https://github.com/stdlib-js/ndarray-base-broadcast-arrays
Broadcast ndarrays to a common shape.
https://github.com/stdlib-js/ndarray-base-broadcast-arrays
array base broadcast broadcasting javascript multidimensional ndarray node node-js nodejs reshape stdlib types util utilities utility utils
Last synced: 4 months ago
JSON representation
Broadcast ndarrays to a common shape.
- Host: GitHub
- URL: https://github.com/stdlib-js/ndarray-base-broadcast-arrays
- Owner: stdlib-js
- License: apache-2.0
- Created: 2023-12-27T22:54:40.000Z (over 2 years ago)
- Default Branch: main
- Last Pushed: 2026-03-02T05:46:55.000Z (4 months ago)
- Last Synced: 2026-03-02T07:46:10.780Z (4 months ago)
- Topics: array, base, broadcast, broadcasting, javascript, multidimensional, ndarray, node, node-js, nodejs, reshape, stdlib, types, util, utilities, utility, utils
- Language: JavaScript
- Homepage: https://github.com/stdlib-js/stdlib
- Size: 869 KB
- Stars: 1
- Watchers: 2
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- Contributing: CONTRIBUTING.md
- License: LICENSE
- Code of conduct: CODE_OF_CONDUCT.md
- Citation: CITATION.cff
- Security: SECURITY.md
- Notice: NOTICE
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README
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# broadcastArrays
[![NPM version][npm-image]][npm-url] [![Build Status][test-image]][test-url] [![Coverage Status][coverage-image]][coverage-url]
> Broadcast [ndarrays][@stdlib/ndarray/base/ctor] to a common shape.
## Installation
```bash
npm install @stdlib/ndarray-base-broadcast-arrays
```
Alternatively,
- To load the package in a website via a `script` tag without installation and bundlers, use the [ES Module][es-module] available on the [`esm`][esm-url] branch (see [README][esm-readme]).
- If you are using Deno, visit the [`deno`][deno-url] branch (see [README][deno-readme] for usage intructions).
- For use in Observable, or in browser/node environments, use the [Universal Module Definition (UMD)][umd] build available on the [`umd`][umd-url] branch (see [README][umd-readme]).
The [branches.md][branches-url] file summarizes the available branches and displays a diagram illustrating their relationships.
To view installation and usage instructions specific to each branch build, be sure to explicitly navigate to the respective README files on each branch, as linked to above.
## Usage
```javascript
var broadcastArrays = require( '@stdlib/ndarray-base-broadcast-arrays' );
```
#### broadcastArrays( arrays )
Broadcasts a list of [ndarrays][@stdlib/ndarray/base/ctor] to a common shape.
```javascript
var array = require( '@stdlib/ndarray-array' );
var zeros = require( '@stdlib/ndarray-zeros' );
// Create a 2x2 ndarray:
var x = array( [ [ 1, 2 ], [ 3, 4 ] ] );
// returns
// Create a 2x2x2 ndarray:
var y = zeros( [ 2, 2, 2 ] );
// returns
// Broadcast to a common shape:
var out = broadcastArrays( [ x, y ] );
// returns [ , ]
```
## Notes
- The function throws an error if provided [broadcast-incompatible][@stdlib/ndarray/base/broadcast-shapes] ndarrays.
- Returned [ndarrays][@stdlib/ndarray/base/ctor] are views on their respective underlying data buffers. The views are typically **not** contiguous. As more than one element of a returned view may refer to the same memory location, writing to a view may affect multiple elements. If you need to write to a returned [ndarray][@stdlib/ndarray/base/ctor], copy the [ndarray][@stdlib/ndarray/base/ctor] **before** performing operations which may mutate elements.
- Returned [ndarrays][@stdlib/ndarray/base/ctor] are "base" [ndarrays][@stdlib/ndarray/base/ctor], and, thus, the returned [ndarrays][@stdlib/ndarray/base/ctor] do not perform bounds checking or afford any of the guarantees of the non-base [ndarray][@stdlib/ndarray/ctor] constructor. The primary intent of this function is to broadcast ndarray-like objects within internal implementations and to do so with minimal overhead.
- The function always returns new [ndarray][@stdlib/ndarray/base/ctor] instances even if an input [ndarray][@stdlib/ndarray/base/ctor] shape and the broadcasted shape are the same.
## Examples
```javascript
var array = require( '@stdlib/ndarray-array' );
var zeros = require( '@stdlib/ndarray-zeros' );
var numel = require( '@stdlib/ndarray-base-numel' );
var ind2sub = require( '@stdlib/ndarray-ind2sub' );
var broadcastArrays = require( '@stdlib/ndarray-base-broadcast-arrays' );
// Create a 2x2 array:
var x = array( [ [ 1, 2 ], [ 3, 4 ] ] );
// returns
// Create a 3x2x2 array:
var y = zeros( [ 3, 2, 2 ] );
// returns
// Broadcast the arrays to a common shape:
var out = broadcastArrays( [ x, y ] );
// returns [ , ]
// Retrieve the common shape:
var sh = out[ 0 ].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( 'X[%s] = %d', ind2sub( sh, i ).join( ', ' ), out[ 0 ].iget( i ) );
}
```
* * *
## 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 © 2016-2026. The Stdlib [Authors][stdlib-authors].
[npm-image]: http://img.shields.io/npm/v/@stdlib/ndarray-base-broadcast-arrays.svg
[npm-url]: https://npmjs.org/package/@stdlib/ndarray-base-broadcast-arrays
[test-image]: https://github.com/stdlib-js/ndarray-base-broadcast-arrays/actions/workflows/test.yml/badge.svg?branch=main
[test-url]: https://github.com/stdlib-js/ndarray-base-broadcast-arrays/actions/workflows/test.yml?query=branch:main
[coverage-image]: https://img.shields.io/codecov/c/github/stdlib-js/ndarray-base-broadcast-arrays/main.svg
[coverage-url]: https://codecov.io/github/stdlib-js/ndarray-base-broadcast-arrays?branch=main
[chat-image]: https://img.shields.io/badge/zulip-join_chat-brightgreen.svg
[chat-url]: https://stdlib.zulipchat.com
[stdlib]: https://github.com/stdlib-js/stdlib
[stdlib-authors]: https://github.com/stdlib-js/stdlib/graphs/contributors
[umd]: https://github.com/umdjs/umd
[es-module]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Modules
[deno-url]: https://github.com/stdlib-js/ndarray-base-broadcast-arrays/tree/deno
[deno-readme]: https://github.com/stdlib-js/ndarray-base-broadcast-arrays/blob/deno/README.md
[umd-url]: https://github.com/stdlib-js/ndarray-base-broadcast-arrays/tree/umd
[umd-readme]: https://github.com/stdlib-js/ndarray-base-broadcast-arrays/blob/umd/README.md
[esm-url]: https://github.com/stdlib-js/ndarray-base-broadcast-arrays/tree/esm
[esm-readme]: https://github.com/stdlib-js/ndarray-base-broadcast-arrays/blob/esm/README.md
[branches-url]: https://github.com/stdlib-js/ndarray-base-broadcast-arrays/blob/main/branches.md
[stdlib-license]: https://raw.githubusercontent.com/stdlib-js/ndarray-base-broadcast-arrays/main/LICENSE
[@stdlib/ndarray/ctor]: https://github.com/stdlib-js/ndarray-ctor
[@stdlib/ndarray/base/ctor]: https://github.com/stdlib-js/ndarray-base-ctor
[@stdlib/ndarray/base/broadcast-shapes]: https://github.com/stdlib-js/ndarray-base-broadcast-shapes