time-to-botec/js/node_modules/@stdlib/strided/napi/dmap/README.md

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 assigning results to elements in a double-precision floating-point strided output array.

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

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.