add method: Uniform Risk Minimization (URM)

[kiranchari]

I am first author of "Uniformly Distributed Feature Representations for Fair and Robust Learning" (TMLR 2024) paper. Link: https://openreview.net/forum?id=PgLbS5yp8n

In this pull request I am adding code for the proposed Uniform Risk Minimization (URM) method for domain generalization. The key idea is to encourage the distribution of feature representations learned by the encoder/featurizer to be uniformly distributed. The paper provides theoretical and empirical support for the proposed method for domain generalization and also robustness to sub-population shifts.

Changes include:

• added URM class in algorithms.py
• added hyper-parameters in hparams_registry.py
• added method and link to paper in README.md
• modified networks.py and lib/wide_resnet.py to add an activation function to the output of the featurizer/encoder networks (before the linear classifier). This does not affect other algorithms in DomainBed as the default activation is nn.Identity(): https://github.com/kiranchari/DomainBed/blob/2b47e0ce5f6ad6560c93ba4a40c3aa617ca78053/domainbed/lib/wide_resnet.py#L87

Thank you.

[piotr-teterwak]

Hi! Thank you for the contribution. I will take a look early next week.

[piotr-teterwak]

Hi @kiranchari , could you run the unit tests, which are launched as described at the bottom of the README.md?

[kiranchari]

Hi @piotr-teterwak, I ran the tests and they appear to pass (see attached screenshot). Thanks

[piotr-teterwak]

Could you also run the unit tests with DATA_DIR set? Thank you!

[kiranchari]

Hi @piotr-teterwak, I tried running the tests with DATA_DIR set (/home/user/project/datasets)
and with all the datasets downloaded in that directory, but I am getting some runtime errors that are not related to my method. Please see attached error log here: unittest_error_log.txt

1. There is an error in loading the FMOW dataset: ValueError: time data "2011-02-07T02:48:56.643Z" doesn't match format "%Y-%m-%dT%H:%M:%S%z", at position 92. I have the dataset in /home/user/project/datasets/fmow_v1.1
2. There is an error loading Spawrious dataset as the code is looking for the images in the root of the DATA_DIR ( /home/user/project/datasets) rather than inside /home/user/project/datasets/spawrious224

[kiranchari]

@piotr-teterwak Please let me know any tips to prevent these errors, thanks!