Is there a case or need for radially-oriented Sankey diagrams? Is this something the world needs?
Sankey diagrams are great for showing relative flows by incorporating arrow-thicknesses into the graphics. While they often show a process from “start” to “finish” by flowing from left-to-right or top-to-bottom, they have the flexibility to show other data, such as specific dates (History of Parties and Armies) or geographical position (Minard’s famous “Napoleon’s March” Sankey)
They can also illustrate feedback or regeneration by having arrows loop back on each other, sending output flow back in to previous processes. This isn’t a problem with the Sankey diagrams that are out there.
So I’m wondering if there are processes that are so circular-oriented or so “feedbacky” that they would be better illustrated by wrapping the Sankey concept around a circle?
Here are some prototypes that I came up with:
“Everything Radial” Circular Sankey Diagram
The second idea made a point of having arrows come off tangentially. I think this view is a bit more clear. Only arrows feeding back to the start remain as in the first example.
“Tangential Fly-off” Circular Sankey Diagram
While I did create these with Visio, the process is still manual and cumbersome (translation: there’s no download!) But perhaps someday there could be Visio SmartShapes (and code?) to create such diagrams.
I’d be interested in hearing your feedback. You can leave your input in the comments section at the end of the article. Some questions to ponder:
- Have you been looking for this type of diagram?
- What features would you like to see?
- What kind of data would you show with a radial Sankey diagram?
- What processes would fit best with this diagram?
- Which of the above layouts do you find the most pleasing or useful?
- What would you change?
- Have you ever needed to create this kind of diagram? (Or wished you could have?)