def glover_hrf(tr, oversampling=50, time_length=32., onset=0.):
    """ Implementation of the Glover hrf model

    Parameters
    ----------
    tr : float
        scan repeat time, in seconds

    oversampling : int, optional
        temporal oversampling factor

    time_length : float, optional
        hrf kernel length, in seconds

    onset : float, optional
        onset of the response

    Returns
    -------
    hrf: array of shape(length / tr * oversampling, dtype=float)
         hrf sampling on the oversampled time grid
    """
    return _gamma_difference_hrf(tr, oversampling, time_length, onset,
                                delay=6, undershoot=12., dispersion=.9,
                                u_dispersion=.9, ratio=.35)