Relationship
Three-dimensional scatterplot
Positions observations with three numeric coordinates.
- Plot
- Relationship
- Multivariate exploration
What it answers
Is there structure across three numeric dimensions?
- Shape
- Points on three numeric axes
- What it shows
- 3D clusters and spatial outliers.
Example
The question
How do price, rating and sales combine across our products?
Products by price, rating and units sold (3D scatter)
Illustrative data. It belongs to no company.
When to use it
Use it when
Exploring genuinely three-dimensional relationships.
Avoid it when
When a 2D projection answers the question or occlusion hides data.
How to read it
Rotate or inspect projections and read all three coordinate axes.
Note
Viewpoint and occlusion can hide patterns.
The data you need
- Layout
- Long table
- Fields
- X: number; Y: number; Z: number
- One row is
- One observation with three numeric coordinates. What is the grain?
- Rules
- Keep all coordinates paired. State units and coordinate conventions.
- Optional
- Optional ID,Group,Size.
- Preparation
- Align measurements by observation ID, select relevant variables and handle missingness. Scale or standardise only where the analytical method requires it.
- Units
- State the unit of every coordinate/variable. A unitless transformed or standardised scale must be identified; no common denominator is assumed.
Worked example
Points(2,10,5),(4,100,8),(6,50,6). The second has the largest Y and Z; confirm via labels or projections.
| X | Y | Z |
|---|---|---|
| 2 | 10 | 5 |
| 4 | 100 | 8 |
| 6 | 50 | 6 |
