lightning/tests/trainer/test_lr_finder.py

265 lines
8.1 KiB
Python
Executable File

# Copyright The PyTorch Lightning team.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import os
from copy import deepcopy
import pytest
import torch
from pytorch_lightning import Trainer
from pytorch_lightning.utilities.exceptions import MisconfigurationException
from tests.base import EvalModelTemplate
from tests.base.datamodules import TrialMNISTDataModule
def test_error_on_more_than_1_optimizer(tmpdir):
""" Check that error is thrown when more than 1 optimizer is passed """
model = EvalModelTemplate()
model.configure_optimizers = model.configure_optimizers__multiple_schedulers
# logger file to get meta
trainer = Trainer(
default_root_dir=tmpdir,
max_epochs=1,
)
with pytest.raises(MisconfigurationException):
trainer.tuner.lr_find(model)
def test_model_reset_correctly(tmpdir):
""" Check that model weights are correctly reset after lr_find() """
model = EvalModelTemplate()
# logger file to get meta
trainer = Trainer(
default_root_dir=tmpdir,
max_epochs=1,
)
before_state_dict = deepcopy(model.state_dict())
_ = trainer.tuner.lr_find(model, num_training=5)
after_state_dict = model.state_dict()
for key in before_state_dict.keys():
assert torch.all(torch.eq(before_state_dict[key], after_state_dict[key])), \
'Model was not reset correctly after learning rate finder'
assert not os.path.exists(tmpdir / 'lr_find_temp_model.ckpt')
def test_trainer_reset_correctly(tmpdir):
""" Check that all trainer parameters are reset correctly after lr_find() """
model = EvalModelTemplate()
# logger file to get meta
trainer = Trainer(
default_root_dir=tmpdir,
max_epochs=1,
)
changed_attributes = ['callbacks', 'logger', 'max_steps', 'auto_lr_find',
'accumulate_grad_batches', 'checkpoint_callback']
attributes_before = {}
for ca in changed_attributes:
attributes_before[ca] = getattr(trainer, ca)
_ = trainer.tuner.lr_find(model, num_training=5)
attributes_after = {}
for ca in changed_attributes:
attributes_after[ca] = getattr(trainer, ca)
for key in changed_attributes:
assert attributes_before[key] == attributes_after[key], \
f'Attribute {key} was not reset correctly after learning rate finder'
@pytest.mark.parametrize('use_hparams', [False, True])
def test_trainer_arg_bool(tmpdir, use_hparams):
""" Test that setting trainer arg to bool works """
hparams = EvalModelTemplate.get_default_hparams()
model = EvalModelTemplate(**hparams)
before_lr = hparams.get('learning_rate')
if use_hparams:
del model.learning_rate
model.configure_optimizers = model.configure_optimizers__lr_from_hparams
# logger file to get meta
trainer = Trainer(
default_root_dir=tmpdir,
max_epochs=2,
auto_lr_find=True,
)
trainer.tune(model)
if use_hparams:
after_lr = model.hparams.learning_rate
else:
after_lr = model.learning_rate
assert before_lr != after_lr, \
'Learning rate was not altered after running learning rate finder'
@pytest.mark.parametrize('use_hparams', [False, True])
def test_trainer_arg_str(tmpdir, use_hparams):
""" Test that setting trainer arg to string works """
hparams = EvalModelTemplate.get_default_hparams()
model = EvalModelTemplate(**hparams)
model.my_fancy_lr = 1.0 # update with non-standard field
model.hparams['my_fancy_lr'] = 1.0
before_lr = model.my_fancy_lr
if use_hparams:
del model.my_fancy_lr
model.configure_optimizers = model.configure_optimizers__lr_from_hparams
# logger file to get meta
trainer = Trainer(
default_root_dir=tmpdir,
max_epochs=2,
auto_lr_find='my_fancy_lr',
)
trainer.tune(model)
if use_hparams:
after_lr = model.hparams.my_fancy_lr
else:
after_lr = model.my_fancy_lr
assert before_lr != after_lr, \
'Learning rate was not altered after running learning rate finder'
@pytest.mark.parametrize('optimizer', ['Adam', 'Adagrad'])
def test_call_to_trainer_method(tmpdir, optimizer):
""" Test that directly calling the trainer method works """
hparams = EvalModelTemplate.get_default_hparams()
model = EvalModelTemplate(**hparams)
if optimizer == 'adagrad':
model.configure_optimizers = model.configure_optimizers__adagrad
before_lr = hparams.get('learning_rate')
# logger file to get meta
trainer = Trainer(
default_root_dir=tmpdir,
max_epochs=2,
)
lrfinder = trainer.tuner.lr_find(model, mode='linear')
after_lr = lrfinder.suggestion()
model.learning_rate = after_lr
trainer.tune(model)
assert before_lr != after_lr, \
'Learning rate was not altered after running learning rate finder'
def test_datamodule_parameter(tmpdir):
""" Test that the datamodule parameter works """
# trial datamodule
dm = TrialMNISTDataModule(tmpdir)
hparams = EvalModelTemplate.get_default_hparams()
model = EvalModelTemplate(**hparams)
before_lr = hparams.get('learning_rate')
# logger file to get meta
trainer = Trainer(
default_root_dir=tmpdir,
max_epochs=2,
)
lrfinder = trainer.tuner.lr_find(model, datamodule=dm)
after_lr = lrfinder.suggestion()
model.learning_rate = after_lr
assert before_lr != after_lr, \
'Learning rate was not altered after running learning rate finder'
def test_accumulation_and_early_stopping(tmpdir):
""" Test that early stopping of learning rate finder works, and that
accumulation also works for this feature """
hparams = EvalModelTemplate.get_default_hparams()
model = EvalModelTemplate(**hparams)
before_lr = hparams.get('learning_rate')
# logger file to get meta
trainer = Trainer(
default_root_dir=tmpdir,
accumulate_grad_batches=2,
)
lrfinder = trainer.tuner.lr_find(model, early_stop_threshold=None)
after_lr = lrfinder.suggestion()
expected_num_lrs = 100
expected_batch_idx = 200 - 1
assert before_lr != after_lr, \
'Learning rate was not altered after running learning rate finder'
assert len(lrfinder.results['lr']) == expected_num_lrs, \
'Early stopping for learning rate finder did not work'
assert lrfinder._total_batch_idx == expected_batch_idx, \
'Accumulation parameter did not work'
def test_suggestion_parameters_work(tmpdir):
""" Test that default skipping does not alter results in basic case """
hparams = EvalModelTemplate.get_default_hparams()
model = EvalModelTemplate(**hparams)
# logger file to get meta
trainer = Trainer(
default_root_dir=tmpdir,
max_epochs=3,
)
lrfinder = trainer.tuner.lr_find(model)
lr1 = lrfinder.suggestion(skip_begin=10) # default
lr2 = lrfinder.suggestion(skip_begin=80) # way too high, should have an impact
assert lr1 != lr2, \
'Skipping parameter did not influence learning rate'
def test_suggestion_with_non_finite_values(tmpdir):
""" Test that non-finite values does not alter results """
hparams = EvalModelTemplate.get_default_hparams()
model = EvalModelTemplate(**hparams)
# logger file to get meta
trainer = Trainer(
default_root_dir=tmpdir,
max_epochs=3,
)
lrfinder = trainer.tuner.lr_find(model)
before_lr = lrfinder.suggestion()
lrfinder.results['loss'][-1] = float('nan')
after_lr = lrfinder.suggestion()
assert before_lr == after_lr, \
'Learning rate was altered because of non-finite loss values'