转 用Python画Mandelbrot集
照着oldj同学的方法画曼德勃罗集，需要PIL库的支持，我生成的图是1280×800，迭代了1024次，花费了20多分钟。效果如下：
代码如下：
1 # -*- coding: utf-8 -*- 2 import time 3 import Image, ImageDraw 4 5 g_size = (1280, 800) # 图形最终尺寸 6 g_max_iteration = 1024 # 最大迭代次数 7 g_bailout = 4 # 最大域 8 g_zoom = 2.5 / g_size[0] # 缩放参数 9 g_offset = (-g_size[0] * 0.25, 0) # 偏移量 10 g_HSL = (210, 80, 50) # HSL色彩基调 11 12 def draw(antialias = True): 13 zi = 2 if antialias else 1 # antialias: 抗锯齿 size = [i * zi 14 size = [i * zi for i in g_size] 15 zoom = g_zoom / zi 16 offset = [i * zi for i in g_offset] 17 bailout = g_bailout * zi 18 img = Image.new("RGB", size, 0xffffff) 19 dr = ImageDraw.Draw(img) 20 21 print "painting Mandelbrot Set.." 22 for xy, color in getPoints(size, offset, zoom): 23 dr.point(xy, fill = color) 24 print "100%\n" 25 26 del dr 27 if antialias: 28 img = img.resize(g_size, Image.ANTIALIAS) 29 img.show() 30 img.save("mandelbrot_set_%dx%d.png" % g_size) 31 32 def getPoints(size, offset, zoom, ti = 0, tstep = 1): 33 "生成需要绘制的点的坐标及颜色" 34 35 def getRepeats(c): 36 z = c 37 repeats = 0 38 while abs(z) < g_bailout and repeats < g_max_iteration: 39 z = z * z + c 40 repeats += 1 41 return repeats 42 43 def getColor(r): 44 color = "hsl(0, 0%, 0%)" 45 if r < g_max_iteration: 46 v = 1.0 * r / g_max_iteration 47 h = ch * (1 - v) 48 s = cs 49 l = cl * (1 + v) 50 color = "hsl(%d, %d%%, %d%%)" % (h, s, l) 51 return color 52 53 xs, ys = size 54 xw, yh = xs / 2, ys / 2 55 xo, yo = offset 56 ch, cs, cl = g_HSL 57 58 progress = 0 59 for iy in xrange(ys): 60 p = iy * 100 / ys 61 if iy % 10 == 0 and p != progress: 62 print ("%d%%..." % p) # 显示进度 63 progress = p 64 for ix in xrange(ti, xs, tstep): 65 x = (ix - xw + xo) * zoom 66 y = (iy - yh + yo) * zoom 67 c = complex(x, y) 68 r = getRepeats(c) 69 yield (ix, iy), getColor(r) 70 71 def main(): 72 t0 = time.time() 73 draw() 74 t = time.time() - t0 75 print "%dm%.3fs" % (t / 60, t % 60) 76 77 if __name__ == "__main__": 78 main()
