使用matplotlib.animation.FuncAnimation将y轴下限固定为0，同时不对两个子图施加上限

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

# 创建两个子图
fig, (ax1, ax2) = plt.subplots(2, 1)

# 初始化数据
x = np.linspace(0, 10, 100)
y1 = np.sin(x)
y2 = np.cos(x)

# 绘制初始图像
line1, = ax1.plot(x, y1)
line2, = ax2.plot(x, y2)

# 设置y轴下限为0
ax1.set_ylim(0, None)
ax2.set_ylim(0, None)

# 更新函数，用于更新图像
def update(frame):
    # 更新数据
    y1 = np.sin(x + frame/10)
    y2 = np.cos(x + frame/10)
    
    # 更新图像数据
    line1.set_ydata(y1)
    line2.set_ydata(y2)
    
    return line1, line2

# 创建动画
ani = animation.FuncAnimation(fig, update, frames=100, interval=50)

# 显示动画
plt.show()