empty

Create an uninitialized ndarray having a specified shape and data type.

Installation

npm install @stdlib/ndarray-empty

Usage

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

empty( shape[, options] )

Creates an uninitialized ndarray having a specified shape and data type.

var arr = empty( [ 2, 2 ] );
// returns <ndarray>

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

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

The specified output ndarray shape may be either an array-like object or an integer value.

var arr = empty( 2 );
// returns <ndarray>

var sh = arr.shape;
// returns [ 2 ]

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

The function accepts the following options:

• dtype: underlying data type. Default: 'float64'.
• order: specifies whether an ndarray 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). 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 ].

By default, the function returns an ndarray having a float64 data type. To specify an alternative data type, provide a dtype option.

var arr = empty( [ 2, 2 ], {
    'dtype': 'float32'
});
// returns <ndarray>

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 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' );

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

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

License

See LICENSE.

Copyright

Copyright © 2016-2024. The Stdlib Authors.