python 动画之抛球运动轨迹

import matplotlib.pyplot as plt
import matplotlib.animation as animation
import numpy as np
  

fig = plt.figure()
ax = plt.axes(xlim=(-50, 100), ylim=(-50, 50))
line, = ax.plot([], [], lw=2)
  

def init():

    line.set_data([], [])
    return line,
  

xdata, ydata = [], []

def animate(i):

    t = 0.1*i
      
    
    # 初始化抛小球的速度 
    vy=30
    vx=30
    # 重力系数
    g=10
    # x 计算
    x = vx*t
    # 最高高度计算
    h=vy**2/2*g
    # y分两种情况 未达到最大高度前 ，达到最大高度后
    if  t>np.sqrt(2*h/g):
        y = h-5*t**2
    else:
        y=vy*t-g*t**2
      
    
    xdata.append(x)
    ydata.append(y)
      

    line.set_data(xdata, ydata)
      

    return line,
      

plt.title('ball')

plt.axis('off')
  
  
anim = animation.FuncAnimation(fig, animate, init_func=init,
                               frames=500, interval=20, blit=True)
  
anim.save(filename="t.gif",fps=10,dpi=100)

plt.show()