from Tkinter import *
import math
root = Tk()
fram = Frame(root)
Label(fram,text='f(x):').pack(side=LEFT)
func = Entry(fram)
func.pack(side=LEFT, fill=BOTH, expand=1)
butt = Button(fram, text='Plot')
butt.pack(side=RIGHT)
fram.pack(side=TOP)
fram = Frame(root)
bounds = []
for label in 'minX', 'maxX', 'minY', 'maxY':
Label(fram,text=label+':').pack(side=LEFT)
edit = Entry(fram, width=6)
edit.pack(side=LEFT)
bounds.append(edit)
fram.pack(side=TOP)
c = Canvas(root)
c.pack(side=TOP, fill=BOTH, expand=1)
def minimax(values=[0.0, 1.0, 0.0, 1.0]):
for i in range(4):
edit = bounds[i]
try: values[i] = float(edit.get())
except: pass
edit.delete(0, END)
edit.insert(END, '%.2f'%values[i])
return values
def plot():
minx, maxx, miny, maxy = minimax()
f = func.get()
f = compile(f, f, 'eval')
CX = c.winfo_width()
CY = c.winfo_height()
coords = []
for i in range(0,CX,5):
coords.append(i)
x = minx + ((maxx-minx)*i)/CX
y = eval(f, vars(math), {'x':x})
j = CY*(y-miny)/(maxy-miny)
coords.append(j)
c.delete(ALL)
c.create_line(*coords)
butt.config(command=plot)
f = 'sin(x) + cos(x)'
func.insert(END, f)
minimax([0.0, 10.0, -2.0, 2.0])
root.mainloop()