         unselected.fill()
         
         let selected = UIBezierPath()
-        selected.move(to: CGPoint(x: rect.width/2, y: 0))
-        let selected_point = CGPoint(x: rect.width/2, y: chunk.centerPosition)
+        selected.move(to: CGPoint(x: chunk.center.x, y: 0))
+        let selected_point = CGPoint(x: chunk.center.x, y: chunk.center.y)
         selected.addLine(to: selected_point)
         selected.close()
         

            // 根据chunk的y值，计算value
            let value = calcValueByY()
            print("value:\(value)")
        }
    }
    

    
    override func draw(_ rect: CGRect) {
        let unselected = UIBezierPath()
        unselected.move(to: CGPoint(x: chunk.center.x, y: chunk.center.y))
        unselected.addLine(to: CGPoint(x: chunk.center.x, y: rect.height))
        unselected.close()
        
        unselectColor.set()
