Description
The purpose of this programming assignment is to generate a canvas that plots points at specific locations to create
a Sierpinski triangle. You will be using the Point class from earlier, and tweaking the CoordinateSystem class from
earlier. This can be achieved by the following pseudo-code:
v1, v2, v3 ← three vertices of an equilateral triangle
plot v1, v2, and v3
p1, p2 ← two randomly selected vertices from v1, v2, and v3
m ← the midpoint of p1 and p2
plot m (black color)
repeat
v ← a randomly selected vertex from v1, v2, and v3
m’ ← the midpoint of m and v
plot m’
m ← m’
until midpoints plotted >= 1500 or tired
Specification
The program consists of two parts:
• Make sure the size of the canvas is 600 * 520
• A Point class that defines a blueprint for a 2D point.
• A ChaosGame class that manages a Tkinter Canvas and plots Point objects in random colors onto the canvas.
Point Class
Your Point class will likely remain unchanged from last programming assignment.
ChaosGame Class
Rename CoordinateSystem class to ChaosGame.
• Set the window title to “The Chaos Game”.
• Set the number of points to plot to 50,000 by default.
• Plotted points should be individual instances of your Point class.
• Vertices should be plotted in a color of your choice and have a radius greater than 0 (i.e., they must be larger
than the generated midpoints that make up the fractal).
• Midpoints making up the fractal should be formed from the last plotted midpoint and a randomly chosen
vertex (i.e., through the midpt() function in your Point class).
• Plot the first midpoint using any two vertices of the equilateral triangle.
• Midpoints making up the fractal should be plotted in a color that is different than the vertices so that the
vertices are clearly visible. The midpoints must all be of the same color.
• You are free to set the canvas background to a color of your choice (however, ensure that the vertices and
fractal are clearly visible).
• You are free to define other functions in your ChaosGame class as appropriate.
Hint: First, plot the three vertices. Experiment with the color and radius of the vertices. Once plotted, then move
on to plot the midpoints.
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CSC 102 The Science of Computing – II
Program 4
The Chaos Game
Figure 1: Sample Output
Deliverable
• Submit the Point.py and ChaosGame.py. Both classes can also be present in the same file.
Rubric
Item Points
Good coding style 2
Appropriate Comments & Header 3
Window size & Title 3
Point class 5
50,000 Instances plotted 4
Vertices (color & size) 5
Midpoints (color & size) 5
Midpoints correctly calculated 4
First midpoint from two random vertices 3
Output is correct 6
Total 40
終わる
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