2019-01-15 创建二维数组

1. 二维数组

1创建二维数组M*N维

myList = [([0] * N) for i in range(M)]

2. 取值

import numpy as np

Ni = np.array([([0] * 50) for i in range(80)])
print(Ni[0,1])

3. 每一个元素求平方

import numpy as np
from numpy.matlib import repmat
zhen1=np.array([[1,2,3,4],[5,6,7,8]])
#zhen=np.array([[1,1,1,1]])
 
zhen2= [[zhen1[i][j]**2 for j in range(len(zhen1[i]))] for i in range(len(zhen1))]
print(zhen2,np.shape(zhen2),type(zhen2),type(zhen2[0]),type(zhen2[0][0]))