
Returns a tuple of arrays (row,col) containing the indices
of the non-zero elements of the array.

Examples
--------
>>> from scipy.sparse import csr_array
>>> A = csr_array([[1, 2, 0], [0, 0, 3], [4, 0, 5]])
>>> A.nonzero()
(array([0, 0, 1, 2, 2], dtype=int32), array([0, 1, 2, 0, 2], dtype=int32))

r