如何在tkinter中清除嵌入的matplotlib条形图？

import tkinter as tk
from matplotlib.figure import Figure
from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg

root = tk.Tk()
fig = Figure(figsize=(5, 4), dpi=100)

ax = fig.add_subplot(111)

data = [1, 2, 3, 4, 5]
ax.bar(range(len(data)), data)
canvas = FigureCanvasTkAgg(fig, master=root)
canvas.draw()
canvas.get_tk_widget().pack(side=tk.TOP, fill=tk.BOTH, expand=1)

def clear_chart():
    ax.clear()
    canvas.draw()

clear_button = tk.Button(root, text="Clear Chart", command=clear_chart)
clear_button.pack()

tk.mainloop()