diff --git a/exp/diagram.py b/exp/diagram.py
new file mode 100644
--- /dev/null
+++ b/exp/diagram.py
@@ -0,0 +1,40 @@
+import PIL.Image
+import PIL.ImageDraw
+
+
+width=360
+height=width
+padding=12
+stoneSize=(width-2*padding)/18
+yellow=(255,200,0)
+white=(255,255,255)
+black=(0,0,0)
+
+
+def createDiagram(board):
+	img=PIL.Image.new("RGB",(width,height),yellow)
+	canvas=PIL.ImageDraw.Draw(img)
+
+	# grid
+	for i in range(19):
+		canvas.line((padding,padding+i*stoneSize,width-padding,padding+i*stoneSize),black,1)
+		canvas.line((padding+i*stoneSize,padding,padding+i*stoneSize,height-padding),black,1)
+
+	# stars
+	radius=2
+	for r in range(3,19,6):
+		for c in range(3,19,6):
+			x=c*stoneSize+padding
+			y=r*stoneSize+padding
+			canvas.ellipse((x-radius,y-radius,x+radius,y+radius),black)
+
+	# stones
+	radius=stoneSize/2
+	for (r,row) in enumerate(board):
+		for (c,color) in enumerate(row):
+			if color=="X" or color=="O":
+				x=c*stoneSize+padding
+				y=r*stoneSize+padding
+				canvas.ellipse((x-radius,y-radius,x+radius,y+radius),black if color=="X" else white)
+
+	return img
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