npm package: @stdlib/ndarray-base-unary
Description: Apply a unary callback to elements in an input ndarray and assign results to elements in an output ndarray.
Author: The Stdlib Authors
Latest version: 0.3.1

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<details>
  <summary>
    About stdlib...
  </summary>
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</details>

# Unary

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

> Apply a unary callback to elements in an input ndarray and assign results to elements in an output ndarray.

<section class="intro">

</section>

<!-- /.intro -->

<section class="installation">

## Installation

```bash
npm install @stdlib/ndarray-base-unary
```

</section>

<section class="usage">

## Usage

```javascript
var unary = require( '@stdlib/ndarray-base-unary' );
```

#### unary( arrays, fcn )

Applies a unary callback to elements in an input ndarray and assigns results to elements in an output ndarray.

<!-- eslint-disable max-len -->

```javascript
var Float64Array = require( '@stdlib/array-float64' );

function scale( x ) {
    return x * 10.0;
}

// Create data buffers:
var xbuf = new Float64Array( [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0, 11.0, 12.0 ] );
var ybuf = new Float64Array( 6 );

// Define the shape of the input and output arrays:
var shape = [ 3, 1, 2 ];

// Define the array strides:
var sx = [ 4, 4, 1 ];
var sy = [ 2, 2, 1 ];

// Define the index offsets:
var ox = 1;
var oy = 0;

// Create the input and output ndarray-like objects:
var x = {
    'dtype': 'float64',
    'data': xbuf,
    'shape': shape,
    'strides': sx,
    'offset': ox,
    'order': 'row-major'
};
var y = {
    'dtype': 'float64',
    'data': ybuf,
    'shape': shape,
    'strides': sy,
    'offset': oy,
    'order': 'row-major'
};

// Apply the unary function:
unary( [ x, y ], scale );

console.log( y.data );
// => <Float64Array>[ 20.0, 30.0, 60.0, 70.0, 100.0, 110.0 ]
```

The function accepts the following arguments:

-   **arrays**: array-like object containing one input ndarray and one output ndarray.
-   **fcn**: unary function to apply.

Each provided ndarray should be an object with the following properties:

-   **dtype**: data type.
-   **data**: data buffer.
-   **shape**: dimensions.
-   **strides**: stride lengths.
-   **offset**: index offset.
-   **order**: specifies whether an ndarray is row-major (C-style) or column major (Fortran-style).

</section>

<!-- /.usage -->

<section class="notes">

## Notes

-   For very high-dimensional ndarrays which are non-contiguous, one should consider copying the underlying data to contiguous memory before applying a unary function in order to achieve better performance.

</section>

<!-- /.notes -->

<section class="examples">

## Examples

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

```javascript
var discreteUniform = require( '@stdlib/random-base-discrete-uniform' ).factory;
var filledarray = require( '@stdlib/array-filled' );
var filledarrayBy = require( '@stdlib/array-filled-by' );
var abs = require( '@stdlib/math-base-special-abs' );
var shape2strides = require( '@stdlib/ndarray-base-shape2strides' );
var ndarray2array = require( '@stdlib/ndarray-base-to-array' );
var unary = require( '@stdlib/ndarray-base-unary' );

var N = 10;
var x = {
    'dtype': 'generic',
    'data': filledarrayBy( N, 'generic', discreteUniform( -100, 100 ) ),
    'shape': [ 5, 2 ],
    'strides': [ 2, 1 ],
    'offset': 0,
    'order': 'row-major'
};
var y = {
    'dtype': 'generic',
    'data': filledarray( 0, N, 'generic' ),
    'shape': x.shape.slice(),
    'strides': shape2strides( x.shape, 'column-major' ),
    'offset': 0,
    'order': 'column-major'
};

unary( [ x, y ], abs );
console.log( ndarray2array( x.data, x.shape, x.strides, x.offset, x.order ) );
console.log( ndarray2array( y.data, y.shape, y.strides, y.offset, y.order ) );
```

</section>

<!-- /.examples -->

<!-- C interface documentation. -->

* * *

<section class="c">

## C APIs

<!-- Section to include introductory text. Make sure to keep an empty line after the intro `section` element and another before the `/section` close. -->

<section class="intro">

Character codes for data types:

<!-- The following is auto-generated. Do not manually edit. See scripts/loops.js. -->

<!-- charcodes -->

-   **x**: `bool` (boolean).
-   **c**: `complex64` (single-precision floating-point complex number).
-   **z**: `complex128` (double-precision floating-point complex number).
-   **f**: `float32` (single-precision floating-point number).
-   **d**: `float64` (double-precision floating-point number).
-   **k**: `int16` (signed 16-bit integer).
-   **i**: `int32` (signed 32-bit integer).
-   **s**: `int8` (signed 8-bit integer).
-   **t**: `uint16` (unsigned 16-bit integer).
-   **u**: `uint32` (unsigned 32-bit integer).
-   **b**: `uint8` (unsigned 8-bit integer).

<!-- ./charcodes -->

Function name suffix naming convention:

```text
stdlib_ndarray_<input_data_type>_<output_data_type>[_as_<callback_arg_data_type>_<callback_return_data_type>]
```

For example,

<!-- run-disable -->

```c
void stdlib_ndarray_d_d(...) {...}
```

is a function which accepts one double-precision floating-point input ndarray and one double-precision floating-point output ndarray. In other words, the suffix encodes the function type signature.

To support callbacks whose input arguments and/or return values are of a different data type than the input and/or output ndarray data types, the naming convention supports appending an `as` suffix. For example,

<!-- run-disable -->

```c
void stdlib_ndarray_f_f_as_d_d(...) {...}
```

is a function which accepts one single-precision floating-point input ndarray and one single-precision floating-point output ndarray. However, the callback accepts and returns double-precision floating-point numbers. Accordingly, the input and output values need to be cast using the following conversion sequence

```c
// Convert each input array element to double-precision:
double in1 = (double)x[ i ];

// Evaluate the callback:
double out = f( in1 );

// Convert the callback return value to single-precision:
y[ i ] = (float)out;
```

When the input ndarray and the callback (i.e., the input argument and return value) share the same data type, the `as` suffix can be omitted. For example,

<!-- run-disable -->

```c
void stdlib_ndarray_f_d(...) {...}
```

is a function which accepts one single-precision floating-point input ndarray and one double-precision floating-point output ndarray. The callback is assumed to accept and return single-precision floating-point numbers. Accordingly, the input and output values are cast according to the following conversion sequence

<!-- run-disable -->

```c
// Retrieve each input array element as single-precision:
float in1 = (float)x[ i ];

// Evaluate the callback:
float out = f( in1 );

// Convert the callback return value to double-precision:
y[ i ] = (double)out;
```

</section>

<!-- /.intro -->

<!-- C usage documentation. -->

<section class="usage">

### Usage

```c
#include "stdlib/ndarray/base/unary.h"
```

<!-- The following is auto-generated. Do not manually edit. See scripts/loops.js. -->

<!-- loops -->

#### stdlib_ndarray_b_b( \*arrays\[], \*fcn )

Applies a unary callback to an input ndarray and assigns results to elements in an output ndarray.

```c
#include "stdlib/ndarray/dtypes.h"
#include "stdlib/ndarray/index_modes.h"
#include "stdlib/ndarray/orders.h"
#include "stdlib/ndarray/ctor.h"
#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>

// Define the ndarray data types:
enum STDLIB_NDARRAY_DTYPE xdtype = STDLIB_NDARRAY_UINT8;
enum STDLIB_NDARRAY_DTYPE ydtype = STDLIB_NDARRAY_UINT8;

// Create underlying byte arrays:
uint8_t xbuf[] = { 0, 0, 0, 0 };
uint8_t ybuf[] = { 0, 0, 0, 0 };

// Define the number of dimensions:
int64_t ndims = 2;

// Define the array shapes:
int64_t shape[] = { 2, 2 };

// Define the strides:
int64_t sx[] = { 2, 1 };
int64_t sy[] = { 2, 1 };

// Define the offsets:
int64_t ox = 0;
int64_t oy = 0;

// Define the array order:
enum STDLIB_NDARRAY_ORDER order = STDLIB_NDARRAY_ROW_MAJOR;

// Specify the index mode:
enum STDLIB_NDARRAY_INDEX_MODE imode = STDLIB_NDARRAY_INDEX_ERROR;

// Specify the subscript index modes:
int8_t submodes[] = { imode };
int64_t nsubmodes = 1;

// Create an input ndarray:
struct ndarray *x = stdlib_ndarray_allocate( xdtype, xbuf, ndims, shape, sx, ox, order, imode, nsubmodes, submodes );
if ( x == NULL ) {
    fprintf( stderr, "Error allocating memory.\n" );
    exit( EXIT_FAILURE );
}

// Create an output ndarray:
struct ndarray *y = stdlib_ndarray_allocate( ydtype, ybuf, ndims, shape, sy, oy, order, imode, nsubmodes, submodes );
if ( y == NULL ) {
    fprintf( stderr, "Error allocating memory.\n" );
    exit( EXIT_FAILURE );
}

// Create an array containing the ndarrays:
struct ndarray *arrays[] = { x, y };

// Define a callback:
static uint8_t fcn( const uint8_t x ) {
    return x;
}

// Apply the callback:
int8_t status = stdlib_ndarray_b_b( arrays, (void *)fcn );
if ( status != 0 ) {
    fprintf( stderr, "Error during computation.\n" );
    exit( EXIT_FAILURE );
}

// ...

// Free allocated memory:
stdlib_ndarray_free( x );
stdlib_ndarray_free( y );
```

The function accepts the following arguments:

-   **arrays**: `[inout] struct ndarray**` array whose first element is a pointer to an input ndarray and whose second element is a pointer to an output ndarray.
-   **fcn**: `[in] void*` a `uint8_t (*f)(uint8_t)` function to apply provided as a `void` pointer.

```c
int8_t stdlib_ndarray_b_b( struct ndarray *arrays[], void *fcn );
```

#### stdlib_ndarray_b_b_as_u_u( \*arrays\[], \*fcn )

Applies a unary callback to an input ndarray and assigns results to elements in an output ndarray.

```c
#include "stdlib/ndarray/dtypes.h"
#include "stdlib/ndarray/index_modes.h"
#include "stdlib/ndarray/orders.h"
#include "stdlib/ndarray/ctor.h"
#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>

// Define the ndarray data types:
enum STDLIB_NDARRAY_DTYPE xdtype = STDLIB_NDARRAY_UINT8;
enum STDLIB_NDARRAY_DTYPE ydtype = STDLIB_NDARRAY_UINT8;

// Create underlying byte arrays:
uint8_t xbuf[] = { 0, 0, 0, 0 };
uint8_t ybuf[] = { 0, 0, 0, 0 };

// Define the number of dimensions:
int64_t ndims = 2;

// Define the array shapes:
int64_t shape[] = { 2, 2 };

// Define the strides:
int64_t sx[] = { 2, 1 };
int64_t sy[] = { 2, 1 };

// Define the offsets:
int64_t ox = 0;
int64_t oy = 0;

// Define the array order:
enum STDLIB_NDARRAY_ORDER order = STDLIB_NDARRAY_ROW_MAJOR;

// Specify the index mode:
enum STDLIB_NDARRAY_INDEX_MODE imode = STDLIB_NDARRAY_INDEX_ERROR;

// Specify the subscript index modes:
int8_t submodes[] = { imode };
int64_t nsubmodes = 1;

// Create an input ndarray:
struct ndarray *x = stdlib_ndarray_allocate( xdtype, xbuf, ndims, shape, sx, ox, order, imode, nsubmodes, submodes );
if ( x == NULL ) {
    fprintf( stderr, "Error allocating memory.\n" );
    exit( EXIT_FAILURE );
}

// Create an output ndarray:
struct ndarray *y = stdlib_ndarray_allocate( ydtype, ybuf, ndims, shape, sy, oy, order, imode, nsubmodes, submodes );
if ( y == NULL ) {
    fprintf( stderr, "Error allocating memory.\n" );
    exit( EXIT_FAILURE );
}

// Create an array containing the ndarrays:
struct ndarray *arrays[] = { x, y };

// Define a callback:
static uint32_t fcn( const uint32_t x ) {
    return x;
}

// Apply the callback:
int8_t status = stdlib_ndarray_b_b_as_u_u( arrays, (void *)fcn );
if ( status != 0 ) {
    fprintf( stderr, "Error during computation.\n" );
    exit( EXIT_FAILURE );
}

// ...

// Free allocated memory:
stdlib_ndarray_free( x );
stdlib_ndarray_free( y );
```

The function accepts the following arguments:

-   **arrays**: `[inout] struct ndarray**` array whose first element is a pointer to an input ndarray and whose second element is a pointer to an output ndarray.
-   **fcn**: `[in] void*` a `uint32_t (*f)(uint32_t)` function to apply provided as a `void` pointer.

```c
int8_t stdlib_ndarray_b_b_as_u_u( struct ndarray *arrays[], void *fcn );
```

#### stdlib_ndarray_b_b_as_v_v( \*arrays\[], \*fcn )

Applies a unary callback to an input ndarray and assigns results to elements in an output ndarray.

```c
#include "stdlib/ndarray/dtypes.h"
#include "stdlib/ndarray/index_modes.h"
#include "stdlib/ndarray/orders.h"
#include "stdlib/ndarray/ctor.h"
#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>

// Define the ndarray data types:
enum STDLIB_NDARRAY_DTYPE xdtype = STDLIB_NDARRAY_UINT8;
enum STDLIB_NDARRAY_DTYPE ydtype = STDLIB_NDARRAY_UINT8;

// Create underlying byte arrays:
uint8_t xbuf[] = { 0, 0, 0, 0 };
uint8_t ybuf[] = { 0, 0, 0, 0 };

// Define the number of dimensions:
int64_t ndims = 2;

// Define the array shapes:
int64_t shape[] = { 2, 2 };

// Define the strides:
int64_t sx[] = { 2, 1 };
int64_t sy[] = { 2, 1 };

// Define the offsets:
int64_t ox = 0;
int64_t oy = 0;

// Define the array order:
enum STDLIB_NDARRAY_ORDER order = STDLIB_NDARRAY_ROW_MAJOR;

// Specify the index mode:
enum STDLIB_NDARRAY_INDEX_MODE imode = STDLIB_NDARRAY_INDEX_ERROR;

// Specify the subscript index modes:
int8_t submodes[] = { imode };
int64_t nsubmodes = 1;

// Create an input ndarray:
struct ndarray *x = stdlib_ndarray_allocate( xdtype, xbuf, ndims, shape, sx, ox, order, imode, nsubmodes, submodes );
if ( x == NULL ) {
    fprintf( stderr, "Error allocating memory.\n" );
    exit( EXIT_FAILURE );
}

// Create an output ndarray:
struct ndarray *y = stdlib_ndarray_allocate( ydtype, ybuf, ndims, shape, sy, oy, order, imode, nsubmodes, submodes );
if ( y == NULL ) {
    fprintf( stderr, "Error allocating memory.\n" );
    exit( EXIT_FAILURE );
}

// Create an array containing the ndarrays:
struct ndarray *arrays[] = { x, y };

// Define a callback:
static uint64_t fcn( const uint64_t x ) {
    return x;
}

// Apply the callback:
int8_t status = stdlib_ndarray_b_b_as_v_v( arrays, (void *)fcn );
if ( status != 0 ) {
    fprintf( stderr, "Error during computation.\n" );
    exit( EXIT_FAILURE );
}

// ...

// Free allocated memory:
stdlib_ndarray_free( x );
stdlib_ndarray_free( y );
```

The function accepts the following arguments:

-   **arrays**: `[inout] struct ndarray**` array whose first element is a pointer to an input ndarray and whose second element is a pointer to an output ndarray.
-   **fcn**: `[in] void*` a `uint64_t (*f)(uint64_t)` function to apply provided as a `void` pointer.

```c
int8_t stdlib_ndarray_b_b_as_v_v( struct ndarray *arrays[], void *fcn );
```

#### stdlib_ndarray_b_c( \*arrays\[], \*fcn )

Applies a unary callback to an input ndarray and assigns results to elements in an output ndarray.

```c
#include "stdlib/ndarray/dtypes.h"
#include "stdlib/ndarray/index_modes.h"
#include "stdlib/ndarray/orders.h"
#include "stdlib/ndarray/ctor.h"
#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>

// Define the ndarray data types:
enum STDLIB_NDARRAY_DTYPE xdtype = STDLIB_NDARRAY_UINT8;
enum STDLIB_NDARRAY_DTYPE ydtype = STDLIB_NDARRAY_COMPLEX64;

// Create underlying byte arrays:
uint8_t xbuf[] = { 0, 0, 0, 0 };
uint8_t ybuf[] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };

// Define the number of dimensions:
int64_t ndims = 2;

// Define the array shapes:
int64_t shape[] = { 2, 2 };

// Define the strides:
int64_t sx[] = { 2, 1 };
int64_t sy[] = { 16, 8 };

// Define the offsets:
int64_t ox = 0;
int64_t oy = 0;

// Define the array order:
enum STDLIB_NDARRAY_ORDER order = STDLIB_NDARRAY_ROW_MAJOR;

// Specify the index mode:
enum STDLIB_NDARRAY_INDEX_MODE imode = STDLIB_NDARRAY_INDEX_ERROR;

// Specify the subscript index modes:
int8_t submodes[] = { imode };
int64_t nsubmodes = 1;

// Create an input ndarray:
struct ndarray *x = stdlib_ndarray_allocate( xdtype, xbuf, ndims, shape, sx, ox, order, imode, nsubmodes, submodes );
if ( x == NULL ) {
    fprintf( stderr, "Error allocating memory.\n" );
    exit( EXIT_FAILURE );
}

// Create an output ndarray:
struct ndarray *y = stdlib_ndarray_allocate( ydtype, ybuf, ndims, shape, sy, oy, order, imode, nsubmodes, submodes );
if ( y == NULL ) {
    fprintf( stderr, "Error allocating memory.\n" );
    exit( EXIT_FAILURE );
}

// Create an array containing the ndarrays:
struct ndarray *arrays[] = { x, y };

// Define a callback:
static uint8_t fcn( const uint8_t x ) {
    return x;
}

// Apply the callback:
int8_t status = stdlib_ndarray_b_c( arrays, (void *)fcn );
if ( status != 0 ) {
    fprintf( stderr, "Error during computation.\n" );
    exit( EXIT_FAILURE );
}

// ...

// Free allocated memory:
stdlib_ndarray_free( x );
stdlib_ndarray_free( y );
```

The function accepts the following arguments:

-   **arrays**: `[inout] struct ndarray**` array whose first element is a pointer to an input ndarray and whose second element is a pointer to an output ndarray.
-   **fcn**: `[in] void*` a `uint8_t (*f)(uint8_t)` function to apply provided as a `void` pointer.

```c
int8_t stdlib_ndarray_b_c( struct ndarray *arrays[], void *fcn );
```

#### stdlib_ndarray_b_c_as_b_c( \*arrays\[], \*fcn )

Applies a unary callback to an input ndarray and assigns results to elements in an output ndarray.

```c
#include "stdlib/ndarray/dtypes.h"
#include "stdlib/ndarray/index_modes.h"
#include "stdlib/ndarray/orders.h"
#include "stdlib/ndarray/ctor.h"
#include "stdlib/complex/float32/ctor.h"
#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>

// Define the ndarray data types:
enum STDLIB_NDARRAY_DTYPE xdtype = STDLIB_NDARRAY_UINT8;
enum STDLIB_NDARRAY_DTYPE ydtype = STDLIB_NDARRAY_COMPLEX64;

// Create underlying byte arrays:
uint8_t xbuf[] = { 0, 0, 0, 0 };
uint8_t ybuf[] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };

// Define the number of dimensions:
int64_t ndims = 2;

// Define the array shapes:
int64_t shape[] = { 2, 2 };

// Define the strides:
int64_t sx[] = { 2, 1 };
int64_t sy[] = { 16, 8 };

// Define the offsets:
int64_t ox = 0;
int64_t oy = 0;

// Define the array order:
enum STDLIB_NDARRAY_ORDER order = STDLIB_NDARRAY_ROW_MAJOR;

// Specify the index mode:
enum STDLIB_NDARRAY_INDEX_MODE imode = STDLIB_NDARRAY_INDEX_ERROR;

// Specify the subscript index modes:
int8_t submodes[] = { imode };
int64_t nsubmodes = 1;

// Create an input ndarray:
struct ndarray *x = stdlib_ndarray_allocate( xdtype, xbuf, ndims, shape, sx, ox, order, imode, nsubmodes, submodes );
if ( x == NULL ) {
    fprintf( stderr, "Error allocating memory.\n" );
    exit( EXIT_FAILURE );
}

// Create an output ndarray:
struct ndarray *y = stdlib_ndarray_allocate( ydtype, ybuf, ndims, shape, sy, oy, order, imode, nsubmodes, submodes );
if ( y == NULL ) {
    fprintf( stderr, "Error allocating memory.\n" );
    exit( EXIT_FAILURE );
}

// Create an array containing the ndarrays:
struct ndarray *arrays[] = { x, y };

// Define a callback:
static stdlib_complex64_t fcn( const uint8_t x ) {
    // ...
}

// Apply the callback:
int8_t status = stdlib_ndarray_b_c_as_b_c( arrays, (void *)fcn );
if ( status != 0 ) {
    fprintf( stderr, "Error during computation.\n" );
    exit( EXIT_FAILURE );
}

// ...

// Free allocated memory:
stdlib_ndarray_free( x );
stdlib_ndarray_free( y );
```

The function accepts the following arguments:

-   **arrays**: `[inout] struct ndarray**` array whose first element is a pointer to an input ndarray and whose second element is a pointer to an output ndarray.
-   **fcn**: `[in] void*` a `stdlib_complex64_t (*f)(uint8_t)` function to apply provided as a `void` pointer.

```c
int8_t stdlib_ndarray_b_c_as_b_c( struct ndarray *arrays[], void *fcn );
```

#### stdlib_ndarray_b_c_as_c_c( \*arrays\[], \*fcn )

Applies a unary callback to an input ndarray and assigns results to elements in an output ndarray.

```c
#include "stdlib/ndarray/dtypes.h"
#include "stdlib/ndarray/index_modes.h"
#include "stdlib/ndarray/orders.h"
#include "stdlib/ndarray/ctor.h"
#include "stdlib/complex/float32/ctor.h"
#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>

// Define the ndarray data types:
enum STDLIB_NDARRAY_DTYPE xdtype = STDLIB_NDARRAY_UINT8;
enum STDLIB_NDARRAY_DTYPE ydtype = STDLIB_NDARRAY_COMPLEX64;

// Create underlying byte arrays:
uint8_t xbuf[] = { 0, 0, 0, 0 };
uint8_t ybuf[] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };

// Define the number of dimensions:
int64_t ndims = 2;

// Define the array shapes:
int64_t shape[] = { 2, 2 };

// Define the strides:
int64_t sx[] = { 2, 1 };
int64_t sy[] = { 16, 8 };

// Define the offsets:
int64_t ox = 0;
int64_t oy = 0;

// Define the array order:
enum STDLIB_NDARRAY_ORDER order = STDLIB_NDARRAY_ROW_MAJOR;

// Specify the index mode:
enum STDLIB_NDARRAY_INDEX_MODE imode = STDLIB_NDARRAY_INDEX_ERROR;

// Specify the subscript index modes:
int8_t submodes[] = { imode };
int64_t nsubmodes = 1;

// Create an input ndarray:
struct ndarray *x = stdlib_ndarray_allocate( xdtype, xbuf, ndims, shape, sx, ox, order, imode, nsubmodes, submodes );
if ( x == NULL ) {
    fprintf( stderr, "Error allocating memory.\n" );
    exit( EXIT_FAILURE );
}

// Create an output ndarray:
struct ndarray *y = stdlib_ndarray_allocate( ydtype, ybuf, ndims, shape, sy, oy, order, imode, nsubmodes, submodes );
if ( y == NULL ) {
    fprintf( stderr, "Error allocating memory.\n" );
    exit( EXIT_FAILURE );
}

// Create an array containing the ndarrays:
struct ndarray *arrays[] = { x, y };

// Define a callback:
static stdlib_complex64_t fcn( const stdlib_complex64_t x ) {
    // ...
}

// Apply the callback:
int8_t status = stdlib_ndarray_b_c_as_c_c( arrays, (void *)fcn );
if ( status != 0 ) {
    fprintf( stderr, "Error during computation.\n" );
    exit( EXIT_FAILURE );
}

// ...

// Free allocated memory:
stdlib_ndarray_free( x );
stdlib_ndarray_free( y );
```

The function accepts the following arguments:

-   **arrays**: `[inout] struct ndarray**` array whose first element is a pointer to an input ndarray and whose second element is a pointer to an output ndarray.
-   **fcn**: `[in] void*` a `stdlib_complex64_t (*f)(stdlib_complex64_t)` function to apply provided as a `void` pointer.

```c
int8_t stdlib_ndarray_b_c_as_c_c( struct ndarray *arrays[], void *fcn );
```

#### stdlib_ndarray_b_c_as_z_z( \*arrays\[], \*fcn )

Applies a unary callback to an input ndarray and assigns results to elements in an output ndarray.

```c
#include "stdlib/ndarray/dtypes.h"
#include "stdlib/ndarray/index_modes.h"
#include "stdlib/ndarray/orders.h"
#include "stdlib/ndarray/ctor.h"
#include "stdlib/complex/float64/ctor.h"
#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>

// Define the ndarray data types:
enum STDLIB_NDARRAY_DTYPE xdtype = STDLIB_NDARRAY_UINT8;
enum STDLIB_NDARRAY_DTYPE ydtype = STDLIB_NDARRAY_COMPLEX64;

// Create underlying byte arrays:
uint8_t xbuf[] = { 0, 0, 0, 0 };
uint8_t ybuf[] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };

// Define the number of dimensions:
int64_t ndims = 2;

// Define the array shapes:
int64_t shape[] = { 2, 2 };

// Define the strides:
int64_t sx[] = { 2, 1 };
int64_t sy[] = { 16, 8 };

// Define the offsets:
int64_t ox = 0;
int64_t oy = 0;

// Define the array order:
enum STDLIB_NDARRAY_ORDER order = STDLIB_NDARRAY_ROW_MAJOR;

// Specify the index mode:
enum STDLIB_NDARRAY_INDEX_MODE imode = STDLIB_NDARRAY_INDEX_ERROR;

// Specify the subscript index modes:
int8_t submodes[] = { imode };
int64_t nsubmodes = 1;

// Create an input ndarray:
struct ndarray *x = stdlib_ndarray_allocate( xdtype, xbuf, ndims, shape, sx, ox, order, imode, nsubmodes, submodes );
if ( x == NULL ) {
    fprintf( stderr, "Error allocating memory.\n" );
    exit( EXIT_FAILURE );
}

// Create an output ndarray:
struct ndarray *y = stdlib_ndarray_allocate( ydtype, ybuf, ndims, shape, sy, oy, order, imode, nsubmodes, submodes );
if ( y == NULL ) {
    fprintf( stderr, "Error allocating memory.\n" );
    exit( EXIT_FAILURE );
}

// Create an array containing the ndarrays:
struct ndarray *arrays[] = { x, y };

// Define a callback:
static stdlib_complex128_t fcn( const stdlib_complex128_t x ) {
    // ...
}

// Apply the callback:
int8_t status = stdlib_ndarray_b_c_as_z_z( arrays, (void *)fcn );
if ( status != 0 ) {
    fprintf( stderr, "Error during computation.\n" );
    exit( EXIT_FAILURE );
}

// ...

// Free allocated memory:
stdlib_ndarray_free( x );
stdlib_ndarray_free( y );
```

The function accepts the following arguments:

-   **arrays**: `[inout] struct ndarray**` array whose first element is a pointer to an input ndarray and whose second element is a pointer to an output ndarray.
-   **fcn**: `[in] void*` a `stdlib_complex128_t (*f)(stdlib_complex128_t)` function to apply provided as a `void` pointer.

```c
int8_t stdlib_ndarray_b_c_as_z_z( struct ndarray *arrays[], void *fcn );
```

#### stdlib_ndarray_b_d( \*arrays\[], \*fcn )

Applies a unary callback to an input ndarray and assigns results to elements in an output ndarray.

```c
#include "stdlib/ndarray/dtypes.h"
#include "stdlib/ndarray/index_modes.h"
#include "stdlib/ndarray/orders.h"
#include "stdlib/ndarray/ctor.h"
#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>

// Define the ndarray data types:
enum STDLIB_NDARRAY_DTYPE xdtype = STDLIB_NDARRAY_UINT8;
enum STDLIB_NDARRAY_DTYPE ydtype = STDLIB_NDARRAY_FLOAT64;

// Create underlying byte arrays:
uint8_t xbuf[] = { 0, 0, 0, 0 };
uint8_t ybuf[] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };

// Define the number of dimensions:
int64_t ndims = 2;

// Define the array shapes:
int64_t shape[] = { 2, 2 };

// Define the strides:
int64_t sx[] = { 2, 1 };
int64_t sy[] = { 16, 8 };

// Define the offsets:
int64_t ox = 0;
int64_t oy = 0;

// Define the array order:
enum STDLIB_NDARRAY_ORDER order = STDLIB_NDARRAY_ROW_MAJOR;

// Specify the index mode:
enum STDLIB_NDARRAY_INDEX_MODE imode = STDLIB_NDARRAY_INDEX_ERROR;

// Specify the subscript index modes:
int8_t submodes[] = { imode };
int64_t nsubmodes = 1;

// Create an input ndarray:
struct ndarray *x = stdlib_ndarray_allocate( xdtype, xbuf, ndims, shape, sx, ox, order, imode, nsubmodes, submodes );
if ( x == NULL ) {
    fprintf( stderr, "Error allocating memory.\n" );
    exit( EXIT_FAILURE );
}

// Create an output ndarray:
struct ndarray *y = stdlib_ndarray_allocate( ydtype, ybuf, ndims, shape, sy, oy, order, imode, nsubmodes, submodes );
if ( y == NULL ) {
    fprintf( stderr, "Error allocating memory.\n" );
    exit( EXIT_FAILURE );
}

// Create an array containing the ndarrays:
struct ndarray *arrays[] = { x, y };

// Define a callback:
static uint8_t fcn( const uint8_t x ) {
    return x;
}

// Apply the callback:
int8_t status = stdlib_ndarray_b_d( arrays, (void *)fcn );
if ( status != 0 ) {
    fprintf( stderr, "Error during computation.\n" );
    exit( EXIT_FAILURE );
}

// ...

// Free allocated memory:
stdlib_ndarray_free( x );
stdlib_ndarray_free( y );
```

The function accepts the following arguments:

-   **arrays**: `[inout] struct ndarray**` array whose first element is a pointer to an input ndarray and whose second element is a pointer to an output ndarray.
-   **fcn**: `[in] void*` a `uint8_t (*f)(uint8_t)` function to apply provided as a `void` pointer.

```c
int8_t stdlib_ndarray_b_d( struct ndarray *arrays[], void *fcn );
```

#### stdlib_ndarray_b_d_as_b_d( \*arrays\[], \*fcn )

Applies a unary callback to an input ndarray and assigns results to elements in an output ndarray.

```c
#include "stdlib/ndarray/dtypes.h"
#include "stdlib/ndarray/index_modes.h"
#include "stdlib/ndarray/orders.h"
#include "stdlib/ndarray/ctor.h"
#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>

// Define the ndarray data types:
enum STDLIB_NDARRAY_DTYPE xdtype = STDLIB_NDARRAY_UINT8;
enum STDLIB_NDARRAY_DTYPE ydtype = STDLIB_NDARRAY_FLOAT64;

// Create underlying byte arrays:
uint8_t xbuf[] = { 0, 0, 0, 0 };
uint8_t ybuf[] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };

// Define the number of dimensions:
int64_t ndims = 2;

// Define the array shapes:
int64_t shape[] = { 2, 2 };

// Define the strides:
int64_t sx[] = { 2, 1 };
int64_t sy[] = { 16, 8 };

// Define the offsets:
int64_t ox = 0;
int64_t oy = 0;

// Define the array order:
enum STDLIB_NDARRAY_ORDER order = STDLIB_NDARRAY_ROW_MAJOR;

// Specify the index mode:
enum STDLIB_NDARRAY_INDEX_MODE imode = STDLIB_NDARRAY_INDEX_ERROR;

// Specify the subscript index modes:
int8_t submodes[] = { imode };
int64_t nsubmodes = 1;

// Create an input ndarray:
struct ndarray *x = stdlib_ndarray_allocate( xdtype, xbuf, ndims, shape, sx, ox, order, imode, nsubmodes, submodes );
if ( x == NULL ) {
    fprintf( stderr, "Error allocating memory.\n" );
    exit( EXIT_FAILURE );
}

// Create an output ndarray:
struct ndarray *y = stdlib_ndarray_allocate( ydtype, ybuf, ndims, shape, sy, oy, order, imode, nsubmodes, submodes );
if ( y == NULL ) {
    fprintf( stderr, "Error allocating memory.\n" );
    exit( EXIT_FAILURE );
}

// Create an array containing the ndarrays:
struct ndarray *arrays[] = { x, y };

// Define a callback:
static double fcn( const uint8_t x ) {
    // ...
}

// Apply the callback:
int8_t status = stdlib_ndarray_b_d_as_b_d( arrays, (void *)fcn );
if ( status != 0 ) {
    fprintf( stderr, "Error during computation.\n" );
    exit( EXIT_FAILURE );
}

// ...

// Free allocated memory:
stdlib_ndarray_free( x );
stdlib_ndarray_free( y );
```

The function accepts the following arguments:

-   **arrays**: `[inout] struct ndarray**` array whose first element is a pointer to an input ndarray and whose second element is a pointer to an output ndarray.
-   **fcn**: `[in] void*` a `double (*f)(uint8_t)` function to apply provided as a `void` pointer.

```c
int8_t stdlib_ndarray_b_d_as_b_d( struct ndarray *arrays[], void *fcn );
```

#### stdlib_ndarray_b_d_as_d_d( \*arrays\[], \*fcn )

Applies a unary callback to an input ndarray and assigns results to elements in an output ndarray.

```c
#include "stdlib/ndarray/dtypes.h"
#include "stdlib/ndarray/index_modes.h"
#include "stdlib/ndarray/orders.h"
#include "stdlib/ndarray/ctor.h"
#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>

// Define the ndarray data types:
enum STDLIB_NDARRAY_DTYPE xdtype = STDLIB_NDARRAY_UINT8;
enum STDLIB_NDARRAY_DTYPE ydtype = STDLIB_NDARRAY_FLOAT64;

// Create underlying byte arrays:
uint8_t xbuf[] = { 0, 0, 0, 0 };
uint8_t ybuf[] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };

// Define the number of dimensions:
int64_t ndims = 2;

// Define the array shapes:
int64_t shape[] = { 2, 2 };

// Define the strides:
int64_t sx[] = { 2, 1 };
int64_t sy[] = { 16, 8 };

// Define the offsets:
int64_t ox = 0;
int64_t oy = 0;

// Define the array order:
enum STDLIB_NDARRAY_ORDER order = STDLIB_NDARRAY_ROW_MAJOR;

// Specify the index mode:
enum STDLIB_NDARRAY_INDEX_MODE imode = STDLIB_NDARRAY_INDEX_ERROR;

// Specify the subscript index modes:
int8_t submodes[] = { imode };
int64_t nsubmodes = 1;

// Create an input ndarray:
struct ndarray *x = stdlib_ndarray_allocate( xdtype, xbuf, ndims, shape, sx, ox, order, imode, nsubmodes, submodes );
if ( x == NULL ) {
    fprintf( stderr, "Error allocating memory.\n" );
    exit( EXIT_FAILURE );
}

// Create an output ndarray:
struct ndarray *y = stdlib_ndarray_allocate( ydtype, ybuf, ndims, shape, sy, oy, order, imode, nsubmodes, submodes );
if ( y == NULL ) {
    fprintf( stderr, "Error allocating memory.\n" );
    exit( EXIT_FAILURE );
}

// Create an array containing the ndarrays:
struct ndarray *arrays[] = { x, y };

// Define a callback:
static double fcn( const double x ) {
    return x;
}

// Apply the callback:
int8_t status = stdlib_ndarray_b_d_as_d_d( arrays, (void *)fcn );
if ( status != 0 ) {
    fprintf( stderr, "Error during computation.\n" );
    exit( EXIT_FAILURE );
}

// ...

// Free allocated memory:
stdlib_ndarray_free( x );
stdlib_ndarray_free( y );
```

The function accepts the following arguments:

-   **arrays**: `[inout] struct ndarray**` array whose first element is a pointer to an input ndarray and whose second element is a pointer to an output ndarray.
-   **fcn**: `[in] void*` a `double (*f)(double)` function to apply provided as a `void` pointer.

```c
int8_t stdlib_ndarray_b_d_as_d_d( struct ndarray *arrays[], void *fcn );
```

#### stdlib_ndarray_b_f( \*arrays\[], \*fcn )

Applies a unary callback to an input ndarray and assigns results to elements in an output ndarray.

```c
#include "stdlib/ndarray/dtypes.h"
#include "stdlib/ndarray/index_modes.h"
#include "stdlib/ndarray/orders.h"
#include "stdlib/ndarray/ctor.h"
#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>

// Define the ndarray data types:
enum STDLIB_NDARRAY_DTYPE xdtype = STDLIB_NDARRAY_UINT8;
enum STDLIB_NDARRAY_DTYPE ydtype = STDLIB_NDARRAY_FLOAT32;

// Create underlying byte arrays:
uint8_t xbuf[] = { 0, 0, 0, 0 };
uint8_t ybuf[] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };

// Define the number of dimensions:
int64_t ndims = 2;

// Define the array shapes:
int64_t shape[] = { 2, 2 };

// Define the strides:
int64_t sx[] = { 2, 1 };
int64_t sy[] = { 8, 4 };

// Define the offsets:
int64_t ox = 0;
int64_t oy = 0;

// Define the array order:
enum STDLIB_NDARRAY_ORDER order = STDLIB_NDARRAY_ROW_MAJOR;

// Specify the index mode:
enum STDLIB_NDARRAY_INDEX_MODE imode = STDLIB_NDARRAY_INDEX_ERROR;

// Specify the subscript index modes:
int8_t submodes[] = { imode };
int64_t nsubmodes = 1;

// Create an input ndarray:
struct ndarray *x = stdlib_ndarray_allocate( xdtype, xbuf, ndims, shape, sx, ox, order, imode, nsubmodes, submodes );
if ( x == NULL ) {
    fprintf( stderr, "Error allocating memory.\n" );
    exit( EXIT_FAILURE );
}

// Create an output ndarray:
struct ndarray *y = stdlib_ndarray_allocate( ydtype, ybuf, ndims, shape, sy, oy, order, imode, nsubmodes, submodes );
if ( y == NULL ) {
    fprintf( stderr, "Error allocating memory.\n" );
    exit( EXIT_FAILURE );
}

// Create an array containing the ndarrays:
struct ndarray *arrays[] = { x, y };

// Define a callback:
static uint8_t fcn( const uint8_t x ) {
    return x;
}

// Apply the callback:
int8_t status = stdlib_ndarray_b_f( arrays, (void *)fcn );
if ( status != 0 ) {
    fprintf( stderr, "Error during computation.\n" );
    exit( EXIT_FAILURE );
}

// ...

// Free allocated memory:
stdlib_ndarray_free( x );
stdlib_ndarray_free( y );
```

The function accepts the following arguments:

-   **arrays**: `[inout] struct ndarray**` array whose first element is a pointer to an input ndarray and whose second element is a pointer to an output ndarray.
-   **fcn**: `[in] void*` a `uint8_t (*f)(uint8_t)` function to apply provided as a `void` pointer.

```c
int8_t stdlib_ndarray_b_f( struct ndarray *arrays[], void *fcn );
```

#### stdlib_ndarray_b_f_as_b_f( \*arrays\[], \*fcn )

Applies a unary callback to an input ndarray and assigns results to elements in an output ndarray.

```c
#include "stdlib/ndarray/dtypes.h"
#include "stdlib/ndarray/index_modes.h"
#include "stdlib/ndarray/orders.h"
#include "stdlib/ndarray/ctor.h"
#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>

// Define the ndarray data types:
enum STDLIB_NDARRAY_DTYPE xdtype = STDLIB_NDARRAY_UINT8;
enum STDLIB_NDARRAY_DTYPE ydtype = STDLIB_NDARRAY_FLOAT32;

// Create underlying byte arrays:
uint8_t xbuf[] = { 0, 0, 0, 0 };
uint8_t ybuf[] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };

// Define the number of dimensions:
int64_t ndims = 2;

// Define the array shapes:
int64_t shape[] = { 2, 2 };

// Define the strides:
int64_t sx[] = { 2, 1 };
int64_t sy[] = { 8, 4 };

// Define the offsets:
int64_t ox = 0;
int64_t oy = 0;

// Define the array order:
enum STDLIB_NDARRAY_ORDER order = STDLIB_NDARRAY_ROW_MAJOR;

// Specify the index mode:
enum STDLIB_NDARRAY_INDEX_MODE imode = STDLIB_NDARRAY_INDEX_ERROR;

// Specify the subscript index modes:
int8_t submodes[] = { imode };
int64_t nsubmodes = 1;

// Create an input ndarray:
struct ndarray *x = stdlib_ndarray_allocate( xdtype, xbuf, ndims, shape, sx, ox, order, imode, nsubmodes, submodes );
if ( x == NULL ) {
    fprintf( stderr, "Error allocating memory.\n" );
    exit( EXIT_FAILURE );
}

// Create an output ndarray:
struct ndarray *y = stdlib_ndarray_allocate( ydtype, ybuf, ndims, shape, sy, oy, order, imode, nsubmodes, submodes );
if ( y == NULL ) {
    fprintf( stderr, "Error allocating memory.\n" );
    exit( EXIT_FAILURE );
}

// Create an array containing the ndarrays:
struct ndarray *arrays[] = { x, y };

// Define a callback:
static float fcn( const uint8_t x ) {
    // ...
}

// Apply the callback:
int8_t status = stdlib_ndarray_b_f_as_b_f( arrays, (void *)fcn );
if ( status != 0 ) {
    fprintf( stderr, "Error during computation.\n" );
    exit( EXIT_FAILURE );
}

// ...

// Free allocated memory:
stdlib_ndarray_free( x );
stdlib_ndarray_free( y );
```

The function accepts the following arguments:

-   **arrays**: `[inout] struct ndarray**` array whose first element is a pointer to an input ndarray and whose second element is a pointer to an output ndarray.
-   **fcn**: `[in] void*` a `float (*f)(uint8_t)` function to apply provided as a `void` pointer.

```c
int8_t stdlib_ndarray_b_f_as_b_f( struct ndarray *arrays[], void *fcn );
```

#### stdlib_ndarray_b_f_as_d_d( \*arrays\[], \*fcn )

Applies a unary callback to an input ndarray and assigns results to elements in an output ndarray.

```c
#include "stdlib/ndarray/dtypes.h"
#include "stdlib/ndarray/index_modes.h"
#include "stdlib/ndarray/orders.h"
#include "stdlib/ndarray/ctor.h"
#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>

// Define the ndarray data types:
enum STDLIB_NDARRAY_DTYPE xdtype = STDLIB_NDARRAY_UINT8;
enum STDLIB_NDARRAY_DTYPE ydtype = STDLIB_NDARRAY_FLOAT32;

// Create underlying byte arrays:
uint8_t xbuf[] = { 0, 0, 0, 0 };
uint8_t ybuf[] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };

// Define the number of dimensions:
int64_t ndims = 2;

// Define the array shapes:
int64_t shape[] = { 2, 2 };

// Define the strides:
int64_t sx[] = { 2, 1 };
int64_t sy[] = { 8, 4 };

// Define the offsets:
int64_t ox = 0;
int64_t oy = 0;

// Define the array order:
enum STDLIB_NDARRAY_ORDER order = STDLIB_NDARRAY_ROW_MAJOR;

// Specify the index mode:
enum STDLIB_NDARRAY_INDEX_MODE imode = STDLIB_NDARRAY_INDEX_ERROR;

// Specify the subscript index modes:
int8_t submodes[] = { imode };
int64_t nsubmodes = 1;

// Create an input ndarray:
struct ndarray *x = stdlib_ndarray_allocate( xdtype, xbuf, ndims, shape, sx, ox, order, imode, nsubmodes, submodes );
if ( x == NULL ) {
    fprintf( stderr, "Error allocating memory.\n" );
    exit( EXIT_FAILURE );
}

// Create an output ndarray:
struct ndarray *y = stdlib_ndarray_allocate( ydtype, ybuf, ndims, shape, sy, oy, order, imode, nsubmodes, submodes );
if ( y == NULL ) {
    fprintf( stderr, "Error allocating memory.\n" );
    exit( EXIT_FAILURE );
}

// Create an array containing the ndarrays:
struct ndarray *arrays[] = { x, y };

// Define a callback:
static double fcn( const double x ) {
    return x;
}

// Apply the callback:
int8_t status = stdlib_ndarray_b_f_as_d_d( arrays, (void *)fcn );
if ( status != 0 ) {
    fprintf( stderr, "Error during computation.\n" );
    exit( EXIT_FAILURE );
}

// ...

// Free allocated memory:
stdlib_ndarray_free( x );
stdlib_ndarray_free( y );
```

The function accepts the following arguments:

-   **arrays**: `[inout] struct ndarray**` array whose first element is a pointer to an input ndarray and whose second element is a pointer to an output ndarray.
-   **fcn**: `[in] void*` a `double (*f)(double)` function to apply provided as a `void` pointer.

```c
int8_t stdlib_ndarray_b_f_as_d_d( struct ndarray *arrays[], void *fcn );
```

#### stdlib_ndarray_b_f_as_f_f( \*arrays\[], \*fcn )

Applies a unary callback to an input ndarray and assigns results to elements in an output ndarray.

```c
#include "stdlib/ndarray/dtypes.h"
#include "stdlib/ndarray/index_modes.h"
#include "stdlib/ndarray/orders.h"
#include "stdlib/ndarray/ctor.h"
#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>

// Define the ndarray data types:
enum STDLIB_NDARRAY_DTYPE xdtype = STDLIB_NDARRAY_UINT8;
enum STDLIB_NDARRAY_DTYPE ydtype = STDLIB_NDARRAY_FLOAT32;

// Create underlying byte arrays:
uint8_t xbuf[] = { 0, 0, 0, 0 };
uint8_t ybuf[] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };

// Define the number of dimensions:
int64_t ndims = 2;

// Define the array shapes:
int64_t shape[] = { 2, 2 };

// Define the strides:
int64_t sx[] = { 2, 1 };
int64_t sy[] = { 8, 4 };

// Define the offsets:
int64_t ox = 0;
int64_t oy = 0;

// Define the array order:
enum STDLIB_NDARRAY_ORDER order = STDLIB_NDARRAY_ROW_MAJOR;

// Specify the index mode:
enum STDLIB_NDARRAY_INDEX_MODE imode = STDLIB_NDARRAY_INDEX_ERROR;

// Specify the subscript index modes:
int8_t submodes[] = { imode };
int64_t nsubmodes = 1;

// Create an input ndarray:
struct ndarray *x = stdlib_ndarray_allocate( xdtype, xbuf, ndims, shape, sx, ox, order, imode, nsubmodes, submodes );
if ( x == NULL ) {
    fprintf( stderr, "Error allocating memory.\n" );
    exit( EXIT_FAILURE );
}

// Create an output ndarray:
struct ndarray *y = stdlib_ndarray_allocate( ydtype, ybuf, ndims, shape, sy, oy, order, imode, nsubmodes, submodes );
if ( y == NULL ) {
    fprintf( stderr, "Error allocating memory.\n" );
    exit( EXIT_FAILURE );
}

// Create an array containing the ndarrays:
struct ndarray *arrays[] = { x, y };

// Define a callback:
static float fcn( const float x ) {
    return x;
}

// Apply the callback:
int8_t status = stdlib_ndarray_b_f_as_f_f( arrays, (void *)fcn );
if ( status != 0 ) {
    fprintf( stderr, "Error during computation.\n" );
    exit( EXIT_FAILURE );
}

// ...

// Free allocated memory:
stdlib_ndarray_free( x );
stdlib_ndarray_free( y );
```

The function accepts the following arguments:

-   **arrays**: `[inout] struct ndarray**` array whose first element is a pointer to an input ndarray and whose second element is a pointer to an output ndarray.
-   **fcn**: `[in] void*` a `float (*f)(float)` function to apply provided as a `void` pointer.

```c
int8_t stdlib_ndarray_b_f_as_f_f( struct ndarray *arrays[], void *fcn );
```

#### stdlib_ndarray_b_i( \*arrays\[], \*fcn )

Applies a unary callback to an input ndarray and assigns results to elements in an output ndarray.

```c
#include "stdlib/ndarray/dtypes.h"
#include "stdlib/ndarray/index_modes.h"
#include "stdlib/ndarray/orders.h"
#include "stdlib/ndarray/ctor.h"
#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>

// Define the ndarray data types:
enum STDLIB_NDARRAY_DTYPE xdtype = STDLIB_NDARRAY_UINT8;
enum STDLIB_NDARRAY_DTYPE ydtype = STDLIB_NDARRAY_INT32;

// Create underlying byte arrays:
uint8_t xbuf[] = { 0, 0, 0, 0 };
uint8_t ybuf[] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };

// Define the number of dimensions:
int64_t ndims = 2;

// Define the array shapes:
int64_t shape[] = { 2, 2 };

// Define the strides:
int64_t sx[] = { 2, 1 };
int64_t sy[] = { 8, 4 };

// Define the offsets:
int64_t ox = 0;
int64_t oy = 0;

// Define the array order:
enum STDLIB_NDARRAY_ORDER order = STDLIB_NDARRAY_ROW_MAJOR;

// Specify the index mode:
enum STDLIB_NDARRAY_INDEX_MODE imode = STDLIB_NDARRAY_INDEX_ERROR;

// Specify the subscript index modes:
int8_t submodes[] = { imode };
int64_t nsubmodes = 1;

// Create an input ndarray:
struct ndarray *x = stdlib_ndarray_allocate( xdtype, xbuf, ndims, shape, sx, ox, order, imode, nsubmodes, submodes );
if ( x == NULL ) {
    fprintf( stderr, "Error allocating memory.\n" );
    exit( EXIT_FAILURE );
}

// Create an output ndarray:
struct ndarray *y = stdlib_ndarray_allocate( ydtype, ybuf, ndims, shape, sy, oy, order, imode, nsubmodes, submodes );
if ( y == NULL ) {
    fprintf( stderr, "Error allocating memory.\n" );
    exit( EXIT_FAILURE );
}

// Create an array containing the ndarrays:
struct ndarray *arrays[] = { x, y };

// Define a callback:
static uint8_t fcn( const uint8_t x ) {
    return x;
}

// Apply the callback:
int8_t status = stdlib_ndarray_b_i( arrays, (void *)fcn );
if ( status != 0 ) {
    fprintf( stderr, "Error during computation.\n" );
    exit( EXIT_FAILURE );
}

// ...

// Free allocated memory:
stdlib_ndarray_free( x );
stdlib_ndarray_free( y );
```

The function accepts the following arguments:

-   **arrays**: `[inout] struct ndarray**` array whose first element is a pointer to an input ndarray and whose second element is a pointer to an output ndarray.
-   **fcn**: `[in] void*` a `uint8_t (*f)(uint8_t)` function to apply provided as a `void` pointer.

```c
int8_t stdlib_ndarray_b_i( struct ndarray *arrays[], void *fcn );
```

#### stdlib_ndarray_b_i_as_b_i( \*arrays\[], \*fcn )

Applies a unary callback to an input ndarray and assigns results to elements in an output ndarray.

```c
#include "stdlib/ndarray/dtypes.h"
#include "stdlib/ndarray/index_modes.h"
#include "stdlib/ndarray/orders.h"
#include "stdlib/ndarray/ctor.h"
#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>

// Define the ndarray data types:
enum STDLIB_NDARRAY_DTYPE xdtype = STDLIB_NDARRAY_UINT8;
enum STDLIB_NDARRAY_DTYPE ydtype = STDLIB_NDARRAY_INT32;

// Create underlying byte arrays:
uint8_t xbuf[] = { 0, 0, 0, 0 };
uint8_t ybuf[] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };

// Define the number of dimensions:
int64_t ndims = 2;

// Define the array shapes:
int64_t shape[] = { 2, 2 };

// Define the strides:
int64_t sx[] = { 2, 1 };
int64_t sy[] = { 8, 4 };

// Define the offsets:
int64_t ox = 0;
int64_t oy = 0;

// Define the array order:
enum STDLIB_NDARRAY_ORDER order = STDLIB_NDARRAY_ROW_MAJOR;

// Specify the index mode:
enum STDLIB_NDARRAY_INDEX_MODE imode = STDLIB_NDARRAY_INDEX_ERROR;

// Specify the subscript index modes:
int8_t submodes[] = { imode };
int64_t nsubmodes = 1;

// Create an input ndarray:
struct ndarray *x = stdlib_ndarray_allocate( xdtype, xbuf, ndims, shape, sx, ox, order, imode, nsubmodes, submodes );
if ( x == NULL ) {
    fprintf( stderr, "Error allocating memory.\n" );
    exit( EXIT_FAILURE );
}

// Create an output ndarray:
struct ndarray *y = stdlib_ndarray_allocate( ydtype, ybuf, ndims, shape, sy, oy, order, imode, nsubmodes, submodes );
if ( y == NULL ) {
    fprintf( stderr, "Error allocating memory.\n" );
    exit( EXIT_FAILURE );
}

// Create an array containing the ndarrays:
struct ndarray *arrays[] = { x, y };

// Define a callback:
static int32_t fcn( const uint8_t x ) {
    // ...
}

// Apply the callback:
int8_t status = stdlib_ndarray_b_i_as_b_i( arrays, (void *)fcn );
if ( status != 0 ) {
    fprintf( stderr, "Error during computation.\n" );
    exit( EXIT_FAILURE );
}

// ...

// Free allocated memory:
stdlib_ndarray_free( x );
stdlib_ndarray_free( y );
```

The function accepts the following arguments:

-   **arrays**: `[inout] struct ndarray**` array whose first element is a pointer to an input ndarray and whose second element is a pointer to an output ndarray.
-   **fcn**: `[in] void*` a `int32_t (*f)(uint8_t)` function to apply provided as a `void` pointer.

```c
int8_t stdlib_ndarray_b_i_as_b_i( struct ndarray *arrays[], void *fcn );
```

#### stdlib_ndarray_b_i_as_i_i( \*arrays\[], \*fcn )

Applies a unary callback to an input ndarray and assigns results to elements in an output ndarray.

```c
#include "stdlib/ndarray/dtypes.h"
#include "stdlib/ndarray/index_modes.h"
#include "stdlib/ndarray/orders.h"
#include "stdlib/ndarray/ctor.h"
#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>

// Define the ndarray data types:
enum STDLIB_NDARRAY_DTYPE xdtype = STDLIB_NDARRAY_UINT8;
enum STDLIB_NDARRAY_DTYPE ydtype = STDLIB_NDARRAY_INT32;

// Create underlying byte arrays:
uint8_t xbuf[] = { 0, 0, 0, 0 };
uint8_t ybuf[] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };

// Define the number of dimensions:
int64_t ndims = 2;

// Define the array shapes:
int64_t shape[] = { 2, 2 };

// Define the strides:
int64_t sx[] = { 2, 1 };
int64_t sy[] = { 8, 4 };

// Define the offsets:
int64_t ox = 0;
int64_t oy = 0;

// Define the array order:
enum STDLIB_NDARRAY_ORDER order = STDLIB_NDARRAY_ROW_MAJOR;

// Specify the index mode:
enum STDLIB_NDARRAY_INDEX_MODE imode = STDLIB_NDARRAY_INDEX_ERROR;

// Specify the subscript index modes:
int8_t submodes[] = { imode };
int64_t nsubmodes = 1;

// Create an input ndarray:
struct ndarray *x = stdlib_ndarray_allocate( xdtype, xbuf, ndims, shape, sx, ox, order, imode, nsubmodes, submodes );
if ( x == NULL ) {
    fprintf( stderr, "Error allocating memory.\n" );
    exit( EXIT_FAILURE );
}

// Create an output ndarray:
struct ndarray *y = stdlib_ndarray_allocate( ydtype, ybuf, ndims, shape, sy, oy, order, imode, nsubmodes, submodes );
if ( y == NULL ) {
    fprintf( stderr, "Error allocating memory.\n" );
    exit( EXIT_FAILURE );
}

// Create an array containing the ndarrays:
struct ndarray *arrays[] = { x, y };

// Define a callback:
static int32_t fcn( const int32_t x ) {
    return x;
}

// Apply the callback:
int8_t status = stdlib_ndarray_b_i_as_i_i( arrays, (void *)fcn );
if ( status != 0 ) {
    fprintf( stderr, "Error during computation.\n" );
    exit( EXIT_FAILURE );
}

// ...

// Free allocated memory:
stdlib_ndarray_free( x );
stdlib_ndarray_free( y );
```

The function accepts the following arguments:

-   **arrays**: `[inout] struct ndarray**` array whose first element is a pointer to an input ndarray and whose second element is a pointer to an output ndarray.
-   **fcn**: `[in] void*` a `int32_t (*f)(int32_t)` function to apply provided as a `void` pointer.

```c
int8_t stdlib_ndarray_b_i_as_i_i( struct ndarray *arrays[], void *fcn );
```

#### stdlib_ndarray_b_k( \*arrays\[], \*fcn )

Applies a unary callback to an input ndarray and assigns results to elements in an output ndarray.

```c
#include "stdlib/ndarray/dtypes.h"
#include "stdlib/ndarray/index_modes.h"
#include "stdlib/ndarray/orders.h"
#include "stdlib/ndarray/ctor.h"
#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>

// Define the ndarray data types:
enum STDLIB_NDARRAY_DTYPE xdtype = STDLIB_NDARRAY_UINT8;
enum STDLIB_NDARRAY_DTYPE ydtype = STDLIB_NDARRAY_INT16;

// Create underlying byte arrays:
uint8_t xbuf[] = { 0, 0, 0, 0 };
uint8_t ybuf[] = { 0, 0, 0, 0, 0, 0, 0, 0 };

// Define the number of dimensions:
int64_t ndims = 2;

// Define the array shapes:
int64_t shape[] = { 2, 2 };

// Define the strides:
int64_t sx[] = { 2, 1 };
int64_t sy[] = { 4, 2 };

// Define the offsets:
int64_t ox = 0;
int64_t oy = 0;

// Define the array order:
enum STDLIB_NDARRAY_ORDER order = STDLIB_NDARRAY_ROW_MAJOR;

// Specify the index mode:
enum STDLIB_NDARRAY_INDEX_MODE imode = STDLIB_NDARRAY_INDEX_ERROR;

// Specify the subscript index modes:
int8_t submodes[] = { imode };
int64_t nsubmodes = 1;

// Create an input ndarray:
struct ndarray *x = stdlib_ndarray_allocate( xdtype, xbuf, ndims, shape, sx, ox, order, imode, nsubmodes, submodes );
if ( x == NULL ) {
    fprintf( stderr, "Error allocating memory.\n" );
    exit( EXIT_FAILURE );
}

// Create an output ndarray:
struct ndarray *y = stdlib_ndarray_allocate( ydtype, ybuf, ndims, shape, sy, oy, order, imode, nsubmodes, submodes );
if ( y == NULL ) {
    fprintf( stderr, "Error allocating memory.\n" );
    exit( EXIT_FAILURE );
}

// Create an array containing the ndarrays:
struct ndarray *arrays[] = { x, y };

// Define a callback:
static uint8_t fcn( const uint8_t x ) {
    return x;
}

// Apply the callback:
int8_t status = stdlib_ndarray_b_k( arrays, (void *)fcn );
if ( status != 0 ) {
    fprintf( stderr, "Error during computation.\n" );
    exit( EXIT_FAILURE );
}

// ...

// Free allocated memory:
stdlib_ndarray_free( x );
stdlib_ndarray_free( y );
```

The function accepts the following arguments:

-   **arrays**: `[inout] struct ndarray**` array whose first element is a pointer to an input ndarray and whose second element is a pointer to an output ndarray.
-   **fcn**: `[in] void*` a `uint8_t (*f)(uint8_t)` function to apply provided as a `void` pointer.

```c
int8_t stdlib_ndarray_b_k( struct ndarray *arrays[], void *fcn );
```

#### stdlib_ndarray_b_k_as_b_k( \*arrays\[], \*fcn )

Applies a unary callback to an input ndarray and assigns results to elements in an output ndarray.

```c
#include "stdlib/ndarray/dtypes.h"
#include "stdlib/ndarray/index_modes.h"
#include "stdlib/ndarray/orders.h"
#include "stdlib/ndarray/ctor.h"
#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>

// Define the ndarray data types:
enum STDLIB_NDARRAY_DTYPE xdtype = STDLIB_NDARRAY_UINT8;
enum STDLIB_NDARRAY_DTYPE ydtype = STDLIB_NDARRAY_INT16;

// Create underlying byte arrays:
uint8_t xbuf[] = { 0, 0, 0, 0 };
uint8_t ybuf[] = { 0, 0, 0, 0, 0, 0, 0, 0 };

// Define the number of dimensions:
int64_t ndims = 2;

// Define the array shapes:
int64_t shape[] = { 2, 2 };

// Define the strides:
int64_t sx[] = { 2, 1 };
int64_t sy[] = { 4, 2 };

// Define the offsets:
int64_t ox = 0;
int64_t oy = 0;

// Define the array order:
enum STDLIB_NDARRAY_ORDER order = STDLIB_NDARRAY_ROW_MAJOR;

// Specify the index mode:
enum STDLIB_NDARRAY_INDEX_MODE imode = STDLIB_NDARRAY_INDEX_ERROR;

// Specify the subscript index modes:
int8_t submodes[] = { imode };
int64_t nsubmodes = 1;

// Create an input ndarray:
struct ndarray *x = stdlib_ndarray_allocate( xdtype, xbuf, ndims, shape, sx, ox, order, imode, nsubmodes, submodes );
if ( x == NULL ) {
    fprintf( stderr, "Error allocating memory.\n" );
    exit( EXIT_FAILURE );
}

// Create an output ndarray:
struct ndarray *y = stdlib_ndarray_allocate( ydtype, ybuf, ndims, shape, sy, oy, order, imode, nsubmodes, submodes );
if ( y == NULL ) {
    fprintf( stderr, "Error allocating memory.\n" );
    exit( EXIT_FAILURE );
}

// Create an array containing the ndarrays:
struct ndarray *arrays[] = { x, y };

// Define a callback:
static int16_t fcn( const uint8_t x ) {
    // ...
}

// Apply the callback:
int8_t status = stdlib_ndarray_b_k_as_b_k( arrays, (void *)fcn );
if ( status != 0 ) {
    fprintf( stderr, "Error during computation.\n" );
    exit( EXIT_FAILURE );
}

// ...

// Free allocated memory:
stdlib_ndarray_free( x );
stdlib_ndarray_free( y );
```

The function accepts the following arguments:

-   **arrays**: `[inout] struct ndarray**` array whose first element is a pointer to an input ndarray and whose second element is a pointer to an output ndarray.
-   **fcn**: `[in] void*` a `int16_t (*f)(uint8_t)` function to apply provided as a `void` pointer.

```c
int8_t stdlib_ndarray_b_k_as_b_k( struct ndarray *arrays[], void *fcn );
```

#### stdlib_ndarray_b_k_as_i_i( \*arrays\[], \*fcn )

Applies a unary callback to an input ndarray and assigns results to elements in an output ndarray.

```c
#include "stdlib/ndarray/dtypes.h"
#include "stdlib/ndarray/index_modes.h"
#include "stdlib/ndarray/orders.h"
#include "stdlib/ndarray/ctor.h"
#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>

// Define the ndarray data types:
enum STDLIB_NDARRAY_DTYPE xdtype = STDLIB_NDARRAY_UINT8;
enum STDLIB_NDARRAY_DTYPE ydtype = STDLIB_NDARRAY_INT16;

// Create underlying byte arrays:
uint8_t xbuf[] = { 0, 0, 0, 0 };
uint8_t ybuf[] = { 0, 0, 0, 0, 0, 0, 0, 0 };

// Define the number of dimensions:
int64_t ndims = 2;

// Define the array shapes:
int64_t shape[] = { 2, 2 };

// Define the strides:
int64_t sx[] = { 2, 1 };
int64_t sy[] = { 4, 2 };

// Define the offsets:
int64_t ox = 0;
int64_t oy = 0;

// Define the array order:
enum STDLIB_NDARRAY_ORDER order = STDLIB_NDARRAY_ROW_MAJOR;

// Specify the index mode:
enum STDLIB_NDARRAY_INDEX_MODE imode = STDLIB_NDARRAY_INDEX_ERROR;

// Specify the subscript index modes:
int8_t submodes[] = { imode };
int64_t nsubmodes = 1;

// Create an input ndarray:
struct ndarray *x = stdlib_ndarray_allocate( xdtype, xbuf, ndims, shape, sx, ox, order, imode, nsubmodes, submodes );
if ( x == NULL ) {
    fprintf( stderr, "Error allocating memory.\n" );
    exit( EXIT_FAILURE );
}

// Create an output ndarray:
struct ndarray *y = stdlib_ndarray_allocate( ydtype, ybuf, ndims, shape, sy, oy, order, imode, nsubmodes, submodes );
if ( y == NULL ) {
    fprintf( stderr, "Error allocating memory.\n" );
    exit( EXIT_FAILURE );
}

// Create an array containing the ndarrays:
struct ndarray *arrays[] = { x, y };

// Define a callback:
static int32_t fcn( const int32_t x ) {
    return x;
}

// Apply the callback:
int8_t status = stdlib_ndarray_b_k_as_i_i( arrays, (void *)fcn );
if ( status != 0 ) {
    fprintf( stderr, "Error during computation.\n" );
    exit( EXIT_FAILURE );
}

// ...

// Free allocated memory:
stdlib_ndarray_free( x );
stdlib_ndarray_free( y );
```

The function accepts the following arguments:

-   **arrays**: `[inout] struct ndarray**` array whose first element is a pointer to an input ndarray and whose second element is a pointer to an output ndarray.
-   **fcn**: `[in] void*` a `int32_t (*f)(int32_t)` function to apply provided as a `void` pointer.

```c
int8_t stdlib_ndarray_b_k_as_i_i( struct ndarray *arrays[], void *fcn );
```

#### stdlib_ndarray_b_k_as_k_k( \*arrays\[], \*fcn )

Applies a unary callback to an input ndarray and assigns results to elements in an output ndarray.

```c
#include "stdlib/ndarray/dtypes.h"
#include "stdlib/ndarray/index_modes.h"
#include "stdlib/ndarray/orders.h"
#include "stdlib/ndarray/ctor.h"
#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>

// Define the ndarray data types:
enum STDLIB_NDARRAY_DTYPE xdtype = STDLIB_NDARRAY_UINT8;
enum STDLIB_NDARRAY_DTYPE ydtype = STDLIB_NDARRAY_INT16;

// Create underlying byte arrays:
uint8_t xbuf[] = { 0, 0, 0, 0 };
uint8_t ybuf[] = { 0, 0, 0, 0, 0, 0, 0, 0 };

// Define the number of dimensions:
int64_t ndims = 2;

// Define the array shapes:
int64_t shape[] = { 2, 2 };

// Define the strides:
int64_t sx[] = { 2, 1 };
int64_t sy[] = { 4, 2 };

// Define the offsets:
int64_t ox = 0;
int64_t oy = 0;

// Define the array order:
enum STDLIB_NDARRAY_ORDER order = STDLIB_NDARRAY_ROW_MAJOR;

// Specify the index mode:
enum STDLIB_NDARRAY_INDEX_MODE imode = STDLIB_NDARRAY_INDEX_ERROR;

// Specify the subscript index modes:
int8_t submodes[] = { imode };
int64_t nsubmodes = 1;

// Create an input ndarray:
struct ndarray *x = stdlib_ndarray_allocate( xdtype, xbuf, ndims, shape, sx, ox, order, imode, nsubmodes, submodes );
if ( x == NULL ) {
    fprintf( stderr, "Error allocating memory.\n" );
    exit( EXIT_FAILURE );
}

// Create an output ndarray:
struct ndarray *y = stdlib_ndarray_allocate( ydtype, ybuf, ndims, shape, sy, oy, order, imode, nsubmodes, submodes );
if ( y == NULL ) {
    fprintf( stderr, "Error allocating memory.\n" );
    exit( EXIT_FAILURE );
}

// Create an array containing the ndarrays:
struct ndarray *arrays[] = { x, y };

// Define a callback:
static int16_t fcn( const int16_t x ) {
    return x;
}

// Apply the callback:
int8_t status = stdlib_ndarray_b_k_as_k_k( arrays, (void *)fcn );
if ( status != 0 ) {
    fprintf( stderr, "Error during computation.\n" );
    exit( EXIT_FAILURE );
}

// ...

// Free allocated memory:
stdlib_ndarray_free( x );
stdlib_ndarray_free( y );
```

The function accepts the following arguments:

-   **arrays**: `[inout] struct ndarray**` array whose first element is a pointer to an input ndarray and whose second element is a pointer to an output ndarray.
-   **fcn**: `[in] void*` a `int16_t (*f)(int16_t)` function to apply provided as a `void` pointer.

```c
int8_t stdlib_ndarray_b_k_as_k_k( struct ndarray *arrays[], void *fcn );
```

#### stdlib_ndarray_b_k_as_l_l( \*arrays\[], \*fcn )

Applies a unary callback to an input ndarray and assigns results to elements in an output ndarray.

```c
#include "stdlib/ndarray/dtypes.h"
#include "stdlib/ndarray/index_modes.h"
#include "stdlib/ndarray/orders.h"
#include "stdlib/ndarray/ctor.h"
#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>

// Define the ndarray data types:
enum STDLIB_NDARRAY_DTYPE xdtype = STDLIB_NDARRAY_UINT8;
enum STDLIB_NDARRAY_DTYPE ydtype = STDLIB_NDARRAY_INT16;

// Create underlying byte arrays:
uint8_t xbuf[] = { 0, 0, 0, 0 };
uint8_t ybuf[] = { 0, 0, 0, 0, 0, 0, 0, 0 };

// Define the number of dimensions:
int64_t ndims = 2;

// Define the array shapes:
int64_t shape[] = { 2, 2 };

// Define the strides:
int64_t sx[] = { 2, 1 };
int64_t sy[] = { 4, 2 };

// Define the offsets:
int64_t ox = 0;
int64_t oy = 0;

// Define the array order:
enum STDLIB_NDARRAY_ORDER order = STDLIB_NDARRAY_ROW_MAJOR;

// Specify the index mode:
enum STDLIB_NDARRAY_INDEX_MODE imode = STDLIB_NDARRAY_INDEX_ERROR;

// Specify the subscript index modes:
int8_t submodes[] = { imode };
int64_t nsubmodes = 1;

// Create an input ndarray:
struct ndarray *x = stdlib_ndarray_allocate( xdtype, xbuf, ndims, shape, sx, ox, order, imode, nsubmodes, submodes );
if ( x == NULL ) {
    fprintf( stderr, "Error allocating memory.\n" );
    exit( EXIT_FAILURE );
}

// Create an output ndarray:
struct ndarray *y = stdlib_ndarray_allocate( ydtype, ybuf, ndims, shape, sy, oy, order, imode, nsubmodes, submodes );
if ( y == NULL ) {
    fprintf( stderr, "Error allocating memory.\n" );
    exit( EXIT_FAILURE );
}

// Create an array containing the ndarrays:
struct ndarray *arrays[] = { x, y };

// Define a callback:
static int64_t fcn( const int64_t x ) {
    return x;
}

// Apply the callback:
int8_t status = stdlib_ndarray_b_k_as_l_l( arrays, (void *)fcn );
if ( status != 0 ) {
    fprintf( stderr, "Error during computation.\n" );
    exit( EXIT_FAILURE );
}

// ...

// Free allocated memory:
stdlib_ndarray_free( x );
stdlib_ndarray_free( y );
```

The function accepts the following arguments:

-   **arrays**: `[inout] struct ndarray**` array whose first element is a pointer to an input ndarray and whose second element is a pointer to an output ndarray.
-   **fcn**: `[in] void*` a `int64_t (*f)(int64_t)` function to apply provided as a `void` pointer.

```c
int8_t stdlib_ndarray_b_k_as_l_l( struct ndarray *arrays[], void *fcn );
```

#### stdlib_ndarray_b_l( \*arrays\[], \*fcn )

Applies a unary callback to an input ndarray and assigns results to elements in an output ndarray.

```c
#include "stdlib/ndarray/dtypes.h"
#include "stdlib/ndarray/index_modes.h"
#include "stdlib/ndarray/orders.h"
#include "stdlib/ndarray/ctor.h"
#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>

// Define the ndarray data types:
enum STDLIB_NDARRAY_DTYPE xdtype = STDLIB_NDARRAY_UINT8;
enum STDLIB_NDARRAY_DTYPE ydtype = STDLIB_NDARRAY_INT64;

// Create underlying byte arrays:
uint8_t xbuf[] = { 0, 0, 0, 0 };
uint8_t ybuf[] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };

// Define the number of dimensions:
int64_t ndims = 2;

// Define the array shapes:
int64_t shape[] = { 2, 2 };

// Define the strides:
int64_t sx[] = { 2, 1 };
int64_t sy[] = { 16, 8 };

// Define the offsets:
int64_t ox = 0;
int64_t oy = 0;

// Define the array order:
enum STDLIB_NDARRAY_ORDER order = STDLIB_NDARRAY_ROW_MAJOR;

// Specify the index mode:
enum STDLIB_NDARRAY_INDEX_MODE imode = STDLIB_NDARRAY_INDEX_ERROR;

// Specify the subscript index modes:
int8_t submodes[] = { imode };
int64_t nsubmodes = 1;

// Create an input ndarray:
struct ndarray *x = stdlib_ndarray_allocate( xdtype, xbuf, ndims, shape, sx, ox, order, imode, nsubmodes, submodes );
if ( x == NULL ) {
    fprintf( stderr, "Error allocating memory.\n" );
    exit( EXIT_FAILURE );
}

// Create an output ndarray:
struct ndarray *y = stdlib_ndarray_allocate( ydtype, ybuf, ndims, shape, sy, oy, order, imode, nsubmodes, submodes );
if ( y == NULL ) {
    fprintf( stderr, "Error allocating memory.\n" );