BNAF

Pytorch implementation of Block Neural Autoregressive Flow based on our paper:

De Cao Nicola, Titov Ivan and Aziz Wilker, Block Neural Autoregressive Flow (2019)

Requirements

• python>=3.6 (it will probably work on older versions but I have not tested on them)
• pytorch>=1.0.0

Optional for visualization and plotting: numpy, matplotlib and tensorboardX

Structure

• bnaf.py: Implementation of Block Neural Normalzing Flow.
• toy2d.py: Experiments of 2d toy task (density estimation and energy matching).
• density_estimation.py: Experiments on density estimation on real datasets.
• optim: A custom extension of torch.optim.Adam and torch.optim.Adamax with Polyak averaging. A custom extension of torch.optim.lr_scheduler.ReduceLROnPlateau with callbacks.
• data: Data classes to handle the real datasets.

Usage

Below, example commands are given for running experiments.

Download datasets

Run the following command to download the datasets:

./download_datasets.sh

Run 2D toy density estimation

This example runs density estimation on the 8 Gaussians dataset using 1 flow of BNAF with 2 layers and 100 hidden units (50 * 2 since the data dimensionality is 2).

python toy2d.py --dataset 8gaussians \    # which dataset to use
                --experiment density2d \  # which experiment to run
                --flows 1 \               # BNAF flows to concatenate
                --layers 2 \              # layers for each flow of BNAF
                --hidden_dim 50 \         # hidden units per dimension for each hidden layer
                --save                    # save the model after training
                --savefig                 # save the density plot on disk

Run 2D toy energy matching

This example runs energy matching on the t4 function using 1 flow of BNAF with 2 layers and 100 hidden units (50 * 2 since the data dimensionality is 2).

python toy2d.py --dataset t4 \            # which dataset to use
                --experiment energy2d \   # which experiment to run
                --flows 1 \               # BNAF flows to concatenate
                --layers 2 \              # layers for each flow of BNAF
                --hidden_dim 50 \         # hidden units per dimension for each hidden layer
                --save                    # save the model after training
                --savefig                 # save the density plot on disk

Run real dataset density estimation

This example runs density estimation on the MINIBOONE dataset using 5 flows of BNAF with 0 layers.

python density_estimation.py --dataset miniboone \  # which dataset to use
                             --flows 5 \            # BNAF flows to concatenate
                             --layers 0 \           # layers for each flow of BNAF
                             --hidden_dim 10 \      # hidden units per dimension for each hidden layer
                             --save                 # save the model after training

Citation

De Cao Nicola, Titov Ivan, Aziz Wilker,
Block Neural Autoregressive Flow,
35th Conference on Uncertainty in Artificial Intelligence (UAI19) (2019).

BibTeX format:

@article{bnaf19,
  title={Block Neural Autoregressive Flow},
  author={De Cao, Nicola and
          Titov, Ivan and
          Aziz, Wilker},
  journal={35th Conference on Uncertainty in Artificial Intelligence (UAI19)},
  year={2019}
}

Feedback

For questions and comments, feel free to contact Nicola De Cao.

License

MIT