I have a tkinter application with a canvas containing a figure. I am trying to change the height of the figure.

I created an entry field (“figure_height_entry”) to get the figure height from the user. Upon pressing “Enter”, the figure is resized using the function update_figure_size().

The resizing works but if making the figure smaller (let’s say by entering “500”), the old figure, larger, is still visible below.

I tried to add fig.clear() in the update_figure_size() function, it gives a blank square with the old figure still visible below.

How can I remove/hide the old figure when resizing it?

MWE:

from tkinter import Label, Tk, IntVar, Entry
import matplotlib.pyplot as plt
import matplotlib
matplotlib.use("TkAgg")
from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg

def plot_data():
    ax.clear()
    ax.plot([20,22,24,26,28],[5,10,8,3,6])
    canvas.draw_idle()
    
def update_figure_size():
    fig.set_size_inches(700*px, figure_height.get()*px)
    plot_data()
    
# MAIN CODE

root = Tk()

px = 1/plt.rcParams['figure.dpi']# with default figure.dpi = 100
figure_height = IntVar(value=600)
figure_height_entry = Entry(master=root,textvariable=figure_height)
        
fig = plt.Figure(figsize=(700*px, figure_height.get()*px))
ax = fig.add_subplot(111)
canvas = FigureCanvasTkAgg(fig, master = root)
canvas.get_tk_widget().grid(column=0, row=0)

label = Label(root, text="Figure height:")
label.grid(column=1,row=0)

figure_height_entry.bind('<Return>', lambda e: update_figure_size())
figure_height_entry.grid(column=2,row=0)  

plot_data()

root.mainloop()