add Mandelbrot example

examples/mandelbrot.py

@@ -0,0 +1,50 @@
+import sys
+
+from artiq.experiment import *
+
+
+class Mandelbrot(EnvExperiment):
+    """Mandelbrot set demo"""
+
+    def build(self):
+        self.setattr_device("core")
+
+    @rpc(flags={"async"})
+    def col(self, i):
+        sys.stdout.write(" .,-:;i+hHM$*#@ "[i])
+
+    @rpc(flags={"async"})
+    def row(self):
+        print("")
+
+    @rpc(flags={"async"})
+    def prt(self, x):
+        print(x)
+
+
+    # based on: http://warp.povusers.org/MandScripts/python.html
+    @kernel
+    def run(self):
+        minX = -2.0
+        maxX = 1.0
+        width = 78
+        height = 36
+        aspectRatio = 2
+
+        yScale = (maxX-minX)*(height/width)*aspectRatio
+
+        for y in range(height):
+            for x in range(width):
+                c_r = minX+x*(maxX-minX)/width
+                c_i = y*yScale/height-yScale/2
+                z_r = c_r
+                z_i = c_i
+                i = 0
+                for i in range(16):
+                    if z_r*z_r + z_i*z_i > 4:
+                        break
+                    new_z_r = (z_r*z_r)-(z_i*z_i) + c_r
+                    z_i = 2*z_r*z_i + c_i
+                    z_r = new_z_r
+                self.col(i)
+            self.row()