 	}
 	
 	func nearlyEqualTo(transform: CGAffineTransform, epsilon: CGFloat) -> Bool {
-		return fabs(self.a - transform.a) < epsilon && fabs(self.b - transform.b) < epsilon && fabs(self.c - transform.c) < epsilon && fabs(self.d - transform.d) < epsilon && fabs(self.tx - transform.tx) < epsilon && fabs(self.ty - transform.ty) < epsilon
+		return fabs(a - transform.a) < epsilon && fabs(b - transform.b) < epsilon && fabs(c - transform.c) < epsilon && fabs(d - transform.d) < epsilon && fabs(tx - transform.tx) < epsilon && fabs(ty - transform.ty) < epsilon
 	}
 }
 


extension CGPoint {
	var description: String {
		return "(\(self.x), \(self.y))"
	}
	
	var length: CGFloat {
		return sqrt(self.squareLength)
	}
	
	var squareLength: CGFloat {
		return sqrt(self.squareLength)
	}
	
	var unit: CGPoint {
		return self * (1.0 / self.length)
	}
	
	var phase: CGFloat {
		return atan2(self.y, self.x)
	}
	
	func distanceFrom(point: CGPoint) -> CGFloat {

	}
	
	func angleFrom(point: CGPoint) -> CGFloat {
		return acos(cosOfAngleFrom(point))
	}
	
	func cosOfAngleFrom(point: CGPoint) -> CGFloat {
