在tkinter框架中加载matplotlib泡菜图

Question

我有一个小的接口，可以将数据加载到matplotlib图中。我希望能够加载含有以前制作的情节的泡菜，但不知怎的，我无法使其发挥作用。

这是matplotlib在tkinter中嵌入绘图的示例之一：

import sys
import pickle
import matplotlib
from numpy import arange, sin, pi, cos
from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg, NavigationToolbar2TkAgg
from matplotlib.backend_bases import key_press_handler
from matplotlib.figure import Figure
if sys.version_info[0] < 3:
    import Tkinter as Tk
else:
    import tkinter as Tk

def restore_from_pickle(pickle_address, fig):
    fig.clear()
    with open(pickle_address, 'rb') as fid:
        fig = pickle.load(fid)
    return

def _quit():
    root.quit()
    root.destroy()

def on_key_event(event):
    print('you pressed %s' % event.key)
    key_press_handler(event, canvas, toolbar)

matplotlib.use('TkAgg')
root = Tk.Tk()
root.wm_title("Embedding in TK")

f = Figure(figsize=(5, 4), dpi=100)
t = arange(0.0, 3.0, 0.01)

#Plot to store
a = f.add_subplot(111)
s = sin(2*pi*t)
a.plot(t, s)

#Saving to pickle
with open('figure_pickle', 'wb') as fid:
    pickle.dump(f, fid)

#Initial plot display
f.clear()
a = f.add_subplot(111)
s = cos(2*pi*t)
a.plot(t, s)

# a tk.DrawingArea
canvas = FigureCanvasTkAgg(f, master=root)
canvas.show()
canvas.get_tk_widget().pack(side=Tk.TOP, fill=Tk.BOTH, expand=1)

toolbar = NavigationToolbar2TkAgg(canvas, root)
toolbar.update()
canvas._tkcanvas.pack(side=Tk.TOP, fill=Tk.BOTH, expand=1)

canvas.mpl_connect('key_press_event', on_key_event)

button = Tk.Button(master=root, text='f(sin)', command=restore_from_pickle('figure_pickle', f))
#button = Tk.Button(master=root, text='Quit', command=_quit)
button.pack(side=Tk.BOTTOM)

Tk.mainloop() 

这会产生类似：

如果按下按钮，它会关闭窗口。我修改了它，因此它保存了一个包含一个数字的pickle，现在按钮加载了这个图像。但是，当我运行它时：

原始情节没有绘制，也没有画出那个......

发生了什么事？

感谢您的任何建议