numpy.empty_like — NumPy v1.24 Manual (original) (raw)

numpy.empty_like(prototype, dtype=None, order='K', subok=True, shape=None)#

Return a new array with the same shape and type as a given array.

Parameters:

prototypearray_like

The shape and data-type of prototype define these same attributes of the returned array.

dtypedata-type, optional

Overrides the data type of the result.

New in version 1.6.0.

order{‘C’, ‘F’, ‘A’, or ‘K’}, optional

Overrides the memory layout of the result. ‘C’ means C-order, ‘F’ means F-order, ‘A’ means ‘F’ if prototype is Fortran contiguous, ‘C’ otherwise. ‘K’ means match the layout of _prototype_as closely as possible.

New in version 1.6.0.

subokbool, optional.

If True, then the newly created array will use the sub-class type of prototype, otherwise it will be a base-class array. Defaults to True.

shapeint or sequence of ints, optional.

Overrides the shape of the result. If order=’K’ and the number of dimensions is unchanged, will try to keep order, otherwise, order=’C’ is implied.

New in version 1.17.0.

Returns:

outndarray

Array of uninitialized (arbitrary) data with the same shape and type as prototype.

See also

ones_like

Return an array of ones with shape and type of input.

zeros_like

Return an array of zeros with shape and type of input.

full_like

Return a new array with shape of input filled with value.

empty

Return a new uninitialized array.

Notes

This function does not initialize the returned array; to do that usezeros_like or ones_like instead. It may be marginally faster than the functions that do set the array values.

Examples

a = ([1,2,3], [4,5,6]) # a is array-like np.empty_like(a) array([[-1073741821, -1073741821, 3], # uninitialized [ 0, 0, -1073741821]]) a = np.array([[1., 2., 3.],[4.,5.,6.]]) np.empty_like(a) array([[ -2.00000715e+000, 1.48219694e-323, -2.00000572e+000], # uninitialized [ 4.38791518e-305, -2.00000715e+000, 4.17269252e-309]])