Installation¶

From PyPI (recommended)¶

pip install skein-glm

Pre-built ABI3 wheels are published for:

Linux x86_64 and aarch64
macOS x86_64 (Intel) and arm64 (Apple Silicon)
Windows AMD64

Wheels target Python 3.10+ (one ABI3 wheel per platform covers all supported minor versions). Runtime dependencies are numpy>=1.24, scipy>=1.10, and scikit-learn>=1.3.

From source¶

If a wheel isn’t available for your platform (or you want to develop against the Rust core), build from source. You’ll need a Rust toolchain (stable channel) and maturin:

# 1. Install Rust if you don't have it.
curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh

# 2. Build + install the package into the active Python env.
pip install maturin
git clone https://github.com/dvillacis/skein
cd skein
# Pass the BLAS feature flag for your platform — the shipped PyPI
# wheels are built this way, and skipping it leaves ndarray on a
# pure-Rust matvec fallback that's ~3× slower on the GLM hot path.
maturin develop --release --features=blas-accelerate   # macOS
maturin develop --release --features=blas-openblas     # Linux

maturin develop builds the Rust extension and registers an editable install. Subsequent edits to the Rust core require re-running maturin develop --release --features=...; edits to pure-Python code under python/skein_glm/ take effect immediately.

Development install¶

If you want to run the test suite, lint, or build docs locally:

maturin develop --release --features=blas-accelerate   # or blas-openblas on Linux
pip install -e ".[dev,docs]"

The [dev] extras pull in pytest, pytest-cov, ruff, and mypy; [docs] adds Sphinx (sphinx, furo, myst-parser, sphinx-copybutton, sphinx-design). After that:

# Rust tests (fast iteration, no Python rebuild needed).
cargo test -p skein-core --lib

# Python tests (require maturin develop first).
pytest

# Lint.
cargo fmt --all -- --check
cargo clippy --workspace --all-targets -- -D warnings
ruff check python/ tests/
mypy python/

# Docs (build to docs/_build/html). CI runs with -W (warnings = errors).
sphinx-build -b html docs docs/_build/html

Platform notes¶

Apple Silicon (macOS arm64)¶

Wheels are native arm64 — no Rosetta translation. If you previously ran pip install under x86_64 Python and switch to arm64 Python, delete the cached wheel (pip cache purge) before reinstalling.

Linux aarch64¶

The aarch64 wheel is built under QEMU emulation in CI (the test step is skipped under emulation; we run the full suite on x86_64). On a real aarch64 host the wheel runs at native speed.

Windows¶

Pure MSVC build, no Cygwin / MSYS2 dependency. Building from source requires the MSVC toolchain (Visual Studio Build Tools is enough); rustup will pick it up automatically.

Verifying the install¶

import skein_glm
import numpy as np

rng = np.random.default_rng(0)
X = rng.standard_normal((100, 10))
y = X[:, 0] - 2 * X[:, 1] + 0.1 * rng.standard_normal(100)
model = skein_glm.MCPRegressor(lambda_=0.05, gamma=3.0).fit(X, y)
print(model.coef_)         # should recover [~1, ~-2, 0, ..., 0]
print(model.intercept_)    # near 0

If that runs, you’re good.