python3.7安装numpy模块-Python3.7模块numpy

numpy官网

0.numpy的基本属性

import numpy as np

#0.numpy的属性:长宽，size，维度

array = np.array([[1, 3, 5],

[2, 4, 6]])

print(array)

print('number of dim:', array.ndim)

print('shape:', array.shape)

print('size:', array.size)

1.矩阵的创建

import numpy as np

a = np.array([2, 3, 4, 5], dtype=np.int)

b = np.array([2.1, 3.2, 4.3, 5.4], dtype=np.float)

print(a)

print(a.dtype)

print(b)

print(b.dtype)

print(b.ndim)

c = np.array([[1, 2, 3], [4, 5, 6]], dtype=np.int)

print(c)

print(c.ndim)

#1.1创建全0/1矩阵

d = np.zeros((3, 4))

print(d)

e = np.ones((4, 5), dtype=np.int)

print(e)

#1.2 arange创建矩阵,设置步长为1

f = np.arange(1, 21, 1).reshape(4, 5)

print(f)

g = np.arange(12).reshape(3, 4)

print(g)

#1.3 linspace创建矩阵,平均分段

h = np.linspace(10, 20, 6).reshape(2, 3)

print(h)

#1.4 random创建随机矩阵

i = np.random.random((2,4))

print(i)

2.numpy基础运算

#2.0矩阵四则运算

import numpy as np

a = np.arange(1, 12, 2).reshape(2, 3)

b = np.arange(1, 7, 1).reshape(2, 3)

c = a + b

d = b - a

e = a * b

f = a / b

g = a ** b

h = a % b

print(a)

print(b)

print(c)

print(d)

print(e)

print(f)

print(g)

print(h)

#2.1 三角函数计算：sin cos tan

i = 10*np.sin(a)

j = 10*np.cos(a)

k = 10*np.tan(a)

print(i)

print(j)

print(k)

#2.2 比较运算

print(a < 5)

print(a == 5)

#2.3 矩阵乘法

a = np.array([[1, 2],

[3, 4]])

b = np.arange(4).reshape(2,2)

print(a)

print(b)

e = a * b

e_dot = np.dot(a, b)

e_dot1 = a.dot(b)

print(e)

print(e_dot)

print(e_dot1)

矩阵相乘最重要的方法是一般矩阵乘积。它只有在第一个矩阵的列数（column）和第二个矩阵的行数（row）相同时才有意义

矩阵相乘

#2.4 矩阵运算

import numpy as np

f = np.random.random((3,4))

print(f)

#每一行中的最大/最小值

print(np.max(f, axis=1))

print(np.min(f, axis=1))

#每一列中的最大/最小值

print(np.max(f, axis=0))

print(np.min(f, axis=0))

#每一行的平均值

print(np.mean(f, axis=1))

print(np.average(f, axis=1))

#每一列的平均值

print(np.mean(f, axis=0))

print(np.average(f, axis=0))

#每一行的中值

print(np.median(f, axis=1))

#每一列的中值

print(np.median(f, axis=0))

#每一行的和

print(np.sum(f, axis=1))

#每一列的和

print(np.sum(f, axis=0))

#累加

print(np.cumsum(f))

#差值

print(np.diff(f))

#最大值的索引

print(np.argmax(f))

#最小值的索引

print(np.argmin(f))

#逐行进行排序

print(np.sort(f))

#矩阵转置

print(np.transpose(f))

#滤波

print(np.clip(f, 0.4, 0.6))

3.numpy索引

import numpy as np

A = np.arange(3, 15)

print(A)

print(A[3])

B = np.arange(3,15).reshape((3, 4))

print(B)

#第3行的所有值

print(B[2])

#第3行第2列的值

print(B[2][1])

#第3列的所有值

print(B[:, 2])

#迭代每一行

for row in B:

print(row)

#迭代每一列

for column in np.transpose(B):

print(column)

#迭代每一项

print(B.flatten())

for i in B.flat:

print(i)

4.矩阵合并

import numpy as np

A = np.array([1, 1, 1])

B = np.array([2, 2, 2])

C1 = np.vstack((A, B))

C2 = np.hstack((A, B))

print(C1)

print(C1.shape)

print(C2)

print(C2.shape)

5.矩阵分割

import numpy as np

A = np.arange(1, 13).reshape(3, 4)

print(A)

#两种方式纵向分割

print(np.hsplit(A, 2))

print(np.split(A, 2, axis=1))

#两种方式横向分割

print(np.vsplit(A, 3))

print(np.split(A, 3, axis=0))

#另一种分割方式

print(np.array_split(A, 4, axis=0))

6.numpy的copy和deep copy

import numpy as np

A = np.arange(12).reshape(3,4)

print(A)

B = A

C = A.copy() #deep copy

print(B is A)

print(C is A)

A[2] = 10

A[2, 2] = 20

print(B is A)

print(B)

print(C)

python3.7安装numpy模块-Python3.7模块numpy相关推荐

ModuleNotFoundError: No module named ‘pygame’——Python3.6安装pip并下载pygame模块
问题: 今天学习python的时候,运行时报错:ModuleNotFoundError: No module named 'pygame'.意思就是没有 pygame 这个模块解决办法: 下载一下这 ...
python3.5安装numpy_win7的python3.5安装numpy包
原博文 2017-05-27 17:37 − 1.你需要先确保已经安装了pip(因为我是我们需要用pip安装numpy包),我在cmd里面输入pip能显示pip的有关信息,所以我已经安装了pip了(其 ...
python3.6安装pandas_python3.6更新pandas和numpy包
python3.6更新包 python 3.6更新pandas1.0和numpy包更新pandas 更新numpy python 3.6更新pandas1.0和numpy包 pandas版本过低的话 ...
python3.5安装scrapy_在Python3.5下安装和测试Scrapy爬网站
###1. 引言 Scrapy框架结构清晰,基于twisted的异步架构可以充分利用计算机资源,是爬虫做大的必备基础.本文将讲解如何快速安装此框架并使用起来. ###2. 安装Twisted #### ...
python3.5安装-linux系统安装python3.5
1.python源代码安装步骤:先安装依赖包,便于解析安装包数据,否则会报错 [root@localhost ]# yum -y install gcc-c++ pcre pcre-devel zl ...
python3.7安装turtle步骤-Python3安装turtle问题
Python3.5安装turtle: pip3 install turtle 提示错误: Collecting turtle Using cached https://files.pythonhost ...
python2与python3同时安装_Win10下python3和python2同时安装并解决pip共存问题
转载自:https://www.cnblogs.com/hkgov/p/7504082.html 特别说明,本文是在Windows64位系统下进行的,32位系统请下载相应版本的安装包,安装方法类似. ...
python3.5安装tensorflow_win10下python3.5.2和tensorflow安装环境搭建教程
在win10环境下搭建python3.5.2和tensorflow平台,供大家参考,具体内容如下操作步骤如下: 1.官网(https://www.python.org/ )下载python3.5.2 ...
python3.7安装turtle步骤-Python3.6安装turtle模块
安装turtle提示错误:Command "python setup.py egg_info" failed with error code 1 仔细查看安装turtle出错的错误 ...
python3.8安装xlwings出错_Python xlwings模块简单使用
Python xlwings模块简单使用xlwings 安装 xlwings excel-book-打开-新建 xlwings sheet-api xlwings 操作数据 xlwings 读取数据 ...

python3.7安装numpy模块-Python3.7模块numpy

python3.7安装numpy模块-Python3.7模块numpy相关推荐

最新文章

热门文章