npm package: @stdlib/strided-napi-zmap
Description: C API for registering a Node-API module exporting a strided array interface for applying a unary callback to a double-precision complex floating-point strided input array and assigning results to a double-precision complex floating-point strided output ar
Author: The Stdlib Authors
Latest version: 0.2.3

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<details>
  <summary>
    About stdlib...
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  <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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# zmap

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

> C API for registering a Node-API module exporting a strided array interface for applying a unary callback to a double-precision complex floating-point strided input array and assigning results to a double-precision complex floating-point strided output array.

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<section class="intro">

</section>

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<!-- Package usage documentation. -->

<section class="installation">

## Installation

```bash
npm install @stdlib/strided-napi-zmap
```

</section>

<section class="usage">

## Usage

```javascript
var headerDir = require( '@stdlib/strided-napi-zmap' );
```

#### headerDir

Absolute file path for the directory containing header files for C APIs.

```javascript
var dir = headerDir;
// returns <string>
```

</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>

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<!-- Package usage examples. -->

<section class="examples">

## Examples

```javascript
var headerDir = require( '@stdlib/strided-napi-zmap' );

console.log( headerDir );
// => <string>
```

</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/strided/napi/zmap.h"
```

#### stdlib_strided_napi_zmap( env, info, fcn )

Invokes a strided array interface which applies a unary callback to a double-precision complex floating-point strided input array and assigns results to a double-precision complex floating-point strided output array.

```c
#include <node_api.h>
#include <complex.h>

// ...

static double complex cidentity( const double complex z ) {
    return z;
}

// ...

/**
* Receives JavaScript callback invocation data.
*
* @param env    environment under which the function is invoked
* @param info   callback data
* @return       Node-API value
*/
napi_value addon( napi_env env, napi_callback_info info ) {
    stdlib_strided_napi_zmap( env, info, cidentity );
    return NULL;
}

// ...
```

The function accepts the following arguments:

-   **env**: `[in] napi_env` environment under which the function is invoked.
-   **info**: `[in] napi_callback_info` callback data.
-   **fcn**: `[in] double complex (*fcn)( double complex )` unary callback.

```c
void stdlib_strided_napi_zmap( napi_env env, napi_callback_info info, double complex (*fcn)( double complex ) );
```

#### STDLIB_STRIDED_NAPI_MODULE_ZMAP( clbk )

Macro for registering a Node-API module exporting a strided array interface for applying a unary callback to a double-precision complex floating-point strided input array and assigning results to a double-precision complex floating-point strided output array.

```c
#include <complex.h>

static double complex scale( const double complex z ) {
    double complex re = creal( z );
    double complex im = cimag( z );
    return ( re*10.0 ) + ( im*10.0 )*I;
}

// ...

// Register a Node-API module:
STDLIB_STRIDED_NAPI_MODULE_ZMAP( scale )
```

The macro expects the following arguments:

-   **clbk**: `double complex (*fcn)( double complex )` unary callback.

When used, this macro should be used **instead of** `NAPI_MODULE`. The macro includes `NAPI_MODULE`, thus ensuring Node-API module registration.

</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">

### Notes

-   The function expects that the callback `info` argument provides access to the following JavaScript arguments:

    -   **N**: number of indexed elements.
    -   **X**: input [`Float64Array`][@stdlib/array/float64] view of a [`Complex128Array`][@stdlib/array/complex128].
    -   **strideX**: stride length for the input [`Complex128Array`][@stdlib/array/complex128].
    -   **Y**: destination [`Float64Array`][@stdlib/array/float64] view of a [`Complex128Array`][@stdlib/array/complex128].
    -   **strideY**: stride length for the destination [`Complex128Array`][@stdlib/array/complex128].

</section>

<!-- /.notes -->

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

<section class="examples">

</section>

<!-- /.examples -->

</section>

<!-- /.c -->

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</section>

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</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].

#### 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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