Source: Shawn Day.
Sankey diagrams visualize the magnitude of flow between nodes in a network. This diagram visualises the variety of beer types produced in Ireland by nano, micro and macro breweries by the actual number of specific brews produced. It uses the the type ontology developed by the Brewers Association of America. Hierarchy flows from left to right. The thickness of each link represents the number of specific brews within each subtypes.
The fully automatic layout is convenient for rapid visualization—positioning nodes manually is tedious! However, the algorithm is not perfect; links are drawn with partial transparency to highlight crossings. To improve readability and further disambiguate links, this example also lets you reposition nodes interactively. The algorithm could be improved in the future, say to minimize link crossing or to support loopback in cyclical networks.