argv_strided_float64array2d

Convert a Node-API value representing a two-dimensional strided array to a double-precision floating-point array.

Usage

var headerDir = require( '@stdlib/napi/argv-strided-float64array2d' );

headerDir

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

var dir = headerDir;
// returns <string>

Examples

var headerDir = require( '@stdlib/napi/argv-strided-float64array2d' );

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

C APIs

Usage

#include "stdlib/napi/argv_strided_float64array2d.h"

stdlib_napi_argv_strided_float64array2d( env, M, N, strideX1, strideX2, value, **data, *message1, *message2, *err )

Converts a Node-API value representing a two-dimensional strided array to a double-precision floating-point array.

#include "stdlib/napi/argv_strided_float64array2d.h"
#include <node_api.h>
#include <stdint.h>

static napi_value addon( napi_env env, napi_callback_info info ) {
    napi_value value;

    // ...

    int64_t M = 100;
    int64_t N = 100;
    int64_t strideX1 = 100;
    int64_t strideX2 = 1;

    // ...

    double *X;
    napi_value err;
    napi_status status = stdlib_napi_argv_strided_float64array2d( env, M, N, strideX1, strideX2, value, &X, "Must be a typed array.", "Must have sufficient elements.", &err );
    assert( status == napi_ok );
    if ( err != NULL ) {
        assert( napi_throw( env, err ) == napi_ok );
        return NULL;
    }

    // ...
}

The function accepts the following arguments:

  • env: [in] napi_env environment under which the function is invoked.
  • M: [in] int64_t number of rows.
  • N: [in] int64_t number of columns.
  • strideX1: [in] int64_t stride length along the first dimension.
  • strideX2: [in] int64_t stride length along the second dimension.
  • value: [in] napi_value Node-API value.
  • data: [out] double** pointer for returning a reference to the output array.
  • message1: [in] char* error message if a value is not a Float64Array.
  • message2: [in] char* error message if a value has insufficient elements.
  • err: [out] napi_value* pointer for storing a JavaScript error. If not provided a number, the function sets err with a JavaScript error; otherwise, err is set to NULL.
napi_status stdlib_napi_argv_strided_float64array2d( const napi_env env, const int64_t M, const int64_t N, const int64_t strideX1, const int64_t strideX2, const napi_value value, double **data, const char *message1, const char *message2, napi_value *err );

The function returns a napi_status status code indicating success or failure (returns napi_ok if success).

STDLIB_NAPI_ARGV_STRIDED_FLOAT64ARRAY2D( env, X, M, N, strideX1, strideX2, argv, index )

Macro for converting an add-on callback argument to a strided double-precision floating-point array.

#include "stdlib/napi/argv_strided_float64array2d.h"
#include "stdlib/napi_argv_int64.h"
#include "stdlib/napi/argv.h"
#include <node_api.h>
#include <stdint.h>

static void fcn( const int64_t M, const int64_t N, const double *X, const int64_t strideX1, const int64_t strideX2, double *Y, const int64_t strideY1, const int64_t strideY2 ) {
    int64_t i;
    int64_t j;
    for ( i = 0; i < M; i++ ) {
        for ( j = 0; j < N; j++ ) {
            Y[ (i*strideY1)+(j*strideY2) ] = X[ (i*strideX1)+(j*strideX2) ];
        }
    }
}

// ...

static napi_value addon( napi_env env, napi_callback_info info ) {
    // Retrieve add-on callback arguments:
    STDLIB_NAPI_ARGV( env, info, argv, argc, 8 );

    // Convert the number of rows and columns to C types:
    STDLIB_NAPI_ARGV_INT64( env, M, argv, 0 );
    STDLIB_NAPI_ARGV_INT64( env, N, argv, 1 );

    // Convert the stride arguments to C types:
    STDLIB_NAPI_ARGV_INT64( env, strideX1, argv, 3 );
    STDLIB_NAPI_ARGV_INT64( env, strideX2, argv, 4 );
    STDLIB_NAPI_ARGV_INT64( env, strideY1, argv, 6 );
    STDLIB_NAPI_ARGV_INT64( env, strideY2, argv, 7 );

    // Convert the arrays to C types:
    STDLIB_NAPI_ARGV_STRIDED_FLOAT64ARRAY2D( env, X, M, N, strideX1, strideX2, argv, 2 );
    STDLIB_NAPI_ARGV_STRIDED_FLOAT64ARRAY2D( env, Y, M, N, strideY1, strideY2, argv, 5 );

    // ...

    fcn( M, N, X, strideX1, strideX2, Y, strideY1, strideY2 );
}

The macro expects the following arguments:

  • env: environment under which the callback is invoked.
  • X: output variable name for the array.
  • M: number of rows.
  • N: number of columns.
  • strideX1: stride length along the first dimension.
  • strideX2: stride length along the second dimension.
  • argv: name of the variable containing add-on callback arguments.
  • index: argument index.
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