def unpack_vis(vis_vec, shape):
    """Unpack visibility vector into order for unpolarised data.

    Parameters
    ----------
    vis_vec : np.ndarray[:]
        Packed visibility data.
    shape : tuple
        Shape of the data (baseline, time, freq).

    Returns
    -------
    vis_vec : np.ndarray[baseline, time, freq]
        Unpolarised visibility data
    """
    vecr = vis_vec.reshape((shape[-1], 2) + shape[:-1])
    return (vecr[:, 0] + 1.0J * vecr[:, 1]).transpose(1, 2, 0)