Commit Graph

3 Commits

Author SHA1 Message Date
Sam Estep
8c798e0622 Forbid trailing whitespace (#53406)
Summary:
Context: https://github.com/pytorch/pytorch/pull/53299#discussion_r587882857

These are the only hand-written parts of this diff:
- the addition to `.github/workflows/lint.yml`
- the file endings changed in these four files (to appease FB-internal land-blocking lints):
  - `GLOSSARY.md`
  - `aten/src/ATen/core/op_registration/README.md`
  - `scripts/README.md`
  - `torch/csrc/jit/codegen/fuser/README.md`

The rest was generated by running this command (on macOS):
```
git grep -I -l ' $' -- . ':(exclude)**/contrib/**' ':(exclude)third_party' | xargs gsed -i 's/ *$//'
```

I looked over the auto-generated changes and didn't see anything that looked problematic.

Pull Request resolved: https://github.com/pytorch/pytorch/pull/53406

Test Plan:
This run (after adding the lint but before removing existing trailing spaces) failed:
- https://github.com/pytorch/pytorch/runs/2043032377

This run (on the tip of this PR) succeeded:
- https://github.com/pytorch/pytorch/runs/2043296348

Reviewed By: walterddr, seemethere

Differential Revision: D26856620

Pulled By: samestep

fbshipit-source-id: 3f0de7f7c2e4b0f1c089eac9b5085a58dd7e0d97
2021-03-05 17:22:55 -08:00
Jasha
a651696ab4 fix misspelling in swa_utils.pyi (#51608)
Summary:
Change `avg_fun -> avg_fn` to match the spelling in the `.py` file.
(`swa_utils.pyi` should match `swa_utils.py`)

Pull Request resolved: https://github.com/pytorch/pytorch/pull/51608

Reviewed By: glaringlee

Differential Revision: D26224779

Pulled By: zou3519

fbshipit-source-id: 01ff7173ba0a996f1b7a653438acb6b6b4659de6
2021-02-03 10:51:22 -08:00
Pavel Izmailov
22ac071d9a Add SWA to PyTorch mainline (#35032)
Summary:
This PR is based on the issue https://github.com/pytorch/pytorch/issues/29994#issue-524418771 and the discussion in the previous version of the PR https://github.com/pytorch/pytorch/pull/30559. Specifically, I followed the interface outlined in this [comment](https://github.com/pytorch/pytorch/pull/30559#issuecomment-574864768).

## Structure
- `torch/optim/swa_utils.py` contains the implementation of  `AveragedModel` class, `SWALR` learning rate scheduler and `update_bn` utility
- `test/test_optim.py` contains unit tests for the three components of SWA
- `torch/optim/swa_utils.pyi` describes the interface of `torch/optim/swa_utils.py`

The new implementation consists of
- `AveragedModel` class; this class creates a copy of a given model and allows to compute running averages of the parameters.
- `SWALR` learning rate scheduler; after a certain number of epochs switches to a constant learning rate; this scheduler is supposed to be chained with other schedulers.
- `update_bn` utility; updates the Batch Normalization activation statistics for a given model and dataloader; this utility is meant to be applied to `AveragedModel` instances.

For `update_bn` I simplified the implementation compared to the [original PR](https://github.com/pytorch/pytorch/pull/30559) according to the sugestions by vadimkantorov.

## Example
```python
loader, optimizer, model = ...
swa_model = torch.optim.swa_utils.AveragedModel(model)
# You can use custom averaging functions with `avg_fun` parameter
ema_avg = lambda p_avg, p, n_avg: 0.1 * p_avg + 0.9 * p
ema_model = torch.optim.swa_utils.AveragedModel(model,
                                    avg_function=ema_avg)
scheduler = torch.optim.lr_scheduler.CosineAnnealingLR(optimizer,
                                    T_max=300)
swa_start = 160
swa_scheduler = SWALR(optimizer, start_epoch=swa_start, swa_lr=0.05)

for i in range(300):
     for input, target in loader:
         optimizer.zero_grad()
         loss_fn(model(input), target).backward()
         optimizer.step()
         scheduler.step()
         swa_scheduler.step()

     if i > swa_start:
         swa_model.update_parameters(model)

# Update bn statistics for the swa_model at the end
torch.optim.swa_utils.update_bn(loader, swa_model)
```

UPDATED:
```python3
loader, optimizer, model, loss_fn = ...
swa_model = torch.optim.swa_utils.AveragedModel(model)
scheduler = torch.optim.lr_scheduler.CosineAnnealingLR(optimizer, T_max=300)
swa_start = 160
swa_scheduler = SWALR(optimizer, swa_lr=0.05)
for i in range(300):
     for input, target in loader:
         optimizer.zero_grad()
         loss_fn(model(input), target).backward()
         optimizer.step()
     if i > swa_start:
         swa_model.update_parameters(model)
         swa_scheduler.step()
     else:
         scheduler.step()

# Update bn statistics for the swa_model at the end
torch.optim.swa_utils.update_bn(loader, swa_model)
```

Fixes https://github.com/pytorch/pytorch/issues/29994
cc soumith vincentqb andrewgordonwilson vadimkantorov
Pull Request resolved: https://github.com/pytorch/pytorch/pull/35032

Differential Revision: D21079606

Pulled By: vincentqb

fbshipit-source-id: e07f5e821f72ada63789814c2dcbdc31f0160c37
2020-04-27 07:42:19 -07:00