Pysimple GUI 不清除 matplotlib 图形画布

Question

Context: Posted a similar q before and now I have to use radio buttons instead of a list of functions. The reason is that when I input my file for processing, the input variables for the graphs will be defined at this point and not earlier in the code, so the only way to do this is to use radio buttons so I can add the function input params here.

Issue: My issue is that when I click the radio button, the previous graph is not cleared, and the new graph prints below the original one. Please could someone help out - thank you!

Minimum code example here:

import PySimpleGUI as sg
import time
import os
import matplotlib
matplotlib.use('TkAgg')
from matplotlib.ticker import NullFormatter  
import matplotlib.pyplot as plt
import numpy as np
from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg
sg.theme('Dark')

def PyplotSimple():
    import numpy as np
    import matplotlib.pyplot as plt
    t = np.arange(0., 5., 0.2)          

    plt.plot(t, t, 'r--', t, t ** 2, 'bs', t, t ** 3, 'g^')

    fig = plt.gcf()  # get the figure to show
    return fig

def PyplotSimple2():
    import numpy as np
    import matplotlib.pyplot as plt
    t = np.arange(0., 5., 0.2)        
    plt.plot(t, t, 'r--', t, t ** 2, 'b--', t, t ** 3, 'b--')

    fig = plt.gcf()  # get the figure to show
    return fig

def draw_plot():
    plt.plot([0.1, 0.2, 0.5, 0.7])
    fig = plt.gcf()  # get the figure to show
    return fig



def draw_figure(canvas, figure):
    figure_canvas_agg = FigureCanvasTkAgg(figure, canvas)
    figure_canvas_agg.draw()
    figure_canvas_agg.get_tk_widget().pack(side='top', fill='both', expand=1)
    return figure_canvas_agg


def delete_figure_agg(figure_agg):
    figure_agg.get_tk_widget().forget()
    plt.close('all')


layout= [
    [sg.Text('my GUI', size=(40,1),justification='c', font=("Arial 10"))],
    [sg.Text('Browse to file:'), sg.Input(size=(40,1), key='input'),sg.FileBrowse (key='filebrowse')],

    [sg.Button('Process' ,bind_return_key=True), 
     sg.Radio('1',key= 'RADIO1',group_id='1', enable_events = True,default=False, size=(10,1)),
          sg.Radio('2', key= 'RADIO2',group_id='1',enable_events = True, default=False, size=(10,1)),
           sg.Radio('3', key='RADIO3',group_id='1',enable_events = True, default=False, size=(12,1))],

    [sg.Canvas(size=(200,200), background_color='white',key='-CANVAS-')],
    [sg.Exit()]] 


window = sg.Window('my gui', layout, grab_anywhere=False, finalize=True)
#window.Maximize()
figure_agg = None
# The GUI Event Loop

while True:
    event, values = window.read()
    #print(event, values)                  # helps greatly when debugging
    if event in (sg.WIN_CLOSED, 'Exit'):             # if user closed window or clicked Exit button
        break
          
    if figure_agg:
        delete_figure_agg(figure_agg)
        figure_agg = draw_figure(window['-CANVAS-'].TKCanvas, fig)
    if event == 'Process':
        #my function here 
        #the output of this function will decide the inputs to the graph which is why i need to use radio buttons
        sg.popup('Complete - view graphs',button_color=('#ffffff','#797979'))
    
    if event ==  'RADIO1':
        fig= PyplotSimple()
        figure_agg = draw_figure(window['-CANVAS-'].TKCanvas, fig)

    if event ==  'RADIO2':
        fig= PyplotSimple2()
        figure_agg = draw_figure(window['-CANVAS-'].TKCanvas, fig)
        
    
    if event ==  'RADIO3':
        fig= draw_plot()
        figure_agg = draw_figure(window['-CANVAS-'].TKCanvas, fig)
  
    
    elif event == 'Exit':
        break

window.close()

Answer 1

Before you draw new figure or axes, you may need method cla() or clf() to clear your figure. Find them in Matplotlib.

It is not necessary to do following imports in function PyplotSimple and PyplotSimple2 .

    import numpy as np
    import matplotlib.pyplot as plt

Here, you create the figure_agg again after you delete it. Remove comment-marked line.

    if figure_agg:
        delete_figure_agg(figure_agg)
        #figure_agg = draw_figure(window['-CANVAS-'].TKCanvas, fig)

Actually

• One more canvas added on your PSG canvas when draw_figure called
• Not delete canvas when delete_figure_agg called, just forgot it in pack

Here's another example show how I work matplotlib figure on PSG canvas.

import math

from matplotlib import use as use_agg
from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg
import matplotlib.pyplot as plt

import PySimpleGUI as sg

# Use Tkinter Agg
use_agg('TkAgg')

# PySimplGUI window
layout = [[sg.Graph((640, 480), (0, 0), (640, 480), key='Graph')]]
window = sg.Window('Matplotlib', layout, finalize=True)

# Default settings for matplotlib graphics
fig, ax = plt.subplots()

# Link matplotlib to PySimpleGUI Graph
canvas = FigureCanvasTkAgg(fig, window['Graph'].Widget)
plot_widget = canvas.get_tk_widget()
plot_widget.grid(row=0, column=0)

theta = 0   # offset angle for each sine curve
while True:

    event, values = window.read(timeout=10)

    if event == sg.WINDOW_CLOSED:
        break

    # Generate points for sine curve.
    x = [degree for degree in range(1080)]
    y = [math.sin((degree+theta)/180*math.pi) for degree in range(1080)]

    # Reset ax
    ax.cla()
    ax.set_title("Sensor Data")
    ax.set_xlabel("X axis")
    ax.set_ylabel("Y axis")
    ax.set_xscale('log')
    ax.grid()

    plt.plot(x, y)      # Plot new curve
    fig.canvas.draw()   # Draw curve really

    theta = (theta + 10) % 360  # change offset angle for curve shift on Graph

window.close()

You can find just call once to FigureCanvasTkAgg or something like your FigureCanvasTkAgg here, and no delete_figure_agg called here, but just ax.cla() called to clear figure.