Discrepancy measure for GOF using the Freeman-Tukey statistic

def expected_values(early_mean=early_mean,
                    late_mean=late_mean,
                    switchpoint=switchpoint):
    """Discrepancy measure for GOF using the Freeman-Tukey statistic"""

    # Sample size
    n = len(disasters_array)
    # Expected values
    return concatenate(
        (ones(switchpoint) * early_mean, ones(n - switchpoint) * late_mean))