pyghl 0.2.1

Python bindings for GRHayL (EOS-first preview)

pyghl

Python bindings and neural-network tooling for GRHayL.

pyghl packages a pinned GRHayL build together with a CPython extension and Python utilities for tabulated equations of state, conservative-to-primitive experiments, and neural-network initial guesses.

Warning

While revised by humans, the majority of the code in this repository has leveraged AI assistance. Users should review results carefully and use this package at their own risk.

At a high level:

• pyghl exposes selected GRHayL C structs and routines to Python.
• pyghl.eos provides tabulated-EOS loading and interpolation helpers.
• pyghl.nn provides neural-network con2prim data, training, export, and EOS embedding helpers.
• pyghl train trains a neural-network model for an EOS table.
• pyghl append-eos embeds a trained model into an EOS HDF5 file.

Installation

For end users installing from PyPI:

python -m pip install pyghl

Check the installed package:

pyghl --version

For contributors working from a clone of this repository:

git clone https://github.com/GRHayL/pyghl.git
cd pyghl
git submodule update --init --recursive
python -m pip install -e .

The local build compiles the pinned GRHayL submodule in extern/GRHayL and then builds the Python extension against the resulting libghl.

If you need to build against a different local GRHayL checkout:

GRHAYL_DIR=/path/to/GRHayL python -m pip install -e .

Prerequisites by Workflow

python -m pip install pyghl should install a prebuilt wheel on supported platforms. Source builds need additional system tools:

• Local extension builds: a C compiler, make, HDF5, and Python build tooling.
• Editable contributor installs: initialized extern/GRHayL submodule.
• Neural-network training: torch, numpy, and h5py from package dependencies.
• EOS workflows: a GRHayL-compatible tabulated EOS HDF5 file.

Current CI builds wheels for Linux x86_64 and macOS arm64.

First Successful Run

The quickest useful workflow is to train a small model for an EOS table and append the result back into that EOS file.

1. Train a model

pyghl train path/to/eos_table.h5

This creates training data if no dataset is supplied, trains a small neural network, writes model artifacts such as tiny_mlp_model.h5, and registers the installed model by the EOS canonical MD5 hash.

To train from an existing dataset:

pyghl train path/to/eos_table.h5 path/to/nn_training_dataset.bin

2. Append a model to an EOS file

Append an explicit model:

pyghl append-eos path/to/eos_table.h5 tiny_mlp_model.h5

Or append the installed model matching the EOS canonical MD5 hash:

pyghl append-eos path/to/eos_table.h5

3. Inspect installed models

python -m pyghl.nn_c2p.list_installed_models

Python API Example

import pyghl as ghl

params = ghl.initialize_params()
eos = ghl.eos.initialize_tabulated_eos_functions_and_params(
    params,
    "path/to/eos_table.h5",
)

rho = 1.0e-12
Y_e = 0.05
T = 1.0e2

rho, Y_e, T = eos.tabulated_enforce_bounds_rho_Ye_T(rho, Y_e, T)
pressure = eos.tabulated_compute_P_from_T(rho, Y_e, T)
print(pressure)

Command-Line Tools

Primary commands:

pyghl train <eos-file> [dataset]
pyghl append-eos <eos-file> [nn-hdf5]
pyghl --version

Additional module entry points:

python -m pyghl.nn_c2p.nn_c2p_generate_dataset ...
python -m pyghl.nn_c2p.nn_c2p_train ...
python -m pyghl.nn_c2p.nn_c2p_test ...
python -m pyghl.nn_c2p.append_eos_file ...
python -m pyghl.nn_c2p.check_eos ...
python -m pyghl.nn_c2p.list_installed_models
python -m pyghl.nn_c2p.remove_eos_nn ...

What Is Exposed?

Selected top-level bindings include:

• initialize_params
• initialize_metric
• compute_ADM_auxiliaries
• initialize_primitives
• initialize_diagnostics
• compute_conservs
• undensitize_conservatives
• compute_SU_Bsq_Ssq_BdotS
• limit_v_and_compute_u0
• limit_utilde_and_compute_v
• guess_primitives
• tabulated_Palenzuela1D_energy
• tabulated_con2prim_multi_method
• nn_c2p_guess
• nn_c2p_guess_x

Struct wrappers include:

• Primitive
• Conservative
• Metric
• ADMAux
• Diagnostics
• Params
• TabulatedEOS

Repository Map

• csrc/: CPython extension source.
• src/pyghl/: Python package.
• src/pyghl/nn_c2p/: command-line neural-network workflows.
• examples/: direct example scripts.
• extern/GRHayL/: pinned GRHayL submodule used for builds.
• .github/workflows/: wheel and PyPI publishing automation.
• PUBLISHING.md: release and PyPI publishing checklist.

Contributor Setup

Recommended local workflow:

git submodule update --init --recursive
python -m pip install -e .
python -m compileall -q src setup.py

Build a local wheel:

python -m pip wheel . -w /tmp/pyghl-wheel --no-deps --no-build-isolation

If editable installs are not available in your environment, many Python-only checks can be run from the repository root with:

PYTHONPATH=src python -m pyghl.nn_c2p.list_installed_models