npm package: @stdlib/ndarray-spread-dimensions
Description: Return a read-only view of an input ndarray where the dimensions of the input ndarray are expanded to a specified dimensionality by spreading dimensions to specified dimension indices and inserting dimensions of size one for the remaining dimensions.
Author: The Stdlib Authors
Latest version: 0.1.1

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# spreadDimensions

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

> 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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<section class="intro">

</section>

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<section class="installation">

## Installation

```bash
npm install @stdlib/ndarray-spread-dimensions
```

</section>

<section class="usage">

## 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 ndarray2array = require( '@stdlib/ndarray-to-array' );
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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<section class="examples">

## Examples

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

```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 ) );
```

</section>

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* * *

## Notice

This package is part of [stdlib][stdlib], a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.

For more information on the project, filing bug reports and feature requests, and guidance on how to develop [stdlib][stdlib], see the main project [repository][stdlib].

#### Community

[![Chat][chat-image]][chat-url]

---

## License

See [LICENSE][stdlib-license].


## Copyright

Copyright &copy; 2016-2026. The Stdlib [Authors][stdlib-authors].

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[@stdlib/ndarray/ctor]: https://www.npmjs.com/package/@stdlib/ndarray-ctor

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