0], [0, 0, 3]])
>>> A.toarray()
array([[1, 0, 0],
       [0, 2, 0],
       [0, 0, 3]], dtype=int64)
>>> Aexp = expm(A)
>>> Aexp
<Compressed Sparse Column sparse array of dtype 'float64'
    with 3 stored elements and shape (3, 3)>
>>> Aexp.toarray()
array([[  2.71828183,   0.        ,   0.        ],
       [  0.        ,   7.3890561 ,   0.        ],
       [  0.        ,   0.        ,  20.08553692]])
Ú