Goodman and Kruskal's gamma correlation coefficient wrapper
    :param values_list1: a list of values
    :param values_list2: a second list of values of equal length with corresponding entries
    :return: Gamma correlation coefficient (rank correlation ignoring ties)

def gamma_CC(values_list1, values_list2):
    '''
    Goodman and Kruskal's gamma correlation coefficient wrapper
    :param values_list1: a list of values
    :param values_list2: a second list of values of equal length with corresponding entries
    :return: Gamma correlation coefficient (rank correlation ignoring ties)
    '''
    ranks1 = get_ranks(values_list1)
    ranks_list1 = []
    for value in values_list1:
        rank = ranks1[value]
        ranks_list1.append(rank)
    ranks2 = get_ranks(values_list2)
    ranks_list2 = []
    for value in values_list2:
        rank = ranks2[value]
        ranks_list2.append(rank)
    return gamma(ranks_list1, ranks_list2)[3]