Part of a whole
Circular dendrogram
Displays a hierarchical clustering tree in a circular layout.
- Diagram
- Hierarchy
- Clustering
What it answers
How does clustering form a circular hierarchy?
- Shape
- Clustering branches around a circle
- What it shows
- Nested clusters and membership.
Example
The question
Which of our twelve products sell in similar patterns?
Products clustered by weekly sales pattern (circular dendrogram)
Illustrative data. It belongs to no company.
When to use it
Use it when
A compact overview of many clustered leaves.
Avoid it when
When exact merge-height reading is central.
How to read it
Trace leaf branches toward merges using the height/distance key.
Note
Circular layout may make merge distances harder to read.
The data you need
- Layout
- Wide observation table
- Fields
- ObservationID: text; V1...Vp: numeric columns
- One row is
- One observation with several measured numeric variables. What is the grain?
- Rules
- Align variables by observation. Decide scaling, missing-data handling and which columns are features.
- Optional
- Optional Group. PCA, clustering and correlations require calculations before rendering their derived results.
- Preparation
- Fit the hierarchy as for a dendrogram, then use a circular display without changing the underlying merge distances.
- Units
- Merge distance retains the clustering scale despite the circular display.
Worked example
IfA and B merge at distance 1 and joinC at 5, they share an earlier branch. Circular placement does not change those merge distances.
| ID | V1 | V2 | V3 |
|---|---|---|---|
| A | 10 | 30 | 5 |
| B | 12 | 20 | 8 |
| C | 18 | 25 | 6 |