Answer
code
Work Step by Step
# 15.31 (Tkinter: Recursive tree) Write a program to display a recursive tree, as shown in
# Figure 15.17.
import math
from tkinter import * # Import tkinter
class Recursive_Tree:
def __init__(self):
window = Tk() # Create a window
window.title("Recursive tree") # Set a title
self.width = 600
self.height = 600
self.canvas = Canvas(window,
width=self.width, height=self.height)
self.canvas.pack()
# Add a label, an entry, and a button to frame1
frame1 = Frame(window) # Create and add a frame to window
frame1.pack()
self.angleFactor = math.pi / 5
self.sizeFactor = 0.58
Label(frame1,
text="Enter an order: ").pack(side=LEFT)
self.order = StringVar()
entry = Entry(frame1, textvariable=self.order,
justify=RIGHT).pack(side=LEFT)
Button(frame1, text="Display Recursive tree",
command=self.display).pack(side=LEFT)
window.mainloop() # Create an event loop
def display(self):
self.canvas.delete("line")
self.displayRTree(int(self.order.get()), self.width/2, self.height-100, self.height / 3, math.pi / 2)
def displayRTree(self, depth, x1, y1, length, angle):
if depth >= 0:
x2 = x1 - math.cos(angle) * length
y2 = y1 - math.sin(angle) * length
# Draw the line
self.canvas.create_line(x1, y1, x2, y2, tag="line")
# Draw the left branch
self.displayRTree(depth - 1, x2, y2, length * self.sizeFactor, angle + self.angleFactor)
# Draw the right branch
self.displayRTree(depth - 1, x2, y2, length * self.sizeFactor, angle - self.angleFactor)
Recursive_Tree() # Create GUI
