# python # # 分形 # 圆

# coding: utf-8

import turtle
import random

def draw_circles(pen, xy, radius, step, is_homocentric = True):
   (x, y) = xy
   pen.ht()
   pen.color("#FFFFFF")
   pen.goto(x, y)
    for r in range(radius, step, step):
       rgb =tuple(color for color in (random.random(), random.random(), random.random()))
       pen.begin_fill()
       pen.fillcolor(rgb)
       pen.color(rgb)
       pen.circle(r)
       pen.end_fill()
        if is_homocentric:
           y = y-step
           pen.goto(x, y)
        
def main():
   radius = 300
   step = -20
   xy = (-50, -radius)
   my_pen = turtle.Turtle()   draw_circles(my_pen, xy, radius, step)
   my_pen.getscreen().getcanvas().postscript(file="homocentric_circle.eps")
   my_pen.clear()   draw_circles(my_pen, xy, radius, step, False)
   my_pen.getscreen().getcanvas().postscript(file="nonhomocentric_circle.eps")
   my_pen.clear()

if __name__ == "__main__":
   main()    pass

for f in `ls *.eps`; do
    convert -density 500 $f -flatten ${f%.*}.png;
done