/// <summary>
/// Pans the specified axis.
/// </summary>
/// <param name="axis">
/// The axis.
/// </param>
/// <param name="ppt">
/// The previous point (screen coordinates).
/// </param>
/// <param name="cpt">
/// The current point (screen coordinates).
/// </param>
public void Pan(Axes.Axis axis, ScreenPoint ppt, ScreenPoint cpt)
{
axis.Pan(ppt, cpt);
this.InvalidatePlot(false);
}