# L-30 MCS 260 Mon 5 Nov 2007 : guieval.py
#
# GUI to evaluation a user given function.

from Tkinter import *
from math import *

top = Tk()
top.title("Evaluate Expressions")
Label(top,text="f(x) =").grid(row=0)
f = Entry(top)
f.grid(row=0,column=1)
Label(top,text="x =").grid(row=0,column=2)
e = Entry(top)
e.grid(row=0,column=3)
r = Entry(top)
r.grid(row=0,column=5)

def calc():
   "evaluates the function"
   r.delete(0,END)
   x = float(e.get())
   y = eval(f.get())
   r.insert(INSERT,y)

b = Button(top,text="equals",command=calc)
b.grid(row=0,column=4)
top.mainloop()