Bayesian Subspace Multinomial Model (BaySMM)

• Model for learning document embeddings (i-vectors) along with their uncertainties.
• Gaussian linear classifier exploiting the uncertainties in document embeddings.
• See paper http://arxiv.org/abs/1908.07599

S. Kesiraju, O. Plchot, L. Burget and S. V. Gangashetty, "Learning Document Embeddings Along With Their Uncertainties," in IEEE/ACM Transactions on Audio, Speech, and Language Processing, vol. 28, pp. 2319-2332, 2020, doi: 10.1109/TASLP.2020.3012062.

Requirements

• Python >= 3.7

• PyTorch >= 1.1 <=1.4

• scipy >= 1.3

• numpy >= 1.16.4

• scikit-learn >= 0.21.2

• h5py >= 2.9.0

• See INSTALL.md for detailed instructions.

Data preparation - sample from 20Newsgroups

python src/create_sample_data.py.py sample_data/

Training the model

• For help:

  python src/run_baysmm.py --help

• To train on GPU set CUDA_VISIBLE_DEVICES=$GPU_ID where the $GPU_ID is the free GPU index

• Following code trains the model for 1000 VB iterations and saves the model in an automatically created sub-directory: exp/s_1.00_rp_1_lw_1e+01_l1_1e-03_50_adam/

  python src/run_baysmm.py train \
      sample_data/train.mtx \
      sample_data/vocab \
      exp/ \
      -K 50 \
      -trn 1000 \
      -lw 1e+01 \
      -var_p 1e+01 \
      -lt 1e-03

• ELBO and KLD for every iteration, log file, etc are saved in the sub-directory.

Extracting the posterior distributions of embeddings

• Extract embeddings [mean, log.std.dev] for 1000 iterations for each of the stats file present in sample_data/mtx.flist file list.

• Using -nth 100 argument, embeddings for every 100th iteration are also saved.

  python src/run_baysmm.py extract \
      sample_data/mtx.flist \
      exp/s_1.00_rp_1_lw_1e+01_l1_1e-03_50_adam/model_T1000.h5 \
      -xtr 1000 \
      -nth 100

• Extracted embedding posterior distributions are saved in exp/*/ivecs/ sub-directory with appropriate names.

Training and testing the classifier

• Three classifiers can be trained on these embeddings.
• Use --final option to train and test classifier on embeddings from the final iteration.

1. Gaussian linear classifier - uses only the mean parameter

   python src/train_and_clf_cv.py exp/s_1.00_rp_1_lw_1e+01_l1_1e-03_50_adam/ivecs/train_model_T1000_e1000.h5 sample_data/train.labels glc

2. Multi-class logistic regression - uses only the mean parameter

   python src/train_and_clf_cv.py exp/s_1.00_rp_1_lw_1e+01_l1_1e-03_50_adam/ivecs/train_model_T1000_e1000.h5 sample_data/train.labels lr

3. Gaussian linear classifier with uncertainty - uses full posterior distribution

   python src/train_and_clf_cv.py exp/s_1.00_rp_1_lw_1e+01_l1_1e-03_50_adam/ivecs/train_model_T1000_e1000.h5 sample_data/train.labels glcu

• All the results and predicted classes are saved in exp/*/results/

Citation

@ARTICLE{Kesiraju:2020:BaySMM,
  author={Kesiraju, Santosh and Plchot, Oldřich and Burget, Lukáš and Gangashetty, Suryakanth V.},
  journal={IEEE/ACM Transactions on Audio, Speech, and Language Processing}, 
  title={Learning Document Embeddings Along With Their Uncertainties}, 
  year={2020},
  volume={28},
  number={},
  pages={2319-2332},
  doi={10.1109/TASLP.2020.3012062}}