basis matrix type returned by different methods.

[ccshao]

I found methods return basis / coefficient matrix in different data type.

For example,
pmf and nsnmf (as far as I noticed) return basis matrix in _sparse matrix of type '<type 'numpy.float64'_;

bd, lfnmf and nmf return basis matrix in _matrix_ format.

Could you kindly make the return matrix in same data type?

Thanks,

[marinkaz]

Fixed in 4d6a695.