The language of graphics

We describe a system, called the Graphics production Library (GPL), that im plements a language for quantitative graphics. The structure of this system differs from existing statistical graphics, visualization, and mapping sys tems. Instead of treating a graphics display as a viewer for underlying dat a, GPL treats data as an accessory to viewing a graph. GPL is based on the mathematical definition of the graph of a function and uses that definition to organize data linked to the graph.