Vsgd

Variational Stochastic Gradient Descent for Deep Neural Networks

This repository contains the source code accompanying the paper:

Variational Stochastic Gradient Descent for Deep Neural Networks
<br/> [Demos]

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<br/>Anna Kuzina*, Haotian Chen*, Babak Esmaeili, & Jakub M. Tomczak.

Abstract

Optimizing deep neural networks is one of the main tasks in successful deep learning. Current state-of-the-art optimizers are adaptive gradient-based optimization methods such as Adam. Recently, there has been an increasing interest in formulating gradient-based optimizers in a probabilistic framework for better estimation of gradients and modeling uncertainties. Here, we propose to combine both approaches, resulting in the Variational Stochastic Gradient Descent (VSGD) optimizer. We model gradient updates as a probabilistic model and utilize stochastic variational inference (SVI) to derive an efficient and effective update rule. Further, we show how our VSGD method relates to other adaptive gradient-based optimizers like Adam. Lastly, we carry out experiments on two image classification datasets and four deep neural network architectures, where we show that VSGD outperforms Adam and SGD.

<img src="pics/pgm_vsgd_2.png" height="180"/> <img src="pics/cifar100_res.png" height="180"/>

Repository structure

Folders

This repository is organized as follows:

• src contains the main PyTorch library
• configs contains the default configuration for src/run_experiment.py
• notebooks contains a demo of using VSGD optimizer

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Reproduce

Install conda (recommended)

conda env create -f environment.yml
conda activate vsgd

Login wandb (recommended)

wandb login 

Download TinyImagenet dataset

cd data/
wget http://cs231n.stanford.edu/tiny-imagenet-200.zip
unzip tiny-imagenet-200.zip 

Starting an experiment

All the experiments are run with src/run_experiment.py. Experiment configuration is handled by Hydra, one can find default configuration in the configs/ folder.

configs/experiment/ contains configs for dataset-architecture pairs. For example, to train VGG model on cifar100 dataset with VSGD optimizer, run:

PYTHONPATH=src/ python src/run_experiment.py experiment=cifar100_vgg  train/optimizer=vsgd 

One can also change any default hyperparameters using the command line:

PYTHONPATH=src/ python src/run_experiment.py experiment=cifar100_vgg  train/optimizer=vsgd train.optimizer.weight_decay=0.01 

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Cite

If you found this work useful in your research, please consider citing:

@article{
    chen2024variational,
    title={Variational Stochastic Gradient Descent for Deep Neural Networks},
    author={Chen, Haotian and Kuzina, Anna and Esmaeili, Babak and Tomczak, Jakub},
    year={2024},
}

Acknowledgements

Anna Kuzina is funded by the Hybrid Intelligence Center, a 10-year programme funded by the Dutch Ministry of Education, Culture and Science through the Netherlands Organisation for Scientific Research, https://hybrid-intelligence-centre.nl. This work was carried out on the Dutch national e-infrastructure with the support of SURF Cooperative.