Python中生成ndarray实例讲解

import numpy as np
data1 = [1, 2, 3, 4]
data2 = [[1, 2, 3, 4], [5, 6, 7, 8]]
arr1 = np.array(data1)
arr2 = np.array(data2)
arr1 = arr1 * 10
arr2 = arr2 + arr1
print(arr1)
print(arr2)

> a = np.array([[1,2,3], [2,3,4]])
> b = np.array([[1,2], [3,4], [5,6]])
> a
array([[1, 2, 3],
  [2, 3, 4]])
> b
array([[1, 2],
  [3, 4],
  [5, 6]])
> np.dot(a, b)  #方法一
array([[22, 28],
  [31, 40]])
> np.matmul(a,b) #方法二
array([[22, 28],

> a = np.array([[1,2],[3,4]])
> b = np.array([[1,1],[2,2]])
> a
array([[1, 2],
  [3, 4]])
> b
array([[1, 1],
  [2, 2]])
> a * b     #方法一
array([[1, 2],
  [6, 8]])
> np.multiply(a, b) #方法二
array([[1, 2],
  [6, 8]])