Installation

Requirements

The Free Fermion Library requires Python 3.8 or higher and the following dependencies:

  • NumPy >= 1.20.0

  • SciPy >= 1.7.0

  • NetworkX >= 2.6.0

  • Matplotlib >= 3.3.0

Install from PyPI

The easiest way to install the Free Fermion Library is using pip:

pip install free-fermion-lib

This will automatically install all required dependencies.

Install from Source

To install the latest development version from GitHub:

git clone https://github.com/jdwhitfield/free-fermion-lib.git
cd free-fermion-lib
pip install -e .

Development Installation

For development work, install with optional development dependencies:

git clone https://github.com/jdwhitfield/free-fermion-lib.git
cd free-fermion-lib
pip install -e ".[dev]"

This includes additional tools for testing and code quality:

  • pytest >= 6.0

  • pytest-cov >= 2.0

  • black >= 21.0

  • flake8 >= 3.8

  • mypy >= 0.800

Documentation Dependencies

To build the documentation locally:

pip install -e ".[docs]"

This includes:

  • sphinx >= 4.0

  • sphinx-rtd-theme >= 1.0

  • nbsphinx >= 0.8

Virtual Environment Setup

It’s recommended to use a virtual environment:

# Create virtual environment
python -m venv ff-env

# Activate (Linux/macOS)
source ff-env/bin/activate

# Activate (Windows)
ff-env\Scripts\activate

# Install the library
pip install free-fermion-lib

Conda Installation

If you prefer conda, you can create an environment with the required dependencies:

conda create -n ff-env python=3.9 numpy scipy matplotlib networkx
conda activate ff-env
pip install free-fermion-lib

Verification

To verify your installation, run:

python -c "import ff; print(f'Free Fermion Library v{ff.__version__} installed successfully!')"

You should see output confirming the installation and version number.

Troubleshooting

Common Issues

ImportError: No module named ‘ff’

Make sure you’ve installed the package correctly. Try reinstalling with:

pip uninstall free-fermion-lib
pip install free-fermion-lib
Dependency conflicts

If you encounter dependency conflicts, try creating a fresh virtual environment:

python -m venv fresh-env
source fresh-env/bin/activate  # or fresh-env\Scripts\activate on Windows
pip install free-fermion-lib
Jupyter notebook issues

If using Jupyter notebooks, make sure to install the library in the same environment as Jupyter:

pip install jupyter
pip install free-fermion-lib

Getting Help

If you encounter issues:

  1. Check the GitHub Issues

  2. Create a new issue with details about your system and the error

  3. Include the output of:

    python -c "import sys; print(sys.version)"
pip list | grep -E "(numpy|scipy|networkx|matplotlib|free-fermion)"