如何在CustomTkinter与Matplotlib中实现双函数同图绘制？

我是Python初学者，正在学习结合CustomTkinter与Matplotlib绘图。现有代码可通过点击不同按钮分别绘制三角隶属函数（Triangle function）和梯形隶属函数（Trapz function），想实现将两个函数显示在同一幅图中，请问该怎么做？

原代码如下：

from tkinter import * 
from matplotlib.figure import Figure 
from matplotlib.backends.backend_tkagg import (FigureCanvasTkAgg,  
NavigationToolbar2Tk)
import customtkinter as ctk
import numpy as np

def plot(MF):
    fig = Figure()

    plot1= fig.add_subplot(111)
    fig.set_facecolor("grey")
    fig.set_edgecolor("blue")

    plot1.plot(MF)

    canvas = FigureCanvasTkAgg(fig, win)
    canvas.draw()

    toolbar = NavigationToolbar2Tk(canvas, win)
    toolbar.update()
    toolbar.place(relx=0.2, rely=0.4)
    canvas.get_tk_widget().place(relx=0.05, rely=0.4)

def Triangle_function():
    a = 100
    b = 500
    c = 700

    MF = np.zeros(1000)

    for x in range(1000):
        if x < a:
            MF[x] = 0
        elif x >= a and x <= b:
            MF[x] = (x-a)/(b-a)
        elif x >= b and x <= c:
            MF[x] = (c-x)/(c-b)
        elif x > c:
            MF[x] = 0
    plot (MF)
    
def Trapz():
    a = 100
    b = 500
    c = 700
    d = 900

    MF = np.zeros(1000)

    for x in range(1000):
        if x < a:
            MF[x] = 0
        elif x >= a and x < b:
            MF[x] = (x-a)/(b-a)
        elif x >= b and x < c:
            MF[x] = 1
        elif x >= c and x < d:
            MF[x] = (d-x)/(d-c)
        elif x >= d:
            MF[x] = 0 
    plot(MF)

win = ctk.CTk() 
win.geometry("1000x1000")
win.title("Fuzzy Logic Designer")
win.resizable(False, False)

plot_Button = ctk.CTkButton(win, text="plot", command = Triangle_function)
plot_Button.pack()

plot_Button1 = ctk.CTkButton(win, text="plot", command = Trapz)
plot_Button1.pack(pady=20)

win.mainloop()

解决方案 #

你可以通过以下修改实现两个函数同图显示：

修改后的完整代码 #

from tkinter import * 
from matplotlib.figure import Figure 
from matplotlib.backends.backend_tkagg import (FigureCanvasTkAgg,  
NavigationToolbar2Tk)
import customtkinter as ctk
import numpy as np

# 重构plot函数，支持传入多个隶属函数数据
def plot(*MFs):
    fig = Figure()
    plot1 = fig.add_subplot(111)
    fig.set_facecolor("grey")
    fig.set_edgecolor("blue")
    
    # 遍历所有传入的隶属函数，分别绘制并添加标签
    labels = ["三角隶属函数", "梯形隶属函数"]
    for idx, mf in enumerate(MFs):
        plot1.plot(mf, label=labels[idx] if idx < len(labels) else f"函数{idx+1}")
    # 添加图例方便区分
    plot1.legend()

    canvas = FigureCanvasTkAgg(fig, win)
    canvas.draw()

    toolbar = NavigationToolbar2Tk(canvas, win)
    toolbar.update()
    toolbar.place(relx=0.2, rely=0.4)
    canvas.get_tk_widget().place(relx=0.05, rely=0.4)

def Triangle_function():
    a = 100
    b = 500
    c = 700

    MF = np.zeros(1000)

    for x in range(1000):
        if x < a:
            MF[x] = 0
        elif x >= a and x <= b:
            MF[x] = (x-a)/(b-a)
        elif x >= b and x <= c:
            MF[x] = (c-x)/(c-b)
        elif x > c:
            MF[x] = 0
    plot(MF)
    
def Trapz():
    a = 100
    b = 500
    c = 700
    d = 900

    MF = np.zeros(1000)

    for x in range(1000):
        if x < a:
            MF[x] = 0
        elif x >= a and x < b:
            MF[x] = (x-a)/(b-a)
        elif x >= b and x < c:
            MF[x] = 1
        elif x >= c and x < d:
            MF[x] = (d-x)/(d-c)
        elif x >= d:
            MF[x] = 0 
    plot(MF)

# 新增函数：同时生成两个隶属函数并传入plot
def plot_both():
    # 生成三角隶属函数数据
    a_t, b_t, c_t = 100, 500, 700
    mf_triangle = np.zeros(1000)
    for x in range(1000):
        if x < a_t:
            mf_triangle[x] = 0
        elif x >= a_t and x <= b_t:
            mf_triangle[x] = (x-a_t)/(b_t-a_t)
        elif x >= b_t and x <= c_t:
            mf_triangle[x] = (c_t-x)/(c_t-b_t)
        elif x > c_t:
            mf_triangle[x] = 0
    
    # 生成梯形隶属函数数据
    a_tr, b_tr, c_tr, d_tr = 100, 500, 700, 900
    mf_trapz = np.zeros(1000)
    for x in range(1000):
        if x < a_tr:
            mf_trapz[x] = 0
        elif x >= a_tr and x < b_tr:
            mf_trapz[x] = (x-a_tr)/(b_tr-a_tr)
        elif x >= b_tr and x < c_tr:
            mf_trapz[x] = 1
        elif x >= c_tr and x < d_tr:
            mf_trapz[x] = (d_tr-x)/(d_tr-c_tr)
        elif x >= d_tr:
            mf_trapz[x] = 0 
    
    # 同时传入两个数据
    plot(mf_triangle, mf_trapz)

win = ctk.CTk() 
win.geometry("1000x1000")
win.title("Fuzzy Logic Designer")
win.resizable(False, False)

# 修改按钮文本，功能更明确
plot_tri_btn = ctk.CTkButton(win, text="绘制三角隶属函数", command=Triangle_function)
plot_tri_btn.pack()

plot_trapz_btn = ctk.CTkButton(win, text="绘制梯形隶属函数", command=Trapz)
plot_trapz_btn.pack(pady=20)

# 新增同时绘制的按钮
plot_both_btn = ctk.CTkButton(win, text="同时绘制两个隶属函数", command=plot_both)
plot_both_btn.pack(pady=10)

win.mainloop()

关键改动说明 #

1. 重构plot函数：将参数改为*MFs（可变长度参数），支持一次性传入多个隶属函数数组。循环遍历每个数组进行绘制，并添加标签和图例，方便区分不同函数。
2. 新增plot_both函数：分别生成三角和梯形隶属函数的数据，然后一起传入plot函数实现同图显示。
3. 优化按钮文本：将原有按钮的“plot”改为明确的功能描述，避免混淆；新增“同时绘制两个隶属函数”按钮，触发合并绘制逻辑。

内容的提问来源于stack exchange，提问作者Luka Tekk