Area-Proportional Euler and Venn Diagrams

Fit set sizes and intersections with circles, ellipses, squares, and rectangles. A Rust engine shared by JavaScript, Python, Julia, and R.

- [Try it in the browser](/app/)
- [Read the docs](/docs/)

# Eunoia

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## See It in Action

A three-set diagram, fitted in your browser by the same WASM core the packages ship. Drag the region sizes or switch the shape and watch it re-solve live. 

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Eunoia fits shapes to the sizes of sets and their intersections. Use the [diagram builder](/app/) to explore your own data, or follow a [quickstart](/docs/) to use Eunoia in your preferred language. 

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## Install

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### Rust

```bash
cargo add eunoia
```

Read the [Rust quickstart](/docs/quickstart/rust/) or the full [Rust API reference](<https://docs.rs/eunoia/>). 

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### JavaScript

```bash
npm install @jolars/eunoia
```

Read the [JavaScript quickstart](/docs/quickstart/javascript/). The WASM bindings power the web app and every interactive example on this site. 

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### Python

```bash
pip install eunoia
```

Read the [Python quickstart](/docs/quickstart/python/). The Python package provides bindings to the Rust core and plotting with matplotlib. 

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### Julia

```julia
using Pkg
Pkg.add("Eunoia")
```

Read the [Julia quickstart](/docs/quickstart/julia/). Eunoia.jl provides bindings to the Rust core and plotting with Makie. 

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### R

```r
install.packages("eulerr")
```

Read the [R quickstart](/docs/quickstart/r/) or the [eulerr documentation](<https://jolars.github.io/eulerr/>). 

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## Why Eunoia?

- Exact n-way intersection geometry for circles and ellipses, with analytical gradients and efficient optimizers.
- Circles, ellipses, squares, rectangles, and rotated rectangles.
- Multiple loss functions and selectable optimizers, including CMA-ES, Levenberg–Marquardt, L-BFGS, and Nelder–Mead.
- Optional bounding containers for fitting the complement of the named sets.
- Customizable labels, glyphs, colors, and exports.
- A pure Rust core with bindings for JavaScript, Python, Julia, and R.

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## Citing Eunoia

If you use Eunoia or its language bindings in academic work, please cite: 

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

The [citation page](/cite/) provides BibTeX, BibLaTeX, CSL, APA, Vancouver, and Chicago formats, along with software-release citations.