Home / Statistical Tools / Analysis Tools / Boxplot / Preparing Your Data

Preparing Your Data¶

Quantum XL is flexible about data layout. This page explains how different data types behave in box plots and helps you prepare your data correctly.

How Data Types Work¶

The table below shows what happens when you assign each column type to each role in the Box Plot dialog. Click a numbered badge to see an example using that configuration.

		Data Column
		Nominal	Continuous	Integer	Count	DateTime
Frequency Column	None	Not Allowed	Column header is name of box, values in column are included in box plot. One chart for all columns. 1 2	Column header is name of box, values in column are included in box plot. One chart for all columns.	Column header is name of box, values in column are included in box plot. One chart for all columns.	Column header is name of box, values in column are included in box plot. One chart for all columns.
	Nominal	—
	Continuous	—
	Integer	—
	Count	Not Allowed	Expand dataset by count 3	Expand dataset by count	Expand dataset by count	Expand dataset by count
	DateTime	—

— indicates this frequency type is not available for selection

Examples¶

1 Quick Start — Single data column, counting all values

2 Multiple Data Columns — Compare distributions across several columns

3 Count Frequency — Pre-aggregated data expanded by count

GroupBy — Compare segments side by side

Data Layout Options¶

Raw Data (One Row Per Observation)¶

Best for most situations. Each row represents a single measurement or observation.

Weight
12.3
15.7
11.2
18.4

Each row is one data point. When you select multiple data columns, each column becomes its own box on the chart. All columns appear in a single chart.

Pre-Aggregated Data (With Frequency Counts)¶

Use when your data has already been summarized with counts.

Measurement	Frequency
15.3	18
16.1	15
17.8	10

Select Measurement as Data Column and Frequency as Frequency Data. Quantum XL expands the dataset — a row with frequency 18 is treated as 18 observations of that value. The chart label shows the expanded count (N = sum of frequencies), not the number of rows.

Common Mistakes¶

Avoid These Issues

Selecting a Nominal column as data — Box plots require numeric data (Continuous, Integer, Count, or DateTime). Nominal columns cannot be used as data columns. Use Nominal columns for GroupBy instead.
Fewer than 4 data points — Quantum XL requires at least 4 values to compute a box plot. Columns with fewer than 4 points will be marked as "insufficient data."
Forgetting that frequency expands the dataset — When using a Count frequency column, the chart label shows the expanded N (sum of all frequencies), not the number of rows in your spreadsheet. This is correct — the statistics are computed on the expanded data.
Missing data — Empty cells in data columns are excluded from analysis.