I am trying to make a simple interactive plot, where a value of single variable can be changed by the slider. I already have non-interactive code which is working, where I use pandas DataFrame. I am using PySimpleGUI, to which I am completely new. I have managed to get a window with the slider, but no plot which changes. Where do I do an error in my code?

import pandas as pd
import matplotlib.pyplot as plt
import numpy as np
import copy as copy
import PySimpleGUI as sg
import matplotlib.pyplot as plt
from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg

V_A=5

dfN_A=np.array([[-1, 1], [0, 3], [1, -1]])

dfN=copy.deepcopy(dfN_A)
dfN[:,-1]=dfN_A[:,-1]*V_A


DC = pd.DataFrame(dfN, 
             columns=['X','value'])


_VARS = {'window': False,
         'fig_agg': False,
         'pltFig': False,
         'V_A': 5}




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



AppFont = 'Any 16'
SliderFont = 'Any 14'
sg.theme('black')


layout = [[sg.Canvas(key='figCanvas', background_color='#FDF6E3')],
          # pad ((left, right), (top, bottom))
          [sg.Text(text="V_A :",
                   font=SliderFont,
                   background_color='#FDF6E3',
                   pad=((0, 0), (10, 0)),
                   text_color='Black'),
        sg.Slider(range=(-10,10), size=(60, 10),
            orientation='h', key='-SLIDERV_A-')],
        [sg.Button('Exit', font=AppFont, pad=((540, 0), (0, 0)))]]

_VARS['window'] = sg.Window('Simple GUI', layout, finalize=True,resizable=True, element_justification='center', font='Helvetica 18')


def drawChart():
    _VARS['pltFig'] = plt.figure()
    fig = plt.gcf()
    DC.plot(y='value',x='X')
    _VARS['fig_agg'] = draw_figure(
        _VARS['window']['figCanvas'].TKCanvas, _VARS['pltFig'])



def updateChart():
    _VARS['fig_agg'].get_tk_widget().forget()
    plt.cla()
    plt.clf()
    _VARS['fig_agg'] = draw_figure(
        _VARS['window']['figCanvas'].TKCanvas, _VARS['pltFig'])


def updateDataV_A(val):
    _VARS['V_A'] = val
    updateChart()


drawChart()

while True:
    event, values = _VARS['window'].read(timeout=2000)
    if event == sg.WIN_CLOSED or event == 'Exit':
        break
    elif event == '-SliderV_A-':
        updateDataV_A(int(values['-SliderV_A-']))
_VARS['window'].close()

CodePudding user response：

There're some issues in your code. Try not to say much about those issues, for easily, so a different code here for you.

import numpy as np
from matplotlib.figure import Figure
from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg
import PySimpleGUI as sg

# 1. Define the class as the interface between matplotlib and PySimpleGUI

class Canvas(FigureCanvasTkAgg):
    """
    Create a canvas for matplotlib pyplot under tkinter/PySimpleGUI canvas
    """
    def __init__(self, figure=None, master=None):
        super().__init__(figure=figure, master=master)
        self.canvas = self.get_tk_widget()
        self.canvas.pack(side='top', fill='both', expand=1)


# 2. Define a function to draw the figure

def plot_figure(var):
    ax.cla()
    ax.plot(x0, y0*var)
    canvas.draw()               # Rendor figure into canvas

# 3. Initial Values

var = 5
x0, y0 = np.array([-1, 0, 1]), np.array([1, 3, -1])

# 4. create PySimpleGUI window

sg.theme('DarkBlue3')

layout = [
    [sg.Canvas(size=(640, 480), key='Canvas')],
    [sg.Text(text="Var"),
     sg.Slider(range=(-10, 10), default_value=var, size=(10, 20), expand_x=True, enable_events=True, orientation='h', key='Slider')],
    [sg.Push(), sg.Button('Exit'), sg.Push()],
]
window = sg.Window('Simple GUI', layout, finalize=True, resizable=True)

# 5. Create a matplotlib canvas under sg.Canvas or sg.Graph

fig = Figure()
ax = fig.add_subplot()
canvas = Canvas(fig, window['Canvas'].Widget)

# 6. initial for figure

plot_figure(var)


# 7. PySimpleGUI event loop

while True:

    event, values = window.read()

    if event in (sg.WIN_CLOSED, 'Exit'):
        break
    elif event == 'Slider':
        var = values[event]
        plot_figure(var)

# 8. Close window to exit

window.close()