關於用python的turtle畫樹葉
感興趣的可以百度一下分形樹葉的數學幾何原理——含概率的迭代函式系統。程式碼不難，關鍵是數學原理哦~還有，繪製過程有助於對程式碼和數學原理理解，大家動手自己試試吧！很有意思。

from numpy import *
from random import random
import turtle
turtle.reset()
x = array([[.5],[.5]])
p = [0.85,0.92,0.99,1.00]
A1 = array([[.85, 0.04],
      [-0.04,.85]])
b1 = array([[0],[1.6]])
A2 = array([[0.20,-0.26],
      [0.23,0.22]]
 
)
b2 = array([[0],[1.6]])
A3 = array([[-0.15,0.28],
      [0.26,0.24]])
b3 = array([[0],[0.44]])

A4 = array([[0,0],
      [0,0.16]])

#含概率的迭代函式系統

turtle.color("blue")
cnt = 1
while True:
  cnt += 1
  if cnt == 2000:
    break
  r = random()
  if r < p[0]:
    x = dot(A1 , x) + b1
  elif r < p[1]:
    x = dot(A2 , x) + b2
  elif r < p[2
 
]:
    x = dot(A3 , x) + b3
  else:
    x = dot(A4 , x)
  #print x[1]
  turtle.up()
  turtle.goto(x[0][0] * 50,x[1][0] * 40 - 240)
  turtle.down()
  turtle.dot()

完成以後的圖大概是這個樣子：