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emptyLike

Create an uninitialized ndarray having the same shape and data type as a provided ndarray.

Installation

npm install @stdlib/ndarray-empty-like

Alternatively,

• To load the package in a website via a script tag without installation and bundlers, use the ES Module available on the esm branch (see README).
• If you are using Deno, visit the deno branch (see README for usage intructions).
• For use in Observable, or in browser/node environments, use the Universal Module Definition (UMD) build available on the umd branch (see README).

The branches.md 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

var emptyLike = require( '@stdlib/ndarray-empty-like' );

emptyLike( x[, options] )

Creates an uninitialized ndarray having the same shape and data type as a provided ndarray.

var zeros = require( '@stdlib/ndarray-zeros' );

var x = zeros( [ 2, 2 ] );
// returns <ndarray>

var y = emptyLike( x );
// returns <ndarray>

var sh = y.shape;
// returns [ 2, 2 ]

var dt = y.dtype;
// returns 'float64'

The function supports the following options:

• dtype: output ndarray data type. Overrides the input ndarray's inferred data type.
• shape: output ndarray shape. Overrides the input ndarray's inferred shape.
• order: specifies whether the output ndarray should be 'row-major' (C-style) or 'column-major' (Fortran-style). Overrides the input ndarray's inferred order.
• mode: specifies how to handle indices which exceed array dimensions (see ndarray). Default: 'throw'.
• submode: a mode array which specifies for each dimension how to handle subscripts which exceed array dimensions (see ndarray). If provided fewer modes than dimensions, the constructor recycles modes using modulo arithmetic. Default: [ options.mode ].

To override either the dtype, shape, or order, specify the corresponding option. For example, to override the inferred data type,

var zeros = require( '@stdlib/ndarray-zeros' );

var x = zeros( [ 2, 2 ] );
// returns <ndarray>

var dt = x.dtype;
// returns 'float64'

var y = emptyLike( x, {
    'dtype': 'int32'
});
// returns <ndarray>

var sh = y.shape;
// returns [ 2, 2 ]

dt = y.dtype;
// returns 'int32'

Notes

• If the resolved output data type is 'generic', the function always returns a zero-filled array.
• For returned ndarrays whose underlying memory is not initialized, memory contents are unknown and may contain sensitive data.

Examples

var dtypes = require( '@stdlib/ndarray-dtypes' );
var empty = require( '@stdlib/ndarray-empty' );
var emptyLike = require( '@stdlib/ndarray-empty-like' );

// Get a list of data types:
var dt = dtypes();

// Generate uninitialized arrays...
var x;
var y;
var i;
for ( i = 0; i < dt.length; i++ ) {
    x = empty( [ 2, 2 ], {
        'dtype': dt[ i ]
    });
    y = emptyLike( x );
    console.log( y.data );
}

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See Also

• @stdlib/ndarray-empty: create an uninitialized ndarray having a specified shape and data type.
• @stdlib/ndarray-zeros-like: create a zero-filled ndarray having the same shape and data type as a provided ndarray.

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Notice

This package is part of 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, see the main project repository.

Community

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License

See LICENSE.

Copyright

Copyright © 2016-2024. The Stdlib Authors.