# unflattenShape
> Expand a dimension over multiple dimensions.
## Usage
```javascript
var unflattenShape = require( '@stdlib/ndarray/base/unflatten-shape' );
```
#### unflattenShape( shape, dim, sizes )
Expands a dimension over multiple dimensions.
```javascript
var sh = unflattenShape( [ 6, 2, 1 ], 0, [ 3, 2 ] );
// returns [ 3, 2, 2, 1 ]
```
The function accepts the following parameters:
- **shape**: array shape.
- **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.
#### unflattenShape.assign( shape, dim, sizes, out )
Expands a dimension over multiple dimensions and assigns results to a provided output array.
```javascript
var o = [ 0, 0, 0, 0 ];
var out = unflattenShape.assign( [ 6, 2, 1 ], 0, [ 3, 2 ], o );
// returns [ 3, 2, 2, 1 ]
var bool = ( out === o );
// returns true
```
The function accepts the following parameters:
- **shape**: array shape.
- **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.
- **out**: output array.
## Examples
```javascript
var unflattenShape = require( '@stdlib/ndarray/base/unflatten-shape' );
var out = unflattenShape( [ 2, 4, 1 ], 1, [ 2, 2 ] );
// returns [ 2, 2, 2, 1 ]
out = unflattenShape( [ 2, 4, 1 ], 1, [ 2, 1, 2 ] );
// returns [ 2, 2, 1, 2, 1 ]
out = unflattenShape( [ 2, 4, 1 ], 1, [ 2, 1, 1, 2 ] );
// returns [ 2, 2, 1, 1, 2, 1 ]
```