numpy pandas matplotlib 学习资源

在线学习环境 百度aistudio notebook在线开发

(内置paddlepaddle  numpy pandas matplotlib)

https://aistudio.baidu.com

 

 

numpy博文：

https://docs.scipy.org/doc/numpy/reference/

https://numpy.org/devdocs/user/quickstart.html

快速入门教程

https://www.numpy.org.cn/user/quickstart.html

NumPy 教程

https://www.runoob.com/numpy/numpy-tutorial.html

00Numpy - 知识点总结（五）

https://blog.csdn.net/u011587322/article/details/80816121

00这是我见过最好的NumPy图解教程 

http://www.sohu.com/a/325758681_505915

00代码详解：Numpy

https://baijiahao.baidu.com/s?id=1628604854481957865&wfr=spider&for=pc

numpy与图像

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
import cv2 as cv
import numpy as np
import os ,os.path

def access_pixels(image):  # 获取图片高宽通道
    print(image.shape)
    height = image.shape[0]
    width = image.shape[1]
    channels = image.shape[2]
    # 也可以直接写成：
    # height, width, channels = image.shape[:]
    print("width: %s, height: %s, channels: %s"%(width, height, channels))

    new_image = image.copy()  # 复制image图片
    for row in range(height):
        for col in range(width):
            for c in range(channels):
                pv = image[row, col, c]
                new_image[row, col, c] = 256 - pv  # 图像反转

    cv.imshow('pixels_demo', new_image)


def create_image():
    """创建三维数组，0维为B，1维为G，2维为R"""
    img = np.zeros([400, 400, 3], np.uint8)
    img[:, :, 0] = np.ones([400, 400]) * 255
    cv.imshow("new_image", img)


def inverse(image):
    dst = cv.bitwise_not(image)  # 按位取反，白变黑，黑变白，效果和new_image一样
    cv.imshow("inverse_demo",dst)


if __name__ == '__main__':
    src = cv.imread(os.path.join(os.path.abspath('.'),"images/circle.png"))
    cv.namedWindow("Crystal Liu", cv.WINDOW_AUTOSIZE)  # 创建窗口, 窗口尺寸自动调整
    cv.imshow("Crystal Liu", src)  # 将src图片放入该创建的窗口中
    create_image()

    t1 = cv.getTickCount()  # 获取当前电脑时钟滴答数

    access_pixels(src)
    inverse(src)
    t2 = cv.getTickCount()
    time = (t2 - t1)/cv.getTickFrequency()  # 函数执行前后滴答数之差与滴答频率之比为前后时间差
    print("time: %s ms"%(time * 1000))
    cv.waitKey(0)

 

 

pandas

官方 https://pandas.pydata.org/pandas-docs/stable/getting_started/tutorials.html

十分钟入门  

https://www.jb51.net/article/163606.htm

https://zhuanlan.zhihu.com/p/99889912

入门  https://blog.csdn.net/weixin_44489066/article/details/89494395

Pandas系列

https://www.yiibai.com/pandas/python_pandas_data_structures.html

菜鸟教程

https://blog.csdn.net/qq_42196922/article/details/90043750

http://www.360doc.com/content/19/0518/12/41651190_836499424.shtml

莫烦

https://morvanzhou.github.io/tutorials/data-manipulation/np-pd/

 

matplotlib