hugin

Hugin

Declarative plotting and visualization library for OCaml.

Hugin is part of the Raven ecosystem, providing a functional API to create publication-quality charts and figures from Nx arrays. You build immutable plot specifications with mark constructors, compose them with |> pipelines, and render to PNG, SVG, PDF, or an interactive SDL window.

Features

• Line, scatter, bar, histogram, error bar, fill-between, hline/vline, hspan/vspan
• Heatmap, colormapped image display (imshow), contour plots
• Multi-panel layouts with Layout.grid, Layout.hstack, Layout.vstack
• Perceptually uniform OKLCH colors with colorblind-friendly Okabe-Ito palette
• Predefined colormaps: viridis, plasma, inferno, magma, cividis, coolwarm
• Themes with context scaling (paper, notebook, talk, poster)
• Axis scales: linear, log, sqrt, asinh, symlog
• Cairo rendering (PNG, PDF), pure-OCaml SVG backend, interactive SDL display
• Format printer for Quill notebooks (#install_printer)

Quick Start

open Hugin

let () =
  let x = Nx.linspace Nx.float32 0. 6.28 100 in
  let y = Nx.sin x in
  line ~x ~y () |> title "Sine wave" |> render_png "sine.png"

Contributing

See the Raven monorepo README for guidelines.

License

ISC License. See LICENSE for details.