Calculate Overall_CEN (Overall confusion entropy).

    :param classes: classes
    :type classes : list
    :param TP: true positive dict for all classes
    :type TP : dict
    :param TOP: test outcome positive
    :type TOP : dict
    :param P: condition positive
    :type P : dict
    :param CEN_dict: CEN dictionary for each class
    :type CEN_dict : dict
    :param modified : modified mode flag
    :type modified : bool
    :return: Overall_CEN(MCEN) as float

def overall_CEN_calc(classes, TP, TOP, P, CEN_dict, modified=False):
    """
    Calculate Overall_CEN (Overall confusion entropy).

    :param classes: classes
    :type classes : list
    :param TP: true positive dict for all classes
    :type TP : dict
    :param TOP: test outcome positive
    :type TOP : dict
    :param P: condition positive
    :type P : dict
    :param CEN_dict: CEN dictionary for each class
    :type CEN_dict : dict
    :param modified : modified mode flag
    :type modified : bool
    :return: Overall_CEN(MCEN) as float
    """
    try:
        result = 0
        for i in classes:
            result += (convex_combination(classes, TP, TOP, P, i, modified) *
                       CEN_dict[i])
        return result
    except Exception:
        return "None"