I'm trying to write a program on Python that would plot a function defined by the user on the entry box. I am using matplotlib with tkinter and I have a defined interval on x within I wish to plot the function defined by the user. The problem is how to get the function the user inputs and read it as a command. I'd like for instance, that when the user types y = x* *2 (or y = np.sin(x), etc.) on the entry, the command is understood as a logical expression instead of as a string "x**2" that will generate an error. Is there any way to do this? Any help is welcomed.
import matplotlib
matplotlib.use("TkAgg")
import numpy as np
from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg, NavigationToolbar2Tk
from matplotlib.figure import Figure
import tkinter as tk
from tkinter import *
from tkinter import ttk
LARGE_FONT=("Times New Roman",12)
x=np.linspace(-5,5,100)
class MyApp(tk.Tk):
def __init__(self, *args, **kwargs):
tk.Tk.__init__(self,*args,**kwargs)
#tk.Tk.iconbitmap(self,default="myicon.ico") #to add icons
tk.Tk.wm_title(self, "My app")
container = tk.Frame(self)
container.pack(side="top", fill="both", expand=True)
container.grid_rowconfigure(0, weight=1)
container.grid_columnconfigure(0, weight=1)
self.frames = {}
for F in (StartPage, GraphPage):
frame = F(container, self)
self.frames[F] = frame
frame.grid(row=0, column = 0, sticky="nsew")
self.show_frame(StartPage)
def show_frame(self, cont):
frame = self.frames[cont]
frame.tkraise()
class StartPage(tk.Frame):
def __init__(self,parent,controller):
tk.Frame.__init__(self,parent)
label = tk.Label(self,text="Ed. App - Start Page",font = LARGE_FONT)
label.pack(pady=10,padx=10)
button3 = ttk.Button(self, text="Go to graph page ->", command = lambda:controller.show_frame(GraphPage))
button3.pack()
class GraphPage(tk.Frame):
def __init__(self,parent,controller):
tk.Frame.__init__(self,parent)
e = Entry(self, width =50)
e.pack()
label = tk.Label(self,text="Graph your function!",font = LARGE_FONT)
label.pack(pady=10,padx=10)
button1 = ttk.Button(self, text="Back to Home", command = lambda:controller.show_frame(StartPage))
button1.pack()
f = Figure(figsize=(5,5), dpi=100)
a = f.add_subplot(111)
def myClick():
# y = e.get() i'd like something like this to work, instead of line below
y = x**2
a.plot(x,y,'r')
canvas = FigureCanvasTkAgg(f, self)
canvas.draw()
canvas.get_tk_widget().pack(side=tk.TOP, fill=tk.BOTH, expand=True)
toolbar = NavigationToolbar2Tk(canvas, self)
toolbar.update()
canvas._tkcanvas.pack(side=tk.TOP, fill=tk.BOTH, expand=True)
button4 = ttk.Button(self, text="plot", command = myClick)
button4.pack()
app = MyApp()
app.mainloop()
