%matplotlib inline
import math
import time
import numpy as np
import torch
from d2l import torch as d2l

n=10000
a=torch.ones([n])
b=torch.ones([n])

#定义计时器
class Timer: #@save
    #记录多次运行时间
    def __init__(self):
        self.times=[]
        self.start()
        
    def start(self):
        #启动计时器
        self.tik=time.time()
    
    def stop(self):
        #停止计时器并将时间记录在列表中
        self.times.append(time.time()-self.tik)
        return self.times[-1]
    
    def avg(self):
        #返回平均时间
        return sum(self.times)/len(self.times)
    
    def sum(self):
        #返回时间总和
        return sum(self.times)
    
    def cumsum(self):
        #返回累计时间
        return np.array(self.times).cumsum().tolist()
    

import torch
x = torch.arange(12)
x