Introduction

NCVX (NonConVeX) is a user-friendly and scalable python software package targeting general nonsmooth NCVX problems with nonsmooth constraints. NCVX is being developed by GLOVEX at the Department of Computer Science & Engineering, University of Minnesota, Twin Cities.

The initial release of NCVX contains the solver PyGRANSO, a PyTorch-enabled port of GRANSO incorporating auto-differentiation, GPU acceleration, tensor input, and support for new QP solvers. As a highlight, PyGRANSO can solve deep learning problems with nontrivial constraints (e.g., constraints with neural networks), the first of its kind.

NCVX is AGPL v3.0 licensed but also contains some code under other compatible licenses. More information on this can be found in LICENSE_INFO subfolders.

Solver/Module

PyGRANSO: A PyTorch-enabled port of GRANSO with auto-differentiation Documentation | Repository

Installation

1. Clone the NCVX git repository and submodules

    git clone https://github.com/sun-umn/NCVX
    git submodule update --init --recursive

2. Follow the install instructions in the README.md of each submodule you wish to use (currently, only PyGRANSO)

Note: Downloading a zip file of the NCVX repo directly from GitHub will NOT contain submodules files.

Citation

If you publish work that uses or refers to NCVX, please cite the following two papers:

[1] Buyun Liang, Tim Mitchell, and Ju Sun, NCVX: A User-Friendly and Scalable Package for Nonconvex Optimization in Machine Learning, arXiv preprint arXiv:2111.13984 (2021). Available at https://arxiv.org/abs/2111.13984

[2] Frank E. Curtis, Tim Mitchell, and Michael L. Overton, A BFGS-SQP method for nonsmooth, nonconvex, constrained optimization and its evaluation using relative minimization profiles, Optimization Methods and Software, 32(1):148-181, 2017. Available at https://dx.doi.org/10.1080/10556788.2016.1208749

BibTex:

@article{liang2021ncvx,
    title={{NCVX}: {A} User-Friendly and Scalable Package for Nonconvex 
    Optimization in Machine Learning}, 
    author={Buyun Liang, Tim Mitchell, and Ju Sun},
    year={2021},
    eprint={2111.13984},
    archivePrefix={arXiv},
    primaryClass={cs.LG}
}

@article{curtis2017bfgssqp,
    title={A {BFGS-SQP} method for nonsmooth, nonconvex, constrained optimization and its evaluation using relative minimization profiles},
    author={Frank E. Curtis, Tim Mitchell, and Michael L. Overton},
    journal={Optimization Methods and Software},
    volume={32},
    number={1},
    pages={148--181},
    year={2017},
    publisher={Taylor \& Francis}
}