Does the world need another Venn tool?
You may think the world has enough Venn.
Venndir boldly suggests there is room for more,
with arrows, labels, and points to make.
Venndir is customizable
In fact, Venndir enables some of the most customizable Venn and Euler diagrams available, short of using a graphics design tool. Set labels, fonts, borders, colors, placement, highlights, and item labels, are all customizable when needed. Text labels even support Markdown, and with robust Unicode character rendering.
That said, Venndir aims to deliver publication-ready figures, as closely as possible, using default settings. But still, they're still just Venn diagrams.
Directionality is important
This book focuses on the techniques used to create Venn diagrams, including the use of directionality where appropriate. The need to indicate directionality depends on the questions asked and the conclusions one hopes to draw from the figure.
5.2.1 Seehawer Kmt2 Gene Venns Examples such as Section 5 illustrate a common pattern: They tested only the items showing concordance, agreement in direction, then interpreted the findings without evaluating discordance at all.
Without also evaluating the discordance, they lacked the proper context to interpret the results.
Conclusions drawn when testing only concordance, without also assessing discordance, are inherently biased, with limited validity of interpretation.
In the study of genes and their effects, change is more than just up or down -- it can signify sickness or health, disease or cure, even life or death.
The arrows aren't just decorative, they're insightful
It is quietly satisfying when Venndir illustrates that although two sets my overlap, they are moving in different directions -- revealing inconsistencies that may otherwise be missed. Clarity doesn't just come from what overlaps, but from how things move together.
Visualize with purpose. Annotate with direction.
One of the most challenging components in Venndir is placing the labels.
Who knew?
Venndir automates the job of placing labels inside or outside the Venn circles,
then allows you to nudge, style, highlight, and customize.
Together with marquee (Pedersen and Mitáš 2025), Venndir provides robust support for custom fonts across all graphics devices, with Unicode character substitution, Markdown and inline styling, and ability to embed images or other graphics.
Venndir figures use grid graphics, are compatible with patchwork (Pedersen 2024) for multi-panel figures, and can be customized down to the level of grid graphics objects (grobs).
Put ‘What are those?’ to rest, one label at a time.
One of the most unexpectedly fun features in Venndir is
the ability to display item names inside the figure.
The best data visualizations anticipate and answer that "next question."
For a Venn diagram it is most often:
‘What are those?’
Inspired by curiosity, designed for clarity, sharpened by use.
Venndir exists mostly because I thoroughly enjoyed creating it. It touches many interesting aspects of algorithm development, problem solving, data visualization design, and the practical driver of publication. It has received substantial feedback, and I always love listening to new ideas and suggestions.
Yes, there are a lot of labels.
Yes, the figures can become very busy.
And yes, I still think the results are useful and necessary.
All that said, Venndir with directionality (see "each" in Overlap Type) is a lot to look at, and may be most useful during analysis. The final published figure may or may not be simplified for visual clarity.
My philosophy is to make the figure useful for me before anyone else, then for my colleagues next, finally polishing it to present to others. Venndir tries to accomplish that in one step, but failing that it tries to make it useful for your.
The typical Venndir figure often follows the same progression: complicated details for me, optimized improvements for colleagues, then clear and simplified for others.
This book roughly follow the same progression:
- Introduction
- Data Import
- Venndir Basics
- Advanced Customization
- Venn Figures and Case Studies