eunoia 0.1.0

Area-proportional Euler and Venn diagrams

eunoia

Python bindings for the eunoia Rust library — area-proportional Euler and Venn diagrams. Sister package to the R package eulerr.

Status: v0.1.0 — initial release. The user-facing surface may evolve.

Install

pip install eunoia

Quickstart

import eunoia as eu
import matplotlib.pyplot as plt

# Disjoint (per-region) input is the default.
fit = eu.euler({"A": 10, "B": 5, "A&B": 3})
print(fit)
# EulerFit (2 circles, diag_error=2.776e-17, stress=5.887e-33, loss=5.887e-33)
#                  original      fitted    residual regionError
#   A                    10          10           0           0
#   B                     5           5           0           0
#   A&B                   3           3   8.882e-16   2.776e-17

fit.plot()
plt.show()

Inclusive input

If your numbers are set sizes that already include their overlaps, pass input="inclusive" and the eunoia core handles the inclusion-exclusion conversion:

fit = eu.euler({"A": 13, "B": 8, "A&B": 3}, input="inclusive")

Ellipses

Ellipses are more flexible than circles and fit many three-set arrangements exactly:

fit = eu.euler(
    {"A": 2, "B": 2, "C": 2, "A&B": 1, "A&C": 1, "B&C": 1},
    shape="ellipse",
)
print(fit.diag_error)  # ~1e-14
fit.plot(quantities=True)

Plot styling

fit.plot(
    colors=["#e41a1c", "#377eb8", "#4daf4a"],   # per-set
    quantities="fitted",                          # show fitted areas at region anchors
    labels=True,                                  # set names at set anchors
    edges={"linewidth": 1.5},
)

Public API

Function / class	Purpose
eunoia.euler(values, …)	Fit a diagram from a {combination: area} dict
eunoia.EulerFit	Result class with shapes, fitted values, metrics
eunoia.Circle / Ellipse	Per-set fitted shape
eunoia.Point	2D point
eunoia.EunoiaError	Base error type (subclass of ValueError)

Status & roadmap (v0.1.0 → v0.2)

In v0.1.0:

• dict input only, with input="exclusive" / "inclusive"
• circle and ellipse shapes
• matplotlib-based plotting

Deferred to v0.2+:

• venn() (non-proportional, 1–5 sets)
• error_plot() diagnostic
• list-of-sets / DataFrame input
• complement (universe area outside all sets)
• square and rectangle shapes
• exposed optimizer / tolerance knobs

License

MIT