
var arr = new Complex64Array( uniform( 200, -100.0, 100.0 ) );

// Compute the argument of each number in the array:
logEachMap( 'cphasef(%s) = %0.4f', arr, cphasef );
```

</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/special/cphasef.h"
```

#### stdlib_base_cphasef( z )

Computes the [argument][complex-number-argument] of 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( 5.0f, 3.0f );
float out = stdlib_base_cphasef( z );
// returns ~0.5404f
```

The function accepts the following arguments:

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

```c
float stdlib_base_cphasef( 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>

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

<section class="examples">

### Examples

```c
#include "stdlib/math/base/special/cphasef.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;
    float re;
    float im;
    float y;
    int i;
    for ( i = 0; i < 4; i++ ) {
        v = x[ i ];
        y = stdlib_base_cphasef( v );
        stdlib_complex64_reim( v, &re, &im );
        printf( "cphasef(%f + %fi) = %f\n", re, im, y );
    }
}
```

</section>

<!-- /.examples -->

</section>

<!-- /.c -->

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

<section class="related">

</section>

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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].

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---

## License

See [LICENSE][stdlib-license].


## Copyright

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

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[complex-number-argument]: https://en.wikipedia.org/wiki/Argument_%28complex_analysis%29

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