@stdlib/strided-napi-dmap

C API for registering a Node-API module exporting a strided array interface for applying a unary callback accepting and returning double-precision floating-point numbers to each element in a double-precision floating-point strided input array and assignin

Usage no npm install needed!

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README

dmap

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C API for registering a Node-API module exporting a strided array interface for applying a unary callback accepting and returning double-precision floating-point numbers to each element in a double-precision floating-point strided input array and assigning results to elements in a double-precision floating-point strided output array.

Installation

npm install @stdlib/strided-napi-dmap

Usage

var headerDir = require( '@stdlib/strided-napi-dmap' );

headerDir

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

var dir = headerDir;
// returns <string>

Examples

var headerDir = require( '@stdlib/strided-napi-dmap' );

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

C APIs

Installation

npm install @stdlib/strided-napi-dmap

Usage

#include "stdlib/strided/napi/dmap.h"

stdlib_strided_napi_dmap( env, info, fcn )

Invokes a strided array interface which applies a unary callback accepting and returning double-precision floating-point numbers to each element in a double-precision floating-point strided input array and assigns results to elements in a double-precision floating-point strided output array.

#include <node_api.h>

// ...

static double identity( const double x ) {
    return x;
}

// ...

/**
* 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_dmap( env, info, identity );
    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 (*fcn)( double ) unary callback.
void stdlib_strided_napi_dmap( napi_env env, napi_callback_info info, double (*fcn)( double ) );

STDLIB_STRIDED_NAPI_MODULE_DMAP( clbk )

Macro for registering a Node-API module exporting a strided array interface for applying a unary callback accepting and return double-precision floating-point numbers to each element in a double-precision floating-point strided input array and assigning results to elements in a double-precision floating-point strided output array.

static double scale( const double x ) {
    return x * 10.0;
}

// ...

// Register a Node-API module:
STDLIB_STRIDED_NAPI_MODULE_DMAP( scale );

The macro expects the following arguments:

  • clbk: double (*fcn)( double ) unary callback.

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

Notes

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

    • N: number of indexed elements.
    • X: input Float64Array.
    • strideX: X stride length.
    • Y: destination Float64Array.
    • strideY: Y stride length.

Notice

This package is part of 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, see the main project repository.

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License

See LICENSE.

Copyright

Copyright © 2016-2021. The Stdlib Authors.