The repository includes:

1. notebooks - Jupyter notebooks illustrating use of MDNF with various models:

• GaussianMixture - GMM with MDNF
• BayesianNetwork - BN with MDNF
• VAEFlows - VAE with MDNF
• PartialFlows - partial vs. location-scale flows

2. mdnf - main files implementing flows, mixtures, inference etc.:

• one_hot.py - Operations on one-hot encoded vectors.

• flows_mixture.py - Mixture of discrete normalizing flows.

• inference.py - Variational inference algorithms for discrete normalizing flows.

• Base distributions:

  • base_mixtures.py - Base for mixture of categorical distributions.
  • base_categorical.py - Factorized categorical distribution.
  • base_constructors.py - Creating base mixtures of categorical distributions.

• Individual discrete flows:

  • flows_transformations.py - Networks calculating transformations for discrete flows.
  • flows.py - Basic flows.
  • flows_factorized.py - Discrete flows for factorized distributions.
  • flows_edward2_made.py - Masked autoencoders.
  • flows_edward2.py - Discrete autoregressive flows.

• Models:

  • bayesian_networks.py - Evaluation of joint probability of x and y for arbitrary Bayesian networks.
  • gmvi.py - Variational Gaussian Mixture using Discrete Normalizing Flows.

• Auxiliary:

  • prob_recovery.py - Recovering probability tables from samples or flows.
  • aux.py - General auxiliary functions.
  • time_profiling.py - Auxiliary functions for measuring time.

• Unit tests:

  • one_hot_test.py
  • flows_test.py
  • flows_mixture_test.py

The code was tested with Python 3.7.4 (on a Linux platform), using tensorflow 2.2.0 and tensorflow_probability 0.9.0 (can be installed with pip install tensorflow tensorflow_probability). It also requires numpy, pandas, sklearn and scipy, that can be installed with pip install numpy pandas sklearn scipy, but are also available by default in for example, python Anaconda distributions. Potential problems with scipy 1.4.1 can be solved by downgrading it to version 1.2.1 with pip install scipy==1.2.1.

Notebooks .ipynb can be previewed using Jupyter Notebook and run from a command line with runipy. Visualizing results requires matplotlib and seaborn to be available (pip install matplotlib seaborn).

Parts of the code for Bayesian networks require PGMPY (pip install pgmpy==0.1.10) and code for Gaussian mixture models builds on Python codes implementing algorithms described in Bishop's book (can by installed with git clone https://github.com/ctgk/PRML; cd PRML; python setup.py install).

Finally, the code comparing partial and location-scale flows uses Edward2 that can be installed with pip install "git+https://github.com/google/edward2.git#egg=edward2"