/ecole

Extensible Combinatorial Optimization Learning Environments

Primary LanguageC++BSD 3-Clause "New" or "Revised" LicenseBSD-3-Clause

Ecole logo

Ecole

CircleCI

Conda Version

Conda Platforms

Ecole (pronounced [ekɔl]) stands for Extensible Combinatorial Optimization Learning Environments and aims to expose a number of control problems arising in combinatorial optimization solvers as Markov Decision Processes (i.e., Reinforcement Learning environments). Rather than trying to predict solutions to combinatorial optimization problems directly, the philosophy behind Ecole is to work in cooperation with a state-of-the-art Mixed Integer Linear Programming solver that acts as a controllable algorithm.

The underlying solver used is SCIP, and the user facing API is meant to mimic the OpenAi Gym API (as much as possible).

import ecole

env = ecole.environment.Branching(
    reward_function=-1.5 * ecole.reward.LpIterations() ** 2,
    observation_function=ecole.observation.NodeBipartite(),
)
instances = ecole.instance.SetCoverGenerator()

for _ in range(10):
    obs, action_set, reward_offset, done, info = env.reset(next(instances))
    while not done:
       obs, action_set, reward, done, info = env.step(action_set[0])

Documentation

Consult the user Documentation for tutorials, examples, and library reference.

Discussions and help

Head to Github Discussions for interaction with the community: give and recieve help, discuss intresting envirnoment, rewards function, and instances generators.

Installation

Conda

conda install -c scipopt -c conda-forge ecole

Pip

Currently unavailable

From Source and Other Options

Checkout the installation instructions in the documentation for more information, including manually installing from source.

Use It, Cite It

If you use Ecole in a scientific publication, please cite the Ecole publication.

@inproceedings{
    prouvost2020ecole,
    title={Ecole: A Gym-like Library for Machine Learning in Combinatorial Optimization Solvers},
    author={Antoine Prouvost and Justin Dumouchelle and Lara Scavuzzo and Maxime Gasse and Didier Ch{\'e}telat and Andrea Lodi},
    booktitle={Learning Meets Combinatorial Algorithms at NeurIPS2020},
    year={2020},
    url={https://openreview.net/forum?id=IVc9hqgibyB}
}