Tetration fractal (Python)

tetration.py

#!/usr/bin/env python

import sys, os, math, time
from PIL import Image

def tetration(l, t, w, h, sw, sh, mit):
    data = []
    for ky in range(sh):
        for kx in range(sw):
            x = l + w * kx / (sw - 1)
            y = t + h * ky / (sh - 1)
            for i in range(mit):
                try:
                    e = math.exp(-0.5 * math.pi * y)
                    p = math.pi * x / 2
                    x = e * math.cos(p)
                    y = e * math.sin(p)
                except:
                    break
                if math.hypot(x, y) > 1000000:
                    break
            data.append((i % 4 * 64, i % 8 * 32, i % 16 * 16))
    return data

def main(args):
    if len(args) < 6:
        print >>sys.stderr, "Usage: %s imagefile left top width height [screen_width=512 screen_height=512 max_iters=256]" % os.path.basename(args[0])
        print >>sys.stderr, "  Ex. %s tetration.png -1.5 0.0 0.75 0.75" % os.path.basename(args[0])
        sys.exit(1)

    imagefile = args[1]
    l, t, w, h = map(float, args[2:6])
    sw, sh, mit = 512, 512, 256
    if len(args) >= 7: sw = int(args[6])
    if len(args) >= 8: sh = int(args[7])
    if len(args) >= 9: mit = int(args[8])

    print "Range: (%f, %f) - (%f, %f)" % (l, t, l + w, t + h)
    print "Image: %d x %d" % (sw, sh)
    print "Max number of iterations: %d" % mit

    start_time = time.time()
    data = tetration(l, t, w, h, sw, sh, mit)
    print "Time: %f" % (time.time() - start_time)

    im = Image.new("RGB", (sw, sh))
    for i, rgb in enumerate(data):
        im.putpixel((i % sw, i / sh), rgb)
    im.show()
    im.save(imagefile)

if __name__ == "__main__": main(sys.argv)

http://handasse.blogspot.com/2012/05/blog-post.html