Chapters:
1: Introduction
2: Simple example
3: Invocation
4: Finer Control
5: X-Y Plots
6: Contour Plots
7: Image Plots
8: Examples
9: Gri Commands
10: Programming
11: Environment
12: Emacs Mode
13: History
14: Installation
15: Gri Bugs
16: Test Suite
17: Gri in Press
18: Acknowledgments
19: License
Indices:
Concepts
Commands
Variables

## 8.1: Box plots

Box plots were invented by Tukey for eda (exploratory data analysis). They show nonparametric statistics. The centre of the box is the median. The box edges show the first quartile (q1) and the third quartile (q3). The distance from q3 to q1 is called the inter-quartile range. The whiskers (lines with crosses on them) extend to the furthest points still within 1.5 inter-quartile ranges of q1 and q3. Beyond the whiskers, all outliers are shown, in open circles up to a distance of 3 inter-quartile ranges beyond q1 and q3, and in closed circles beyond that. Below is an example that uses a "new command" to define each box plot (see Adding New Commands).

The command-file.