[SciPy-dev] Difference between A = sparse.lil_matrix((3, 3), dtype=complex) and A = sparse.lil_matrix((3, 3), complex)

[Nils Wagner]

Hi all,

Can someone explain the difference between

A = sparse.lil_matrix((3, 3),dtype=complex) and

A = sparse.lil_matrix((3, 3),complex)

The first definition produces a complex matrix while
the second one results in a  r e a l  matrix.

This is counterintuitive.


In [1]: from scipy import sparse

In [2]: A = sparse.lil_matrix((3, 3),complex)

In [3]: A
Out[3]:
<3x3 sparse matrix of type '<type 'numpy.float64'>'
         with 0 stored elements in LInked List format>

In [4]: A = sparse.lil_matrix((3, 3),dtype=complex)

In [5]: A
Out[5]:
<3x3 sparse matrix of type '<type 'numpy.complex128'>'
         with 0 stored elements in LInked List format>


Cheers,
            Nils