# unflatten
> Return a view of an input ndarray in which a specified dimension is expanded over multiple dimensions.
## Usage
```javascript
var unflatten = require( '@stdlib/ndarray/base/unflatten' );
```
#### unflatten( x, dim, sizes, writable )
Returns a view of an input ndarray in which a specified dimension is expanded over multiple dimensions.
```javascript
var array = require( '@stdlib/ndarray/array' );
var x = array( [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 ] );
// returns [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 ]
var out = unflatten( x, 0, [ 2, 3 ], false );
// returns [ [ 1.0, 2.0, 3.0 ], [ 4.0, 5.0, 6.0 ] ]
```
The function accepts the following arguments:
- **x**: input ndarray.
- **dim**: dimension to be unflattened. If provided an integer less than zero, the dimension index is resolved relative to the last dimension, with the last dimension corresponding to the value `-1`.
- **sizes**: new shape of the unflattened dimension.
- **writable**: boolean indicating whether a returned ndarray should be writable.
## Notes
- The `writable` parameter **only** applies to ndarray constructors supporting **read-only** instances.
## Examples
```javascript
var uniform = require( '@stdlib/random/discrete-uniform' );
var ndarray2array = require( '@stdlib/ndarray/to-array' );
var unflatten = require( '@stdlib/ndarray/base/unflatten' );
var x = uniform( [ 12 ], -100, 100 );
console.log( ndarray2array( x ) );
var out = unflatten( x, 0, [ 3, 4 ], false );
console.log( ndarray2array( out ) );
```