def get_delta_TR(tail_check_max, y_int):
    """
    input: tail_check_max, y_intercept
    output: delta_TR
    """
    if tail_check_max == 0 or numpy.isnan(tail_check_max):
        return float('nan')
    delta_TR = (old_div(tail_check_max, abs(y_int))) * 100.
    return delta_TR