Distribution

Two-dimensional histogram

Bins paired observations in two numeric dimensions and shows bin frequency or density.

Plot
Distribution
Relationship

What it answers

Which combinations of numeric ranges occur most?

Shape: Rectangular XY bins
What it shows: Joint frequency and concentration.

Example

The question

Which combinations of order size and delivery time are most common?

Orders by number of items and days to deliver (2D histogram, illustrative)

Rectangular cells coloured by number of orders. The most common combination is 4 to 6 items delivered in 1 to 3 days (about 120 orders); larger orders take a little longer.

Illustrative data. It belongs to no company.

When to use it

Use it when

Aggregating large paired numeric datasets.

Avoid it when

When precise observations or arbitrary binning dominate the task.

How to read it

Read X and Y bin boundaries and cell intensity.

Note

Specify bin boundaries and normalisation.

The data you need

Layout: Long table
Fields: X: number; Y: number
One row is: One observation with paired numeric measurements. What is the grain?
Rules: X and Y must refer to the same observation. Do not independently sort either column.
Optional: Optional ID,Group,Weight. Binning and smoothing settings belong to chart configuration.
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.

A long table: one row per observation, few columns. New data adds rows.

Worked example

In two X bins and two Y bins, counts are 12,3,2,8. The cell with 12 is most frequent; its position identifies both ranges.

X	Y
2	10
4	100
6	50

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