Koch curve的python实现

Koch curve

A variant of the Koch curve which uses only right-angles.

variables : F

constants : + −

start  : F

rules  : (F → F+F−F−F+F)

Here, F means "draw forward", + means "turn left 90°", and - means "turn right 90°".

n = 0:

F

n = 1:

F+F-F-F+F

n = 2:

F+F-F-F+F+F+F-F-F+F-F+F-F-F+F-F+F-F-F+F+F+F-F-F+F

n = 3:

F+F-F-F+F+F+F-F-F+F-F+F-F-F+F-F+F-F-F+F+F+F-F-F+F+ F+F-F-F+F+F+F-F-F+F-F+F-F-F+F-F+F-F-F+F+F+F-F-F+F- F+F-F-F+F+F+F-F-F+F-F+F-F-F+F-F+F-F-F+F+F+F-F-F+F- F+F-F-F+F+F+F-F-F+F-F+F-F-F+F-F+F-F-F+F+F+F-F-F+F+ F+F-F-F+F+F+F-F-F+F-F+F-F-F+F-F+F-F-F+F+F+F-F-F+F

 

 

import turtle

def F():
    turtle.forward(10)
def add():
    turtle.left(90)
def minus():
    turtle.right(90)

def Koch(n):
    if n == 0:
        F()
    elif n == 1:
        F(),add(),F(),minus(),F(),minus(),F(),add(),F()
    else:
        Koch(n-1),add(),Koch(n-1), minus(),Koch(n-1),minus(),Koch(n-1),add(),Koch(n-1)
    
if __name__ == '__main__':
    Koch(3)

 

注意：值不要设的太大，要不然画的时间很长。