This section will eventually give a brief outline of how to override the behavior of a plot. The basic idea is to redefine some of the standard methods used by the interaction system. For example, every time a plot needs to be redrawn the system sends the plot the "2D :redraw message. By defining a new method for this message you can change the way a plot is drawn. Similarly, when the mouse is moved or clicked in a plot the plot is sent the "2D :do-mouse message. Defining a new method for this message changes the way the plot responds to mouse actions.
There are a few wrinkles in the protocol for communicating between the system and a plot that still need to be worked out before I can finish this section.