# broadcastArray
> Broadcast an [ndarray][@stdlib/ndarray/ctor] to a specified shape.
## Usage
```javascript
var broadcastArray = require( '@stdlib/ndarray/broadcast-array' );
```
#### broadcastArray( x, shape )
Broadcasts an [ndarray][@stdlib/ndarray/ctor] to a specified `shape`.
```javascript
var array = require( '@stdlib/ndarray/array' );
// Create a 2x2 ndarray:
var x = array( [ [ 1, 2 ], [ 3, 4 ] ] );
// returns
// Broadcast to a 2x2x2 ndarray:
var y = broadcastArray( x, [ 2, 2, 2 ] );
// returns
```
## Notes
- The function throws an error if a provided [ndarray][@stdlib/ndarray/ctor] is [incompatible][@stdlib/ndarray/base/broadcast-shapes] with a provided shape.
- The returned [ndarray][@stdlib/ndarray/ctor] is a **read-only** view on the input [ndarray][@stdlib/ndarray/ctor] data buffer. The view is typically **not** contiguous. As more than one element of a returned view may refer to the same memory location, writing to the input [ndarray][@stdlib/ndarray/ctor] may affect multiple elements. If you need to write to the input [ndarray][@stdlib/ndarray/ctor], copy the input [ndarray][@stdlib/ndarray/ctor] **before** broadcasting.
- The function always returns a new [ndarray][@stdlib/ndarray/ctor] instance even if the input [ndarray][@stdlib/ndarray/ctor] shape and the desired shape are the same.
## Examples
```javascript
var array = require( '@stdlib/ndarray/array' );
var numel = require( '@stdlib/ndarray/base/numel' );
var ind2sub = require( '@stdlib/ndarray/ind2sub' );
var broadcastArray = require( '@stdlib/ndarray/broadcast-array' );
// Create a 2x2 array:
var x = array( [ [ 1, 2 ], [ 3, 4 ] ] );
// returns
// Broadcast the array to 3x2x2:
var y = broadcastArray( x, [ 3, 2, 2 ] );
// returns
// Retrieve the shape:
var sh = y.shape;
// returns [ 3, 2, 2 ]
// Retrieve the number of elements:
var N = numel( sh );
// Loop through the array elements...
var i;
for ( i = 0; i < N; i++ ) {
console.log( 'Y[%s] = %d', ind2sub( sh, i ).join( ', ' ), y.iget( i ) );
}
```
[@stdlib/ndarray/ctor]: https://github.com/stdlib-js/ndarray/tree/main/ctor
[@stdlib/ndarray/base/broadcast-shapes]: https://github.com/stdlib-js/ndarray/tree/main/base/broadcast-shapes
[@stdlib/ndarray/array]: https://github.com/stdlib-js/ndarray/tree/main/array
[@stdlib/ndarray/broadcast-arrays]: https://github.com/stdlib-js/ndarray/tree/main/broadcast-arrays
[@stdlib/ndarray/maybe-broadcast-array]: https://github.com/stdlib-js/ndarray/tree/main/maybe-broadcast-array