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| # File: tdemo_chaos.py
| # Author: Gregor Lingl
| # Date: 2009-06-24
|
| # A demonstration of chaos
|
| from turtle import *
|
| N = 80
|
| def f(x):
| return 3.9*x*(1-x)
|
| def g(x):
| return 3.9*(x-x**2)
|
| def h(x):
| return 3.9*x-3.9*x*x
|
| def jumpto(x, y):
| penup(); goto(x,y)
|
| def line(x1, y1, x2, y2):
| jumpto(x1, y1)
| pendown()
| goto(x2, y2)
|
| def coosys():
| line(-1, 0, N+1, 0)
| line(0, -0.1, 0, 1.1)
|
| def plot(fun, start, color):
| pencolor(color)
| x = start
| jumpto(0, x)
| pendown()
| dot(5)
| for i in range(N):
| x=fun(x)
| goto(i+1,x)
| dot(5)
|
| def main():
| reset()
| setworldcoordinates(-1.0,-0.1, N+1, 1.1)
| speed(0)
| hideturtle()
| coosys()
| plot(f, 0.35, "blue")
| plot(g, 0.35, "green")
| plot(h, 0.35, "red")
| # Now zoom in:
| for s in range(100):
| setworldcoordinates(0.5*s,-0.1, N+1, 1.1)
| return "Done!"
|
| if __name__ == "__main__":
| main()
| mainloop()
|
|
