import sys
from datetime import datetime
import numpy as np
import matplotlib.pyplot as plt
#使用NumPy计算
def numpysum(n) :
a = np.arange(n)**2
b = np.arange (n)** 3
c =a + b
return c
#使用Python计算
#并这里由于源码为Python 2的，python 3中range的用法有变,不再直接返回列表#所以强制转化列表
def pythonsum(n) :
a=list(range(n))
b =list(range(n))
c = []
for i in range(len(a)):
a[i]=i**2
b[i]=i**3
c.append(a[i] +b[i])
return c
# prt表示是否打印结果
def printest (func,size, prt=True):
start = datetime.now()
c=func(size)
delta = datetime.now() - start
if prt==True:
print ( "The last 2 elements of the sum ",c[-2: ])
print ( 'Elapsed time in microsecondas ' , delta.microseconds)
return delta.microseconds
#用于作n-time图
def timeplot () :
pts = [ ]
for i in range (100,10000,100):
t_numpy = printest (numpysum,i, prt=False)
t_python = printest (pythonsum,i,prt=False)
pts.append ([t_numpy,t_python])
plt.plot(pts)
plt.legend ( [ ' Numpy' , 'Python' ])
plt.show ( )
if __name__=='__main__':
size = int(sys.argv[1])
print(' Numpysum. . .')
printest(numpysum,size)
print ( 'Pythonsum. . . ')
printest(pythonsum,size)
timeplot()
