diff --git a/exp/ransac.py b/exp/ransac.py
new file mode 100644
--- /dev/null
+++ b/exp/ransac.py
@@ -0,0 +1,70 @@
+import random
+
+from geometry import Line
+
+
+class LineBag:
+	def __init__(self,capacity):
+		self._capacity=capacity
+		self._bag=[]
+
+	def put(self,item):
+		# early abort
+		if self._bag and item>self._bag[-1]: return
+
+		(v,p)=item
+		# mostly filter duplicates
+		for (i,(vi,pi)) in enumerate(self._bag):
+			if abs(p.alpha-pi.alpha)<0.02 and abs(p.d-pi.d)<5:
+				if v<vi: self._bag[i]=item
+				return
+
+		# add new and remove the last
+		self._bag.append(item)
+		self._bag.sort()
+		if len(self._bag)>self._capacity:
+			self._bag.pop()
+
+	def pull(self,count=0):
+		return self._bag[:count] if count else self._bag[:]
+
+
+class Ransac:
+	def __init__(self,points):
+		self._points=points
+
+	def extract(self,count,iterations):
+		bag=LineBag(count)
+
+		for i in range(iterations):
+			line=self._generateLine()
+			score=self._scoreLine(line)
+			bag.put((score+random.random()/1000,line))
+
+		return [line for (score,line) in bag.pull()]
+
+	def _generateLine(self):
+		(a,b)=random.sample(self._points,2)
+		return Line.fromPoints(a,b)
+
+	def _scoreLine(self,line):
+		return sum(min(line.distanceTo(p),5) for p in self._points)
+
+
+class DiagonalRansac(Ransac):
+	def __init__(self,points,sideLen):
+		super().__init__(points)
+		self._sideLen=sideLen
+
+	def _generateLine(self):
+		n=len(self._points)
+		m=self._sideLen
+		ka=random.randrange(0,n)
+		kb=ka
+
+		while ka//m==kb//m or ka%m==kb%m:
+			kb=random.randrange(0,n)
+		a=self._points[ka]
+		b=self._points[kb]
+
+		return Line.fromPoints(a,b)