{"id":990,"date":"2016-12-29T16:02:14","date_gmt":"2016-12-29T16:02:14","guid":{"rendered":"http:\/\/ofalcao.pt\/blog\/?p=990"},"modified":"2016-12-29T16:02:14","modified_gmt":"2016-12-29T16:02:14","slug":"ev3-chaos","status":"publish","type":"post","link":"https:\/\/ofalcao.pt\/blog\/2016\/ev3-chaos","title":{"rendered":"EV3 Chaos"},"content":{"rendered":"

Need to practice with Python. Not just for ev3dev\/EV3 but surely this will be my main target.<\/p>\n

So today I remembered the 80’s… Chaos and fractals and my 8088 taking hours to draw a Mandelbrot on an ambar Hercules screen.<\/p>\n

So I found a simple python script from Lennart Poettering<\/a> and adapted it to work on EV3:<\/p>\n

#!\/usr\/bin\/python3\r\n\r\n# EV3 03m58s - video: https:\/\/youtu.be\/w5aKqmXz_Wk\r\n# based on a python script from\u00a0 Lennart Poettering\r\n# found here http:\/\/0pointer.de\/blog\/projects\/mandelbrot.html\r\n\r\nfrom PIL import Image, ImageDraw\r\nimport math, colorsys\r\nimport ev3dev.ev3 as ev3\r\nfrom time import sleep\r\n\r\nlcd = ev3.Screen()\r\nlcd.clear()\r\n\r\nsleep(1)\r\n\r\ndimensions = (178, 128)\r\nscale = 1.0\/(dimensions[0]\/3)\r\ncenter = (2.0,1.0)\r\niterate_max = 15\r\ncolors_max = 2\r\n\r\nimg = Image.new(\"1\", dimensions,\"white\")\r\n\r\nd = ImageDraw.Draw(img)\r\n\r\n# Calculate the mandelbrot sequence for the point c with start value z\r\ndef iterate_mandelbrot(c, z = 0):\r\n\u00a0\u00a0\u00a0 for n in range(iterate_max + 1):\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 z = z*z +c\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 if abs(z) > 2:\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 return n\r\n\u00a0\u00a0\u00a0 return None\r\n\r\n# Draw our image\r\nfor y in range(dimensions[1]):\r\n\u00a0\u00a0\u00a0 for x in range(dimensions[0]):\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 c = complex(x * scale - center[0], y * scale - center[1])\r\n\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 n = iterate_mandelbrot(c)\r\n\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 if n is None:\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 v = 1\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 else:\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 v = n\/100.0\r\n\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 if v > 0.5 :\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 d.point((x,y), fill = 0)\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 else:\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 d.point((x,y), fill = 1)\r\n\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 lcd.image.paste(img, (0,0))\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 lcd.update()\r\n\r\ndel d\r\nimg.save(\"result.png\")\r\nsleep(1)<\/pre>\n
My EV3 is running ev3dev-jessie-2016-12-21 release. No need to install PIL or anything else, just create the script, give execution permissions and run it.<\/p>\n
The script takes 3m58s to run. next video shows the result (4x speed):<\/p>\n