empty
Create an uninitialized ndarray having a specified shape and data type.
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 );
}