Relations

In numerous scenarios it may be useful to illustrate the connections between categories that represent items, entities, or classes. This chapter is concerned with representing pairwise interaction between categories when the interaction consists of some kind of uni- or bi-directional quantitative flow from one class/entity to another. In this type of chart there is one measure (the amount of flow between the classes/entities) and one or more dimensions that define the classes. This chapter introduces two specific tools for representing relations: chord diagrams and Sankey diagrams.