Maps
Dot-density map
Distributes dots in regions, each representing a fixed number of units.
- Map
- Geography
- Distribution
What it answers
How is a counted population distributed within regions?
- Shape
- Repeated dots within regions
- What it shows
- Broad regional concentration.
Example
The question
Where do our customers live within each region?
Customers by region, one dot = 50 customers (dot-density map)
Illustrative data. It belongs to no company.
When to use it
Use it when
Spatial counts with explicitly illustrative placement.
Avoid it when
When readers might infer exact residential or event locations.
How to read it
Use dots-per-unit and read density within region boundaries.
Note
Dots are illustrative locations unless based on actual point observations.
The data you need
- Layout
- Attribute table plus geographic boundaries
- Fields
- RegionID: text; Count: nonnegative integer; matching region boundaries
- One row is
- One region and its measured value. What is the grain?
- Rules
- Use counts or a quantity suitable for a stated dots-per-unit conversion. Supply placement regions and a spatial placement rule.
- Optional
- Names alone may be ambiguous. Geometry can be GeoJSON, a spatial file or a tool-supported boundary lookup.
- Preparation
- Validate the input grain and missing values. Use counts or a quantity suitable for a stated dots-per-unit conversion. Supply placement regions and a spatial placement rule.
- Units
- Each dot represents a fixed count such as 50 people. Regional totals determine dot counts; dot positions may be illustrative.
Worked example
R1 count 300, R2 count 450 with one dot=50 units gives 6 and 9 dots. Placements within regions are illustrative.
| RegionID | Count |
|---|---|
| R1 | 300 |
| R2 | 450 |