python实现动画演示采样定理

# -*- coding: utf-8 -*-
# @Time : 2020/5/13 18:04
# @Author : Hazel
# @File : test1.py
# @Software : PyCharm

import numpy as np
import matplotlib.pyplot as plt
import matplotlib.animation as animation
import imageio
from PIL import Image, ImageSequence

fig = plt.figure()        #建立一个画板
ax = fig.add_subplot(1,1,1)  
x = np.linspace(0,1,500)
xdata = np.linspace(0,1,21)
ydata = np.cos(80*np.pi*xdata)
sample, = ax.plot([],[],'o')

line1, = ax.plot(x,np.cos(80*np.pi*x),'r--',lw=0.5)
ax.grid()
ax.set_xlim(0, 1)

def run(data):
    xdata = np.linspace(0,1,data)
    ydata = np.cos(80*np.pi*xdata)
    if data<=81:
        sample.set_data(xdata,ydata)
        sample.set_color('r')
    else:
        sample.set_data(xdata,ydata)
        sample.set_color('k')
    return sample,

ani = animation.FuncAnimation(fig,run,frames=np.arange(41,162,2),blit=False,interval=600,repeat=True)
plt.show()