'Initialize this LinearOperator.
To be called by subclasses. ``dtype`` may be None; ``shape`` should
be convertible to a length-2 tuple.'

def __init__(self, dtype, shape):

    if (dtype is not None):
        dtype = np.dtype(dtype)
    shape = tuple(shape)
    if (not isshape(shape)):
        raise ValueError(('invalid    shape    %r    (must    be    2-d)' % (shape,)))
    self.dtype = dtype
    self.shape = shape
