from pandas import Series,DataFrame

import pandas as pd

import matplotlib.pyplot as plt

import numpy as np

fig=plt.figure()

ax=fig.add_subplot(1,1,1)

data=np.random.randn(20)

data.sort()

data=abs(data)

data=sorted(data,reverse=True)

s=Series(data,index=np.arange(20))

s.plot(kind='bar',color='g',)

ax.set_xlabel('order')

ax.set_ylabel('time')

ax2=plt.twinx()#双坐标轴

ax2.set_ylabel('frequency')

data1=s.cumsum()

datamax=data1[19]

data1=data1/datamax

data1.plot(linestyle='--',color='k')