[WIP]Consistency Regularization for Semi-supervised Learning with PyTorch

This repositrory includes consistency regularization algorithms for semi-supervised learning:

• Pi-Model
• Pseudo-label
• Mean Teacher
• Virtual Adversarial Training
• Interpolation Consistency Training
• Unsupervised Data Augmentation
• FixMatch (with RandAugment)

Training and evaluation setting follow Oliver+ 2018 and FixMatch.

Requirements

• Python >= 3.7
• PyTorch >= 1.0
• torchvision >= 0.4
• NumPy
• sklearn (optional)

sklean is used for moon_data_exp.py (two moons dataset experiment)

Usage

One can use sh ./scripts/DATASET_NAME/ALGORITHM.sh /PATH/TO/OUTPUT_DIR NUM_LABELS, for example, to reproduce fixmatch in CIFAR-10 with 250 labels results, run

sh ./scripts/fixmatch-setup/cifar10/fixmatch.sh ./results/cifar10-fixmatch-250labeles 250

The scripts in scripts/fixmatch-setup are for training and evaluating a model with the FixMatch setting, and the scripts in scripst/realistic-evaluation-setup are for training and evaluating a model with the Oliver+ 2018 setting.

If yor would like to train a model with own setting, please see parser.py.

NOTE: train_test.py evaluates a model performance as median of last [1, 10, 20, 50] checkpoint accuracies (FixMatch setting), and train_val_test.py evaluates the test accuracy of the best model on validation data (Oliver+ 2018 setting).

Performance

WIP

	Oliver+ 2018		this repo
	CIFAR-10 4000 labels	SVHN 1000 labels	CIFAR-10 4000 labels	SVHN 1000 labels
Supervised	20.26 ±0.38	12.83 ±0.47	19.85	11.03
Pi-Model	16.37 ±0.63	7.19 ±0.27	14.84	7.87
Mean Teacher	15.87 ±0.28	5.65 ±0.47	14.28	5.83
VAT	13.13 ±0.39	5.35 ±0.19	12.15	6.38

NOTE: Our implementation is different from Oliver+ 2018 as follows:

1. we use not only purely unlabeled data, but also labeled data as unlabeled data. (following Sohn+ 2020)
2. our VAT implementation follows Miyato+, but Oliver+ use KLD with different directions as the loss function. see issue.
3. parameter initialization of WRN-28. (following Sohn+ 2020)

If you would like to evaluate the model with the same conditions as Oliver+ 2018, please see this repo.

	Sohn+ 2020		this repo
	CIFAR-10 250 labels	CIFAR-10 4000 labels	CIFAR-10 250 labels	CIFAR-10 4000 labels
UDA	8.82±1.08	4.88±0.18	10.08	6.32
FixMatch	5.07±0.65	4.26±0.05	9.88	6.84

reported error rates are the median of last 20 checkpoints

Citation

@misc{suzuki2020consistency,
    author = {Teppei Suzuki},
    title = {Consistency Regularization for Semi-supervised Learning with PyTorch},
    year = {2020},
    publisher = {GitHub},
    journal = {GitHub repository},
    howpublished = {\url{https://github.com/perrying/pytorch-consistency-regularization}},
}

References

• Miyato, Takeru, et al. "Distributional smoothing with virtual adversarial training." arXiv preprint arXiv:1507.00677 (2015).
• Laine, Samuli, and Timo Aila. "Temporal ensembling for semi-supervised learning." arXiv preprint arXiv:1610.02242 (2016).
• Sajjadi, Mehdi, Mehran Javanmardi, and Tolga Tasdizen. "Regularization with stochastic transformations and perturbations for deep semi-supervised learning." Advances in neural information processing systems. 2016.
• Tarvainen, Antti, and Harri Valpola. "Mean teachers are better role models: Weight-averaged consistency targets improve semi-supervised deep learning results." Advances in neural information processing systems. 2017.
• Miyato, Takeru, et al. "Virtual adversarial training: a regularization method for supervised and semi-supervised learning." IEEE transactions on pattern analysis and machine intelligence 41.8 (2018): 1979-1993.
• Oliver, Avital, et al. "Realistic evaluation of deep semi-supervised learning algorithms." Advances in Neural Information Processing Systems. 2018.
• Verma, Vikas, et al. "Interpolation consistency training for semi-supervised learning." arXiv preprint arXiv:1903.03825 (2019).
• Sohn, Kihyuk, et al. "Fixmatch: Simplifying semi-supervised learning with consistency and confidence." arXiv preprint arXiv:2001.07685 (2020).