例2.25 数组生成示例1

import numpy as np
a1 = np.array([1,2,3,4])
a2 = a1.astype(float)
a3 = np.array([1,2,3],dtype = float)
print(a1.dtype);print(a2.dtype);print(a3.dtype)
b = np.array([[1,2,3],[4,5,6]])
c = np.arange(1,5)
d = np.linspace(1,4,4)
e = np.logspace(1,3,3,base = 2)

print('学号：3008')

结果如下图所示