python向量化与for循环耗时对比分析_python_

import time import numpy as np a = np.random.rand(1000000) b = np.random.rand(1000000) tic = time.time() c = np.dot(a,b) toc = time.time() print(c) print("Vectorized version: " , str(1000*(toc-tic)) + "ms") c = 0 tic1 = time.time() for i in range(1000000): c += a[i]*b[i] toc1 = time.time() print(c) print("For loop version: " , str(1000*(toc1-tic1)) + "ms")

import numpy as np import time a = np.random.rand(1000000) b = np.random.rand(1000000) tic = time.time() c = np.dot(a,b) toc = time.time() print© print(“vectorized version:” + str((toc-tic))+“s”) c1 = 0 tic = time.time() for i in range(1000000): c1 += a[i]*b[i] toc = time.time() print(c1) print(“Nonvectorized version:” + str(toc-tic)+“s”)