OpenJij : Framework for the Ising model and QUBO.

• Python 3.10-3.14

• (optional) gcc >= 7.0.0

• (optional) cmake >= 3.22

• (optional) Ninja

• OpenJij Website

• Documents

• C++ Docs

Citation

Click the "Cite this repository" button on the right sidebar to get the citation for the latest version (BibTeX and APA formats).

DOI for all versions:

Note for Reproducibility: Please specify the exact version of OpenJij used in your work. You can find the version number by running pip show openjij.

install

install via pip

Note: (2023/08/09) GPGPU algorithms will no longer be supported.

# Binary
$ pip install openjij 
# From Source
$ pip install --no-binary=openjij openjij

install via pip from source codes

To install OpenJij from source codes, please install CMake first then install OpenJij.

cmake setup

For development installation, you will need to install CMake>=3.22.
We highly recommend installing CMake via PYPI.

$ pip install -U cmake

Make sure the enviroment path for CMake is set correctly.

install OpenJij

$ pip install --no-binary=openjij openjij

install from github repository

$ git clone git@github.com:OpenJij/OpenJij.git
$ cd openjij
$ python -m pip install -vvv .

Development Install (Recommended for Contributors)

OpenJij uses uv for efficient dependency management and reproducible development environments.

# Clone repository
$ git clone git@github.com:OpenJij/OpenJij.git
$ cd OpenJij

# Install uv (choose one method)
$ pip install uv                                 # Recommended
# or: curl -LsSf https://astral.sh/uv/install.sh | sh  # macOS/Linux
# or: brew install uv                           # Homebrew

# Set up development environment with exact dependency versions
$ uv sync --locked --group dev

# Verify installation (includes C++ extension build)
$ uv run python -c "import openjij; import openjij.cxxjij; print('OpenJij setup complete')"
$ uv run pytest tests/ -v --tb=short

Dependency Groups

OpenJij uses PEP 735 dependency groups for efficient quantum computing development:

Dependency management:

• Reproducible builds (CI/CD, team collaboration): uv sync --locked --group dev
• Latest versions (local development): uv sync --group dev
• Update dependencies: uv lock or uv lock --upgrade

All dependencies are locked in uv.lock for consistent environments across different systems.

C++ Extension Integration

OpenJij's C++ extensions are built automatically during installation for optimal quantum computing performance:

# Development with C++ code modifications
$ uv sync --group dev                           # Initial setup
# ... modify C++ source files ...
$ uv run pip install .  # Rebuild C++ extension
$ uv run python -c "import openjij.cxxjij; print('C++ extension updated')"

Test

Python Tests

# Install test dependencies with exact versions
$ uv sync --locked --group test

# Run comprehensive test suite
$ uv run pytest tests/ -v --tb=short
$ uv run pytest tests/ -v --cov=openjij --cov-report=html
$ uv run python -m coverage html

C++ Tests

# Build and run C++ tests (independent of Python environment)
$ mkdir build 
$ cmake -DCMAKE_BUILD_TYPE=Debug -S . -B build
$ cmake --build build --parallel
$ cd build
$ ./tests/cxxjij_test

# Alternative: Use CTest for comprehensive testing
$ ctest --extra-verbose --parallel --schedule-random

Requirements: CMake ≥ 3.22, C++17 compatible compiler

Code Quality

# Install formatting tools with exact versions
$ uv sync --locked --group format

# Unified ruff-based quality checks
$ uv run ruff check .                        # Lint check
$ uv run ruff format .                       # Format code
$ uv run ruff check . --fix                  # Auto-fix issues

# All-in-one quality verification
$ uv run ruff check . && uv run ruff format --check .

For Contributors

Contributors are welcome! Please follow these guidelines:

1. Set up development environment: Use uv sync --locked --group dev for consistent setup
2. Follow code standards: Run quality checks before submitting
3. Test thoroughly: Ensure both Python and C++ tests pass
4. Document changes: Update relevant documentation

How to use

Python example

import openjij as oj
sampler = oj.SASampler()
response = sampler.sample_ising(h={0: -1}, J={(0,1): -1})
response.states
# [[1,1]]

# with indices
response = sampler.sample_ising(h={'a': -1}, J={('a','b'): 1})
[{index: s for index, s in zip(response.indices, state)} for state in response.states]
# [{'b': -1, 'a': 1}]

Community

• OpenJij Discord Community

About us

This product is maintained by Jij Inc.

Please visit our website for more information! https://www.j-ij.com/

Licences

Copyright 2023 Jij Inc.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

 http://www.apache.org/licenses/LICENSE-2.0  

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.