Eunoia

A Rust library for Euler and Venn Diagrams. This is a rewrite of the eulerr R package, designed to be more flexible, faster, and support multiple language bindings.

Narrative documentation lives at eunoia.bz/docs/; the rustdoc reference is at docs.rs/eunoia.

JavaScript / TypeScript

WebAssembly bindings are published as @jolars/eunoia:

npm install @jolars/eunoia

import { euler, venn } from "@jolars/eunoia";

// Fit an Euler diagram from set sizes
const layout = euler({
  sets: { A: 5, B: 2, "A&B": 1 },
  shape: "circle",        // "circle" | "ellipse" | "square"
  output: "shapes",       // "shapes" | "polygons" | "regions"
  inputType: "exclusive", // "exclusive" | "inclusive"
  seed: 42,
});

if (layout.mode === "shapes" && layout.shape === "circle") {
  for (const c of layout.circles) {
    console.log(c.label, c.x, c.y, c.radius);
  }
}
console.log(layout.metrics.loss, layout.metrics.fittedAreas);

// Or build a canonical n-set Venn diagram
const v = venn({ n: 3, output: "regions" });

The package is built with wasm-pack --target bundler, so it works with any modern bundler (Vite, Webpack, Rollup, esbuild) and Node 20+.