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It draws a random Gumowski-Mira Strange Attractor. (It would retry until a good one is found to display.)

Python, 43 lines
 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43``` ```# Gumowski-Mira Strange Attractor # http://en.wikipedia.org/wiki/Attractor # FB - 201012072 import random from PIL import Image imgx = 800 imgy = 600 maxIt = 50000 # number of pixels to draw # drawing area (xa < xb and ya < yb) xa = -20.0 xb = 20.0 ya = -20.0 yb = 20.0 def f(x): return a * x + 2.0 * (1.0 - a) * x * x / (1.0 + x * x) def gm(x, y): xnew = b * y + f(x) y = -x + f(xnew) x = xnew return (x, y) while True: image = Image.new("L", (imgx, imgy)) # clear the image a = random.random() * 1.5 - 1.0 b = random.random() * 0.1 + 0.9 x = random.random() * (xb - xa) + xa y = random.random() * (yb - ya) + ya pixelCtr = 0 for i in range(maxIt): (x, y) = gm(x, y) xi = int((imgx - 1) * (x - xa) / (xb - xa)) yi = int((imgy - 1) * (y - ya) / (yb - ya)) if xi >=0 and xi < imgx and yi >= 0 and yi < imgy: if image.getpixel((xi, yi)) == 0: image.putpixel((xi, yi), 255) pixelCtr += 1 if 100 * pixelCtr / maxIt > 10: # retry until a good attractor is found break image.save("strange_attractor.png", "PNG") ```
 Created by FB36 on Sun, 5 Dec 2010 (MIT)