Python tkinter on matplotlib How update?-CodePudding

I use matplotlib in tkinter. I want to update the matplotlib status to a new status as function, how can i solve it?

import matplotlib.pyplot as plt
import numpy as np
from matplotlib.backends.backend_tkagg import (FigureCanvasTkAgg, NavigationToolbar2Tk)

window = tk.Tk()

def change():
    ss =  np.random.randint(100)
    ss1 =  np.random.randint(100)
    ss2 =  np.random.randint(100)
    x = ['Col A', 'Col B', 'Col C']
    y = [ss,ss1,ss2]
    fig = plt.figure(figsize=(4, 5))
    plt.bar(x=x, height=y)

    
    plt.xticks(x, rotation=90)
    canvas = FigureCanvasTkAgg(fig, master=window)
    canvas.draw()
    
btn = tk.Label(window, text='A simple plot')
btn.grid(row=0, column=0, padx=20, pady=10)

x = ['Col A', 'Col B', 'Col C']
y = [50, 20, 80]

fig = plt.figure(figsize=(4, 5))
plt.bar(x=x, height=y)


plt.xticks(x, rotation=90)


canvas = FigureCanvasTkAgg(fig, master=window)
canvas.draw()
canvas.get_tk_widget().grid(row=1, column=0, ipadx=40, ipady=20)

toolbarFrame = tk.Frame(master=window)
toolbarFrame.grid(row=2,column=0)
toolbar = NavigationToolbar2Tk(canvas, toolbarFrame)
button = tk.Button(text='change',command = change)
button.grid(row= 3,column =0)

window.mainloop()

output When this code is executed, when the button is pressed, the graph screen does not change, and when the program ends, the graphs are executed.

CodePudding user response：

You don't need to create new figure, just update current figure:

def change():
    ss =  np.random.randint(100)
    ss1 =  np.random.randint(100)
    ss2 =  np.random.randint(100)
    x = ['Col A', 'Col B', 'Col C']
    y = [ss,ss1,ss2]
    plt.clf()  # clear current figure
    plt.bar(x=x, height=y)  # plot the graph
    plt.xticks(x, rotation=90)
    canvas.draw()  # refresh plot