[FIXED] Plots in Tkinter

Issue

I need the program to display 2 graphs of mathematical functions on the same coordinate line, which the user enters manually into the input window. How can I make this graphs show up in a tkinter window? I heard about using Figure, but then 2 graphs will not be on the same coordinate line

   replacements = {
    'sin' : 'np.sin',
    'cos' : 'np.cos',
    'exp': 'np.exp',
    'sqrt': 'np.sqrt',
    '^': '**',
}

allowed_words = [
    'x',
    'sin',
    'cos',
    'sqrt',
    'exp', 
]


def string2func(string):
    for word in re.findall('[a-zA-Z_]+', string):
        if word not in allowed_words:
            raise ValueError(
                '"{}" is forbidden to use in math expression'.format(word)
            )

    for old, new in replacements.items():
        string = string.replace(old, new)

    def func(x):
        return eval(string)
    return func


def create_plot():
            a = int(value1.get())
            b = int(value2.get())
            x = np.linspace(a, b, 1000)
            func1 = str(value3.get())
            func2 = str(value4.get())

            if func1.isnumeric():
                 func1 = int(value3.get())
                 func1 = [func1] * 1000
                 plt.plot(x, func1 , label = 'F1(X)')
            else:
                 func1 = str(value3.get())
                 strfunc1 = string2func(func1)
                 plt.plot(x, strfunc1(x), label ='F1(X)')

            if func2.isnumeric():
                 func2 = int(value4.get())
                 func2 = [func2] * 1000
                 plt.plot(x, func2, label = 'F2(X)')
            else:
                 func2 = str(value4.get())
                 strfunc2 = string2func(func2)
                 plt.plot(x, strfunc2(x), label ='F2(X)')


            plt.grid(True)
            plt.xlabel('x')
            plt.ylabel('y')
            plt.title("Simple Plot")
            plt.ylim(-50, 50)   
            plt.show()

Solution

You can get axis and use it to draw another line in the same plot - ax.plot().

Matplotlib has special classes to display in different GUIs (tkinter, PyQt, etc.)

Embedding in Tk — Matplotlib 3.6.0 documentation

---

Example which draws two lines on one plot (in Tkinter) when you press button.

import tkinter as tk

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

# --- functions ---

def draw_plots():
    x = np.arange(0, 3.01, .01)

    scale = np.random.randint(1, 10)
    y1 = scale * np.sin(scale * np.pi * x)
    
    scale = np.random.randint(1, 10)
    y2 = scale * np.sin(scale * np.pi * x)

    ax.clear()   # remove previous plots
    #ax.grid(True)

    ax.plot(x, y1)
    ax.plot(x, y2)
    
    canvas.draw()  # refresh window
    
# --- main ---

root = tk.Tk()

fig = Figure()  # Figure(figsize=(5, 4), dpi=100)
canvas = FigureCanvasTkAgg(fig, master=root)
canvas.get_tk_widget().pack(fill='both', expand=True)  # resize plot when window is resized

ax = fig.add_subplot(111)
#ax.grid(True)

button = tk.Button(root, text='Draw', command=draw_plots)
button.pack()

tk.mainloop()

---

EDIT:

Example which draws on separated plots

# author: Bartlomiej "furas" Burek (https://blog.furas.pl)
# date: 2022.10.09
# [python - Plots in Tkinter - Stack Overflow](https://stackoverflow.com/questions/73997593/plots-in-tkinter/)

# [Embedding in Tk — Matplotlib 3.6.0 documentation](https://matplotlib.org/stable/gallery/user_interfaces/embedding_in_tk_sgskip.html)

import tkinter as tk

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

# --- functions ---

def draw_plots():
    x = np.arange(0, 3.01, .01)

    scale = np.random.randint(1, 10)
    y1 = scale * np.sin(scale * np.pi * x)
    
    scale = np.random.randint(1, 10)
    y2 = scale * np.sin(scale * np.pi * x)

    ax1.clear()   # remove previous plots
    ax2.clear()   # remove previous plots
    #ax1.grid(True)
    #ax2.grid(True)    
    
    ax1.plot(x, y1)
    ax2.plot(x, y2)
    
    canvas.draw()  # refresh window
    
# --- main ---

root = tk.Tk()

fig = Figure()  # Figure(figsize=(5, 4), dpi=100)
canvas = FigureCanvasTkAgg(fig, master=root)
canvas.get_tk_widget().pack(fill='both', expand=True)  # resize plot when window is resized

ax1 = fig.add_subplot(211)
ax2 = fig.add_subplot(212)
#ax1.grid(True)
#ax2.grid(True)

button = tk.Button(root, text='Draw', command=draw_plots)
button.pack()

tk.mainloop()

Answered By - furas