# Contributing

Thanks for your interest in improving Greenwood! This project is in active early development (see [`ROADMAP.md`](../ROADMAP.md)). Contributions of code, tests, docs, and R-parity fixtures are all welcome.


# Development setup

``` bash
git clone https://github.com/rich-iannone/greenwood.git
cd greenwood
python -m venv .venv && source .venv/bin/activate
make install          # pip install -e ".[dev]"
pre-commit install    # optional but recommended
```


# The check gate

Before opening a pull request, make sure the full gate is green:

``` bash
make check            # ruff format + ruff check + pyright + pytest
```

Individual targets: `make lint`, `make type-check`, `make test`, `make test-rparity`. Run `make help` for the full list.


# House conventions

- **R-validated numerics.** Correctness to tolerance against R's `survival` (and `cmprsk`/`flexsurv`/`riskRegression`/`mstate` for specialized estimators) is the brand. Regenerate fixtures with `Rscript scripts/regenerate_r_fixtures.R` and validate with `make test-rparity`.
- **Narwhals-native.** Never assume pandas; write data handling against Narwhals and drop to NumPy only inside numeric kernels.
- **Typed & deterministic.** Full type hints (`py.typed`), `pyright` clean, byte-identical output for identical inputs.
- **Prose style.** Docstrings use Quarto/Markdown, not RST: single backticks for inline code, numpydoc section headers (`Parameters`, `Returns`).
- Implementation lives in underscore-prefixed private modules; the public surface is curated explicitly in `__init__.py`.


# Pull requests

- Keep PRs focused and add tests for new behavior (target \>=90% coverage).
- For new/changed statistics, add or update R-parity fixtures.
- Update docs (docstrings, `user_guide/`) alongside code.

By contributing you agree that your contributions are licensed under the MIT License.