radial dendrograms are great for looking at differences between clusters of relationships in trees. thanks for this tool, making viz tools accessible will refine their use cases. one of the challenges with viz is matching the message with the viewer.

re some of the viz comments here, most sankey diagrams can be pie charts (any one with less than a few nested categories) and most people who make pie charts don't reason about trees so all the junk sankey diagrams that flooded in after the birthday party chart aren't a reflection of their use or value.

messages I've used viz for in the past were to solve problems like:

- these things are similar and different (heatmap)

- this is a bounded domain (digraph/ontology)

- these things are related, but only relative to these other things (graph clusters, radial/linear network diagram, boxes+lines/nested boxes)

- the complexity is more here than there (graph clusters)

- the taxonomy hides an inconsistency or gap (sankey diagrams)

- either everybody sees this or nobody does (graph clusters)

- these variations cause combinatoric explosion (sankey diagram)

- this is a hierarchy (dendrogram, radial dendrogram)

- these are categories of things (dendrogram, radial dendrogram)

- these things are the same (heatmap)

- start with these to have the most effect on those (cluster graph)

- solutions are in the form of this grammar (sankey diagram)

- these things happen in order (state machine/flow chart, gantt chart)

- these things happen together (gantt chart)

The statements may seem naive, but when you're working on a viz, you have to think about who it is for and whether it is the right representation and whether the message is valuable. I've made a lot of viz mistakes and they came down to not framing one of these messages correctly or misunderstanding how telling someone this would make them feel. the radial diagrams are pretty, and very useful for showing contrast between patterns and density of relationships.

Circos – Circular Visualization