Informational visualization tools, such as commercial charting packages, provide a standard set of visualizations for tabular data, including bar charts, scatter plots, pie charts, and the like. For some combinations of data and task, these are suitable visualizations. For others, however, novel visualizations over multiple variables would be preferred but are unavailable in the fixed list of standard options. To allow for these cases, we introduce a declarative language for specifying visualizations on the basis of the first principles on which (a subset of) informational graphics are built. The functionality we aim to provide with this language is presented by way of example, from simple scatter plots to versions of two quite famous visualizations: Minard’s depiction of troop strength during Napoleon’s march on Moscow and a map of the early ARPAnet from the ancient history of the Internet. Benefits of our approach include flexibility and expressiveness for specifying a range of visualizations that cannot be rendered with standard commercial systems.
