numpy简单例题

#1、创建一个长度为10的一维全为0的ndarray对象，然后让第5个元素等于1
import numpy as np
s1=np.zeros(shape=10)
s1[4]=1
s1

array([0., 0., 0., 0., 1., 0., 0., 0., 0., 0.])

#2、创建一个元素为从10到49的ndarray对象

np.random.randint(10,50,size=10)

array([10, 35, 33, 19, 34, 33, 29, 42, 19, 22])

np.linspace(10,49,10)  #10到49均分成10份

array([10. , 14.33333333, 18.66666667, 23. , 27.33333333,
31.66666667, 36. , 40.33333333, 44.66666667, 49. ])

a=np.arange(10,50)
a

array([10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26,
27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43,
44, 45, 46, 47, 48, 49])

#3、将第二题元素位置反转
a[::-1]

array([49, 48, 47, 46, 45, 44, 43, 42, 41, 40, 39, 38, 37, 36, 35, 34, 33,
32, 31, 30, 29, 28, 27, 26, 25, 24, 23, 22, 21, 20, 19, 18, 17, 16,
15, 14, 13, 12, 11, 10])

#4、使用np.random.random创建一个10*10的ndarray对象，并打印出最大最小元素
a4=np.random.random(size=(10,10))
a4

array([[0.5622766 , 0.11024025, 0.54759318, 0.0708