Neural Machine Translation Codebase in Matlab
Code to train state-of-the-art neural machine translation systems that can handle very complex languages like Czech using hybrid word-character models described in our ACL'16 paper.
This codebase can also train general attention-based models described in our EMNLP'15 paper and has all the functionalities of our previous nmt.matlab codebase.
Why Matlab? It was a great learning experience for me to be able to derive by hand all gradient formulations and implement everything from crash! Matlab supports GPU, so the code is also very fast.
Features:
- Train hybrid word-character as well as general attention-based models.
- Beam-search decoder that can ensembles models including hybrid ones.
- Code to compute source word representations and evaluate on the word similarity tasks or do tsne plots.
- Code to compute sentence representations and rerank scores.
Citations:
If you make use of this codebase in your research, please cite our paper
@inproceedings{luong2016acl_hybrid,
author = {Luong, Minh-Thang and Manning, Christopher D.},
title = {Achieving Open Vocabulary Neural Machine Translation with Hybrid Word-Character Models},
booktitle = {Association for Computational Linguistics (ACL)},
address = {Berlin, Germany},
month = {August},
year = {2016}
}
- Thang Luong [email protected], 2014, 2015, 2016
Files
README.md - this file
code/ - main Matlab code
trainLSTM.m: train models
testLSTM.m: decode models
computeSentRepresentations.m: compute encoder representations.
computeRerankScores.m: compute decoding scores.
data/ - toy data
scripts/ - scripts
Core scripts
- We provide an one-for-all script that performs all the preprocessing steps & train a translation model
1-prepare_and_train.sh <trainPrefix> <validPrefix> <testPrefix> <srcLang> <tgtLang> <wordVocabSize> <charVocabSize> <outDataDir> <outModelDir> [options]
trainPrefix expect train files trainPrefix.(srcLang|tgtLang)
validPrefix expect valid files validPrefix.(srcLang|tgtLang)
testPrefix expect test files testPrefix.(srcLang|tgtLang)
srcLang Source languague
tgtLang Target languague
wordVocabSize Word vocab size.
charVocabSize Character vocab size. If 0, run word-based models.
outDataDir Output data directory where we save preprocessed data
outModelDir Output model directory that we save during training
options Options to trainLSTM
The script is smart enough to check if preprocessed data files have been created in so that we can reuse. When is greater than 0, we will train hybrid word-character models.
Examples
Training
- Process data & train a hybrid model:
./scripts/1-prepare_and_train.sh data/train.10k data/valid.100 data/test.100 de en 1000 50 data.hybrid.50 model.hybrid.w1000.c50
- We can also add options such as dropout (keep probability = 0.8) and use 2-layer character-level models as below:
./scripts/1-prepare_and_train.sh data/train.10k data/valid.100 data/test.100 de en 1000 50 data.hybrid.50 model.hybrid.w1000.c50.dropout0.8.charLayer2 "'dropout',0.8,'charNumLayers',2"
- To train regular attention-based sequence-to-sequence NMT:
./scripts/1-prepare_and_train.sh data/train.10k data/valid.100 data/test.100 de en 1000 0 data.1000 model.w1000
Testing (Decoding)
Miscellaneous
- Gradient checks:
./scripts/run_grad_checks.sh > output/grad_checks.txt 2>&1
Then compare with the provided grad check outputs data/grad_checks.txt. They should look similar.
- The Matlab code/ directory further divides into sub-directories:
basic/: define basic functions like sigmoid, prime. It also has an efficient way to aggreate embeddings.
layers/: we define various layers like attention, LSTM, etc. with forward and backprop code.
misc/: things that we haven't categorized yet.
preprocess/: deal with data.
print/: print results, logs for debugging purposes.
wordsim/: word similarity task