I am trying to solve my unsolved question: (Python) tkinter figures (with colorbar) overlap when using slider
I applied the following answer: tkinter figure (with colorbar) shrinks every time it's displayed
To avoid the problem shown in the title, I referred to Local (?) variable referenced before assignment
My codes:
from tkinter import *
import tkinter.ttk as ttk
import matplotlib
import matplotlib.pyplot as plt
from matplotlib import cm
import numpy as np
import ipywidgets as wg
import os
import pandas as pd
from matplotlib.ticker import MaxNLocator
from matplotlib.colors import BoundaryNorm
import math
from matplotlib.ticker import LinearLocator
%matplotlib widget
from matplotlib.widgets import Slider
from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg
matplotlib.use('TkAgg')
root = Tk()
root.title('TEST')
root.geometry("800x800")
cbar = None #<-------------------------(1)
def plot_noise():
# ============================================Read .xlsx file=====================================
folder = r'C:\Users\Dian-Jing Chen\Desktop\Work\test_read'
files = os.listdir(folder)
dfs = {}
for i, file in enumerate(files):
if file.endswith('.xlsx'):
dfs[i] = pd.read_excel(os.path.join(folder,file), sheet_name='Z=143', header = None, skiprows=[0], usecols = "B:M")
num = i + 1
rec = np.shape(dfs[0])
rmm = np.concatenate([dfs[0], dfs[1]])
for jj in range(2,num):
rmm = np.concatenate([rmm, dfs[jj]])
# =================================================PLOT===========================================
fig, ax = plt.subplots()
canvas = FigureCanvasTkAgg(fig, root)
canvas.get_tk_widget().grid(row=3, column=0, columnspan=3, rowspan=3, sticky=W+E+N+S, padx=0, pady=0)
# ===============================================contourf=========================================
fig.subplots_adjust(bottom=0.25)
X = np.arange(1,rec[1]+1,1)
Y = np.arange(1,rec[0]+1,1)
x , y = np.meshgrid(X,Y)
# ==============================================color bar=========================================
cbar_max = math.floor(np.min(rmm))
cbar_min = math.ceil(np.max(rmm))
cbar_num_colors = 200
cbar_num_format = "%d"
levels = MaxNLocator(nbins=cbar_num_colors).tick_values(cbar_min, cbar_max)
# ============================================Initial plot========================================
global cbar #<-------------------------(2)
con = ax.contourf(x,y,dfs[1], levels = levels, cmap=cm.jet, alpha = 0.5, antialiased = True)
cbar = fig.colorbar(con,ax = ax)
ax.axis([1, 12, 1, 6])
# ================================================Slider==========================================
global slider_de
slider_bar = fig.add_axes([0.12, 0.1, 0.78, 0.03])
slider_de = Slider(slider_bar, 's_bar', 0, num-1, valinit=1,valfmt='%0.0f', valstep=1)
num_on_slider = []
def update(val):
num_on_slider.append(slider_de.val)
for ii in range(0,num):
if num_on_slider[-1] == ii:
if cbar:
cbar.remove() #<-------------------------(3)
con = ax.contourf(x,y,dfs[ii], levels = levels, cmap=cm.jet, alpha = 0.5, antialiased = True)
cbar = fig.colorbar(con,ax = ax)
ax.axis([1, 12, 1, 6])
slider_de.on_changed(update)
# =================================================GUI - Tkinter=======================================
resultButton = ttk.Button(root, text = 'show', command = plot_noise)
resultButton.grid(column=0, row=1, pady=15, sticky=W)
root.mainloop()
I used <-------------(1),(2) to avoid local variable 'cbar' referenced before assignment
I used <-------------(3) to overcome the original problem.
However, the same error still popped out
UnboundLocalError: local variable 'cbar' referenced before assignment
How to fix that problem?
