Reformer-pytorch

Implements Reformer: The Efficient Transformer in pytorch. (Work in progress)

Prerequisites

• Tested with Python 3.7.5, Pytorch 1.4.0.
• This code is built upon the pytorch-lightning framework.
• pip install -r requirements.txt

How to train

Datasets

• If you want to modify trainer.py or model\model.py, it is recommended that you familiarize with youself the pytorch-lightning library beforehand.
• A custom copy task & music dataset has been implemented under datasets\dataloader.py. Modify as needed.
• A config yaml file must be placed under config. See provided yaml files for basic framework.

Running the code

• python3 trainer.py -c \path\to\config\yaml -n [name of run] -b [batch size] -f [fast dev run] -v [version number]
• The -f flag is used for debugging; only one batch of training, validation, and testing will be calculated.
• The -v flag is used for resuming from checkpoints; leave empty for new version.
• A toy copy task of length 32, vocab 128 converges around ~6k steps using a batch size of 1024, learning rate of 1e-3 and Adam. The checkpoint is located under checkpoints\.

How to sample

Preparing the checkpoints

• A complete checkpoint folder must be placed under logs\. Use the entire folder pytorch-lightning automatically saves.

Running the code

• A corresponding version number must be provided with a -v flag.
• Run the code with the -s flag set to True. This will generate 1 sample under sample\, if using the music dataset.

To-do

• [x] Implement general framework of Reformer
• [x] Rewrite using pytorch-lightning framework
• [x] Implement Label Smoothing
• [x] Implement LSH attention
• [x] Implement reversible layer
• [x] Implement autoregressive sampling
• [ ] Implement various datasets

Implementation Authors

• June Young Yi @ MINDsLab Inc. (julianyi1@snu.ac.kr, julianyi1@mindslab.ai)

License

MIT License

Acknowlegdements

• The general structure of this code is based on The Annotated Transformer, albeit heavily modified.
• I am aware that reformer-lm exists. However, I was frustrated with the original trax implementation that the authors provided, and decided to rewrite the entire thing from the ground up. Naturally, expect bugs everywhere.
• Thanks to MINDsLab for providing training resources.