public void addAxis(Axis axis){
  if (axis.isHorizontal())   xAxisList.add(axis);
 else   yAxisList.add(axis);
  plotArea.addGrid(new Grid(axis));
  add(axis);
  axis.setXyGraph(this);
  revalidate();
}

public void addAxis ( Axis axis ) { if ( axis . isHorizontal ( ) ) xAxisList . add ( axis ) ; else yAxisList . add ( axis ) ; plotArea . addGrid ( new Grid ( axis ) ) ; add ( axis ) ; axis . setXyGraph ( this ) ; revalidate ( ) ; }
add an axis to the graph
