changePoint.py 文件源码

def S_diff(lst):
    '''Given a list of int or float, calculate S_diff and S_point'''

    S_avg = sum(lst) / len(lst)
    S_dist = [i-S_avg for i in lst] #distance to average
    S_cum=[]    #list of cumulative sum
    S_cum.append(0)
    for i in range(0,len(S_dist)):
        S_cum.append(S_cum[i] + S_dist[i])
    return [nlargest(1,range(0,len(S_cum)),key=lambda i: S_cum[i]),(max(S_cum) - min(S_cum))]
    #return the index of maximum_diff index, and maximum_diff