         calculateOffsets()
         setNeedsDisplay()
     }
-    
+
     /// Zooms in or out by the given scale factor.
-    /// x and y are the values which to zoom to or from (the values of the zoom center).
+    /// x and y are the values (**not pixels**) which to zoom to or from (the values of the zoom center).
     ///
     /// - parameter scaleX: if < 1 --> zoom out, if > 1 --> zoom in
     /// - parameter scaleY: if < 1 --> zoom out, if > 1 --> zoom in

    /// Zooms in by 1.4, into the charts center. center.
    public func zoomIn()
    {
        let matrix = _viewPortHandler.zoomIn(x: self.bounds.size.width / 2.0, y: -(self.bounds.size.height / 2.0))
        _viewPortHandler.refresh(newMatrix: matrix, chart: self, invalidate: true)
        
        // Range might have changed, which means that Y-axis labels could have changed in size, affecting Y-axis size. So we need to recalculate offsets.
        calculateOffsets()

        let matrix = _viewPortHandler.fitScreen()
        _viewPortHandler.refresh(newMatrix: matrix, chart: self, invalidate: false)
        
        calculateOffsets()
        setNeedsDisplay()
    }
