How can I have a slideshow with matplotlib graphs in tkinter? - python-3.x

Question

I would like to utilize a tkinter window with integrated matplotlib graphs that cycle every x seconds. However, this is what I have and I am stuck. Any help would be greatly appreciated. Thank you!
import time
import matplotlib.pyplot as plt
from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg
import tkinter as tk
root = tk.Tk()
root.geometry('500x500')
x = [1, 2, 3, 4, 5]
y = [[3, 6, 1, 9, 2], [2, 0, 1, 4, 6], [6, 3, 8, 2, 0]]
fig = plt.figure(figsize=(5,5))
i = 0
while i < len(y):
plt.plot(x, y[i])
canvas = FigureCanvasTkAgg(fig, master=root)
canvas.draw()
canvas.get_tk_widget().pack()
time.sleep(1)
plt.clf()
i += 1
root.mainloop()

Answer 1

What you're looking for is after(). You'll likely have an easier time if you wrap everything up in a simple Root class, so I've done that here.
# imports go here as usual...
class Root(tk.Tk):
def __init__(self):
super().__init__() # init tk.Tk()
self.geometry('500x500')
self.x = [1, 2, 3, 4, 5]
self.y = [[3, 6, 1, 9, 2], [2, 0, 1, 4, 6], [6, 3, 8, 2, 0]]
self.fig = plt.figure(figsize=(5, 5))
# set up the canvas
self.canvas = FigureCanvasTkAgg(fig, master=root)
self.canvas.get_tk_widget().pack()
# begin cycling plots, starting with index 0
self.index = 0
self.cycle_plots(self.index)
def cycle_plots(self, index):
plt.clf # clear plot here
self.index += 1 # go to the next index
if self.index >= len(self.y):
self.index = 0 # wrap around
plt.plot(self.x, self.y[self.index])
self.canvas.draw() # update the canvas
# after 1000mS, call this function again
self.after(1000, lambda i=self.index: self.cycle_plots(i))
if __name__ == '__main__': # run the app!
root = Root()
root.mainloop()
Using a class makes it easier to pass your UI objects - like the Canvas - around between functions (methods). Here, self refers to your Root class, so anything inside it can share variables with self.<varname>, like self.canvas