Puddin

Fair fa' your honest, sonsie face

Puddin is a collection of mathematical and physical routines for use in gravitational-wave astronomy and astrophysics. It is written in Rust and is designed for accuracy, speed, and accessibility.

Puddin doesn't do data analysis, but you can use it as the core of a more complex algorithm. It's intended to provide the building blocks which keep being redeveloped and reimplemented elsewhere. It's the spiritual successor to the LALSuite library, but with a much more modern design and implementation.

What's in puddin?

• Parameter transforms and conversions (binary system: total mass, mass ratio, symmetric mass ratio, chirp mass, χ_eff, χ_p)
• Useful units and constants (solar mass, SI throughout)
• Compile-time physical unit safety via uom

Language interfaces

Language	Status	Notes
Rust	✅ stable	core crate puddin
Python	✅ stable	pip install puddin; numpy, astropy, pint, JAX all supported
JavaScript/TypeScript	✅ stable	npm install puddin-wasm; vectorised Float64Array API + scalar helpers
Julia	✅ stable	ccall into libpuddin_julia; broadcasting works natively
C / C++	✅ stable	link libpuddin_julia, include bindings/julia/include/puddin.h
Fortran	✅ stable	iso_c_binding + bind(C) — no shim needed
Go	✅ stable	cgo with #cgo LDFLAGS pointing at libpuddin_julia
R	✅ stable	R CMD INSTALL bindings/r; vectorised, testthat suite
MATLAB	✅ stable	loadlibrary / calllib using the C header; no compilation needed

Installation

Python

pip install puddin

Works with plain numpy arrays, astropy quantities, pint quantities, and JAX arrays. JAX integration uses jax.pure_callback so Rust functions are callable inside JIT-compiled code.

import numpy as np
import puddin

MSUN = 1.988_416e30  # kg

m1 = np.array([30.0]) * MSUN
m2 = np.array([30.0]) * MSUN

print(puddin.chirp_mass(m1, m2) / MSUN)   # ~26.1 M☉

JavaScript / TypeScript

npm install puddin-wasm

import { MSUN, chirp_mass_scalar, chirp_mass } from 'puddin-wasm/puddin';

// Scalar convenience function
const mc = chirp_mass_scalar(30 * MSUN, 30 * MSUN);   // kg

// Vectorised (Float64Array in, Float64Array out)
const m1 = new Float64Array([30 * MSUN, 10 * MSUN]);
const m2 = new Float64Array([30 * MSUN,  5 * MSUN]);
const mc_arr = chirp_mass(m1, m2);

Julia

# Build the shared library
cargo build --release -p puddin-julia

import Pkg
Pkg.develop(path="bindings/julia")

using Puddin

mc = chirp_mass(30.0 * MSUN, 30.0 * MSUN)  # scalar
mc = chirp_mass.(m1_array, m2_array)         # vectorised via broadcasting

Rust

[dependencies]
puddin = "0.1"

use puddin::binary;
use uom::si::f64::Mass;
use uom::si::mass::kilogram;

let m = Mass::new::<kilogram>(30.0 * puddin::binary::MSUN);
let mc = binary::chirp_mass(m, m);

Development

# Run all core tests
cargo test -p puddin

# Build Python bindings (requires maturin)
pip install maturin
maturin develop --extras dev --manifest-path bindings/python/pyproject.toml

# Build WASM package (requires wasm-pack)
wasm-pack build --target bundler bindings/wasm