数据分析&数据挖掘数组的广播机制

Posted 2020-11-26 tree0108

 1 import numpy as np
 2 
 3 arr1 = np.array([[0, 1], [1, 2]])  # shape(2, 2)
 4 arr2 = np.array([1, 1])  # shape(2, )——>(1, 2)——>[[1, 1]]
 5 print("arr1: 
", arr1)
 6 print("arr2: 
", arr2)
 7 print("arr1+arr2: 
", arr1+arr2)
 8 
 9 arr1 = np.array([[1, 2, 3], [4, 5, 6]])  # shape(2, 3)
10 arr2 = np.array([[1, 1], [1, 1], [1, 1]])  # shape(3, 2)
11 arr3 = np.array([[1], [1]])  # shape(2, 1)
12 
13 print("arr1: 
", arr1)
14 print("arr2: 
", arr2)
15 print("arr2: 
", arr3)
16 # print("arr1+arr2: 
", arr1+arr2)
17 print("arr1+arr3: 
", arr1+arr3)