Eunoia

Area-proportional Euler and Venn diagrams for Julia.

Eunoia fits and draws diagrams in which the areas of overlapping shapes (circles, ellipses, squares, rectangles, or rotated rectangles) are made to match a set of input quantities as closely as possible. It is the Julia binding for eunoia, a Rust library, and a sister package to the R (eulerr) and Python (eunoia-py) bindings.

The fitting engine ships as a native library reached through a small C ABI; its binaries are delivered as a lazily-downloaded Julia artifact, so installing the package needs no Rust toolchain.

Installation

Eunoia is registered in the General registry, so install it with the Julia package manager:

using Pkg
Pkg.add("Eunoia")

Quick start

using Eunoia

# Euler diagram from exclusive areas
fit = euler(Dict("A" => 5, "B" => 3, "A&B" => 1.5))

# Canonical Venn diagram with ellipses
venn(["A", "B", "C"]; shape = "ellipse")

euler returns an EulerFit and venn a VennFit, both carrying the fitted shapes, original/fitted values, per-region residuals and region_error, the overall loss, and (for complement fits) a container. See the API Reference for the full surface.

Plotting

Rendering lives in a Makie package extension that loads automatically once a backend is imported:

using Eunoia, CairoMakie

fit = euler(Dict("A" => 5, "B" => 3, "A&B" => 1.5))
eunoiaplot(fit; quantities = true, legend = true)

See the gallery for a tour of the plotting options.

Citation

If you use Eunoia.jl in your research, please cite the paper:

Larsson, J., & Lee, N. M. (2026). Eunoia: Area-Proportional Euler and Venn Diagrams in Rust, Julia, Python, R, and JavaScript (arXiv:2611.02198). arXiv. https://doi.org/10.48550/arXiv.2611.02198

@misc{larsson2026f,
  title         = {Eunoia: {{Area}}-Proportional {{Euler}} and {{Venn}} Diagrams in {{Rust}}, {{Julia}}, {{Python}}, {{R}}, and {{JavaScript}}},
  shorttitle    = {Eunoia},
  author        = {Larsson, Johan and Lee, Nicole M.},
  year          = {2026},
  month         = nov,
  number        = {arXiv:2611.02198},
  eprint        = {2611.02198},
  primaryclass  = {stat.CO},
  publisher     = {arXiv},
  doi           = {10.48550/arXiv.2611.02198},
  archiveprefix = {arXiv}
}

BibLaTeX

@online{larsson2026f,
  title       = {Eunoia: {{Area}}-Proportional {{Euler}} and {{Venn}} Diagrams in {{Rust}}, {{Julia}}, {{Python}}, {{R}}, and {{JavaScript}}},
  shorttitle  = {Eunoia},
  author      = {Larsson, Johan and Lee, Nicole M.},
  date        = {2026-11-01},
  eprint      = {2611.02198},
  eprinttype  = {arXiv},
  eprintclass = {stat.CO},
  doi         = {10.48550/arXiv.2611.02198},
  pubstate    = {prepublished}
}

CITATION.cff contains the software metadata and preferred paper citation. The Eunoia citation page renders the paper in APA, BibTeX, BibLaTeX, and other formats.