Python: Embed a matplotlib plot with slider in tkinter properly

Question

I have created this plot in pyplot which has a slider to view a certain range of the data.

import random
import matplotlib
import tkinter as Tk
import matplotlib.pyplot as plt
from matplotlib.widgets import Slider

from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg

fig, ax = plt.subplots()
plt.subplots_adjust(bottom=0.25)

y_values = [random.randrange(20, 40, 1) for _ in range(40)]
x_values = [i for i in range(40)]

l, = plt.plot(x_values, y_values)
plt.axis([0, 9, 20, 40])

ax_time = plt.axes([0.12, 0.1, 0.78, 0.03])
s_time = Slider(ax_time, 'Time', 0, 30, valinit=0)


def update(val):
    pos = s_time.val
    ax.axis([pos, pos+10, 20, 40])
    fig.canvas.draw_idle()
s_time.on_changed(update)

#plt.show()

matplotlib.use('TkAgg')

root = Tk.Tk()
root.wm_title("Embedding in TK")

canvas = FigureCanvasTkAgg(fig, master=root)
canvas.show()
canvas.get_tk_widget().pack(side=Tk.TOP, fill=Tk.BOTH, expand=1)

Tk.mainloop()

The problem is, it seems unresponsive when embedded in a tkinter window, although when I show it with plt.show() (meaning the code after this, is commented) works correctly. What is the right way to do this?

Answer 1

I figured this one out. The figure needs to be added to the canvas before creating the plot.

import random
import matplotlib
import tkinter as Tk
import matplotlib.pyplot as plt
from matplotlib.widgets import Slider
from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg

matplotlib.use('TkAgg')

root = Tk.Tk()
root.wm_title("Embedding in TK")
fig = plt.Figure()
canvas = FigureCanvasTkAgg(fig, root)
canvas.get_tk_widget().pack(side=Tk.TOP, fill=Tk.BOTH, expand=1)

ax=fig.add_subplot(111)
fig.subplots_adjust(bottom=0.25)

y_values = [random.randrange(20, 40, 1) for _ in range(40)]
x_values = [i for i in range(40)]

ax.axis([0, 9, 20, 40])
ax.plot(x_values, y_values)

ax_time = fig.add_axes([0.12, 0.1, 0.78, 0.03])
s_time = Slider(ax_time, 'Time', 0, 30, valinit=0)


def update(val):
    pos = s_time.val
    ax.axis([pos, pos+10, 20, 40])
    fig.canvas.draw_idle()
s_time.on_changed(update)

Tk.mainloop()