def get_D(uv_hat, n_channels):
    """Compute the rank 1 dictionary associated with the given uv

    Parameter
    ---------
    uv: array (n_atoms, n_channels + n_times_atom)
    n_channels: int
        number of channels in the original multivariate series

    Return
    ------
    D: array (n_atoms, n_channels, n_times_atom)
    """

    return uv_hat[:, :n_channels, None] * uv_hat[:, None, n_channels:]