} // constructor

        private void Window_Loaded(object sender, RoutedEventArgs e)
        {
            _Zoom = new Zoom(myChart);
            _ViewModel = new ViewModel(myChart);
            DataContext = _ViewModel;
            _Model = new Model(_ViewModel);
        } // 
 public Model(ViewModel xViewModel)
 {
     _ViewModel = xViewModel;
     //DispatcherTimer lTimer = new DispatcherTimer();
     //lTimer.Interval = new TimeSpan(0, 0, 3);
     //lTimer.Tick += new EventHandler(Timer_Tick);
     //lTimer.Start();
 } // constructor