This is the code associated with the paper A Variational Inequality Perspective for Generative Adversarial Networks. If you find this code useful please cite as:

Gauthier Gidel, Hugo Berard, Gaetan Vignoud, Pascal Vincent, Simon Lacoste-Julien, A Variational Inequality Perspective on Generative Adversarial Networks, International Conference on Learning Representations (ICLR 2019), 2019.

Code mostly written by Hugo Berard while at Facebook AI Research, for any questions about the code please contact ([email protected])

The code is in pytorch and was tested for:

• pytorch=0.4.0

(Optional) The inception score is computed using the original implementation from OpenAI , and thus requires tensorflow <= 1.5.0 to be installed.

A conda environement is also provided (requires CUDA 9): conda env create -f environment.yml

The extragradient method is packaged as a torch.optim.Optimizer with an additional method extrapolation(). Two variants are available ExtraSGD and ExtraAdam.

Example of how to run Extragradient:

for i, input, target in enumerate(dataset):
    Extragradient.zero_grad()
    output = model(input)
    loss = loss_fn(output, target)
    loss.backward()
    if i%2:
      Extragradient.extrapolation()
    else:
      Extragradient.step()

Example of how to run Extragradient from the past:

for i, input, target in enumerate(dataset):
    PastExtragradient.extrapolation()
    PastExtragradient.zero_grad()
    output = model(input)
    loss = loss_fn(output, target)
    loss.backward()
    PastExtragradient.step()

Note that for Extragradient from the past the extrapolation is done before computing the forward and the backward pass.

To run the WGAN-GP experiment with ExtraAdam and the ResNet architecture on CIFAR10 with the parameters from the paper: python train_extraadam.py results\ --default --model resnet --cuda

The --default option loads the hyperparameters used in the paper for each experiments, they are available as JSON files in the config folder.

The weights for our WGAN-GP and ResNet model trained with ExtraAdam is available in the results folder.

For evaluation: python eval_inception_score.py results/ExtraAdam/best_model.state

A ipython notebook is also available for the bilinear example here.

with Averaging:

without Averaging: