Question

How do I create a 0 x 0 (i.e. ndim= 2, shape= (0,0)) float numpy.ndarray?

Answer 1

>>> import numpy as np
>>> a = np.empty( shape=(0, 0) )
>>> a
    array([], shape=(0, 0), dtype=float64)

>>> a.shape
    (0, 0)
>>> a.size
    0

The array above is initialized as a 2D array–i.e., two size parameters passed for shape.

Second, the call to empty is not strictly necessary–i.e., an array having 0 size could (i believe) be initialized using other array-creation methods in NumPy, e.g., NP.zeros, Np.ones, etc.

I just chose empty because it gives the smallest array (memory-wise).