https://github.com/stdlib-js/ndarray-empty
Create an uninitialized ndarray having a specified shape and data type.
https://github.com/stdlib-js/ndarray-empty
data empty javascript matrix ndarray node node-js nodejs stdlib structure types vector
Last synced: 8 months ago
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Create an uninitialized ndarray having a specified shape and data type.
- Host: GitHub
- URL: https://github.com/stdlib-js/ndarray-empty
- Owner: stdlib-js
- License: apache-2.0
- Created: 2023-03-25T23:02:48.000Z (almost 3 years ago)
- Default Branch: main
- Last Pushed: 2025-03-10T02:16:36.000Z (10 months ago)
- Last Synced: 2025-04-12T06:58:13.265Z (9 months ago)
- Topics: data, empty, javascript, matrix, ndarray, node, node-js, nodejs, stdlib, structure, types, vector
- Language: JavaScript
- Homepage: https://github.com/stdlib-js/stdlib
- Size: 2.14 MB
- Stars: 1
- Watchers: 3
- 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
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README
About stdlib...
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# empty
[![NPM version][npm-image]][npm-url] [![Build Status][test-image]][test-url] [![Coverage Status][coverage-image]][coverage-url]
> Create an uninitialized [ndarray][@stdlib/ndarray/ctor] having a specified shape and [data type][@stdlib/ndarray/dtypes].
## Installation
```bash
npm install @stdlib/ndarray-empty
```
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 empty = require( '@stdlib/ndarray-empty' );
```
#### empty( shape\[, options] )
Creates an uninitialized [ndarray][@stdlib/ndarray/ctor] having a specified shape and [data type][@stdlib/ndarray/dtypes].
```javascript
var arr = empty( [ 2, 2 ] );
// returns
var sh = arr.shape;
// returns [ 2, 2 ]
var dt = arr.dtype;
// returns 'float64'
```
The specified output [ndarray][@stdlib/ndarray/ctor] `shape` may be either an array-like object or an integer value.
```javascript
var arr = empty( 2 );
// returns
var sh = arr.shape;
// returns [ 2 ]
var dt = arr.dtype;
// returns 'float64'
```
The function accepts the following `options`:
- **dtype**: underlying [data type][@stdlib/ndarray/dtypes]. Default: `'float64'`.
- **order**: specifies whether an [ndarray][@stdlib/ndarray/ctor] is `'row-major'` (C-style) or `'column-major'` (Fortran-style). Default: `'row-major'`.
- **mode**: specifies how to handle indices which exceed array dimensions (see [`ndarray`][@stdlib/ndarray/ctor]). Default: `'throw'`.
- **submode**: a mode array which specifies for each dimension how to handle subscripts which exceed array dimensions (see [`ndarray`][@stdlib/ndarray/ctor]). If provided fewer modes than dimensions, the constructor recycles modes using modulo arithmetic. Default: `[ options.mode ]`.
By default, the function returns an [ndarray][@stdlib/ndarray/ctor] having a [`float64`][@stdlib/ndarray/dtypes] data type. To specify an alternative [data type][@stdlib/ndarray/dtypes], provide a `dtype` option.
```javascript
var arr = empty( [ 2, 2 ], {
'dtype': 'float32'
});
// returns
var sh = arr.shape;
// returns [ 2, 2 ]
var dt = arr.dtype;
// returns 'float32'
```
## Notes
- If the `dtype` option is `'generic'`, the function always returns a zero-filled ndarray.
- For returned [ndarrays][@stdlib/ndarray/ctor] whose underlying memory is **not** initialized, memory contents are unknown and may contain **sensitive** data.
## Examples
```javascript
var dtypes = require( '@stdlib/ndarray-dtypes' );
var empty = require( '@stdlib/ndarray-empty' );
// Get a list of data types:
var dt = dtypes();
// Generate uninitialized arrays...
var arr;
var i;
for ( i = 0; i < dt.length; i++ ) {
arr = empty( [ 2, 2 ], {
'dtype': dt[ i ]
});
console.log( arr.data );
}
```
* * *
## See Also
- [`@stdlib/ndarray-empty-like`][@stdlib/ndarray/empty-like]: create an uninitialized ndarray having the same shape and data type as a provided ndarray.
- [`@stdlib/ndarray-zeros`][@stdlib/ndarray/zeros]: create a zero-filled ndarray having a specified shape and data type.
* * *
## 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 © 2016-2025. The Stdlib [Authors][stdlib-authors].
[npm-image]: http://img.shields.io/npm/v/@stdlib/ndarray-empty.svg
[npm-url]: https://npmjs.org/package/@stdlib/ndarray-empty
[test-image]: https://github.com/stdlib-js/ndarray-empty/actions/workflows/test.yml/badge.svg?branch=main
[test-url]: https://github.com/stdlib-js/ndarray-empty/actions/workflows/test.yml?query=branch:main
[coverage-image]: https://img.shields.io/codecov/c/github/stdlib-js/ndarray-empty/main.svg
[coverage-url]: https://codecov.io/github/stdlib-js/ndarray-empty?branch=main
[chat-image]: https://img.shields.io/gitter/room/stdlib-js/stdlib.svg
[chat-url]: https://app.gitter.im/#/room/#stdlib-js_stdlib:gitter.im
[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-empty/tree/deno
[deno-readme]: https://github.com/stdlib-js/ndarray-empty/blob/deno/README.md
[umd-url]: https://github.com/stdlib-js/ndarray-empty/tree/umd
[umd-readme]: https://github.com/stdlib-js/ndarray-empty/blob/umd/README.md
[esm-url]: https://github.com/stdlib-js/ndarray-empty/tree/esm
[esm-readme]: https://github.com/stdlib-js/ndarray-empty/blob/esm/README.md
[branches-url]: https://github.com/stdlib-js/ndarray-empty/blob/main/branches.md
[stdlib-license]: https://raw.githubusercontent.com/stdlib-js/ndarray-empty/main/LICENSE
[@stdlib/ndarray/ctor]: https://github.com/stdlib-js/ndarray-ctor
[@stdlib/ndarray/dtypes]: https://github.com/stdlib-js/ndarray-dtypes
[@stdlib/ndarray/empty-like]: https://github.com/stdlib-js/ndarray-empty-like
[@stdlib/ndarray/zeros]: https://github.com/stdlib-js/ndarray-zeros