清除 matplotlib 图形以获取新输入以生成整理序列

Question

这里是业余程序员。我使用 tkinter GUI 和 matplotlib 用 Python 编写了一个程序来计算并绘制根据用户输入的数字生成的 Collatz 猜想序列：

import tkinter as tk
from tkinter import ttk
import ttkbootstrap as ttk
from matplotlib.figure import Figure
import matplotlib.pyplot as plt 
from matplotlib.backends.backend_tkagg import (FigureCanvasTkAgg,
NavigationToolbar2Tk)


seq =[]

def calc():
    global num
    num = int(entry.get())

    while num > 2:
        if num % 2 == 0:
         num = num / 2

        else:
            num = 3 * num + 1

        seq.append(int(num))
    

def plot_sequence():

    global ax
    global canvas

    fig = Figure(facecolor='lightblue', edgecolor = "blue")
    ax = fig.add_subplot(111)
    ax.clear()
    ax.plot(seq, marker='o', linestyle='-')
    ax.set_xlabel('Iteration')
    ax.set_ylabel('Value')
    ax.set_title('Collatz Sequence')

    canvas = FigureCanvasTkAgg(fig)
    canvas.draw()
    canvas.get_tk_widget().pack(side=tk.TOP, fill=tk.BOTH, expand=1)
    
    ax.plot(seq)

def clear_graph():

    ax.clear()
    canvas.draw()
    entry.delete(0, 'end')
    seq.clear()

# def seq_display():
#     print(seq)
#     print(f"The length of the sequence generated is: {len(seq)}")



######################################################
# Create main window

root = tk.Tk()
root.title("Collatz Sequence")
root.geometry("500x500")
style = ttk.Style("litera")

# Title
title_label = ttk.Label(root,
    text = "Collatz Sequence Generator",
    font = "Calibri 24",
    foreground = "#4a7e9e")
title_label.pack(pady =10)

# Input
entry_frame = ttk.Frame(root)
entry_frame.pack()

entry_label = ttk.Label(entry_frame, text = "Enter a Number:",
    font = "Calibri 16")
entry_label.pack(side = "left", padx = 30, pady = 30)

entry = ttk.Entry(entry_frame, width = 5)
entry.delete(0, 'end')
entry.focus_set()
entry.pack(side = "left", pady = 30)


entry_button = ttk.Button(entry_frame,text = "SUBMIT", command=lambda: [calc(), plot_sequence()])
entry_button.pack(side = "left", padx = 60, pady = 30)


clear_button = ttk.Button(root,text = "CLEAR", command=clear_graph)
clear_button.pack(side = "bottom", pady = 50)


root.mainloop()

一切正常，除了当我清除输入字段、序列列表和绘图并输入新数字时，绘图不会再次生成。我必须关闭该程序并再次打开它才能工作。我知道序列会再次计算并附加到新清空的序列列表 (seq[]) 中，但当我再次运行程序时，绘图仍为空。

昨天我真的花了一整天的时间试图找出我做错了什么。我在完美运行的示例上对“defclear_graph():”函数进行了建模，但在我的代码中，它根本不起作用。它清除了，但就像我说的，它不会根据新的数字输入绘制新的序列

如果有人可以帮助我，我将不胜感激。

安德烈

Answer 1

当我仅创建

Figure

和

Canvas

一次时，代码对我有用。

import tkinter as tk
from tkinter import ttk
#import ttkbootstrap as ttk
import matplotlib.pyplot as plt 
from matplotlib.figure import Figure
from matplotlib.backends.backend_tkagg import (FigureCanvasTkAgg, NavigationToolbar2Tk)

# --- functions ---

def calc():
    global num
    
    #seq.clear()
    
    num = int(entry.get())

    while num > 2:
        if num % 2 == 0:
            num = num / 2
        else:
            num = 3 * num + 1
        seq.append(int(num))
    
def plot_sequence():
    global ax
    global canvas

    ax.clear()
    ax.plot(seq, marker="o", linestyle="-")
    ax.plot(seq)
    canvas.draw()
    
def create_graph():
    calc()
    plot_sequence()
    
def clear_graph():
    ax.clear()
    canvas.draw()
    entry.delete(0, "end")
    seq.clear()

# def seq_display():
#     print(seq)
#     print(f"The length of the sequence generated is: {len(seq)}")

# --- main ---

seq = []

# Create main window
root = tk.Tk()
root.title("Collatz Sequence")
root.geometry("500x500")
#style = ttk.Style("litera")

# Title
title_label = ttk.Label(root,
    text="Collatz Sequence Generator",
    font="Calibri 24",
    foreground="#4a7e9e")
title_label.pack(pady=10)

# Input
entry_frame = ttk.Frame(root)
entry_frame.pack()

entry_label = ttk.Label(entry_frame, text= "Enter a Number:", font="Calibri 16")
entry_label.pack(side="left", padx=30, pady=30)

entry = ttk.Entry(entry_frame, width=5)
#entry.delete(0, "end")   # no need it at start
entry.focus_set()
entry.pack(side="left", pady=30)

entry_button = ttk.Button(entry_frame, text="SUBMIT", command=create_graph)
entry_button.pack(side="left", padx=60, pady=30)

clear_button = ttk.Button(root, text="CLEAR", command=clear_graph)
clear_button.pack(side="bottom", pady=50)

# Figure and Canvas
fig = Figure(facecolor="lightblue", edgecolor="blue")
ax = fig.add_subplot(111)

ax.set_xlabel("Iteration")
ax.set_ylabel("Value")
ax.set_title("Collatz Sequence")

canvas = FigureCanvasTkAgg(fig)
canvas.draw()
canvas.get_tk_widget().pack(side="top", fill="both", expand=1)

root.mainloop()