An arc diagram of Les Miserables characters ordered by the first chapter they appear in. Arcs represent characters that interact with each other. This can be seen as a 1D semantic substrate.
Arc diagrams can be useful for examining relationships between an ordered variable, like chapters in a book, and the connections between nodes. However, because of limits in screen size, arc diagrams are often limited to graphs with a few hundred nodes at most. It can also be difficult to identify high-level patterns in connections and clusters, depending on the sort order.