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# spreadDimensions

> Return a read-only view of an input [ndarray][@stdlib/ndarray/ctor] where the dimensions of the input [ndarray][@stdlib/ndarray/ctor] are expanded to a specified dimensionality by spreading dimensions to specified dimension indices and inserting dimensions of size one for the remaining dimensions.

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## Usage

```javascript
var spreadDimensions = require( '@stdlib/ndarray/spread-dimensions' );
```

#### spreadDimensions( ndims, x, dims )

Returns a read-only view of an input [ndarray][@stdlib/ndarray/ctor] where the dimensions of the input [ndarray][@stdlib/ndarray/ctor] are expanded to a specified dimensionality by spreading dimensions to specified dimension indices and inserting dimensions of size one for the remaining dimensions.

```javascript
var array = require( '@stdlib/ndarray/array' );

// Create a 2x2 ndarray:
var x = array( [ [ 1, 2 ], [ 3, 4 ] ] );
// returns <ndarray>[ [ 1, 2 ], [ 3, 4 ] ]

// Prepend a singleton dimension:
var y = spreadDimensions( 3, x, [ 1, 2 ] );
// returns <ndarray>[ [ [ 1, 2 ], [ 3, 4 ] ] ]

// Append a singleton dimension:
y = spreadDimensions( 3, x, [ 0, 1 ] );
// returns <ndarray>[ [ [ 1 ], [ 2 ] ], [ [ 3 ], [ 4 ] ] ]

// Insert a singleton dimension:
y = spreadDimensions( 3, x, [ 0, 2 ] );
// returns <ndarray>[ [ [ 1, 2 ] ], [ [ 3, 4 ] ] ]
```

The function accepts the following arguments:

-   **ndims**: number of dimensions in the output [ndarray][@stdlib/ndarray/ctor]. Must be greater than or equal to the number of dimensions in the input [ndarray][@stdlib/ndarray/ctor].
-   **x**: input [ndarray][@stdlib/ndarray/ctor].
-   **dims**: dimension indices specifying where to place the dimensions of the input [ndarray][@stdlib/ndarray/ctor]. Must resolve to normalized indices arranged in ascending order.

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## Examples

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```javascript
var uniform = require( '@stdlib/random/uniform' );
var ndarray2array = require( '@stdlib/ndarray/to-array' );
var spreadDimensions = require( '@stdlib/ndarray/spread-dimensions' );

var x = uniform( [ 3, 3, 3 ], -10.0, 10.0 );
console.log( ndarray2array( x ) );

var y = spreadDimensions( 5, x, [ 0, 1, 2 ] );
console.log( ndarray2array( y ) );
```

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[@stdlib/ndarray/ctor]: https://github.com/stdlib-js/ndarray/tree/main/ctor

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