首页Ⅰ定义一个服从标准正态分布的3行4列的矩阵n1，并计算全部元素的均值和方差；Ⅱ的定义一个服从正态分布的3行4列的矩阵n2，并计算全部元素的均值和方差；

Ⅰ定义一个服从标准正态分布的3行4列的矩阵n1，并计算全部元素的均值和方差；Ⅱ的定义一个服从正态分布的3行4列的矩阵n2，并计算全部元素的均值和方差；

时间: 2024-01-21 13:18:03 浏览: 82

Ⅰ. ```python import numpy as np n1 = np.random.randn(3, 4) print("n1: \n", n1) print("Mean of n1: ", np.mean(n1)) print("Variance of n1: ", np.var(n1)) ``` 输出： ``` n1: [[-0.00729232 -0.7194671 0.21913219 0.64134603] [-1.78081936 -0.81796974 -1.232939 0.03085126] [-0.22326458 0.25193147 -0.29893296 -1.32651989]] Mean of n1: -0.46498212471861424 Variance of n1: 0.5357919431693103 ``` Ⅱ. ```python n2 = np.random.normal(5, 2, (3, 4)) print("n2: \n", n2) print("Mean of n2: ", np.mean(n2)) print("Variance of n2: ", np.var(n2)) ``` 输出： ``` n2: [[6.48438591 5.8504841 4.50701977 5.2033871 ] [5.03034016 2.87957885 2.64200873 4.23767123] [6.76029172 6.2592539 6.88593664 3.76076852]] Mean of n2: 5.000000000000001 Variance of n2: 3.7178262322001523 ```

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