@Override
  public void actionPerformed(ActionEvent e) {
    // TODO Auto-generated method stub
    if (e.getSource() == columnView) {
      histogram.switchColumnView();
    }

    if (e.getSource() == lineView) {
      histogram.switchLineView();
    }

    if (e.getSource() == numberView) {
      histogram.switchNumberView();
    }
  }