pytorch/test/optim/test_lrscheduler.py

2221 lines
82 KiB
Python

# Owner(s): ["module: optimizer", "module: LrScheduler" ]
import types
import warnings
import math
import pickle
import torch
import torch.optim as optim
import torch.nn.functional as F
from torch.nn import Parameter
from torch.optim import Adam, SGD
from torch.optim.lr_scheduler import (
LambdaLR,
MultiplicativeLR,
SequentialLR,
StepLR,
MultiStepLR,
ConstantLR,
LinearLR,
ExponentialLR,
CosineAnnealingLR,
ReduceLROnPlateau,
LRScheduler,
CyclicLR,
CosineAnnealingWarmRestarts,
OneCycleLR,
ChainedScheduler,
PolynomialLR,
EPOCH_DEPRECATION_WARNING,
)
from torch.optim.swa_utils import SWALR
from torch.testing._internal.common_utils import (
TestCase,
load_tests,
parametrize,
instantiate_parametrized_tests,
skipIfTorchDynamo
)
# load_tests from common_utils is used to automatically filter tests for
# sharding on sandcastle. This line silences flake warnings
load_tests = load_tests
class TestLRScheduler(TestCase):
class SchedulerTestNet(torch.nn.Module):
def __init__(self):
super().__init__()
self.conv1 = torch.nn.Conv2d(1, 1, 1)
self.conv2 = torch.nn.Conv2d(1, 1, 1)
def forward(self, x):
return self.conv2(F.relu(self.conv1(x)))
class LambdaLRTestObject:
def __init__(self, value):
self.value = value
def __call__(self, epoch):
return self.value * epoch
def __eq__(self, other):
if isinstance(other, self.__class__):
return self.__dict__ == other.__dict__
else:
return False
exact_dtype = True
def setUp(self):
super().setUp()
self.net = self.SchedulerTestNet()
self.opt = SGD(
[
{"params": self.net.conv1.parameters()},
{"params": self.net.conv2.parameters(), "lr": 0.5},
],
lr=0.05,
)
def _check_warning_is_epoch_deprecation_warning(self, w, *, num_warnings: int = 1):
"""This function swallows the epoch deprecation warning which is produced when we
call `scheduler.step(epoch)` with some not `None` value of `epoch`.
this is deprecated, and this function will need to be removed/updated when
the schedulers no longer accept the parameter at all.
"""
self.assertEqual(len(w), num_warnings)
for warning in w:
self.assertEqual(len(warning.message.args), 1)
self.assertEqual(warning.message.args[0], EPOCH_DEPRECATION_WARNING)
def test_error_when_getlr_has_epoch(self):
class MultiStepLR(torch.optim.lr_scheduler.LRScheduler):
def __init__(self, optimizer, gamma, milestones, last_epoch=-1):
self.init_lr = [group["lr"] for group in optimizer.param_groups]
self.gamma = gamma
self.milestones = milestones
super().__init__(optimizer, last_epoch)
def get_lr(self, step):
global_step = self.last_epoch
gamma_power = (
[0]
+ [i + 1 for i, m in enumerate(self.milestones) if global_step >= m]
)[-1]
return [
init_lr * (self.gamma**gamma_power) for init_lr in self.init_lr
]
optimizer = torch.optim.SGD([torch.rand(1)], lr=1)
with self.assertRaises(TypeError):
scheduler = MultiStepLR(optimizer, gamma=1, milestones=[10, 20])
@skipIfTorchDynamo("Torchdynamo keeps references to optim in the guards and the stack of the graph break frames")
def test_no_cyclic_references(self):
import gc
param = Parameter(torch.empty(10))
optim = SGD([param], lr=0.5)
scheduler = LambdaLR(optim, lambda epoch: 1.0)
del scheduler
self.assertTrue(
len(gc.get_referrers(optim)) == 0,
"Optimizer should contain no cyclic references",
)
gc.collect()
del optim
self.assertEqual(
gc.collect(), 0, msg="Optimizer should be garbage-collected on __del__"
)
@skipIfTorchDynamo("Torchdynamo keeps references to optim in the guards and the stack of the graph break frames")
def test_no_cyclic_references_in_step(self):
import gc
import weakref
def run():
param = torch.empty(10, requires_grad=True)
optim = SGD(params=[param], lr=0.5)
scheduler = LambdaLR(optim, lambda epoch: 1.0)
param.sum().backward()
optim.step()
scheduler.step()
return weakref.ref(scheduler)
# To ensure that there are no reference cycles in scheduler,
# we need to turn off the garbage collector. Since gc will
# automatically collect unreachable objects.
gc.disable()
ref = run()
assert ref() is None
gc.enable() # restore
def test_old_pattern_warning(self):
epochs = 35
with warnings.catch_warnings(record=True) as ws:
warnings.simplefilter("always") # allow any warning to be raised
scheduler = StepLR(self.opt, gamma=0.1, step_size=3)
self.assertTrue(len(ws) == 0, "No warning should be raised")
def old_pattern():
for _ in range(epochs):
scheduler.step()
self.opt.step()
self.assertWarnsRegex(UserWarning, r"how-to-adjust-learning-rate", old_pattern)
def test_old_pattern_warning_with_arg(self):
epochs = 35
with warnings.catch_warnings(record=True) as ws:
warnings.simplefilter("always") # allow any warning to be raised
scheduler = StepLR(self.opt, gamma=0.1, step_size=3)
self.assertTrue(len(ws) == 0, "No warning should be raised")
def old_pattern2():
for _ in range(epochs):
scheduler.step()
self.opt.step()
self.assertWarnsRegex(UserWarning, r"how-to-adjust-learning-rate", old_pattern2)
def test_old_pattern_warning_resuming(self):
epochs = 35
for i, group in enumerate(self.opt.param_groups):
group["initial_lr"] = 0.01
with warnings.catch_warnings(record=True) as ws:
warnings.simplefilter("always") # allow any warning to be raised
scheduler = StepLR(self.opt, gamma=0.1, step_size=3, last_epoch=10)
self.assertTrue(len(ws) == 0, "No warning should be raised")
def old_pattern():
for _ in range(epochs):
scheduler.step()
self.opt.step()
self.assertWarnsRegex(UserWarning, r"how-to-adjust-learning-rate", old_pattern)
def test_old_pattern_warning_resuming_with_arg(self):
epochs = 35
for i, group in enumerate(self.opt.param_groups):
group["initial_lr"] = 0.01
with warnings.catch_warnings(record=True) as ws:
warnings.simplefilter("always") # allow any warning to be raised
scheduler = StepLR(self.opt, gamma=0.1, step_size=3, last_epoch=10)
self.assertTrue(len(ws) == 0, "No warning should be raised")
def old_pattern2():
for _ in range(epochs):
scheduler.step()
self.opt.step()
self.assertWarnsRegex(UserWarning, r"how-to-adjust-learning-rate", old_pattern2)
def test_old_pattern_warning_with_overridden_optim_step(self):
epochs = 35
for i, group in enumerate(self.opt.param_groups):
group["initial_lr"] = 0.01
with warnings.catch_warnings(record=True) as ws:
warnings.simplefilter("always") # allow any warning to be raised
scheduler = StepLR(self.opt, gamma=0.1, step_size=3, last_epoch=10)
self.assertTrue(len(ws) == 0, "No warning should be raised")
# emulate use-case with optimizer.step overridden
import types
old_step = self.opt.step
def new_step(o, *args, **kwargs):
retval = old_step(*args, **kwargs)
return retval
self.opt.step = types.MethodType(new_step, self.opt)
def old_pattern2():
for _ in range(epochs):
scheduler.step()
self.opt.step()
self.assertWarnsRegex(UserWarning, r"how-to-adjust-learning-rate", old_pattern2)
def test_new_pattern_no_warning(self):
epochs = 35
with warnings.catch_warnings(record=True) as ws:
warnings.simplefilter("always") # allow any warning to be raised
scheduler = StepLR(self.opt, gamma=0.1, step_size=3)
self.assertTrue(len(ws) == 0, "No warning should be raised")
with warnings.catch_warnings(record=True) as ws:
warnings.simplefilter("always") # allow any warning to be raised
for _ in range(epochs):
self.opt.step()
scheduler.step()
self.assertTrue(len(ws) == 0, "No warning should be raised")
def test_new_pattern_no_warning_with_arg(self):
epochs = 35
with warnings.catch_warnings(record=True) as ws:
warnings.simplefilter("always") # allow any warning to be raised
scheduler = StepLR(self.opt, gamma=0.1, step_size=3)
self.assertTrue(len(ws) == 0, "No warning should be raised")
with warnings.catch_warnings(record=True) as ws:
warnings.simplefilter("always") # allow any warning to be raised
for _ in range(epochs):
self.opt.step()
scheduler.step()
self.assertTrue(len(ws) == 0, "No warning should be raised")
def test_new_pattern_no_warning_with_overridden_optim_step(self):
epochs = 35
with warnings.catch_warnings(record=True) as ws:
warnings.simplefilter("always") # allow any warning to be raised
scheduler = StepLR(self.opt, gamma=0.1, step_size=3)
self.assertTrue(len(ws) == 0, "No warning should be raised")
# emulate use-case with optimizer.step overridden
import types
old_step = self.opt.step
def new_step(o, *args, **kwargs):
retval = old_step(*args, **kwargs)
return retval
self.opt.step = types.MethodType(new_step, self.opt)
def new_pattern():
for e in range(epochs):
self.opt.step()
scheduler.step()
self.assertWarnsRegex(
UserWarning, r"`optimizer.step\(\)` has been overridden", new_pattern
)
def _test_lr_is_constant_for_constant_epoch(self, scheduler):
l = []
for _ in range(10):
scheduler.optimizer.step()
with warnings.catch_warnings(record=True) as w:
scheduler.step(2)
self._check_warning_is_epoch_deprecation_warning(w)
l.append(self.opt.param_groups[0]["lr"])
self.assertEqual(min(l), max(l))
def test_step_lr_is_constant_for_constant_epoch(self):
scheduler = StepLR(self.opt, 2)
self._test_lr_is_constant_for_constant_epoch(scheduler)
def test_exponential_lr_is_constant_for_constant_epoch(self):
scheduler = ExponentialLR(self.opt, gamma=0.9)
self._test_lr_is_constant_for_constant_epoch(scheduler)
def test_constantlr_is_constant_for_constant_epoch(self):
scheduler = ConstantLR(self.opt)
self._test_lr_is_constant_for_constant_epoch(scheduler)
def test_linear_linearlr_is_constant_for_constant_epoch(self):
scheduler = LinearLR(self.opt)
self._test_lr_is_constant_for_constant_epoch(scheduler)
def test_polynomial_lr_is_constant_for_constant_epoch(self):
scheduler = PolynomialLR(self.opt, power=0.9)
self._test_lr_is_constant_for_constant_epoch(scheduler)
def test_step_lr(self):
# lr = 0.05 if epoch < 3
# lr = 0.005 if 30 <= epoch < 6
# lr = 0.0005 if epoch >= 9
epochs = 10
single_targets = [0.05] * 3 + [0.005] * 3 + [0.0005] * 3 + [0.00005] * 3
targets = [single_targets, [x * epochs for x in single_targets]]
scheduler = StepLR(self.opt, gamma=0.1, step_size=3)
self._test(scheduler, targets, epochs)
def test_get_last_lr_step_lr(self):
from torch.nn import Parameter
epochs = 10
optimizer = torch.optim.SGD(
[Parameter(torch.randn(2, 2, requires_grad=True))], 0.1
)
targets = [[0.1] * 3 + [0.01] * 3 + [0.001] * 3 + [0.0001]]
scheduler = torch.optim.lr_scheduler.StepLR(optimizer, 3, gamma=0.1)
self._test_get_last_lr(scheduler, targets, epochs)
def test_get_last_lr_multi_step_lr(self):
# lr = 0.05 if epoch < 2
# lr = 0.005 if 2 <= epoch < 5
# lr = 0.0005 if 5 <= epoch < 9
# lr = 0.00005 if 9 <= epoch
epochs = 10
single_targets = [0.05] * 2 + [0.005] * 3 + [0.0005] * 4 + [0.00005] * 1
targets = [single_targets, [x * epochs for x in single_targets]]
scheduler = MultiStepLR(self.opt, gamma=0.1, milestones=[2, 5, 9])
self._test_get_last_lr(scheduler, targets, epochs)
def test_multi_step_lr(self):
# lr = 0.05 if epoch < 2
# lr = 0.005 if 2 <= epoch < 5
# lr = 0.0005 if epoch < 9
# lr = 0.00005 if epoch >= 9
epochs = 10
single_targets = [0.05] * 2 + [0.005] * 3 + [0.0005] * 4 + [0.00005] * 3
targets = [single_targets, [x * epochs for x in single_targets]]
scheduler = MultiStepLR(self.opt, gamma=0.1, milestones=[2, 5, 9])
self._test(scheduler, targets, epochs)
def test_multi_step_lr_with_epoch(self):
# lr = 0.05 if epoch < 2
# lr = 0.005 if 2 <= epoch < 5
# lr = 0.0005 if epoch < 9
# lr = 0.00005 if epoch >= 9
epochs = 10
single_targets = [0.05] * 2 + [0.005] * 3 + [0.0005] * 4 + [0.00005] * 3
targets = [single_targets, [x * epochs for x in single_targets]]
scheduler = MultiStepLR(self.opt, gamma=0.1, milestones=[2, 5, 9])
self._test_with_epoch(scheduler, targets, epochs)
def test_get_last_lr_constantlr(self):
# lr = 0.025 if epoch < 5
# lr = 0.005 if 5 <= epoch
epochs = 10
single_targets = [0.025] * 5 + [0.05] * 5
targets = [single_targets, [x * epochs for x in single_targets]]
scheduler = ConstantLR(self.opt, factor=1.0 / 2, total_iters=5)
self._test_get_last_lr(scheduler, targets, epochs)
def test_get_last_lr_linearlr(self):
# lr = 0.025 if epoch == 0
# lr = 0.03125 if epoch == 1
# lr = 0.0375 if epoch == 2
# lr = 0.04375 if epoch == 3
# lr = 0.005 if 4 <= epoch
epochs = 10
start_factor = 1.0 / 4
end_factor = 3.0 / 5
iters = 4
interpolation = [
start_factor + i * (end_factor - start_factor) / iters for i in range(iters)
]
single_targets = [x * 0.05 for x in interpolation] + [0.05 * end_factor] * (
epochs - iters
)
targets = [single_targets, [x * epochs for x in single_targets]]
scheduler = LinearLR(
self.opt,
start_factor=start_factor,
end_factor=end_factor,
total_iters=iters,
)
self._test_get_last_lr(scheduler, targets, epochs)
def test_constantlr(self):
# lr = 0.025 if epoch < 5
# lr = 0.005 if 5 <= epoch
epochs = 10
single_targets = [0.025] * 5 + [0.05] * 5
targets = [single_targets, [x * epochs for x in single_targets]]
scheduler = ConstantLR(self.opt, factor=1.0 / 2, total_iters=5)
self._test(scheduler, targets, epochs)
def test_linearlr(self):
# lr = 0.025 if epoch == 0
# lr = 0.03125 if epoch == 1
# lr = 0.0375 if epoch == 2
# lr = 0.04375 if epoch == 3
# lr = 0.005 if 4 <= epoch
epochs = 10
start_factor = 1.0 / 2
iters = 4
interpolation = [
start_factor + i * (1 - start_factor) / iters for i in range(iters)
]
single_targets = [x * 0.05 for x in interpolation] + [0.05] * (epochs - iters)
targets = [single_targets, [x * epochs for x in single_targets]]
scheduler = LinearLR(self.opt, start_factor=start_factor, total_iters=iters)
self._test(scheduler, targets, epochs)
def test_linearlr_start_factor_limits1(self):
start_factor = 0.0
iters = 4
with self.assertRaises(ValueError):
LinearLR(self.opt, start_factor=start_factor, total_iters=iters)
def test_linearlr_start_factor_limits2(self):
start_factor = 1.1
iters = 4
with self.assertRaises(ValueError):
LinearLR(self.opt, start_factor=start_factor, total_iters=iters)
def test_constantlr_with_epoch(self):
# lr = 0.025 if epoch < 5
# lr = 0.005 if 5 <= epoch
epochs = 10
single_targets = [0.025] * 5 + [0.05] * 5
targets = [single_targets, [x * epochs for x in single_targets]]
scheduler = ConstantLR(self.opt, factor=1.0 / 2, total_iters=5)
self._test_with_epoch(scheduler, targets, epochs)
def test_linearlr_with_epoch(self):
# lr = 0.025 if epoch == 0
# lr = 0.03125 if epoch == 1
# lr = 0.0375 if epoch == 2
# lr = 0.04375 if epoch == 3
# lr = 0.005 if 4 <= epoch
epochs = 10
start_factor = 1.0 / 2
end_factor = 1.0
iters = 4
interpolation = [
start_factor + i * (end_factor - start_factor) / iters for i in range(iters)
]
single_targets = [x * 0.05 for x in interpolation] + [0.05] * (epochs - iters)
targets = [single_targets, [x * epochs for x in single_targets]]
scheduler = LinearLR(self.opt, start_factor=start_factor, total_iters=iters)
self._test_with_epoch(scheduler, targets, epochs)
def test_exp_lr(self):
epochs = 10
single_targets = [0.05 * (0.9**x) for x in range(epochs)]
targets = [single_targets, [x * epochs for x in single_targets]]
scheduler = ExponentialLR(self.opt, gamma=0.9)
self._test(scheduler, targets, epochs)
def test_poly_lr(self):
epochs = 10
power = 0.9
total_iters = 5
single_targets = [
(1.0 - x / total_iters) ** power * 0.05 for x in range(total_iters)
] + [0.0] * (epochs - total_iters)
targets = [single_targets, [x * epochs for x in single_targets]]
scheduler = PolynomialLR(self.opt, power=power, total_iters=total_iters)
self._test(scheduler, targets, epochs)
def test_cos_anneal_lr(self):
epochs = 10
eta_min = 1e-10
single_targets = [
eta_min + (0.05 - eta_min) * (1 + math.cos(math.pi * x / epochs)) / 2
for x in range(epochs)
]
targets = [single_targets, [x * epochs for x in single_targets]]
scheduler = CosineAnnealingLR(self.opt, T_max=epochs, eta_min=eta_min)
self._test(scheduler, targets, epochs)
def test_closed_form_step_lr(self):
scheduler = StepLR(self.opt, gamma=0.1, step_size=3)
closed_form_scheduler = StepLR(self.opt, gamma=0.1, step_size=3)
self._test_against_closed_form(scheduler, closed_form_scheduler, 20)
def test_closed_form_linearlr(self):
scheduler = LinearLR(
self.opt, start_factor=1.0 / 3, end_factor=0.7, total_iters=4
)
closed_form_scheduler = LinearLR(
self.opt, start_factor=1.0 / 3, end_factor=0.7, total_iters=4
)
self._test_against_closed_form(scheduler, closed_form_scheduler, 20)
def test_closed_form_constantlr(self):
scheduler = ConstantLR(self.opt, factor=1.0 / 3, total_iters=4)
closed_form_scheduler = ConstantLR(self.opt, factor=1.0 / 3, total_iters=4)
self._test_against_closed_form(scheduler, closed_form_scheduler, 20)
def test_closed_form_multi_step_lr(self):
scheduler = MultiStepLR(self.opt, gamma=0.1, milestones=[2, 5, 9])
closed_form_scheduler = MultiStepLR(self.opt, gamma=0.1, milestones=[2, 5, 9])
self._test_against_closed_form(scheduler, closed_form_scheduler, 20)
def test_closed_form_exp_lr(self):
scheduler = ExponentialLR(self.opt, gamma=0.9)
closed_form_scheduler = ExponentialLR(self.opt, gamma=0.9)
self._test_against_closed_form(scheduler, closed_form_scheduler, 20)
def test_closed_form_poly_lr(self):
scheduler = PolynomialLR(self.opt, power=0.9)
closed_form_scheduler = PolynomialLR(self.opt, power=0.9)
self._test_against_closed_form(scheduler, closed_form_scheduler, 20)
def test_closed_form_cos_anneal_lr(self):
eta_min = 1e-10
epochs = 20
T_max = 5
scheduler = CosineAnnealingLR(self.opt, T_max=T_max, eta_min=eta_min)
closed_form_scheduler = CosineAnnealingLR(
self.opt, T_max=T_max, eta_min=eta_min
)
self._test_against_closed_form(scheduler, closed_form_scheduler, epochs)
def test_cos_anneal_lr_continue(self):
eta_min = 0.1
T_max = 5
scheduler = CosineAnnealingLR(self.opt, T_max=T_max, eta_min=eta_min)
self.opt.step()
scheduler.step()
original_lrs = scheduler._last_lr
new_scheduler = CosineAnnealingLR(
self.opt, T_max=T_max, eta_min=eta_min, last_epoch=0
)
new_lrs = new_scheduler._last_lr
torch.testing.assert_close(original_lrs, new_lrs, rtol=1e-4, atol=1e-5)
def test_reduce_lr_on_plateau1(self):
epochs = 10
for param_group in self.opt.param_groups:
param_group["lr"] = 0.5
targets = [[0.5] * 20]
metrics = [10 - i * 0.0167 for i in range(20)]
scheduler = ReduceLROnPlateau(
self.opt,
threshold_mode="abs",
mode="min",
threshold=0.01,
patience=5,
cooldown=5,
)
self._test_reduce_lr_on_plateau(scheduler, targets, metrics, epochs)
def test_reduce_lr_on_plateau2(self):
epochs = 22
for param_group in self.opt.param_groups:
param_group["lr"] = 0.5
targets = [[0.5] * 6 + [0.05] * 7 + [0.005] * 7 + [0.0005] * 2]
metrics = [10 - i * 0.0165 for i in range(22)]
scheduler = ReduceLROnPlateau(
self.opt,
patience=5,
cooldown=0,
threshold_mode="abs",
mode="min",
threshold=0.1,
)
self._test_reduce_lr_on_plateau(scheduler, targets, metrics, epochs)
def test_reduce_lr_on_plateau3(self):
epochs = 22
for param_group in self.opt.param_groups:
param_group["lr"] = 0.5
targets = [[0.5] * (2 + 6) + [0.05] * (5 + 6) + [0.005] * 4]
metrics = [-0.8] * 2 + [-0.234] * 20
scheduler = ReduceLROnPlateau(
self.opt, mode="max", patience=5, cooldown=5, threshold_mode="abs"
)
self._test_reduce_lr_on_plateau(scheduler, targets, metrics, epochs)
def test_reduce_lr_on_plateau4(self):
epochs = 20
for param_group in self.opt.param_groups:
param_group["lr"] = 0.5
targets = [[0.5] * 20]
metrics = [1.5 * (1.025**i) for i in range(20)] # 1.025 > 1.1**0.25
scheduler = ReduceLROnPlateau(
self.opt, mode="max", patience=3, threshold_mode="rel", threshold=0.1
)
self._test_reduce_lr_on_plateau(scheduler, targets, metrics, epochs)
def test_reduce_lr_on_plateau5(self):
epochs = 20
for param_group in self.opt.param_groups:
param_group["lr"] = 0.5
targets = [[0.5] * 6 + [0.05] * (5 + 6) + [0.005] * 4]
metrics = [1.5 * (1.005**i) for i in range(20)]
scheduler = ReduceLROnPlateau(
self.opt,
mode="max",
threshold_mode="rel",
threshold=0.1,
patience=5,
cooldown=5,
)
self._test_reduce_lr_on_plateau(scheduler, targets, metrics, epochs)
def test_reduce_lr_on_plateau6(self):
epochs = 20
for param_group in self.opt.param_groups:
param_group["lr"] = 0.5
targets = [[0.5] * 20]
metrics = [1.5 * (0.85**i) for i in range(20)]
scheduler = ReduceLROnPlateau(
self.opt, mode="min", threshold_mode="rel", threshold=0.1
)
self._test_reduce_lr_on_plateau(scheduler, targets, metrics, epochs)
def test_reduce_lr_on_plateau7(self):
epochs = 20
for param_group in self.opt.param_groups:
param_group["lr"] = 0.5
targets = [[0.5] * 6 + [0.05] * (5 + 6) + [0.005] * 4]
metrics = [1] * 7 + [0.6] + [0.5] * 12
scheduler = ReduceLROnPlateau(
self.opt,
mode="min",
threshold_mode="rel",
threshold=0.1,
patience=5,
cooldown=5,
)
self._test_reduce_lr_on_plateau(scheduler, targets, metrics, epochs)
def test_reduce_lr_on_plateau8(self):
epochs = 20
for param_group in self.opt.param_groups:
param_group["lr"] = 0.5
targets = [[0.5] * 6 + [0.4] * 14, [0.5] * 6 + [0.3] * 14]
metrics = [1.5 * (1.005**i) for i in range(20)]
scheduler = ReduceLROnPlateau(
self.opt,
mode="max",
threshold_mode="rel",
min_lr=[0.4, 0.3],
threshold=0.1,
patience=5,
cooldown=5,
)
self._test_reduce_lr_on_plateau(scheduler, targets, metrics, epochs)
def test_sequentiallr1(self):
epochs = 19
schedulers = [None] * 2
targets = [
[0.05, 0.04, 0.032]
+ [0.05 for x in range(4)]
+ [0.05 * 0.1 for x in range(4)]
+ [0.05 * 0.01 for x in range(4)]
+ [0.05 * 0.001 for x in range(4)]
]
milestones = [3]
schedulers[0] = ExponentialLR(self.opt, gamma=0.8)
schedulers[1] = StepLR(self.opt, gamma=0.1, step_size=4)
scheduler = SequentialLR(self.opt, schedulers=schedulers, milestones=milestones)
self._test(scheduler, targets, epochs)
def test_sequentiallr2(self):
epochs = 13
schedulers = [None] * 2
targets = [[0.005, 0.005, 0.005] + [0.05 * 0.9**x for x in range(10)]]
milestones = [3]
schedulers[0] = ConstantLR(self.opt, factor=0.1, total_iters=3)
schedulers[1] = ExponentialLR(self.opt, gamma=0.9)
scheduler = SequentialLR(self.opt, schedulers=schedulers, milestones=milestones)
self._test(scheduler, targets, epochs)
def test_sequentiallr3(self):
epochs = 12
schedulers = [None] * 3
targets = [
[0.005, 0.005, 0.005]
+ [0.05, 0.04, 0.032]
+ [0.05, 0.05, 0.005, 0.005, 0.0005, 0.0005]
]
milestones = [3, 6]
schedulers[0] = ConstantLR(self.opt, factor=0.1, total_iters=3)
schedulers[1] = ExponentialLR(self.opt, gamma=0.8)
schedulers[2] = StepLR(self.opt, gamma=0.1, step_size=2)
scheduler = SequentialLR(self.opt, schedulers=schedulers, milestones=milestones)
self._test(scheduler, targets, epochs)
def test_sequentiallr4(self):
optimizer = torch.optim.SGD([torch.tensor(0.5)], lr=0.1)
prev_lr = optimizer.param_groups[0]["lr"]
schedulers = [
torch.optim.lr_scheduler.ConstantLR(optimizer, factor=1),
torch.optim.lr_scheduler.ConstantLR(optimizer, factor=0.1),
]
scheduler = torch.optim.lr_scheduler.SequentialLR(
optimizer, schedulers, milestones=[10]
)
new_lr = optimizer.param_groups[0]["lr"]
# Ensure that multiple schedulers does not affect the initial learning rate
self.assertEqual(prev_lr, new_lr)
def test_get_last_lr_sequentiallr(self):
epochs = 12
milestones = [3, 6]
schedulers = [None] * 3
schedulers[0] = ConstantLR(self.opt, factor=0.1, total_iters=3)
schedulers[1] = ExponentialLR(self.opt, gamma=0.8)
schedulers[2] = StepLR(self.opt, gamma=0.1, step_size=2)
scheduler = SequentialLR(self.opt, schedulers=schedulers, milestones=milestones)
constant_lr_target = [0.005] * 3
exponential_lr_target = [0.05, 0.04, 0.032]
step_lr_target = [0.05, 0.05, 0.005, 0.005, 0.0005, 0.0005]
single_targets = constant_lr_target + exponential_lr_target + step_lr_target
targets = [single_targets, [x * 10 for x in single_targets]]
self._test_get_last_lr(scheduler, targets, epochs)
def test_chained_lr2_get_last_lr_before_step(self):
schedulers = [
LinearLR(self.opt, start_factor=0.4, total_iters=3),
MultiStepLR(self.opt, milestones=[4, 8, 10], gamma=0.1),
]
scheduler = ChainedScheduler(schedulers)
self.assertEqual(scheduler.get_last_lr(), schedulers[-1].get_last_lr())
def test_chained_lr1(self):
epochs = 10
schedulers = [None] * 1
targets = [[0.05] * 3 + [0.005] * 3 + [0.0005] * 3 + [0.00005] * 3]
schedulers[0] = StepLR(self.opt, gamma=0.1, step_size=3)
scheduler = ChainedScheduler(schedulers)
self._test([scheduler], targets, epochs)
self.assertEqual(scheduler.get_last_lr(), schedulers[-1].get_last_lr())
def test_chained_lr2(self):
epochs = 10
schedulers = [None] * 1
targets = [[0.02, 0.03, 0.04] + [0.05] * 9]
schedulers[0] = LinearLR(self.opt, start_factor=0.4, total_iters=3)
scheduler = ChainedScheduler(schedulers)
self._test([scheduler], targets, epochs)
self.assertEqual(scheduler.get_last_lr(), schedulers[-1].get_last_lr())
def test_chained_lr3(self):
epochs = 10
schedulers = [None] * 2
targets = [
[0.02, 0.03, 0.04, 0.05] + [0.005] * 4 + [0.0005] * 3 + [0.00005] * 3
]
schedulers[0] = LinearLR(self.opt, start_factor=0.4, total_iters=3)
schedulers[1] = MultiStepLR(self.opt, milestones=[4, 8, 10], gamma=0.1)
scheduler = ChainedScheduler(schedulers)
self._test([scheduler], targets, epochs)
self.assertEqual(scheduler.get_last_lr(), schedulers[-1].get_last_lr())
def test_chained_lr4(self):
epochs = 9
schedulers = [None] * 3
targets = [
[0.05 * 0.2 * 0.9**x for x in range(3)]
+ [0.05 * 0.2 * 0.9**3 * 0.1]
+ [0.05 * 0.9**x * 0.1 for x in range(4, 6)]
+ [0.05 * 0.9**x * 0.01 for x in range(6, 9)]
]
schedulers[0] = ExponentialLR(self.opt, gamma=0.9)
schedulers[1] = ConstantLR(self.opt, factor=0.2, total_iters=4)
schedulers[2] = StepLR(self.opt, gamma=0.1, step_size=3)
scheduler = ChainedScheduler(schedulers)
self._test([scheduler], targets, epochs)
self.assertEqual(scheduler.get_last_lr(), schedulers[-1].get_last_lr())
def test_chained_lr5(self):
def poly_lr(lr: float):
return [
(lr * ((1.0 - x / total_iters) ** power)) for x in range(total_iters)
] + [0.0] * (epochs - total_iters)
schedulers = [None] * 2
epochs = 10
power = 0.9
total_iters = 5
const_factor = 0.1
single_targets = [x * const_factor for x in poly_lr(lr=0.05)]
targets = [single_targets, [x * const_factor for x in poly_lr(0.5)]]
schedulers[0] = PolynomialLR(self.opt, power=power, total_iters=total_iters)
schedulers[1] = ConstantLR(self.opt, factor=const_factor)
scheduler = ChainedScheduler(schedulers)
self._test(scheduler, targets, epochs)
self.assertEqual(scheduler.get_last_lr(), schedulers[-1].get_last_lr())
def test_compound_step_and_multistep_lr(self):
epochs = 10
schedulers = [None] * 2
schedulers[0] = StepLR(self.opt, gamma=0.1, step_size=3)
schedulers[1] = MultiStepLR(self.opt, gamma=0.1, milestones=[2, 5, 9])
targets = [[0.05] * 2 + [0.005] * 1 + [5e-4] * 2 + [5e-5] + [5e-6] * 3 + [5e-8]]
self._test(schedulers, targets, epochs)
def test_compound_step_and_exp_lr(self):
epochs = 10
schedulers = [None] * 2
single_targets = [0.05 * (0.9**x) for x in range(3)]
single_targets += [0.005 * (0.9**x) for x in range(3, 6)]
single_targets += [0.0005 * (0.9**x) for x in range(6, 9)]
single_targets += [0.00005 * (0.9**x) for x in range(9, 12)]
targets = [single_targets, [x * epochs for x in single_targets]]
schedulers[0] = StepLR(self.opt, gamma=0.1, step_size=3)
schedulers[1] = ExponentialLR(self.opt, gamma=0.9)
self._test(schedulers, targets, epochs)
def test_compound_exp_and_multistep_lr(self):
epochs = 10
schedulers = [None] * 2
single_targets = [0.05 * (0.9**x) for x in range(2)]
single_targets += [0.005 * (0.9**x) for x in range(2, 5)]
single_targets += [0.0005 * (0.9**x) for x in range(5, 9)]
single_targets += [0.00005 * (0.9**x) for x in range(9, 11)]
targets = [single_targets, [x * epochs for x in single_targets]]
schedulers[0] = MultiStepLR(self.opt, gamma=0.1, milestones=[2, 5, 9])
schedulers[1] = ExponentialLR(self.opt, gamma=0.9)
self._test(schedulers, targets, epochs)
def test_compound_exp_and_linearlr(self):
epochs = 10
iters = 4
start_factor = 0.4
end_factor = 0.9
schedulers = [None] * 2
single_targets = [0.05 * (0.9**x) for x in range(11)]
for i in range(iters):
single_targets[i] *= start_factor + i / iters * (end_factor - start_factor)
for i in range(iters, 11):
single_targets[i] *= end_factor
targets = [single_targets, [x * epochs for x in single_targets]]
schedulers[0] = LinearLR(
self.opt,
start_factor=start_factor,
end_factor=end_factor,
total_iters=iters,
)
schedulers[1] = ExponentialLR(self.opt, gamma=0.9)
self._test(schedulers, targets, epochs)
def test_compound_step_and_constantlr(self):
epochs = 10
iters = 4
factor = 0.4
schedulers = [None] * 2
single_targets = (
[0.05 * 0.4] * 3
+ [0.005 * 0.4]
+ [0.005] * 2
+ [0.0005] * 3
+ [0.00005] * 3
)
targets = [single_targets, [x * epochs for x in single_targets]]
schedulers[0] = StepLR(self.opt, gamma=0.1, step_size=3)
schedulers[1] = ConstantLR(self.opt, factor=0.4, total_iters=4)
self._test(schedulers, targets, epochs)
def test_compound_linearlr_and_multistep_lr(self):
epochs = 10
iters = 4
start_factor = 0.4
schedulers = [None] * 2
single_targets = [0.05] * 2 + [0.005] * 3 + [0.0005] * 4 + [0.00005] * 2
for i in range(iters):
single_targets[i] *= start_factor + i / iters * (1 - start_factor)
targets = [single_targets, [x * epochs for x in single_targets]]
schedulers[0] = MultiStepLR(self.opt, gamma=0.1, milestones=[2, 5, 9])
schedulers[1] = LinearLR(self.opt, start_factor=start_factor, total_iters=iters)
self._test(schedulers, targets, epochs)
def test_compound_cosanneal_and_step_lr(self):
epochs = 10
eta_min = 1e-10
single_targets = [
eta_min + (0.05 - eta_min) * (1 + math.cos(math.pi * x / epochs)) / 2
for x in range(epochs)
]
single_targets = [x * 0.1 ** (i // 3) for i, x in enumerate(single_targets)]
targets = [single_targets, [x * epochs for x in single_targets]]
schedulers = [None] * 2
schedulers[0] = CosineAnnealingLR(self.opt, T_max=epochs, eta_min=eta_min)
schedulers[1] = StepLR(self.opt, gamma=0.1, step_size=3)
self._test(schedulers, targets, epochs)
def test_compound_cosanneal_and_multistep_lr(self):
epochs = 10
eta_min = 1e-10
single_targets = [
eta_min + (0.05 - eta_min) * (1 + math.cos(math.pi * x / epochs)) / 2
for x in range(epochs)
]
multipliers = [1] * 2 + [0.1] * 3 + [0.01] * 4 + [0.001]
single_targets = [x * y for x, y in zip(single_targets, multipliers)]
targets = [single_targets, [x * epochs for x in single_targets]]
schedulers = [None] * 2
schedulers[0] = CosineAnnealingLR(self.opt, T_max=epochs, eta_min=eta_min)
schedulers[1] = MultiStepLR(self.opt, gamma=0.1, milestones=[2, 5, 9])
self._test(schedulers, targets, epochs)
def test_compound_cosanneal_and_linearlr(self):
epochs = 10
iters = 4
start_factor = 0.4
eta_min = 1e-10
schedulers = [None] * 2
single_targets = [
eta_min + (0.05 - eta_min) * (1 + math.cos(math.pi * x / epochs)) / 2
for x in range(epochs)
]
for i in range(iters):
single_targets[i] *= start_factor + i / iters * (1 - start_factor)
targets = [single_targets, [x * epochs for x in single_targets]]
schedulers[0] = LinearLR(self.opt, start_factor=start_factor, total_iters=iters)
schedulers[1] = CosineAnnealingLR(self.opt, T_max=epochs, eta_min=eta_min)
self._test(schedulers, targets, epochs)
def test_compound_cosanneal_and_exp_lr(self):
epochs = 10
eta_min = 1e-10
single_targets = [
eta_min + (0.05 - eta_min) * (1 + math.cos(math.pi * x / epochs)) / 2
for x in range(epochs)
]
multipliers = [0.1**i for i in range(epochs)]
single_targets = [x * y for x, y in zip(single_targets, multipliers)]
targets = [single_targets, [x * epochs for x in single_targets]]
schedulers = [None] * 2
schedulers[0] = CosineAnnealingLR(self.opt, T_max=epochs, eta_min=eta_min)
schedulers[1] = ExponentialLR(self.opt, gamma=0.1)
self._test(schedulers, targets, epochs)
def test_compound_reduce_lr_on_plateau1(self):
epochs = 10
for param_group in self.opt.param_groups:
param_group["lr"] = 0.5
single_targets = [0.5] * 20
multipliers = [0.1 ** (i // 3) for i in range(20)]
single_targets = [x * y for x, y in zip(multipliers, single_targets)]
targets = [single_targets]
targets = targets[1:] # test runs step before checking lr
metrics = [10 - i * 0.0167 for i in range(20)]
schedulers = [None, None]
schedulers[0] = ReduceLROnPlateau(
self.opt,
threshold_mode="abs",
mode="min",
threshold=0.01,
patience=5,
cooldown=5,
)
schedulers[1] = StepLR(self.opt, gamma=0.1, step_size=3)
self._test_reduce_lr_on_plateau(schedulers, targets, metrics, epochs)
def test_compound_reduce_lr_on_plateau2(self):
epochs = 22
for param_group in self.opt.param_groups:
param_group["lr"] = 0.5
single_targets = [0.5] * 6 + [0.05] * 7 + [0.005] * 7 + [0.0005] * 2
multipliers = [1] * 3 + [0.1] * 5 + [0.01] * 4 + [0.001] * 10
single_targets = [x * y for x, y in zip(single_targets, multipliers)]
targets = [single_targets]
targets = targets[1:] # test runs step before checking lr
metrics = [10 - i * 0.0165 for i in range(22)]
schedulers = [None] * 2
schedulers[0] = ReduceLROnPlateau(
self.opt,
patience=5,
cooldown=0,
threshold_mode="abs",
mode="min",
threshold=0.1,
)
schedulers[1] = MultiStepLR(self.opt, gamma=0.1, milestones=[3, 8, 12])
self._test_reduce_lr_on_plateau(schedulers, targets, metrics, epochs)
def test_compound_reduce_lr_on_plateau3(self):
epochs = 22
for param_group in self.opt.param_groups:
param_group["lr"] = 0.5
single_targets = [0.5] * (2 + 6) + [0.05] * (5 + 6) + [0.005] * 4
multipliers = [0.1**i for i in range(epochs)]
single_targets = [x * y for x, y in zip(multipliers, single_targets)]
targets = [single_targets]
targets = targets[1:] # test runs step before checking lr
metrics = [-0.8] * 2 + [-0.234] * 20
schedulers = [None, None]
schedulers[0] = ReduceLROnPlateau(
self.opt, mode="max", patience=5, cooldown=5, threshold_mode="abs"
)
schedulers[1] = ExponentialLR(self.opt, gamma=0.1)
self._test_reduce_lr_on_plateau(schedulers, targets, metrics, epochs)
def test_compound_reduce_lr_on_plateau4(self):
epochs = 20
for param_group in self.opt.param_groups:
param_group["lr"] = 0.05
epochs = 10
eta_min = 1e-10
single_targets = [
eta_min + (0.05 - eta_min) * (1 + math.cos(math.pi * x / epochs)) / 2
for x in range(epochs)
]
targets = [single_targets]
targets = targets[1:] # test runs step before checking lr
metrics = [1.5 * (1.025**i) for i in range(20)] # 1.025 > 1.1**0.25
schedulers = [None, None]
schedulers[0] = ReduceLROnPlateau(
self.opt, mode="max", patience=3, threshold_mode="rel", threshold=0.1
)
schedulers[1] = CosineAnnealingLR(self.opt, epochs, eta_min)
self._test_reduce_lr_on_plateau(schedulers, targets, metrics, epochs)
def test_compound_reduce_lr_on_plateau5(self):
iters = 4
start_factor = 0.4
epochs = 22
for param_group in self.opt.param_groups:
param_group["lr"] = 0.5
single_targets = [0.5] * 6 + [0.05] * 7 + [0.005] * 7 + [0.0005] * 2
multipliers = [1] * 22
for i in range(iters):
multipliers[i] *= start_factor + i / iters * (1 - start_factor)
single_targets = [x * y for x, y in zip(single_targets, multipliers)]
targets = [single_targets]
targets = targets[1:] # test runs step before checking lr
metrics = [10 - i * 0.0165 for i in range(22)]
schedulers = [None] * 2
schedulers[0] = ReduceLROnPlateau(
self.opt,
patience=5,
cooldown=0,
threshold_mode="abs",
mode="min",
threshold=0.1,
)
schedulers[1] = LinearLR(self.opt, start_factor=start_factor, total_iters=iters)
self._test_reduce_lr_on_plateau(schedulers, targets, metrics, epochs)
def test_cycle_lr_invalid_mode(self):
with self.assertRaises(ValueError):
scheduler = CyclicLR(self.opt, base_lr=0, max_lr=0, mode="CATS")
def test_cycle_lr_triangular_mode_one_lr(self):
lr_target = [1, 2, 3, 4, 5, 4, 3, 2, 1, 2, 3]
momentum_target = [5, 4, 3, 2, 1, 2, 3, 4, 5, 4, 3]
lr_targets = [lr_target, lr_target]
momentum_targets = [momentum_target, momentum_target]
scheduler = CyclicLR(
self.opt,
base_lr=1,
max_lr=5,
step_size_up=4,
cycle_momentum=True,
base_momentum=1,
max_momentum=5,
mode="triangular",
)
self._test_cycle_lr(scheduler, lr_targets, momentum_targets, len(lr_target))
def test_cycle_lr_triangular_mode_one_lr_no_momentum(self):
lr_target = [1, 2, 3, 4, 5, 4, 3, 2, 1, 2, 3]
lr_targets = [lr_target, lr_target]
momentum_target = [self.opt.defaults["momentum"]] * len(lr_target)
momentum_targets = [momentum_target, momentum_target]
scheduler = CyclicLR(
self.opt,
base_lr=1,
max_lr=5,
step_size_up=4,
cycle_momentum=False,
mode="triangular",
)
self._test_cycle_lr(scheduler, lr_targets, momentum_targets, len(lr_target))
def test_cycle_lr_triangular2_mode_one_lr(self):
lr_target = [
1,
2,
3,
4,
5,
4,
3,
2,
1,
1.5,
2.0,
2.5,
3.0,
2.5,
2.0,
1.5,
1,
1.25,
1.50,
1.75,
2.00,
1.75,
]
momentum_target = [
5.0,
4.0,
3.0,
2.0,
1.0,
2.0,
3.0,
4.0,
5.0,
4.5,
4.0,
3.5,
3.0,
3.5,
4.0,
4.5,
5.0,
4.75,
4.5,
4.25,
4.0,
4.25,
]
lr_targets = [lr_target, lr_target]
momentum_targets = [momentum_target, momentum_target]
scheduler = CyclicLR(
self.opt,
base_lr=1,
max_lr=5,
step_size_up=4,
cycle_momentum=True,
base_momentum=1,
max_momentum=5,
mode="triangular2",
)
self._test_cycle_lr(scheduler, lr_targets, momentum_targets, len(lr_target))
def test_cycle_lr_exp_range_mode_one_lr(self):
base_lr, max_lr = 1, 5
diff_lr = max_lr - base_lr
gamma = 0.9
xs = [0, 0.25, 0.5, 0.75, 1, 0.75, 0.50, 0.25, 0, 0.25, 0.5, 0.75, 1]
lr_target = [base_lr + x * diff_lr * gamma**i for i, x in enumerate(xs)]
momentum_target = [max_lr - x * diff_lr * gamma**i for i, x in enumerate(xs)]
lr_targets = [lr_target, lr_target]
momentum_targets = [momentum_target, momentum_target]
scheduler = CyclicLR(
self.opt,
base_lr=base_lr,
max_lr=max_lr,
step_size_up=4,
cycle_momentum=True,
base_momentum=base_lr,
max_momentum=max_lr,
mode="exp_range",
gamma=gamma,
)
self._test_cycle_lr(scheduler, lr_targets, momentum_targets, len(lr_target))
def test_cycle_lr_triangular_mode(self):
lr_target_1 = [1, 2, 3, 4, 5, 4, 3, 2, 1, 2, 3]
lr_target_2 = [x + 1 for x in lr_target_1]
lr_targets = [lr_target_1, lr_target_2]
momentum_target_1 = [5, 4, 3, 2, 1, 2, 3, 4, 5, 4, 3]
momentum_target_2 = [x + 1 for x in momentum_target_1]
momentum_targets = [momentum_target_1, momentum_target_2]
scheduler = CyclicLR(
self.opt,
base_lr=[1, 2],
max_lr=[5, 6],
step_size_up=4,
cycle_momentum=True,
base_momentum=[1, 2],
max_momentum=[5, 6],
mode="triangular",
)
self._test_cycle_lr(scheduler, lr_targets, momentum_targets, len(lr_target_1))
def test_cycle_lr_triangular2_mode(self):
lr_target_1 = [
1,
2,
3,
4,
5,
4,
3,
2,
1,
1.5,
2.0,
2.5,
3.0,
2.5,
2.0,
1.5,
1,
1.25,
1.50,
1.75,
2.00,
1.75,
]
lr_target_2 = [x + 2 for x in lr_target_1]
lr_targets = [lr_target_1, lr_target_2]
momentum_target_1 = [
5.0,
4.0,
3.0,
2.0,
1.0,
2.0,
3.0,
4.0,
5.0,
4.5,
4.0,
3.5,
3.0,
3.5,
4.0,
4.5,
5.0,
4.75,
4.5,
4.25,
4.0,
4.25,
]
momentum_target_2 = [x + 2 for x in momentum_target_1]
momentum_targets = [momentum_target_1, momentum_target_2]
scheduler = CyclicLR(
self.opt,
base_lr=[1, 3],
max_lr=[5, 7],
step_size_up=4,
cycle_momentum=True,
base_momentum=[1, 3],
max_momentum=[5, 7],
mode="triangular2",
)
self._test_cycle_lr(scheduler, lr_targets, momentum_targets, len(lr_target_1))
def test_cycle_lr_exp_range_mode(self):
base_lr_1, max_lr_1 = 1, 5
base_lr_2, max_lr_2 = 5, 12
diff_lr_1 = max_lr_1 - base_lr_1
diff_lr_2 = max_lr_2 - base_lr_2
gamma = 0.9
xs = [0, 0.25, 0.5, 0.75, 1, 0.75, 0.50, 0.25, 0, 0.25, 0.5, 0.75, 1]
lr_target_1 = [base_lr_1 + x * diff_lr_1 * gamma**i for i, x in enumerate(xs)]
lr_target_2 = [base_lr_2 + x * diff_lr_2 * gamma**i for i, x in enumerate(xs)]
lr_targets = [lr_target_1, lr_target_2]
momentum_target_1 = [
max_lr_1 - x * diff_lr_1 * gamma**i for i, x in enumerate(xs)
]
momentum_target_2 = [
max_lr_2 - x * diff_lr_2 * gamma**i for i, x in enumerate(xs)
]
momentum_targets = [momentum_target_1, momentum_target_2]
scheduler = CyclicLR(
self.opt,
base_lr=[base_lr_1, base_lr_2],
max_lr=[max_lr_1, max_lr_2],
step_size_up=4,
cycle_momentum=True,
base_momentum=[base_lr_1, base_lr_2],
max_momentum=[max_lr_1, max_lr_2],
mode="exp_range",
gamma=gamma,
)
self._test_cycle_lr(scheduler, lr_targets, momentum_targets, len(lr_target_1))
def test_cycle_lr_triangular_mode_step_size_up_down(self):
lr_target = [
1.0,
2.0,
3.0,
4.0,
5.0,
13.0 / 3,
11.0 / 3,
9.0 / 3,
7.0 / 3,
5.0 / 3,
1.0,
]
lr_targets = [lr_target, lr_target]
momentum_target = [
5.0,
4.0,
3.0,
2.0,
1.0,
5.0 / 3,
7.0 / 3,
3.0,
11.0 / 3,
13.0 / 3,
5.0,
]
momentum_targets = [momentum_target, momentum_target]
scheduler = CyclicLR(
self.opt,
base_lr=1,
max_lr=5,
step_size_up=4,
step_size_down=6,
cycle_momentum=True,
base_momentum=1,
max_momentum=5,
mode="triangular",
)
self._test_cycle_lr(scheduler, lr_targets, momentum_targets, len(lr_target))
def test_cycle_lr_triangular2_mode_step_size_up_down(self):
lr_base_target = [
1.0,
3.0,
5.0,
13.0 / 3,
11.0 / 3,
9.0 / 3,
7.0 / 3,
5.0 / 3,
1.0,
2.0,
3.0,
8.0 / 3,
7.0 / 3,
6.0 / 3,
5.0 / 3,
4.0 / 3,
1.0,
3.0 / 2,
2.0,
11.0 / 6,
10.0 / 6,
9.0 / 6,
8.0 / 6,
7.0 / 6,
]
momentum_base_target = [
5.0,
3.0,
1.0,
5.0 / 3,
7.0 / 3,
3.0,
11.0 / 3,
13.0 / 3,
5.0,
4.0,
3.0,
10.0 / 3,
11.0 / 3,
4.0,
13.0 / 3,
14.0 / 3,
5.0,
4.5,
4.0,
25.0 / 6,
13.0 / 3,
4.5,
14.0 / 3,
29.0 / 6,
]
deltas = [2 * i for i in range(0, 2)]
base_lrs = [1 + delta for delta in deltas]
max_lrs = [5 + delta for delta in deltas]
lr_targets = [[x + delta for x in lr_base_target] for delta in deltas]
momentum_targets = [
[x + delta for x in momentum_base_target] for delta in deltas
]
scheduler = CyclicLR(
self.opt,
base_lr=base_lrs,
max_lr=max_lrs,
step_size_up=2,
step_size_down=6,
cycle_momentum=True,
base_momentum=base_lrs,
max_momentum=max_lrs,
mode="triangular2",
)
self._test_cycle_lr(
scheduler, lr_targets, momentum_targets, len(lr_base_target)
)
def test_cycle_lr_exp_range_mode_step_size_up_down(self):
base_lr, max_lr = 1, 5
diff_lr = max_lr - base_lr
gamma = 0.9
xs = [
0.0,
0.5,
1.0,
5.0 / 6,
4.0 / 6,
3.0 / 6,
2.0 / 6,
1.0 / 6,
0.0,
0.5,
1.0,
5.0 / 6,
4.0 / 6,
]
lr_target = [base_lr + x * diff_lr * gamma**i for i, x in enumerate(xs)]
lr_targets = [lr_target, lr_target]
momentum_target = [max_lr - x * diff_lr * gamma**i for i, x in enumerate(xs)]
momentum_targets = [momentum_target, momentum_target]
scheduler = CyclicLR(
self.opt,
base_lr=base_lr,
max_lr=max_lr,
step_size_up=2,
step_size_down=6,
cycle_momentum=True,
base_momentum=base_lr,
max_momentum=max_lr,
mode="exp_range",
gamma=gamma,
)
self._test_cycle_lr(scheduler, lr_targets, momentum_targets, len(lr_target))
def test_cycle_lr_with_momentumless_optimizer(self):
# Note [Temporarily set optimizer to Adam]
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# The TestLRScheduler object carries around an SGD optimizer to avoid having to
# instantiate one for every test. This gets in the way for our very specific case
# in which we need to use Adam (or really any optimizer that doesn't use momentum)
# in order to test that the momentum bug in CyclicLR is fixed (the bug is described
# in more detail in https://github.com/pytorch/pytorch/issues/19003 ).
old_opt = self.opt
self.opt = Adam(
[
{"params": self.net.conv1.parameters()},
{"params": self.net.conv2.parameters(), "lr": 0.5},
],
lr=0.05,
)
lr_target = [1, 2, 3, 4, 5, 4, 3, 2, 1, 2, 3]
lr_targets = [lr_target, lr_target]
momentum_target = [None] * len(lr_target)
momentum_targets = [momentum_target, momentum_target]
scheduler = CyclicLR(
self.opt,
base_lr=1,
max_lr=5,
step_size_up=4,
cycle_momentum=False,
mode="triangular",
)
self._test_cycle_lr(scheduler, lr_targets, momentum_targets, len(lr_target))
self.opt = old_opt # set optimizer back to SGD
def test_cycle_lr_cycle_momentum_fail_with_momentumless_optimizer(self):
with self.assertRaises(ValueError):
adam_opt = optim.Adam(self.net.parameters())
scheduler = CyclicLR(adam_opt, base_lr=1, max_lr=5, cycle_momentum=True)
def test_cycle_lr_removed_after_out_of_scope(self):
import gc
import weakref
gc.disable()
def test():
adam_opt = optim.Adam(self.net.parameters())
scheduler = CyclicLR(adam_opt, base_lr=1, max_lr=5, cycle_momentum=False)
return weakref.ref(scheduler)
ref = test()
assert ref() is None
gc.enable()
def test_cycle_lr_state_dict_picklable(self):
adam_opt = optim.Adam(self.net.parameters())
scheduler = CyclicLR(adam_opt, base_lr=1, max_lr=5, cycle_momentum=False)
self.assertIsInstance(scheduler._scale_fn_ref, types.FunctionType)
state = scheduler.state_dict()
self.assertNotIn("_scale_fn_ref", state)
pickle.dumps(state)
def test_cycle_lr_scale_fn_restored_from_state_dict(self):
adam_opt = optim.Adam(self.net.parameters())
# Case 1: Built-in mode
scheduler = CyclicLR(adam_opt, base_lr=1, max_lr=5, cycle_momentum=False, mode="triangular2")
restored_scheduler = CyclicLR(adam_opt, base_lr=1, max_lr=5, cycle_momentum=False)
restored_scheduler.load_state_dict(scheduler.state_dict())
self.assertTrue(restored_scheduler.mode == scheduler.mode == "triangular2")
self.assertIsNotNone(restored_scheduler._scale_fn_ref) and self.assertIsNotNone(scheduler._scale_fn_ref)
self.assertIs(restored_scheduler._scale_fn_custom, None)
self.assertIs(scheduler._scale_fn_custom, None)
# Case 2: Custom `scale_fn`
def scale_fn(_):
return 0.5
scheduler = CyclicLR(adam_opt, base_lr=1, max_lr=5, cycle_momentum=False, scale_fn=scale_fn)
restored_scheduler = CyclicLR(adam_opt, base_lr=1, max_lr=5, cycle_momentum=False, scale_fn=scale_fn)
restored_scheduler.load_state_dict(scheduler.state_dict())
self.assertIs(scheduler._scale_fn_custom, scale_fn)
self.assertIs(restored_scheduler._scale_fn_custom, scale_fn)
def test_onecycle_lr_invalid_anneal_strategy(self):
with self.assertRaises(ValueError):
scheduler = OneCycleLR(
self.opt, max_lr=1e-3, total_steps=10, anneal_strategy="CATS"
)
def test_onecycle_lr_invalid_pct_start(self):
with self.assertRaises(ValueError):
scheduler = OneCycleLR(self.opt, max_lr=1e-3, total_steps=10, pct_start=1.1)
def test_onecycle_lr_cannot_calculate_total_steps(self):
with self.assertRaises(ValueError):
scheduler = OneCycleLR(self.opt, max_lr=1e-3)
def test_onecycle_lr_linear_annealing(self):
lr_target = [1, 13, 25, 21.5, 18, 14.5, 11, 7.5, 4, 0.5]
momentum_target = [22, 11.5, 1, 4, 7, 10, 13, 16, 19, 22]
lr_targets = [lr_target, lr_target]
momentum_targets = [momentum_target, momentum_target]
scheduler = OneCycleLR(
self.opt,
max_lr=25,
final_div_factor=2,
base_momentum=1,
max_momentum=22,
total_steps=10,
anneal_strategy="linear",
)
self._test_cycle_lr(scheduler, lr_targets, momentum_targets, 10)
def test_onecycle_lr_linear_annealing_three_phases(self):
lr_target = [1, 9, 17, 25, 17, 9, 1, 0.75, 0.5, 0.25]
momentum_target = [22, 15, 8, 1, 8, 15, 22, 22, 22, 22]
lr_targets = [lr_target, lr_target]
momentum_targets = [momentum_target, momentum_target]
scheduler = OneCycleLR(
self.opt,
max_lr=25,
div_factor=25,
base_momentum=1,
max_momentum=22,
total_steps=10,
anneal_strategy="linear",
pct_start=0.4,
final_div_factor=4,
three_phase=True,
)
self._test_cycle_lr(scheduler, lr_targets, momentum_targets, 10)
def test_onecycle_lr_cosine_annealing(self):
def annealing_cos(start, end, pct):
cos_out = math.cos(math.pi * pct) + 1
return end + (start - end) / 2.0 * cos_out
lr_target = [
1,
13,
25,
annealing_cos(25, 0.5, 1 / 7.0),
annealing_cos(25, 0.5, 2 / 7.0),
annealing_cos(25, 0.5, 3 / 7.0),
annealing_cos(25, 0.5, 4 / 7.0),
annealing_cos(25, 0.5, 5 / 7.0),
annealing_cos(25, 0.5, 6 / 7.0),
0.5,
]
momentum_target = [
22,
11.5,
1,
annealing_cos(1, 22, 1 / 7.0),
annealing_cos(1, 22, 2 / 7.0),
annealing_cos(1, 22, 3 / 7.0),
annealing_cos(1, 22, 4 / 7.0),
annealing_cos(1, 22, 5 / 7.0),
annealing_cos(1, 22, 6 / 7.0),
22,
]
lr_targets = [lr_target, lr_target]
momentum_targets = [momentum_target, momentum_target]
scheduler = OneCycleLR(
self.opt,
max_lr=25,
final_div_factor=2,
base_momentum=1,
max_momentum=22,
total_steps=10,
)
self._test_cycle_lr(scheduler, lr_targets, momentum_targets, 10)
def test_cycle_lr_with_adam(self):
old_opt = self.opt
self.opt = optim.Adam(
[
{"params": self.net.conv1.parameters()},
{"params": self.net.conv2.parameters(), "lr": 0.5},
],
lr=0.05,
)
lr_target = [1, 13, 25, 21.5, 18, 14.5, 11, 7.5, 4, 0.5]
momentum_target = [22, 11.5, 1, 4, 7, 10, 13, 16, 19, 22]
lr_targets = [lr_target, lr_target]
momentum_targets = [momentum_target, momentum_target]
scheduler = OneCycleLR(
self.opt,
max_lr=25,
final_div_factor=2,
base_momentum=1,
max_momentum=22,
total_steps=10,
anneal_strategy="linear",
)
self._test_cycle_lr(scheduler, lr_targets, momentum_targets, 10, use_beta1=True)
self.opt = old_opt # set optimizer back to SGD
def test_lambda_lr(self):
epochs = 10
self.opt.param_groups[0]["lr"] = 0.05
self.opt.param_groups[1]["lr"] = 0.4
targets = [
[0.05 * (0.9**x) for x in range(epochs)],
[0.4 * (0.8**x) for x in range(epochs)],
]
scheduler = LambdaLR(
self.opt, lr_lambda=[lambda x1: 0.9**x1, lambda x2: 0.8**x2]
)
self._test(scheduler, targets, epochs)
def test_multiplicative_lr(self):
epochs = 10
self.opt.param_groups[0]["lr"] = 0.05
self.opt.param_groups[1]["lr"] = 0.4
targets = [
[0.05 * (0.9**x) for x in range(epochs)],
[0.4 * (0.8**x) for x in range(epochs)],
]
scheduler = MultiplicativeLR(
self.opt, lr_lambda=[lambda x1: 0.9, lambda x2: 0.8]
)
self._test(scheduler, targets, epochs)
@parametrize("T_mult", [1, 2, 4])
def test_CosineAnnealingWarmRestarts_lr1(self, T_mult):
iters = 100
eta_min = 1e-10
T_i = 10
T_cur = 0
targets = [[0.05], [0.5]]
scheduler = CosineAnnealingWarmRestarts(
self.opt, T_0=T_i, T_mult=T_mult, eta_min=eta_min
)
for _ in range(1, iters, 1):
T_cur += 1
if T_cur >= T_i:
T_cur = T_cur - T_i
T_i = int(T_mult) * T_i
targets[0] += [
eta_min + (0.05 - eta_min) * (1 + math.cos(math.pi * T_cur / T_i)) / 2
]
targets[1] += [
eta_min + (0.5 - eta_min) * (1 + math.cos(math.pi * T_cur / T_i)) / 2
]
self._test(scheduler, targets, iters)
def test_CosineAnnealingWarmRestarts_lr2(self):
iters = 30
eta_min = 1e-10
T_mults = [1, 2, 4]
for T_mult in T_mults:
T_i = 10
T_cur = 0
targets = [[0.05], [0.5]]
scheduler = CosineAnnealingWarmRestarts(
self.opt, T_0=T_i, T_mult=T_mult, eta_min=eta_min
)
for _ in torch.arange(0.1, iters, 0.1):
T_cur = round(T_cur + 0.1, 1)
if T_cur >= T_i:
T_cur = T_cur - T_i
T_i = int(T_mult) * T_i
targets[0] += [
eta_min
+ (0.05 - eta_min) * (1 + math.cos(math.pi * T_cur / T_i)) / 2
]
targets[1] += [
eta_min
+ (0.5 - eta_min) * (1 + math.cos(math.pi * T_cur / T_i)) / 2
]
self._test_CosineAnnealingWarmRestarts(scheduler, targets, iters)
def test_CosineAnnealingWarmRestarts_lr3(self):
epochs_for_T_mults = [
[0, 1, 2, 3, 4, 5, 12, 27, 3, 4, 5, 6, 13],
[0, 1, 2, 3, 4, 5, 25, 32, 33, 34, 80, 81, 3],
[0, 0.1, 0.2, 0.3, 1.3, 2.3, 17.5, 18.5, 19.5, 29.5, 30.5, 31.5, 50],
]
T_curs_for_T_mults = [
[1, 2, 3, 4, 5, 2, 7, 3, 4, 5, 6, 3],
[1, 2, 3, 4, 5, 15, 2, 3, 4, 10, 11, 3],
[0.1, 0.2, 0.3, 1.3, 2.3, 7.5, 8.5, 9.5, 19.5, 20.5, 21.5, 10],
]
T_is_for_T_mults = [
[10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10],
[10, 10, 10, 10, 10, 20, 40, 40, 40, 80, 80, 10],
[10, 10, 10, 10, 10, 30, 30, 30, 30, 30, 30, 90],
]
eta_min = 1e-10
T_mults = [1, 2, 3]
for epochs, T_mult, T_curs, T_is in zip(
epochs_for_T_mults, T_mults, T_curs_for_T_mults, T_is_for_T_mults
):
targets = [[0.05], [0.5]]
scheduler = CosineAnnealingWarmRestarts(
self.opt, T_0=10, T_mult=T_mult, eta_min=eta_min
)
for T_cur, T_i in zip(T_curs, T_is):
targets[0] += [
eta_min
+ (0.05 - eta_min) * (1 + math.cos(math.pi * T_cur / T_i)) / 2
]
targets[1] += [
eta_min
+ (0.5 - eta_min) * (1 + math.cos(math.pi * T_cur / T_i)) / 2
]
self._test_interleaved_CosineAnnealingWarmRestarts(
scheduler, targets, epochs
)
def test_swalr_no_anneal(self):
epochs, swa_start, swa_lr = 10, 5, 0.01
initial_lrs = [group["lr"] for group in self.opt.param_groups]
targets = [
[lr] * (swa_start + 1) + [swa_lr] * (epochs - swa_start - 1)
for lr in initial_lrs
]
swa_scheduler = SWALR(self.opt, anneal_epochs=1, swa_lr=swa_lr)
self._test_swalr(swa_scheduler, None, targets, swa_start, epochs)
def test_swalr_cosine_anneal_after_multiplicative(self):
# same swa_lr for different param_groups
epochs, swa_start, swa_lr, anneal_epochs = 15, 5, 0.01, 5
mult_factor = 0.9
scheduler = MultiplicativeLR(self.opt, lr_lambda=lambda epoch: mult_factor)
swa_scheduler = SWALR(self.opt, anneal_epochs=anneal_epochs, swa_lr=swa_lr)
def anneal_coef(t):
if t + 1 >= anneal_epochs:
return 0.0
return (1 + math.cos(math.pi * (t + 1) / anneal_epochs)) / 2
initial_lrs = [group["lr"] for group in self.opt.param_groups]
targets_before_swa = [
[lr * mult_factor**i for i in range(swa_start + 1)] for lr in initial_lrs
]
swa_epochs = epochs - swa_start - 1
targets = [
lrs
+ [
lrs[-1] * anneal_coef(t) + swa_lr * (1 - anneal_coef(t))
for t in range(swa_epochs)
]
for lrs in targets_before_swa
]
self._test_swalr(swa_scheduler, scheduler, targets, swa_start, epochs)
def test_swalr_linear_anneal_after_multiplicative(self):
# separate swa_lr for different param_groups
epochs, swa_start, swa_lrs, anneal_epochs = 15, 5, [0.01, 0.02], 4
mult_factor = 0.9
scheduler = MultiplicativeLR(self.opt, lr_lambda=lambda epoch: mult_factor)
swa_scheduler = SWALR(
self.opt,
anneal_epochs=anneal_epochs,
anneal_strategy="linear",
swa_lr=swa_lrs,
)
def anneal_coef(t):
if t + 1 >= anneal_epochs:
return 0.0
return 1 - (t + 1) / anneal_epochs
initial_lrs = [group["lr"] for group in self.opt.param_groups]
targets_before_swa = [
[lr * mult_factor**i for i in range(swa_start + 1)] for lr in initial_lrs
]
swa_epochs = epochs - swa_start - 1
targets = [
lrs
+ [
lrs[-1] * anneal_coef(t) + swa_lr * (1 - anneal_coef(t))
for t in range(swa_epochs)
]
for lrs, swa_lr in zip(targets_before_swa, swa_lrs)
]
self._test_swalr(swa_scheduler, scheduler, targets, swa_start, epochs)
def _test_swalr(self, swa_scheduler, scheduler, targets, swa_start, epochs):
for epoch in range(epochs):
for param_group, target in zip(self.opt.param_groups, targets):
self.assertEqual(
target[epoch],
param_group["lr"],
msg="LR is wrong in epoch {}: expected {}, got {}".format(
epoch, target[epoch], param_group["lr"]
),
atol=1e-5,
rtol=0,
)
if epoch >= swa_start:
self.opt.step()
swa_scheduler.step()
elif scheduler is not None:
self.opt.step()
scheduler.step()
def test_swalr_hypers(self):
# Test that SWALR raises errors for incorrect hyper-parameters
with self.assertRaisesRegex(ValueError, "anneal_strategy must"):
swa_scheduler = SWALR(self.opt, anneal_strategy="exponential", swa_lr=1.0)
with self.assertRaisesRegex(ValueError, "anneal_epochs must"):
swa_scheduler = SWALR(self.opt, anneal_epochs=-1, swa_lr=1.0)
with self.assertRaisesRegex(ValueError, "anneal_epochs must"):
swa_scheduler = SWALR(self.opt, anneal_epochs=1.7, swa_lr=1.0)
with self.assertRaisesRegex(ValueError, "swa_lr must"):
swa_scheduler = SWALR(self.opt, swa_lr=[1.0, 0.1, 0.01])
def test_step_lr_state_dict(self):
self._check_scheduler_state_dict(
lambda: StepLR(self.opt, gamma=0.1, step_size=3),
lambda: StepLR(self.opt, gamma=0.01 / 2, step_size=1),
)
def test_multi_step_lr_state_dict(self):
self._check_scheduler_state_dict(
lambda: MultiStepLR(self.opt, gamma=0.1, milestones=[2, 5, 9]),
lambda: MultiStepLR(self.opt, gamma=0.01, milestones=[1, 4, 6]),
)
def test_exp_step_lr_state_dict(self):
self._check_scheduler_state_dict(
lambda: ExponentialLR(self.opt, gamma=0.1),
lambda: ExponentialLR(self.opt, gamma=0.01),
)
def test_cosine_lr_state_dict(self):
epochs = 10
eta_min = 1e-10
self._check_scheduler_state_dict(
lambda: CosineAnnealingLR(self.opt, T_max=epochs, eta_min=eta_min),
lambda: CosineAnnealingLR(self.opt, T_max=epochs // 2, eta_min=eta_min / 2),
epochs=epochs,
)
def test_reduce_lr_on_plateau_state_dict(self):
scheduler = ReduceLROnPlateau(self.opt, mode="min", factor=0.1, patience=2)
for score in [1.0, 2.0, 3.0, 4.0, 3.0, 4.0, 5.0, 3.0, 2.0, 1.0]:
scheduler.step(score)
scheduler_copy = ReduceLROnPlateau(
self.opt, mode="max", factor=0.5, patience=10
)
scheduler_copy.load_state_dict(scheduler.state_dict())
for key in scheduler.__dict__.keys():
if key not in {"optimizer", "is_better"}:
self.assertEqual(scheduler.__dict__[key], scheduler_copy.__dict__[key])
def test_lambda_lr_state_dict_fn(self):
scheduler = LambdaLR(self.opt, lr_lambda=lambda x: x)
state = scheduler.state_dict()
self.assertIsNone(state["lr_lambdas"][0])
scheduler_copy = LambdaLR(self.opt, lr_lambda=lambda x: x)
scheduler_copy.load_state_dict(state)
for key in scheduler.__dict__.keys():
if key not in {"optimizer", "lr_lambdas"}:
self.assertEqual(scheduler.__dict__[key], scheduler_copy.__dict__[key])
def test_lambda_lr_state_dict_obj(self):
scheduler = LambdaLR(self.opt, lr_lambda=self.LambdaLRTestObject(10))
state = scheduler.state_dict()
self.assertIsNotNone(state["lr_lambdas"][0])
scheduler_copy = LambdaLR(self.opt, lr_lambda=self.LambdaLRTestObject(-1))
scheduler_copy.load_state_dict(state)
for key in scheduler.__dict__.keys():
if key not in {"optimizer"}:
self.assertEqual(scheduler.__dict__[key], scheduler_copy.__dict__[key])
def test_CosineAnnealingWarmRestarts_lr_state_dict(self):
self._check_scheduler_state_dict(
lambda: CosineAnnealingWarmRestarts(self.opt, T_0=10, T_mult=2),
lambda: CosineAnnealingWarmRestarts(self.opt, T_0=100),
)
def test_swa_lr_state_dict(self):
self._check_scheduler_state_dict(
lambda: SWALR(self.opt, anneal_epochs=3, swa_lr=0.5),
lambda: SWALR(
self.opt, anneal_epochs=10, anneal_strategy="linear", swa_lr=5.0
),
)
def _check_scheduler_state_dict(self, constr, constr2, epochs=10):
scheduler = constr()
for _ in range(epochs):
scheduler.optimizer.step()
scheduler.step()
scheduler_copy = constr2()
scheduler_copy.load_state_dict(scheduler.state_dict())
for key in scheduler.__dict__.keys():
if key != "optimizer":
self.assertEqual(scheduler.__dict__[key], scheduler_copy.__dict__[key])
self.assertEqual(scheduler.get_last_lr(), scheduler_copy.get_last_lr())
def _test_get_last_lr(self, schedulers, targets, epochs=10):
if isinstance(schedulers, LRScheduler):
schedulers = [schedulers]
optimizers = {scheduler.optimizer for scheduler in schedulers}
for epoch in range(epochs):
result = [scheduler.get_last_lr() for scheduler in schedulers]
[optimizer.step() for optimizer in optimizers]
[scheduler.step() for scheduler in schedulers]
target = [[t[epoch] for t in targets]] * len(schedulers)
for t, r in zip(target, result):
self.assertEqual(
t,
r,
msg=f"LR is wrong in epoch {epoch}: expected {t}, got {r}",
atol=1e-5,
rtol=0,
)
def _test_with_epoch(self, schedulers, targets, epochs=10):
if isinstance(schedulers, LRScheduler):
schedulers = [schedulers]
optimizers = {scheduler.optimizer for scheduler in schedulers}
for epoch in range(epochs):
[optimizer.step() for optimizer in optimizers]
with warnings.catch_warnings(record=True) as w:
[
scheduler.step(epoch) for scheduler in schedulers
] # step before assert: skip initial lr
self._check_warning_is_epoch_deprecation_warning(
w, num_warnings=len(schedulers)
)
for param_group, target in zip(self.opt.param_groups, targets):
self.assertEqual(
target[epoch],
param_group["lr"],
msg="LR is wrong in epoch {}: expected {}, got {}".format(
epoch, target[epoch], param_group["lr"]
),
atol=1e-5,
rtol=0,
)
def _test(self, schedulers, targets, epochs=10):
if isinstance(schedulers, LRScheduler):
schedulers = [schedulers]
for epoch in range(epochs):
for param_group, target in zip(self.opt.param_groups, targets):
self.assertEqual(
target[epoch],
param_group["lr"],
msg="LR is wrong in epoch {}: expected {}, got {}".format(
epoch, target[epoch], param_group["lr"]
),
atol=1e-5,
rtol=0,
)
[scheduler.step() for scheduler in schedulers]
def _test_CosineAnnealingWarmRestarts(self, scheduler, targets, epochs=10):
for index, epoch in enumerate(torch.arange(0, epochs, 0.1)):
epoch = round(epoch.item(), 1)
scheduler.step(epoch)
for param_group, target in zip(self.opt.param_groups, targets):
self.assertEqual(
target[index],
param_group["lr"],
msg="LR is wrong in epoch {}: expected {}, got {}".format(
epoch, target[index], param_group["lr"]
),
atol=1e-5,
rtol=0,
)
def _test_interleaved_CosineAnnealingWarmRestarts(self, scheduler, targets, epochs):
for index, epoch in enumerate(epochs):
scheduler.step(epoch)
for param_group, target in zip(self.opt.param_groups, targets):
self.assertEqual(
target[index],
param_group["lr"],
msg="LR is wrong in epoch {}: expected {}, got {}".format(
epoch, target[index], param_group["lr"]
),
atol=1e-5,
rtol=0,
)
def _test_against_closed_form(self, scheduler, closed_form_scheduler, epochs=10):
self.setUp()
targets = []
for epoch in range(epochs):
closed_form_scheduler.optimizer.step()
with warnings.catch_warnings(record=True) as w:
closed_form_scheduler.step(epoch)
self._check_warning_is_epoch_deprecation_warning(w)
targets.append([group["lr"] for group in self.opt.param_groups])
self.setUp()
for epoch in range(epochs):
self.opt.step()
scheduler.step()
for i, param_group in enumerate(self.opt.param_groups):
self.assertEqual(
targets[epoch][i],
param_group["lr"],
msg="LR is wrong in epoch {}: expected {}, got {}".format(
epoch, targets[epoch][i], param_group["lr"]
),
atol=1e-5,
rtol=0,
)
def _test_reduce_lr_on_plateau(
self, schedulers, targets, metrics, epochs=10, verbose=False
):
if isinstance(schedulers, (LRScheduler, ReduceLROnPlateau)):
schedulers = [schedulers]
for epoch in range(epochs):
self.opt.step()
for scheduler in schedulers:
if isinstance(scheduler, ReduceLROnPlateau):
scheduler.step(metrics[epoch])
else:
scheduler.step()
if verbose:
print("epoch{}:\tlr={}".format(epoch, self.opt.param_groups[0]["lr"]))
for param_group, target in zip(self.opt.param_groups, targets):
self.assertEqual(
target[epoch],
param_group["lr"],
msg="LR is wrong in epoch {}: expected {}, got {}".format(
epoch, target[epoch], param_group["lr"]
),
atol=1e-5,
rtol=0,
)
def _test_cycle_lr(
self,
scheduler,
lr_targets,
momentum_targets,
batch_iterations,
verbose=False,
use_beta1=False,
):
for batch_num in range(batch_iterations):
if verbose:
if "momentum" in self.opt.param_groups[0].keys():
print(
"batch{}:\tlr={},momentum={}".format(
batch_num,
self.opt.param_groups[0]["lr"],
self.opt.param_groups[0]["momentum"],
)
)
elif use_beta1 and "betas" in self.opt.param_groups[0].keys():
print(
"batch{}:\tlr={},beta1={}".format(
batch_num,
self.opt.param_groups[0]["lr"],
self.opt.param_groups[0]["betas"][0],
)
)
else:
print(
"batch{}:\tlr={}".format(
batch_num, self.opt.param_groups[0]["lr"]
)
)
for param_group, lr_target, momentum_target in zip(
self.opt.param_groups, lr_targets, momentum_targets
):
self.assertEqual(
lr_target[batch_num],
param_group["lr"],
msg="LR is wrong in batch_num {}: expected {}, got {}".format(
batch_num, lr_target[batch_num], param_group["lr"]
),
atol=1e-5,
rtol=0,
)
if use_beta1 and "betas" in param_group.keys():
self.assertEqual(
momentum_target[batch_num],
param_group["betas"][0],
msg="Beta1 is wrong in batch_num {}: expected {}, got {}".format(
batch_num,
momentum_target[batch_num],
param_group["betas"][0],
),
atol=1e-5,
rtol=0,
)
elif "momentum" in param_group.keys():
self.assertEqual(
momentum_target[batch_num],
param_group["momentum"],
msg="Momentum is wrong in batch_num {}: expected {}, got {}".format(
batch_num,
momentum_target[batch_num],
param_group["momentum"],
),
atol=1e-5,
rtol=0,
)
self.opt.step()
scheduler.step()
def test_cosine_then_cyclic(self):
# https://github.com/pytorch/pytorch/issues/21965
max_lr = 0.3
base_lr = 0.1
optim_lr = 0.5
model = torch.nn.Linear(2, 1)
optimizer = torch.optim.SGD(model.parameters(), lr=optim_lr)
lr_scheduler_1 = torch.optim.lr_scheduler.CosineAnnealingLR(
optimizer, T_max=20, eta_min=0.1
)
lr_scheduler_2 = torch.optim.lr_scheduler.CyclicLR(
optimizer, base_lr=base_lr, max_lr=max_lr, step_size_up=1, step_size_down=3
)
for i in range(40):
optimizer.step()
if i <= lr_scheduler_1.T_max:
lr_scheduler_1.step()
else:
lr_scheduler_2.step()
last_lr = optimizer.param_groups[0]["lr"]
self.assertLessEqual(last_lr, max_lr)
instantiate_parametrized_tests(TestLRScheduler)
if __name__ == "__main__":
print("These tests should be run through test/test_optim.py instead")