def main(argv):
del argv # unused arg
tf.io.gfile.makedirs(FLAGS.output_dir)
logging.info('Saving checkpoints at %s', FLAGS.output_dir)
tf.random.set_seed(FLAGS.seed)
data_dir = utils.get_data_dir_from_flags(FLAGS)
if FLAGS.use_gpu:
logging.info('Use GPU')
strategy = tf.distribute.MirroredStrategy()
else:
logging.info('Use TPU at %s',
FLAGS.tpu if FLAGS.tpu is not None else 'local')
resolver = tf.distribute.cluster_resolver.TPUClusterResolver(
tpu=FLAGS.tpu)
tf.config.experimental_connect_to_cluster(resolver)
tf.tpu.experimental.initialize_tpu_system(resolver)
strategy = tf.distribute.TPUStrategy(resolver)
ds_info = tfds.builder(FLAGS.dataset).info
batch_size = ((FLAGS.per_core_batch_size // FLAGS.ensemble_size) *
FLAGS.num_cores)
train_dataset_size = ds_info.splits['train'].num_examples
steps_per_epoch = train_dataset_size // batch_size
test_dataset_size = ds_info.splits['test'].num_examples
steps_per_eval = test_dataset_size // batch_size
num_classes = ds_info.features['label'].num_classes
train_builder = ub.datasets.get(FLAGS.dataset,
data_dir=data_dir,
download_data=FLAGS.download_data,
split=tfds.Split.TRAIN,
validation_percent=1. -
FLAGS.train_proportion)
train_dataset = train_builder.load(batch_size=batch_size)
validation_dataset = None
steps_per_validation = 0
if FLAGS.train_proportion < 1.0:
validation_builder = ub.datasets.get(FLAGS.dataset,
data_dir=data_dir,
download_data=FLAGS.download_data,
split=tfds.Split.VALIDATION,
validation_percent=1. -
FLAGS.train_proportion)
validation_dataset = validation_builder.load(batch_size=batch_size)
validation_dataset = strategy.experimental_distribute_dataset(
validation_dataset)
steps_per_validation = validation_builder.num_examples // batch_size
clean_test_builder = ub.datasets.get(FLAGS.dataset,
data_dir=data_dir,
download_data=FLAGS.download_data,
split=tfds.Split.TEST)
clean_test_dataset = clean_test_builder.load(batch_size=batch_size)
train_dataset = strategy.experimental_distribute_dataset(train_dataset)
test_datasets = {
'clean': strategy.experimental_distribute_dataset(clean_test_dataset),
}
steps_per_epoch = train_builder.num_examples // batch_size
steps_per_eval = clean_test_builder.num_examples // batch_size
num_classes = 100 if FLAGS.dataset == 'cifar100' else 10
if FLAGS.corruptions_interval > 0:
if FLAGS.dataset == 'cifar100':
data_dir = FLAGS.cifar100_c_path
corruption_types, _ = utils.load_corrupted_test_info(FLAGS.dataset)
for corruption_type in corruption_types:
for severity in range(1, 6):
dataset = ub.datasets.get(
f'{FLAGS.dataset}_corrupted',
corruption_type=corruption_type,
data_dir=data_dir,
severity=severity,
split=tfds.Split.TEST).load(batch_size=batch_size)
test_datasets[f'{corruption_type}_{severity}'] = (
strategy.experimental_distribute_dataset(dataset))
summary_writer = tf.summary.create_file_writer(
os.path.join(FLAGS.output_dir, 'summaries'))
with strategy.scope():
logging.info('Building Keras model')
model = ub.models.wide_resnet_rank1(
input_shape=(32, 32, 3),
depth=28,
width_multiplier=10,
num_classes=num_classes,
alpha_initializer=FLAGS.alpha_initializer,
gamma_initializer=FLAGS.gamma_initializer,
alpha_regularizer=FLAGS.alpha_regularizer,
gamma_regularizer=FLAGS.gamma_regularizer,
use_additive_perturbation=FLAGS.use_additive_perturbation,
ensemble_size=FLAGS.ensemble_size,
random_sign_init=FLAGS.random_sign_init,
dropout_rate=FLAGS.dropout_rate,
prior_mean=FLAGS.prior_mean,
prior_stddev=FLAGS.prior_stddev)
logging.info('Model input shape: %s', model.input_shape)
logging.info('Model output shape: %s', model.output_shape)
logging.info('Model number of weights: %s', model.count_params())
# Linearly scale learning rate and the decay epochs by vanilla settings.
base_lr = FLAGS.base_learning_rate * batch_size / 128
lr_decay_epochs = [(int(start_epoch_str) * FLAGS.train_epochs) // 200
for start_epoch_str in FLAGS.lr_decay_epochs]
lr_schedule = ub.schedules.WarmUpPiecewiseConstantSchedule(
steps_per_epoch,
base_lr,
decay_ratio=FLAGS.lr_decay_ratio,
decay_epochs=lr_decay_epochs,
warmup_epochs=FLAGS.lr_warmup_epochs)
optimizer = tf.keras.optimizers.SGD(lr_schedule,
momentum=1.0 -
FLAGS.one_minus_momentum,
nesterov=True)
metrics = {
'train/negative_log_likelihood':
tf.keras.metrics.Mean(),
'train/kl':
tf.keras.metrics.Mean(),
'train/kl_scale':
tf.keras.metrics.Mean(),
'train/elbo':
tf.keras.metrics.Mean(),
'train/loss':
tf.keras.metrics.Mean(),
'train/accuracy':
tf.keras.metrics.SparseCategoricalAccuracy(),
'train/ece':
rm.metrics.ExpectedCalibrationError(num_bins=FLAGS.num_bins),
'test/negative_log_likelihood':
tf.keras.metrics.Mean(),
'test/kl':
tf.keras.metrics.Mean(),
'test/elbo':
tf.keras.metrics.Mean(),
'test/accuracy':
tf.keras.metrics.SparseCategoricalAccuracy(),
'test/ece':
rm.metrics.ExpectedCalibrationError(num_bins=FLAGS.num_bins),
}
eval_dataset_splits = ['test']
if validation_dataset:
metrics.update({
'validation/negative_log_likelihood':
tf.keras.metrics.Mean(),
'validation/kl':
tf.keras.metrics.Mean(),
'validation/elbo':
tf.keras.metrics.Mean(),
'validation/accuracy':
tf.keras.metrics.SparseCategoricalAccuracy(),
'validation/ece':
rm.metrics.ExpectedCalibrationError(num_bins=FLAGS.num_bins),
})
eval_dataset_splits += ['validation']
for i in range(FLAGS.ensemble_size):
for dataset_split in eval_dataset_splits:
metrics[
f'{dataset_split}/nll_member_{i}'] = tf.keras.metrics.Mean(
)
metrics[f'{dataset_split}/accuracy_member_{i}'] = (
tf.keras.metrics.SparseCategoricalAccuracy())
if FLAGS.corruptions_interval > 0:
corrupt_metrics = {}
for intensity in range(1, 6):
for corruption in corruption_types:
dataset_name = '{0}_{1}'.format(corruption, intensity)
corrupt_metrics['test/nll_{}'.format(dataset_name)] = (
tf.keras.metrics.Mean())
corrupt_metrics['test/kl_{}'.format(dataset_name)] = (
tf.keras.metrics.Mean())
corrupt_metrics['test/elbo_{}'.format(dataset_name)] = (
tf.keras.metrics.Mean())
corrupt_metrics['test/accuracy_{}'.format(
dataset_name)] = (
tf.keras.metrics.SparseCategoricalAccuracy())
corrupt_metrics['test/ece_{}'.format(dataset_name)] = (
rm.metrics.ExpectedCalibrationError(
num_bins=FLAGS.num_bins))
checkpoint = tf.train.Checkpoint(model=model, optimizer=optimizer)
latest_checkpoint = tf.train.latest_checkpoint(FLAGS.output_dir)
initial_epoch = 0
if latest_checkpoint:
# checkpoint.restore must be within a strategy.scope() so that optimizer
# slot variables are mirrored.
checkpoint.restore(latest_checkpoint)
logging.info('Loaded checkpoint %s', latest_checkpoint)
initial_epoch = optimizer.iterations.numpy() // steps_per_epoch
def compute_l2_loss(model):
filtered_variables = []
for var in model.trainable_variables:
# Apply l2 on the BN parameters and bias terms. This
# excludes only fast weight approximate posterior/prior parameters,
# but pay caution to their naming scheme.
if ('kernel' in var.name or 'batch_norm' in var.name
or 'bias' in var.name):
filtered_variables.append(tf.reshape(var, (-1, )))
l2_loss = FLAGS.l2 * 2 * tf.nn.l2_loss(
tf.concat(filtered_variables, axis=0))
return l2_loss
@tf.function
def train_step(iterator):
"""Training StepFn."""
def step_fn(inputs):
"""Per-Replica StepFn."""
images = inputs['features']
labels = inputs['labels']
if FLAGS.ensemble_size > 1:
images = tf.tile(images, [FLAGS.ensemble_size, 1, 1, 1])
labels = tf.tile(labels, [FLAGS.ensemble_size])
with tf.GradientTape() as tape:
logits = model(images, training=True)
negative_log_likelihood = tf.reduce_mean(
tf.keras.losses.sparse_categorical_crossentropy(
labels, logits, from_logits=True))
l2_loss = compute_l2_loss(model)
kl = sum(model.losses) / train_dataset_size
kl_scale = tf.cast(optimizer.iterations + 1, kl.dtype)
kl_scale /= steps_per_epoch * FLAGS.kl_annealing_epochs
kl_scale = tf.minimum(1., kl_scale)
kl_loss = kl_scale * kl
# Scale the loss given the TPUStrategy will reduce sum all gradients.
loss = negative_log_likelihood + l2_loss + kl_loss
scaled_loss = loss / strategy.num_replicas_in_sync
elbo = -(negative_log_likelihood + l2_loss + kl)
grads = tape.gradient(scaled_loss, model.trainable_variables)
# Separate learning rate implementation.
if FLAGS.fast_weight_lr_multiplier != 1.0:
grads_and_vars = []
for grad, var in zip(grads, model.trainable_variables):
# Apply different learning rate on the fast weight approximate
# posterior/prior parameters. This is excludes BN and slow weights,
# but pay caution to the naming scheme.
if ('kernel' not in var.name
and 'batch_norm' not in var.name
and 'bias' not in var.name):
grads_and_vars.append(
(grad * FLAGS.fast_weight_lr_multiplier, var))
else:
grads_and_vars.append((grad, var))
optimizer.apply_gradients(grads_and_vars)
else:
optimizer.apply_gradients(zip(grads,
model.trainable_variables))
probs = tf.nn.softmax(logits)
metrics['train/negative_log_likelihood'].update_state(
negative_log_likelihood)
metrics['train/kl'].update_state(kl)
metrics['train/kl_scale'].update_state(kl_scale)
metrics['train/elbo'].update_state(elbo)
metrics['train/loss'].update_state(loss)
metrics['train/accuracy'].update_state(labels, probs)
metrics['train/ece'].add_batch(probs, label=labels)
for _ in tf.range(tf.cast(steps_per_epoch, tf.int32)):
strategy.run(step_fn, args=(next(iterator), ))
@tf.function
def test_step(iterator, dataset_split, dataset_name, num_steps):
"""Evaluation StepFn."""
def step_fn(inputs):
"""Per-Replica StepFn."""
images = inputs['features']
labels = inputs['labels']
if FLAGS.ensemble_size > 1:
images = tf.tile(images, [FLAGS.ensemble_size, 1, 1, 1])
logits = tf.reshape([
model(images, training=False)
for _ in range(FLAGS.num_eval_samples)
], [FLAGS.num_eval_samples, FLAGS.ensemble_size, -1, num_classes])
probs = tf.nn.softmax(logits)
if FLAGS.ensemble_size > 1:
per_probs = tf.reduce_mean(probs,
axis=0) # marginalize samples
for i in range(FLAGS.ensemble_size):
member_probs = per_probs[i]
member_loss = tf.keras.losses.sparse_categorical_crossentropy(
labels, member_probs)
metrics[f'{dataset_split}/nll_member_{i}'].update_state(
member_loss)
metrics[
f'{dataset_split}/accuracy_member_{i}'].update_state(
labels, member_probs)
# Negative log marginal likelihood computed in a numerically-stable way.
labels_broadcasted = tf.broadcast_to(
labels,
[FLAGS.num_eval_samples, FLAGS.ensemble_size, labels.shape[0]])
log_likelihoods = -tf.keras.losses.sparse_categorical_crossentropy(
labels_broadcasted, logits, from_logits=True)
negative_log_likelihood = tf.reduce_mean(
-tf.reduce_logsumexp(log_likelihoods, axis=[0, 1]) +
tf.math.log(float(FLAGS.num_eval_samples *
FLAGS.ensemble_size)))
probs = tf.math.reduce_mean(probs, axis=[0, 1]) # marginalize
l2_loss = compute_l2_loss(model)
kl = sum(model.losses) / test_dataset_size
elbo = -(negative_log_likelihood + l2_loss + kl)
if dataset_name == 'clean':
metrics[
f'{dataset_split}/negative_log_likelihood'].update_state(
negative_log_likelihood)
metrics[f'{dataset_split}/kl'].update_state(kl)
metrics[f'{dataset_split}/elbo'].update_state(elbo)
metrics[f'{dataset_split}/accuracy'].update_state(
labels, probs)
metrics[f'{dataset_split}/ece'].add_batch(probs, label=labels)
else:
corrupt_metrics['test/nll_{}'.format(
dataset_name)].update_state(negative_log_likelihood)
corrupt_metrics['test/kl_{}'.format(
dataset_name)].update_state(kl)
corrupt_metrics['test/elbo_{}'.format(
dataset_name)].update_state(elbo)
corrupt_metrics['test/accuracy_{}'.format(
dataset_name)].update_state(labels, probs)
corrupt_metrics['test/ece_{}'.format(dataset_name)].add_batch(
probs, label=labels)
for _ in tf.range(tf.cast(num_steps, tf.int32)):
strategy.run(step_fn, args=(next(iterator), ))
train_iterator = iter(train_dataset)
start_time = time.time()
for epoch in range(initial_epoch, FLAGS.train_epochs):
logging.info('Starting to run epoch: %s', epoch)
train_step(train_iterator)
current_step = (epoch + 1) * steps_per_epoch
max_steps = steps_per_epoch * FLAGS.train_epochs
time_elapsed = time.time() - start_time
steps_per_sec = float(current_step) / time_elapsed
eta_seconds = (max_steps - current_step) / steps_per_sec
message = ('{:.1%} completion: epoch {:d}/{:d}. {:.1f} steps/s. '
'ETA: {:.0f} min. Time elapsed: {:.0f} min'.format(
current_step / max_steps, epoch + 1, FLAGS.train_epochs,
steps_per_sec, eta_seconds / 60, time_elapsed / 60))
logging.info(message)
if validation_dataset:
validation_iterator = iter(validation_dataset)
test_step(validation_iterator, 'validation', 'clean',
steps_per_validation)
datasets_to_evaluate = {'clean': test_datasets['clean']}
if (FLAGS.corruptions_interval > 0
and (epoch + 1) % FLAGS.corruptions_interval == 0):
datasets_to_evaluate = test_datasets
for dataset_name, test_dataset in datasets_to_evaluate.items():
test_iterator = iter(test_dataset)
logging.info('Testing on dataset %s', dataset_name)
logging.info('Starting to run eval at epoch: %s', epoch)
test_step(test_iterator, 'test', dataset_name, steps_per_eval)
logging.info('Done with testing on %s', dataset_name)
corrupt_results = {}
if (FLAGS.corruptions_interval > 0
and (epoch + 1) % FLAGS.corruptions_interval == 0):
corrupt_results = utils.aggregate_corrupt_metrics(
corrupt_metrics, corruption_types)
logging.info('Train Loss: %.4f, Accuracy: %.2f%%',
metrics['train/loss'].result(),
metrics['train/accuracy'].result() * 100)
logging.info('Test NLL: %.4f, Accuracy: %.2f%%',
metrics['test/negative_log_likelihood'].result(),
metrics['test/accuracy'].result() * 100)
if FLAGS.ensemble_size > 1:
for i in range(FLAGS.ensemble_size):
logging.info(
'Member %d Test Loss: %.4f, Accuracy: %.2f%%', i,
metrics['test/nll_member_{}'.format(i)].result(),
metrics['test/accuracy_member_{}'.format(i)].result() *
100)
total_results = {
name: metric.result()
for name, metric in metrics.items()
}
total_results.update(corrupt_results)
# Metrics from Robustness Metrics (like ECE) will return a dict with a
# single key/value, instead of a scalar.
total_results = {
k: (list(v.values())[0] if isinstance(v, dict) else v)
for k, v in total_results.items()
}
with summary_writer.as_default():
for name, result in total_results.items():
tf.summary.scalar(name, result, step=epoch + 1)
for metric in metrics.values():
metric.reset_states()
if (FLAGS.checkpoint_interval > 0
and (epoch + 1) % FLAGS.checkpoint_interval == 0):
checkpoint_name = checkpoint.save(
os.path.join(FLAGS.output_dir, 'checkpoint'))
logging.info('Saved checkpoint to %s', checkpoint_name)
final_checkpoint_name = checkpoint.save(
os.path.join(FLAGS.output_dir, 'checkpoint'))
logging.info('Saved last checkpoint to %s', final_checkpoint_name)
with summary_writer.as_default():
hp.hparams({
'base_learning_rate': FLAGS.base_learning_rate,
'one_minus_momentum': FLAGS.one_minus_momentum,
'l2': FLAGS.l2,
'fast_weight_lr_multiplier': FLAGS.fast_weight_lr_multiplier,
'num_eval_samples': FLAGS.num_eval_samples,
})
def main(argv):
del argv # unused arg
tf.io.gfile.makedirs(FLAGS.output_dir)
logging.info('Saving checkpoints at %s', FLAGS.output_dir)
tf.random.set_seed(FLAGS.seed)
data_dir = utils.get_data_dir_from_flags(FLAGS)
if FLAGS.use_gpu:
logging.info('Use GPU')
strategy = tf.distribute.MirroredStrategy()
else:
logging.info('Use TPU at %s',
FLAGS.tpu if FLAGS.tpu is not None else 'local')
resolver = tf.distribute.cluster_resolver.TPUClusterResolver(
tpu=FLAGS.tpu)
tf.config.experimental_connect_to_cluster(resolver)
tf.tpu.experimental.initialize_tpu_system(resolver)
strategy = tf.distribute.TPUStrategy(resolver)
ds_info = tfds.builder(FLAGS.dataset).info
batch_size = (FLAGS.per_core_batch_size * FLAGS.num_cores //
FLAGS.num_dropout_samples_training)
test_batch_size = FLAGS.per_core_batch_size * FLAGS.num_cores
steps_per_epoch = ds_info.splits['train'].num_examples // batch_size
steps_per_eval = ds_info.splits['test'].num_examples // test_batch_size
num_classes = ds_info.features['label'].num_classes
train_builder = ub.datasets.get(FLAGS.dataset,
data_dir=data_dir,
download_data=FLAGS.download_data,
split=tfds.Split.TRAIN,
validation_percent=1. -
FLAGS.train_proportion)
train_dataset = train_builder.load(batch_size=batch_size)
validation_dataset = None
steps_per_validation = 0
if FLAGS.train_proportion < 1.0:
validation_builder = ub.datasets.get(FLAGS.dataset,
data_dir=data_dir,
split=tfds.Split.VALIDATION,
validation_percent=1. -
FLAGS.train_proportion)
validation_dataset = validation_builder.load(
batch_size=test_batch_size)
validation_dataset = strategy.experimental_distribute_dataset(
validation_dataset)
steps_per_validation = validation_builder.num_examples // test_batch_size
clean_test_builder = ub.datasets.get(FLAGS.dataset,
data_dir=data_dir,
split=tfds.Split.TEST)
clean_test_dataset = clean_test_builder.load(batch_size=test_batch_size)
train_dataset = strategy.experimental_distribute_dataset(train_dataset)
test_datasets = {
'clean': strategy.experimental_distribute_dataset(clean_test_dataset),
}
steps_per_epoch = train_builder.num_examples // batch_size
steps_per_eval = clean_test_builder.num_examples // batch_size
num_classes = 100 if FLAGS.dataset == 'cifar100' else 10
if FLAGS.corruptions_interval > 0:
if FLAGS.dataset == 'cifar100':
data_dir = FLAGS.cifar100_c_path
corruption_types, _ = utils.load_corrupted_test_info(FLAGS.dataset)
for corruption_type in corruption_types:
for severity in range(1, 6):
dataset = ub.datasets.get(
f'{FLAGS.dataset}_corrupted',
corruption_type=corruption_type,
data_dir=data_dir,
severity=severity,
split=tfds.Split.TEST).load(batch_size=test_batch_size)
test_datasets[f'{corruption_type}_{severity}'] = (
strategy.experimental_distribute_dataset(dataset))
summary_writer = tf.summary.create_file_writer(
os.path.join(FLAGS.output_dir, 'summaries'))
with strategy.scope():
logging.info('Building ResNet model')
model = ub.models.wide_resnet_dropout(
input_shape=(32, 32, 3),
depth=28,
width_multiplier=10,
num_classes=num_classes,
l2=FLAGS.l2,
dropout_rate=FLAGS.dropout_rate,
residual_dropout=FLAGS.residual_dropout,
filterwise_dropout=FLAGS.filterwise_dropout)
logging.info('Model input shape: %s', model.input_shape)
logging.info('Model output shape: %s', model.output_shape)
logging.info('Model number of weights: %s', model.count_params())
# Linearly scale learning rate and the decay epochs by vanilla settings.
base_lr = FLAGS.base_learning_rate * batch_size / 128
lr_decay_epochs = [(int(start_epoch_str) * FLAGS.train_epochs) // 200
for start_epoch_str in FLAGS.lr_decay_epochs]
lr_schedule = ub.schedules.WarmUpPiecewiseConstantSchedule(
steps_per_epoch,
base_lr,
decay_ratio=FLAGS.lr_decay_ratio,
decay_epochs=lr_decay_epochs,
warmup_epochs=FLAGS.lr_warmup_epochs)
optimizer = tf.keras.optimizers.SGD(lr_schedule,
momentum=1.0 -
FLAGS.one_minus_momentum,
nesterov=True)
metrics = {
'train/negative_log_likelihood':
tf.keras.metrics.Mean(),
'train/accuracy':
tf.keras.metrics.SparseCategoricalAccuracy(),
'train/loss':
tf.keras.metrics.Mean(),
'train/ece':
rm.metrics.ExpectedCalibrationError(num_bins=FLAGS.num_bins),
'test/negative_log_likelihood':
tf.keras.metrics.Mean(),
'test/accuracy':
tf.keras.metrics.SparseCategoricalAccuracy(),
'test/ece':
rm.metrics.ExpectedCalibrationError(num_bins=FLAGS.num_bins),
}
if validation_dataset:
metrics.update({
'validation/negative_log_likelihood':
tf.keras.metrics.Mean(),
'validation/accuracy':
tf.keras.metrics.SparseCategoricalAccuracy(),
'validation/ece':
rm.metrics.ExpectedCalibrationError(num_bins=FLAGS.num_bins),
})
if FLAGS.corruptions_interval > 0:
corrupt_metrics = {}
for intensity in range(1, 6):
for corruption in corruption_types:
dataset_name = '{0}_{1}'.format(corruption, intensity)
corrupt_metrics['test/nll_{}'.format(dataset_name)] = (
tf.keras.metrics.Mean())
corrupt_metrics['test/accuracy_{}'.format(
dataset_name)] = (
tf.keras.metrics.SparseCategoricalAccuracy())
corrupt_metrics['test/ece_{}'.format(dataset_name)] = (
rm.metrics.ExpectedCalibrationError(
num_bins=FLAGS.num_bins))
checkpoint = tf.train.Checkpoint(model=model, optimizer=optimizer)
latest_checkpoint = tf.train.latest_checkpoint(FLAGS.output_dir)
initial_epoch = 0
if latest_checkpoint:
# checkpoint.restore must be within a strategy.scope() so that optimizer
# slot variables are mirrored.
checkpoint.restore(latest_checkpoint)
logging.info('Loaded checkpoint %s', latest_checkpoint)
initial_epoch = optimizer.iterations.numpy() // steps_per_epoch
@tf.function
def train_step(iterator):
"""Training StepFn."""
def step_fn(inputs):
"""Per-Replica StepFn."""
images = inputs['features']
labels = inputs['labels']
images = tf.tile(images,
[FLAGS.num_dropout_samples_training, 1, 1, 1])
labels = tf.tile(labels, [FLAGS.num_dropout_samples_training])
with tf.GradientTape() as tape:
logits = model(images, training=True)
negative_log_likelihood = tf.reduce_mean(
tf.keras.losses.sparse_categorical_crossentropy(
labels, logits, from_logits=True))
l2_loss = sum(model.losses)
loss = negative_log_likelihood + l2_loss
# Scale the loss given the TPUStrategy will reduce sum all gradients.
scaled_loss = loss / strategy.num_replicas_in_sync
grads = tape.gradient(scaled_loss, model.trainable_variables)
optimizer.apply_gradients(zip(grads, model.trainable_variables))
probs = tf.nn.softmax(logits)
metrics['train/ece'].add_batch(probs, label=labels)
metrics['train/loss'].update_state(loss)
metrics['train/negative_log_likelihood'].update_state(
negative_log_likelihood)
metrics['train/accuracy'].update_state(labels, logits)
for _ in tf.range(tf.cast(steps_per_epoch, tf.int32)):
strategy.run(step_fn, args=(next(iterator), ))
@tf.function
def test_step(iterator, dataset_split, dataset_name, num_steps):
"""Evaluation StepFn."""
def step_fn(inputs):
"""Per-Replica StepFn."""
images = inputs['features']
labels = inputs['labels']
logits_list = []
for _ in range(FLAGS.num_dropout_samples):
logits = model(images, training=False)
logits_list.append(logits)
# Logits dimension is (num_samples, batch_size, num_classes).
logits_list = tf.stack(logits_list, axis=0)
probs_list = tf.nn.softmax(logits_list)
probs = tf.reduce_mean(probs_list, axis=0)
labels_broadcasted = tf.broadcast_to(
labels, [FLAGS.num_dropout_samples, labels.shape[0]])
log_likelihoods = -tf.keras.losses.sparse_categorical_crossentropy(
labels_broadcasted, logits_list, from_logits=True)
negative_log_likelihood = tf.reduce_mean(
-tf.reduce_logsumexp(log_likelihoods, axis=[0]) +
tf.math.log(float(FLAGS.num_dropout_samples)))
if dataset_name == 'clean':
metrics[
f'{dataset_split}/negative_log_likelihood'].update_state(
negative_log_likelihood)
metrics[f'{dataset_split}/accuracy'].update_state(
labels, probs)
metrics[f'{dataset_split}/ece'].add_batch(probs, label=labels)
else:
corrupt_metrics['test/nll_{}'.format(
dataset_name)].update_state(negative_log_likelihood)
corrupt_metrics['test/accuracy_{}'.format(
dataset_name)].update_state(labels, probs)
corrupt_metrics['test/ece_{}'.format(dataset_name)].add_batch(
probs, label=labels)
for _ in tf.range(tf.cast(num_steps, tf.int32)):
strategy.run(step_fn, args=(next(iterator), ))
metrics.update({'test/ms_per_example': tf.keras.metrics.Mean()})
train_iterator = iter(train_dataset)
start_time = time.time()
for epoch in range(initial_epoch, FLAGS.train_epochs):
logging.info('Starting to run epoch: %s', epoch)
train_step(train_iterator)
current_step = (epoch + 1) * steps_per_epoch
max_steps = steps_per_epoch * FLAGS.train_epochs
time_elapsed = time.time() - start_time
steps_per_sec = float(current_step) / time_elapsed
eta_seconds = (max_steps - current_step) / steps_per_sec
message = ('{:.1%} completion: epoch {:d}/{:d}. {:.1f} steps/s. '
'ETA: {:.0f} min. Time elapsed: {:.0f} min'.format(
current_step / max_steps, epoch + 1, FLAGS.train_epochs,
steps_per_sec, eta_seconds / 60, time_elapsed / 60))
logging.info(message)
if validation_dataset:
validation_iterator = iter(validation_dataset)
test_step(validation_iterator, 'validation', 'clean',
steps_per_validation)
datasets_to_evaluate = {'clean': test_datasets['clean']}
if (FLAGS.corruptions_interval > 0
and (epoch + 1) % FLAGS.corruptions_interval == 0):
datasets_to_evaluate = test_datasets
for dataset_name, test_dataset in datasets_to_evaluate.items():
test_iterator = iter(test_dataset)
logging.info('Testing on dataset %s', dataset_name)
logging.info('Starting to run eval at epoch: %s', epoch)
test_start_time = time.time()
test_step(test_iterator, 'test', dataset_name, steps_per_eval)
ms_per_example = (time.time() - test_start_time) * 1e6 / batch_size
metrics['test/ms_per_example'].update_state(ms_per_example)
logging.info('Done with testing on %s', dataset_name)
corrupt_results = {}
if (FLAGS.corruptions_interval > 0
and (epoch + 1) % FLAGS.corruptions_interval == 0):
corrupt_results = utils.aggregate_corrupt_metrics(
corrupt_metrics, corruption_types)
logging.info('Train Loss: %.4f, Accuracy: %.2f%%',
metrics['train/loss'].result(),
metrics['train/accuracy'].result() * 100)
logging.info('Test NLL: %.4f, Accuracy: %.2f%%',
metrics['test/negative_log_likelihood'].result(),
metrics['test/accuracy'].result() * 100)
total_results = {
name: metric.result()
for name, metric in metrics.items()
}
total_results.update(corrupt_results)
# Metrics from Robustness Metrics (like ECE) will return a dict with a
# single key/value, instead of a scalar.
total_results = {
k: (list(v.values())[0] if isinstance(v, dict) else v)
for k, v in total_results.items()
}
with summary_writer.as_default():
for name, result in total_results.items():
tf.summary.scalar(name, result, step=epoch + 1)
for metric in metrics.values():
metric.reset_states()
if (FLAGS.checkpoint_interval > 0
and (epoch + 1) % FLAGS.checkpoint_interval == 0):
checkpoint_name = checkpoint.save(
os.path.join(FLAGS.output_dir, 'checkpoint'))
logging.info('Saved checkpoint to %s', checkpoint_name)
final_checkpoint_name = checkpoint.save(
os.path.join(FLAGS.output_dir, 'checkpoint'))
logging.info('Saved last checkpoint to %s', final_checkpoint_name)
with summary_writer.as_default():
hp.hparams({
'base_learning_rate':
FLAGS.base_learning_rate,
'one_minus_momentum':
FLAGS.one_minus_momentum,
'l2':
FLAGS.l2,
'dropout_rate':
FLAGS.dropout_rate,
'num_dropout_samples':
FLAGS.num_dropout_samples,
'num_dropout_samples_training':
FLAGS.num_dropout_samples_training,
})
def main(argv):
del argv # unused arg
tf.io.gfile.makedirs(FLAGS.output_dir)
logging.info('Saving checkpoints at %s', FLAGS.output_dir)
tf.random.set_seed(FLAGS.seed)
data_dir = utils.get_data_dir_from_flags(FLAGS)
if FLAGS.use_gpu:
logging.info('Use GPU')
strategy = tf.distribute.MirroredStrategy()
else:
logging.info('Use TPU at %s',
FLAGS.tpu if FLAGS.tpu is not None else 'local')
resolver = tf.distribute.cluster_resolver.TPUClusterResolver(
tpu=FLAGS.tpu)
tf.config.experimental_connect_to_cluster(resolver)
tf.tpu.experimental.initialize_tpu_system(resolver)
strategy = tf.distribute.TPUStrategy(resolver)
per_core_batch_size = FLAGS.per_core_batch_size // FLAGS.ensemble_size
batch_size = per_core_batch_size * FLAGS.num_cores
check_bool = FLAGS.train_proportion > 0 and FLAGS.train_proportion <= 1
assert check_bool, 'Proportion of train set has to meet 0 < prop <= 1.'
drop_remainder_validation = True
if not FLAGS.use_gpu:
# This has to be True for TPU traing, otherwise the batchsize of images in
# the validation set can't be determined by TPU compile.
assert drop_remainder_validation, 'drop_remainder must be True in TPU mode.'
validation_percent = 1 - FLAGS.train_proportion
train_dataset = ub.datasets.get(
FLAGS.dataset,
data_dir=data_dir,
download_data=FLAGS.download_data,
split=tfds.Split.TRAIN,
validation_percent=validation_percent).load(batch_size=batch_size)
validation_dataset = ub.datasets.get(
FLAGS.dataset,
data_dir=data_dir,
download_data=FLAGS.download_data,
split=tfds.Split.VALIDATION,
validation_percent=validation_percent,
drop_remainder=drop_remainder_validation).load(batch_size=batch_size)
validation_dataset = validation_dataset.repeat()
clean_test_dataset = ub.datasets.get(
FLAGS.dataset,
data_dir=data_dir,
download_data=FLAGS.download_data,
split=tfds.Split.TEST).load(batch_size=batch_size)
train_dataset = strategy.experimental_distribute_dataset(train_dataset)
validation_dataset = strategy.experimental_distribute_dataset(
validation_dataset)
test_datasets = {
'clean': strategy.experimental_distribute_dataset(clean_test_dataset),
}
if FLAGS.corruptions_interval > 0:
if FLAGS.dataset == 'cifar100':
data_dir = FLAGS.cifar100_c_path
corruption_types, _ = utils.load_corrupted_test_info(FLAGS.dataset)
for corruption_type in corruption_types:
for severity in range(1, 6):
dataset = ub.datasets.get(
f'{FLAGS.dataset}_corrupted',
corruption_type=corruption_type,
data_dir=data_dir,
severity=severity,
split=tfds.Split.TEST).load(batch_size=batch_size)
test_datasets[f'{corruption_type}_{severity}'] = (
strategy.experimental_distribute_dataset(dataset))
ds_info = tfds.builder(FLAGS.dataset).info
train_sample_size = ds_info.splits[
'train'].num_examples * FLAGS.train_proportion
steps_per_epoch = int(train_sample_size / batch_size)
train_sample_size = int(train_sample_size)
steps_per_eval = ds_info.splits['test'].num_examples // batch_size
num_classes = ds_info.features['label'].num_classes
summary_writer = tf.summary.create_file_writer(
os.path.join(FLAGS.output_dir, 'summaries'))
logging.info('Building Keras model.')
depth = 28
width = 10
dict_ranges = {'min': FLAGS.min_l2_range, 'max': FLAGS.max_l2_range}
ranges = [dict_ranges for _ in range(6)] # 6 independent l2 parameters
model_config = {
'key_to_index': {
'input_conv_l2_kernel': 0,
'group_l2_kernel': 1,
'group_1_l2_kernel': 2,
'group_2_l2_kernel': 3,
'dense_l2_kernel': 4,
'dense_l2_bias': 5,
},
'ranges': ranges,
'test': None
}
lambdas_config = LambdaConfig(model_config['ranges'],
model_config['key_to_index'])
if FLAGS.e_body_hidden_units > 0:
e_body_arch = '({},)'.format(FLAGS.e_body_hidden_units)
else:
e_body_arch = '()'
e_shared_arch = '()'
e_activation = 'tanh'
filters_resnet = [16]
for i in range(0, 3): # 3 groups of blocks
filters_resnet.extend([16 * width * 2**i] *
9) # 9 layers in each block
# e_head dim for conv2d is just the number of filters (only
# kernel) and twice num of classes for the last dense layer (kernel + bias)
e_head_dims = [x for x in filters_resnet] + [2 * num_classes]
with strategy.scope():
e_models = e_factory(
lambdas_config.input_shape,
e_head_dims=e_head_dims,
e_body_arch=eval(e_body_arch), # pylint: disable=eval-used
e_shared_arch=eval(e_shared_arch), # pylint: disable=eval-used
activation=e_activation,
use_bias=FLAGS.e_model_use_bias,
e_head_init=FLAGS.init_emodels_stddev)
model = wide_resnet_hyperbatchensemble(
input_shape=ds_info.features['image'].shape,
depth=depth,
width_multiplier=width,
num_classes=num_classes,
ensemble_size=FLAGS.ensemble_size,
random_sign_init=FLAGS.random_sign_init,
config=lambdas_config,
e_models=e_models,
l2_batchnorm_layer=FLAGS.l2_batchnorm,
regularize_fast_weights=FLAGS.regularize_fast_weights,
fast_weights_eq_contraint=FLAGS.fast_weights_eq_contraint,
version=2)
logging.info('Model input shape: %s', model.input_shape)
logging.info('Model output shape: %s', model.output_shape)
logging.info('Model number of weights: %s', model.count_params())
# build hyper-batchensemble complete -------------------------
# Initialize Lambda distributions for tuning
lambdas_mean = tf.reduce_mean(
log_uniform_mean([lambdas_config.log_min, lambdas_config.log_max]))
lambdas0 = tf.random.normal((FLAGS.ensemble_size, lambdas_config.dim),
lambdas_mean,
0.1 * FLAGS.ens_init_delta_bounds)
lower0 = lambdas0 - tf.constant(FLAGS.ens_init_delta_bounds)
lower0 = tf.maximum(lower0, 1e-8)
upper0 = lambdas0 + tf.constant(FLAGS.ens_init_delta_bounds)
log_lower = tf.Variable(tf.math.log(lower0))
log_upper = tf.Variable(tf.math.log(upper0))
lambda_parameters = [log_lower, log_upper] # these variables are tuned
clip_lambda_parameters(lambda_parameters, lambdas_config)
# Optimizer settings to train model weights
# Linearly scale learning rate and the decay epochs by vanilla settings.
# Note: Here, we don't divide the epochs by 200 as for the other uncertainty
# baselines.
base_lr = FLAGS.base_learning_rate * batch_size / 128
lr_decay_epochs = [int(l) for l in FLAGS.lr_decay_epochs]
lr_schedule = ub.schedules.WarmUpPiecewiseConstantSchedule(
steps_per_epoch,
base_lr,
decay_ratio=FLAGS.lr_decay_ratio,
decay_epochs=lr_decay_epochs,
warmup_epochs=FLAGS.lr_warmup_epochs)
optimizer = tf.keras.optimizers.SGD(lr_schedule,
momentum=1.0 -
FLAGS.one_minus_momentum,
nesterov=True)
# tuner used for optimizing lambda_parameters
tuner = tf.keras.optimizers.Adam(FLAGS.lr_tuning)
metrics = {
'train/negative_log_likelihood':
tf.keras.metrics.Mean(),
'train/accuracy':
tf.keras.metrics.SparseCategoricalAccuracy(),
'train/loss':
tf.keras.metrics.Mean(),
'train/ece':
rm.metrics.ExpectedCalibrationError(num_bins=FLAGS.num_bins),
'train/disagreement':
tf.keras.metrics.Mean(),
'train/average_kl':
tf.keras.metrics.Mean(),
'train/cosine_similarity':
tf.keras.metrics.Mean(),
'test/negative_log_likelihood':
tf.keras.metrics.Mean(),
'test/accuracy':
tf.keras.metrics.SparseCategoricalAccuracy(),
'test/ece':
rm.metrics.ExpectedCalibrationError(num_bins=FLAGS.num_bins),
'test/gibbs_nll':
tf.keras.metrics.Mean(),
'test/gibbs_accuracy':
tf.keras.metrics.SparseCategoricalAccuracy(),
'test/disagreement':
tf.keras.metrics.Mean(),
'test/average_kl':
tf.keras.metrics.Mean(),
'test/cosine_similarity':
tf.keras.metrics.Mean(),
'validation/loss':
tf.keras.metrics.Mean(),
'validation/loss_entropy':
tf.keras.metrics.Mean(),
'validation/loss_ce':
tf.keras.metrics.Mean()
}
corrupt_metrics = {}
for i in range(FLAGS.ensemble_size):
metrics['test/nll_member_{}'.format(i)] = tf.keras.metrics.Mean()
metrics['test/accuracy_member_{}'.format(i)] = (
tf.keras.metrics.SparseCategoricalAccuracy())
if FLAGS.corruptions_interval > 0:
for intensity in range(1, 6):
for corruption in corruption_types:
dataset_name = '{0}_{1}'.format(corruption, intensity)
corrupt_metrics['test/nll_{}'.format(dataset_name)] = (
tf.keras.metrics.Mean())
corrupt_metrics['test/accuracy_{}'.format(
dataset_name)] = (
tf.keras.metrics.SparseCategoricalAccuracy())
corrupt_metrics['test/ece_{}'.format(dataset_name)] = (
rm.metrics.ExpectedCalibrationError(
num_bins=FLAGS.num_bins))
checkpoint = tf.train.Checkpoint(model=model,
lambda_parameters=lambda_parameters,
optimizer=optimizer)
latest_checkpoint = tf.train.latest_checkpoint(FLAGS.output_dir)
initial_epoch = 0
if latest_checkpoint and FLAGS.restore_checkpoint:
# checkpoint.restore must be within a strategy.scope() so that optimizer
# slot variables are mirrored.
checkpoint.restore(latest_checkpoint)
logging.info('Loaded checkpoint %s', latest_checkpoint)
initial_epoch = optimizer.iterations.numpy() // steps_per_epoch
@tf.function
def train_step(iterator):
"""Training StepFn."""
def step_fn(inputs):
"""Per-Replica StepFn."""
images = inputs['features']
labels = inputs['labels']
images = tf.tile(images, [FLAGS.ensemble_size, 1, 1, 1])
# generate lambdas
lambdas = log_uniform_sample(per_core_batch_size,
lambda_parameters)
lambdas = tf.reshape(lambdas,
(FLAGS.ensemble_size * per_core_batch_size,
lambdas_config.dim))
with tf.GradientTape() as tape:
logits = model([images, lambdas], training=True)
if FLAGS.use_gibbs_ce:
# Average of single model CEs
# tiling of labels should be only done for Gibbs CE loss
labels = tf.tile(labels, [FLAGS.ensemble_size])
negative_log_likelihood = tf.reduce_mean(
tf.keras.losses.sparse_categorical_crossentropy(
labels, logits, from_logits=True))
else:
# Ensemble CE uses no tiling of the labels
negative_log_likelihood = ensemble_crossentropy(
labels, logits, FLAGS.ensemble_size)
# Note: Divide l2_loss by sample_size (this differs from uncertainty_
# baselines implementation.)
l2_loss = sum(model.losses) / train_sample_size
loss = negative_log_likelihood + l2_loss
# Scale the loss given the TPUStrategy will reduce sum all gradients.
scaled_loss = loss / strategy.num_replicas_in_sync
grads = tape.gradient(scaled_loss, model.trainable_variables)
# Separate learning rate for fast weights.
grads_and_vars = []
for grad, var in zip(grads, model.trainable_variables):
if (('alpha' in var.name or 'gamma' in var.name)
and 'batch_norm' not in var.name):
grads_and_vars.append(
(grad * FLAGS.fast_weight_lr_multiplier, var))
else:
grads_and_vars.append((grad, var))
optimizer.apply_gradients(grads_and_vars)
probs = tf.nn.softmax(logits)
per_probs = tf.split(probs,
num_or_size_splits=FLAGS.ensemble_size,
axis=0)
per_probs_stacked = tf.stack(per_probs, axis=0)
metrics['train/ece'].add_batch(probs, label=labels)
metrics['train/loss'].update_state(loss)
metrics['train/negative_log_likelihood'].update_state(
negative_log_likelihood)
metrics['train/accuracy'].update_state(labels, logits)
diversity = rm.metrics.AveragePairwiseDiversity()
diversity.add_batch(per_probs_stacked,
num_models=FLAGS.ensemble_size)
diversity_results = diversity.result()
for k, v in diversity_results.items():
metrics['train/' + k].update_state(v)
if grads_and_vars:
grads, _ = zip(*grads_and_vars)
strategy.run(step_fn, args=(next(iterator), ))
@tf.function
def tuning_step(iterator):
"""Tuning StepFn."""
def step_fn(inputs):
"""Per-Replica StepFn."""
images = inputs['features']
labels = inputs['labels']
images = tf.tile(images, [FLAGS.ensemble_size, 1, 1, 1])
with tf.GradientTape(watch_accessed_variables=False) as tape:
tape.watch(lambda_parameters)
# sample lambdas
if FLAGS.sample_and_tune:
lambdas = log_uniform_sample(per_core_batch_size,
lambda_parameters)
else:
lambdas = log_uniform_mean(lambda_parameters)
lambdas = tf.repeat(lambdas, per_core_batch_size, axis=0)
lambdas = tf.reshape(lambdas,
(FLAGS.ensemble_size *
per_core_batch_size, lambdas_config.dim))
# ensemble CE
logits = model([images, lambdas], training=False)
ce = ensemble_crossentropy(labels, logits, FLAGS.ensemble_size)
# entropy penalty for lambda distribution
entropy = FLAGS.tau * log_uniform_entropy(lambda_parameters)
loss = ce - entropy
scaled_loss = loss / strategy.num_replicas_in_sync
gradients = tape.gradient(loss, lambda_parameters)
tuner.apply_gradients(zip(gradients, lambda_parameters))
metrics['validation/loss_ce'].update_state(
ce / strategy.num_replicas_in_sync)
metrics['validation/loss_entropy'].update_state(
entropy / strategy.num_replicas_in_sync)
metrics['validation/loss'].update_state(scaled_loss)
strategy.run(step_fn, args=(next(iterator), ))
@tf.function
def test_step(iterator, dataset_name, num_eval_samples=0):
"""Evaluation StepFn."""
n_samples = num_eval_samples if num_eval_samples >= 0 else -num_eval_samples
if num_eval_samples >= 0:
# the +1 accounts for the fact that we add the mean of lambdas
ensemble_size = FLAGS.ensemble_size * (1 + n_samples)
else:
ensemble_size = FLAGS.ensemble_size * n_samples
def step_fn(inputs):
"""Per-Replica StepFn."""
# Note that we don't use tf.tile for labels here
images = inputs['features']
labels = inputs['labels']
images = tf.tile(images, [ensemble_size, 1, 1, 1])
# get lambdas
samples = log_uniform_sample(n_samples, lambda_parameters)
if num_eval_samples >= 0:
lambdas = log_uniform_mean(lambda_parameters)
lambdas = tf.expand_dims(lambdas, 1)
lambdas = tf.concat((lambdas, samples), 1)
else:
lambdas = samples
# lambdas with shape (ens size, samples, dim of lambdas)
rep_lambdas = tf.repeat(lambdas, per_core_batch_size, axis=1)
rep_lambdas = tf.reshape(rep_lambdas,
(ensemble_size * per_core_batch_size, -1))
# eval on testsets
logits = model([images, rep_lambdas], training=False)
probs = tf.nn.softmax(logits)
per_probs = tf.split(probs,
num_or_size_splits=ensemble_size,
axis=0)
# per member performance and gibbs performance (average per member perf)
if dataset_name == 'clean':
for i in range(FLAGS.ensemble_size):
# we record the first sample of lambdas per batch-ens member
first_member_index = i * (ensemble_size //
FLAGS.ensemble_size)
member_probs = per_probs[first_member_index]
member_loss = tf.keras.losses.sparse_categorical_crossentropy(
labels, member_probs)
metrics['test/nll_member_{}'.format(i)].update_state(
member_loss)
metrics['test/accuracy_member_{}'.format(i)].update_state(
labels, member_probs)
labels_tile = tf.tile(labels, [ensemble_size])
metrics['test/gibbs_nll'].update_state(
tf.reduce_mean(
tf.keras.losses.sparse_categorical_crossentropy(
labels_tile, logits, from_logits=True)))
metrics['test/gibbs_accuracy'].update_state(labels_tile, probs)
# ensemble performance
negative_log_likelihood = ensemble_crossentropy(
labels, logits, ensemble_size)
probs = tf.reduce_mean(per_probs, axis=0)
if dataset_name == 'clean':
metrics['test/negative_log_likelihood'].update_state(
negative_log_likelihood)
metrics['test/accuracy'].update_state(labels, probs)
metrics['test/ece'].add_batch(probs, label=labels)
else:
corrupt_metrics['test/nll_{}'.format(
dataset_name)].update_state(negative_log_likelihood)
corrupt_metrics['test/accuracy_{}'.format(
dataset_name)].update_state(labels, probs)
corrupt_metrics['test/ece_{}'.format(dataset_name)].add_batch(
probs, label=labels)
if dataset_name == 'clean':
per_probs_stacked = tf.stack(per_probs, axis=0)
diversity = rm.metrics.AveragePairwiseDiversity()
diversity.add_batch(per_probs_stacked,
num_models=ensemble_size)
diversity_results = diversity.result()
for k, v in diversity_results.items():
metrics['test/' + k].update_state(v)
strategy.run(step_fn, args=(next(iterator), ))
logging.info('--- Starting training using %d examples. ---',
train_sample_size)
train_iterator = iter(train_dataset)
validation_iterator = iter(validation_dataset)
start_time = time.time()
for epoch in range(initial_epoch, FLAGS.train_epochs):
logging.info('Starting to run epoch: %s', epoch)
for step in range(steps_per_epoch):
train_step(train_iterator)
do_tuning = (epoch >= FLAGS.tuning_warmup_epochs)
if do_tuning and ((step + 1) % FLAGS.tuning_every_x_step == 0):
tuning_step(validation_iterator)
# clip lambda parameters if outside of range
clip_lambda_parameters(lambda_parameters, lambdas_config)
current_step = epoch * steps_per_epoch + (step + 1)
max_steps = steps_per_epoch * FLAGS.train_epochs
time_elapsed = time.time() - start_time
steps_per_sec = float(current_step) / time_elapsed
eta_seconds = (max_steps - current_step) / steps_per_sec
message = ('{:.1%} completion: epoch {:d}/{:d}. {:.1f} steps/s. '
'ETA: {:.0f} min. Time elapsed: {:.0f} min'.format(
current_step / max_steps, epoch + 1,
FLAGS.train_epochs, steps_per_sec, eta_seconds / 60,
time_elapsed / 60))
if step % 20 == 0:
logging.info(message)
# evaluate on test data
datasets_to_evaluate = {'clean': test_datasets['clean']}
if (FLAGS.corruptions_interval > 0
and (epoch + 1) % FLAGS.corruptions_interval == 0):
datasets_to_evaluate = test_datasets
for dataset_name, test_dataset in datasets_to_evaluate.items():
test_iterator = iter(test_dataset)
logging.info('Testing on dataset %s', dataset_name)
for step in range(steps_per_eval):
if step % 20 == 0:
logging.info('Starting to run eval step %s of epoch: %s',
step, epoch)
test_step(test_iterator, dataset_name, FLAGS.num_eval_samples)
logging.info('Done with testing on %s', dataset_name)
corrupt_results = {}
if (FLAGS.corruptions_interval > 0
and (epoch + 1) % FLAGS.corruptions_interval == 0):
corrupt_results = utils.aggregate_corrupt_metrics(
corrupt_metrics, corruption_types)
logging.info('Train Loss: %.4f, Accuracy: %.2f%%',
metrics['train/loss'].result(),
metrics['train/accuracy'].result() * 100)
logging.info('Validation Loss: %.4f, CE: %.4f, Entropy: %.4f',
metrics['validation/loss'].result(),
metrics['validation/loss_ce'].result(),
metrics['validation/loss_entropy'].result())
logging.info('Test NLL: %.4f, Accuracy: %.2f%%',
metrics['test/negative_log_likelihood'].result(),
metrics['test/accuracy'].result() * 100)
for i in range(FLAGS.ensemble_size):
logging.info(
'Member %d Test Loss: %.4f, Accuracy: %.2f%%', i,
metrics['test/nll_member_{}'.format(i)].result(),
metrics['test/accuracy_member_{}'.format(i)].result() * 100)
total_results = {
name: metric.result()
for name, metric in metrics.items()
}
total_results.update({
name: metric.result()
for name, metric in corrupt_metrics.items()
})
total_results.update(corrupt_results)
# Metrics from Robustness Metrics (like ECE) will return a dict with a
# single key/value, instead of a scalar.
total_results = {
k: (list(v.values())[0] if isinstance(v, dict) else v)
for k, v in total_results.items()
}
with summary_writer.as_default():
for name, result in total_results.items():
tf.summary.scalar(name, result, step=epoch + 1)
for metric in metrics.values():
metric.reset_states()
# save checkpoint and lambdas config
if (FLAGS.checkpoint_interval > 0
and (epoch + 1) % FLAGS.checkpoint_interval == 0):
checkpoint_name = checkpoint.save(
os.path.join(FLAGS.output_dir, 'checkpoint'))
lambdas_cf = lambdas_config.get_config()
filepath = os.path.join(FLAGS.output_dir, 'lambdas_config.p')
with tf.io.gfile.GFile(filepath, 'wb') as fp:
pickle.dump(lambdas_cf, fp, protocol=pickle.HIGHEST_PROTOCOL)
logging.info('Saved checkpoint to %s', checkpoint_name)
with summary_writer.as_default():
hp.hparams({
'base_learning_rate':
FLAGS.base_learning_rate,
'one_minus_momentum':
FLAGS.one_minus_momentum,
'l2':
FLAGS.l2,
'random_sign_init':
FLAGS.random_sign_init,
'fast_weight_lr_multiplier':
FLAGS.fast_weight_lr_multiplier,
})
def main(argv):
del argv # unused arg
if not FLAGS.use_gpu:
raise ValueError('Only GPU is currently supported.')
if FLAGS.num_cores > 1:
raise ValueError('Only a single accelerator is currently supported.')
tf.random.set_seed(FLAGS.seed)
tf.io.gfile.makedirs(FLAGS.output_dir)
ds_info = tfds.builder(FLAGS.dataset).info
batch_size = FLAGS.per_core_batch_size * FLAGS.num_cores
steps_per_eval = ds_info.splits['test'].num_examples // batch_size
num_classes = ds_info.features['label'].num_classes
data_dir = utils.get_data_dir_from_flags(FLAGS)
dataset = ub.datasets.get(
FLAGS.dataset,
data_dir=data_dir,
download_data=FLAGS.download_data,
split=tfds.Split.TEST).load(batch_size=batch_size)
validation_percent = 1. - FLAGS.train_proportion
val_dataset = ub.datasets.get(
dataset_name=FLAGS.dataset,
data_dir=data_dir,
download_data=FLAGS.download_data,
split=tfds.Split.VALIDATION,
validation_percent=validation_percent,
drop_remainder=False).load(batch_size=batch_size)
steps_per_val_eval = int(ds_info.splits['train'].num_examples *
validation_percent) // batch_size
test_datasets = {'clean': dataset}
if FLAGS.dataset == 'cifar100':
data_dir = FLAGS.cifar100_c_path
corruption_types, _ = utils.load_corrupted_test_info(FLAGS.dataset)
for corruption_type in corruption_types:
for severity in range(1, 6):
dataset = ub.datasets.get(
f'{FLAGS.dataset}_corrupted',
corruption_type=corruption_type,
data_dir=data_dir,
severity=severity,
split=tfds.Split.TEST).load(batch_size=batch_size)
test_datasets[f'{corruption_type}_{severity}'] = dataset
model = ub.models.wide_resnet(input_shape=ds_info.features['image'].shape,
depth=28,
width_multiplier=10,
num_classes=num_classes,
l2=0.)
logging.info('Model input shape: %s', model.input_shape)
logging.info('Model output shape: %s', model.output_shape)
logging.info('Model number of weights: %s', model.count_params())
# Search for checkpoints
ensemble_filenames = parse_checkpoint_dir(FLAGS.checkpoint_dir)
model_pool_size = len(ensemble_filenames)
logging.info('Model pool size: %s', model_pool_size)
logging.info('Ensemble size: %s', FLAGS.ensemble_size)
logging.info('Ensemble number of weights: %s',
FLAGS.ensemble_size * model.count_params())
logging.info('Ensemble filenames: %s', str(ensemble_filenames))
checkpoint = tf.train.Checkpoint(model=model)
# Compute the logits on the validation set
val_logits, val_labels = [], []
for m, ensemble_filename in enumerate(ensemble_filenames):
# Enforce memory clean-up
tf.keras.backend.clear_session()
checkpoint.restore(ensemble_filename)
val_iterator = iter(val_dataset)
val_logits_m = []
for _ in range(steps_per_val_eval):
inputs = next(val_iterator)
features = inputs['features']
labels = inputs['labels']
val_logits_m.append(model(features, training=False))
if m == 0:
val_labels.append(labels)
val_logits.append(tf.concat(val_logits_m, axis=0))
if m == 0:
val_labels = tf.concat(val_labels, axis=0)
percent = (m + 1.) / model_pool_size
message = ('{:.1%} completion for prediction on validation set: '
'model {:d}/{:d}.'.format(percent, m + 1, model_pool_size))
logging.info(message)
selected_members, val_acc, val_nll = greedy_selection(
val_logits, val_labels, FLAGS.ensemble_size, FLAGS.greedy_objective)
unique_selected_members = list(set(selected_members))
message = ('Members selected by greedy procedure: {} (with {} unique '
'member(s))\n\t{}').format(
selected_members, len(unique_selected_members),
[ensemble_filenames[i] for i in selected_members])
logging.info(message)
val_metrics = {
'val/accuracy': tf.keras.metrics.Mean(),
'val/negative_log_likelihood': tf.keras.metrics.Mean()
}
val_metrics['val/accuracy'].update_state(val_acc)
val_metrics['val/negative_log_likelihood'].update_state(val_nll)
# Write model predictions to files.
num_datasets = len(test_datasets)
for m, member_id in enumerate(unique_selected_members):
ensemble_filename = ensemble_filenames[member_id]
checkpoint.restore(ensemble_filename)
for n, (name, test_dataset) in enumerate(test_datasets.items()):
filename = '{dataset}_{member}.npy'.format(dataset=name,
member=member_id)
filename = os.path.join(FLAGS.output_dir, filename)
if not tf.io.gfile.exists(filename):
logits = []
test_iterator = iter(test_dataset)
for _ in range(steps_per_eval):
features = next(test_iterator)['features'] # pytype: disable=unsupported-operands
logits.append(model(features, training=False))
logits = tf.concat(logits, axis=0)
with tf.io.gfile.GFile(filename, 'w') as f:
np.save(f, logits.numpy())
numerator = m * num_datasets + (n + 1)
denominator = len(unique_selected_members) * num_datasets
percent = numerator / denominator
message = (
'{:.1%} completion for prediction: ensemble member {:d}/{:d}. '
'Dataset {:d}/{:d}'.format(percent, m + 1,
len(unique_selected_members), n + 1,
num_datasets))
logging.info(message)
metrics = {
'test/negative_log_likelihood': tf.keras.metrics.Mean(),
'test/gibbs_cross_entropy': tf.keras.metrics.Mean(),
'test/accuracy': tf.keras.metrics.SparseCategoricalAccuracy(),
'test/ece':
rm.metrics.ExpectedCalibrationError(num_bins=FLAGS.num_bins),
}
metrics.update(val_metrics)
corrupt_metrics = {}
for name in test_datasets:
corrupt_metrics['test/nll_{}'.format(name)] = tf.keras.metrics.Mean()
corrupt_metrics['test/accuracy_{}'.format(name)] = (
tf.keras.metrics.SparseCategoricalAccuracy())
corrupt_metrics['test/ece_{}'.format(name)] = (
rm.metrics.ExpectedCalibrationError(num_bins=FLAGS.num_bins))
for i in range(len(unique_selected_members)):
metrics['test/nll_member_{}'.format(i)] = tf.keras.metrics.Mean()
metrics['test/accuracy_member_{}'.format(i)] = (
tf.keras.metrics.SparseCategoricalAccuracy())
test_diversity = {
'test/disagreement': tf.keras.metrics.Mean(),
'test/average_kl': tf.keras.metrics.Mean(),
'test/cosine_similarity': tf.keras.metrics.Mean(),
}
metrics.update(test_diversity)
# Evaluate model predictions.
for n, (name, test_dataset) in enumerate(test_datasets.items()):
logits_dataset = []
for member_id in selected_members:
filename = '{dataset}_{member}.npy'.format(dataset=name,
member=member_id)
filename = os.path.join(FLAGS.output_dir, filename)
with tf.io.gfile.GFile(filename, 'rb') as f:
logits_dataset.append(np.load(f))
logits_dataset = tf.convert_to_tensor(logits_dataset)
test_iterator = iter(test_dataset)
for step in range(steps_per_eval):
labels = next(test_iterator)['labels'] # pytype: disable=unsupported-operands
logits = logits_dataset[:, (step * batch_size):((step + 1) *
batch_size)]
labels = tf.cast(labels, tf.int32)
negative_log_likelihood_metric = rm.metrics.EnsembleCrossEntropy()
negative_log_likelihood_metric.add_batch(logits, labels=labels)
negative_log_likelihood = list(
negative_log_likelihood_metric.result().values())[0]
per_probs = tf.nn.softmax(logits)
probs = tf.reduce_mean(per_probs, axis=0)
if name == 'clean':
gibbs_ce_metric = rm.metrics.GibbsCrossEntropy()
gibbs_ce_metric.add_batch(logits, labels=labels)
gibbs_ce = list(gibbs_ce_metric.result().values())[0]
metrics['test/negative_log_likelihood'].update_state(
negative_log_likelihood)
metrics['test/gibbs_cross_entropy'].update_state(gibbs_ce)
metrics['test/accuracy'].update_state(labels, probs)
metrics['test/ece'].add_batch(probs, label=labels)
# Attention must be paid to deal with duplicated members:
# e.g.,
#. selected_members = [2, 7, 3, 3]
# unique_selected_members = [2, 3, 7]
# selected_members.index(3) --> 2
for member_id in unique_selected_members:
i = selected_members.index(member_id)
member_probs = per_probs[i]
member_loss = tf.keras.losses.sparse_categorical_crossentropy(
labels, member_probs)
metrics['test/nll_member_{}'.format(i)].update_state(
member_loss)
metrics['test/accuracy_member_{}'.format(i)].update_state(
labels, member_probs)
diversity = rm.metrics.AveragePairwiseDiversity()
diversity.add_batch(per_probs, num_models=len(per_probs))
diversity_results = diversity.result()
for k, v in diversity_results.items():
test_diversity['test/' + k].update_state(v)
else:
corrupt_metrics['test/nll_{}'.format(name)].update_state(
negative_log_likelihood)
corrupt_metrics['test/accuracy_{}'.format(name)].update_state(
labels, probs)
corrupt_metrics['test/ece_{}'.format(name)].add_batch(
probs, label=labels)
message = (
'{:.1%} completion for evaluation: dataset {:d}/{:d}'.format(
(n + 1) / num_datasets, n + 1, num_datasets))
logging.info(message)
corrupt_results = utils.aggregate_corrupt_metrics(corrupt_metrics,
corruption_types)
total_results = {name: metric.result() for name, metric in metrics.items()}
total_results.update(corrupt_results)
# Metrics from Robustness Metrics (like ECE) will return a dict with a
# single key/value, instead of a scalar.
total_results = {
k: (list(v.values())[0] if isinstance(v, dict) else v)
for k, v in total_results.items()
}
logging.info('Metrics: %s', total_results)
def main(argv):
del argv # unused arg
tf.io.gfile.makedirs(FLAGS.output_dir)
logging.info('Saving checkpoints at %s', FLAGS.output_dir)
tf.random.set_seed(FLAGS.seed)
data_dir = utils.get_data_dir_from_flags(FLAGS)
if FLAGS.use_gpu:
logging.info('Use GPU')
strategy = tf.distribute.MirroredStrategy()
else:
logging.info('Use TPU at %s',
FLAGS.tpu if FLAGS.tpu is not None else 'local')
resolver = tf.distribute.cluster_resolver.TPUClusterResolver(
tpu=FLAGS.tpu)
tf.config.experimental_connect_to_cluster(resolver)
tf.tpu.experimental.initialize_tpu_system(resolver)
strategy = tf.distribute.TPUStrategy(resolver)
batch_size = FLAGS.per_core_batch_size * FLAGS.num_cores
test_batch_size = FLAGS.per_core_batch_size * FLAGS.num_cores
if FLAGS.dataset == 'cifar10':
dataset_builder_class = ub.datasets.Cifar10Dataset
else:
dataset_builder_class = ub.datasets.Cifar100Dataset
train_builder = dataset_builder_class(data_dir=data_dir,
download_data=FLAGS.download_data,
split=tfds.Split.TRAIN,
use_bfloat16=FLAGS.use_bfloat16,
validation_percent=1. -
FLAGS.train_proportion)
train_dataset = train_builder.load(batch_size=batch_size)
train_dataset = strategy.experimental_distribute_dataset(train_dataset)
validation_dataset = None
steps_per_validation = 0
if FLAGS.train_proportion < 1.0:
validation_builder = dataset_builder_class(
data_dir=data_dir,
split=tfds.Split.VALIDATION,
use_bfloat16=FLAGS.use_bfloat16,
validation_percent=1. - FLAGS.train_proportion)
validation_dataset = validation_builder.load(batch_size=batch_size)
validation_dataset = strategy.experimental_distribute_dataset(
validation_dataset)
steps_per_validation = validation_builder.num_examples // batch_size
clean_test_dataset_builder = dataset_builder_class(
data_dir=data_dir,
split=tfds.Split.TEST,
use_bfloat16=FLAGS.use_bfloat16)
clean_test_dataset = clean_test_dataset_builder.load(
batch_size=test_batch_size)
test_datasets = {
'clean': strategy.experimental_distribute_dataset(clean_test_dataset),
}
steps_per_epoch = train_builder.num_examples // batch_size
steps_per_eval = clean_test_dataset_builder.num_examples // batch_size
num_classes = 100 if FLAGS.dataset == 'cifar100' else 10
if FLAGS.corruptions_interval > 0:
if FLAGS.dataset == 'cifar10':
load_c_dataset = utils.load_cifar10_c
else:
load_c_dataset = functools.partial(utils.load_cifar100_c,
path=FLAGS.cifar100_c_path)
corruption_types, max_intensity = utils.load_corrupted_test_info(
FLAGS.dataset)
for corruption in corruption_types:
for intensity in range(1, max_intensity + 1):
dataset = load_c_dataset(corruption_name=corruption,
corruption_intensity=intensity,
batch_size=test_batch_size,
use_bfloat16=FLAGS.use_bfloat16)
test_datasets['{0}_{1}'.format(corruption, intensity)] = (
strategy.experimental_distribute_dataset(dataset))
if FLAGS.use_bfloat16:
policy = tf.keras.mixed_precision.experimental.Policy('mixed_bfloat16')
tf.keras.mixed_precision.experimental.set_policy(policy)
summary_writer = tf.summary.create_file_writer(
os.path.join(FLAGS.output_dir, 'summaries'))
with strategy.scope():
logging.info('Building ResNet model')
model = ub.models.wide_resnet_condconv(
input_shape=(32, 32, 3),
depth=28,
width_multiplier=FLAGS.resnet_width_multiplier,
num_classes=num_classes,
num_experts=FLAGS.num_experts,
per_core_batch_size=FLAGS.per_core_batch_size,
use_cond_dense=FLAGS.use_cond_dense,
reduce_dense_outputs=FLAGS.reduce_dense_outputs,
cond_placement=FLAGS.cond_placement,
routing_fn=FLAGS.routing_fn,
normalize_routing=FLAGS.normalize_routing,
normalize_dense_routing=FLAGS.normalize_dense_routing,
top_k=FLAGS.top_k,
routing_pooling=FLAGS.routing_pooling,
l2=FLAGS.l2)
# reuse_routing=FLAGS.reuse_routing,
# shared_routing_type=FLAGS.shared_routing_type)
logging.info('Model input shape: %s', model.input_shape)
logging.info('Model output shape: %s', model.output_shape)
logging.info('Model number of weights: %s', model.count_params())
# Linearly scale learning rate and the decay epochs by vanilla settings.
base_lr = FLAGS.base_learning_rate * batch_size / 128
lr_decay_epochs = [(int(start_epoch_str) * FLAGS.train_epochs) // 200
for start_epoch_str in FLAGS.lr_decay_epochs]
lr_schedule = ub.schedules.WarmUpPiecewiseConstantSchedule(
steps_per_epoch,
base_lr,
decay_ratio=FLAGS.lr_decay_ratio,
decay_epochs=lr_decay_epochs,
warmup_epochs=FLAGS.lr_warmup_epochs)
optimizer = tf.keras.optimizers.SGD(lr_schedule,
momentum=1.0 -
FLAGS.one_minus_momentum,
nesterov=True)
metrics = {
'train/negative_log_likelihood':
tf.keras.metrics.Mean(),
'train/accuracy':
tf.keras.metrics.SparseCategoricalAccuracy(),
'train/loss':
tf.keras.metrics.Mean(),
'train/ece':
rm.metrics.ExpectedCalibrationError(num_bins=FLAGS.num_bins),
'test/negative_log_likelihood':
tf.keras.metrics.Mean(),
'test/accuracy':
tf.keras.metrics.SparseCategoricalAccuracy(),
'test/ece':
rm.metrics.ExpectedCalibrationError(num_bins=FLAGS.num_bins),
}
eval_dataset_splits = ['test']
if validation_dataset:
metrics.update({
'validation/negative_log_likelihood':
tf.keras.metrics.Mean(),
'validation/accuracy':
tf.keras.metrics.SparseCategoricalAccuracy(),
'validation/ece':
rm.metrics.ExpectedCalibrationError(num_bins=FLAGS.num_bins),
})
eval_dataset_splits += ['validation']
if not FLAGS.reduce_dense_outputs and FLAGS.use_cond_dense:
for dataset_split in eval_dataset_splits:
metrics.update({
f'{dataset_split}/nll_poe':
tf.keras.metrics.Mean(),
f'{dataset_split}/nll_moe':
tf.keras.metrics.Mean(),
f'{dataset_split}/nll_unweighted_poe':
tf.keras.metrics.Mean(),
f'{dataset_split}/nll_unweighted_moe':
tf.keras.metrics.Mean(),
f'{dataset_split}/unweighted_gibbs_ce':
tf.keras.metrics.Mean(),
f'{dataset_split}/ece_unweighted_moe':
rm.metrics.ExpectedCalibrationError(
num_bins=FLAGS.num_bins),
f'{dataset_split}/accuracy_unweighted_moe':
tf.keras.metrics.SparseCategoricalAccuracy(),
f'{dataset_split}/ece_poe':
rm.metrics.ExpectedCalibrationError(
num_bins=FLAGS.num_bins),
f'{dataset_split}/accuracy_poe':
tf.keras.metrics.SparseCategoricalAccuracy(),
f'{dataset_split}/ece_unweighted_poe':
rm.metrics.ExpectedCalibrationError(
num_bins=FLAGS.num_bins),
f'{dataset_split}/accuracy_unweighted_poe':
tf.keras.metrics.SparseCategoricalAccuracy(),
})
for idx in range(FLAGS.num_experts):
metrics[f'{dataset_split}/dense_routing_weight_{idx}'] = (
tf.keras.metrics.Mean())
metrics[
f'{dataset_split}/dense_routing_weight_normalized_{idx}'] = (
tf.keras.metrics.Mean())
if FLAGS.corruptions_interval > 0:
corrupt_metrics = {}
for intensity in range(1, max_intensity + 1):
for corruption in corruption_types:
dataset_name = '{0}_{1}'.format(corruption, intensity)
corrupt_metrics['test/nll_{}'.format(dataset_name)] = (
tf.keras.metrics.Mean())
corrupt_metrics['test/accuracy_{}'.format(
dataset_name)] = (
tf.keras.metrics.SparseCategoricalAccuracy())
corrupt_metrics['test/ece_{}'.format(dataset_name)] = (
rm.metrics.ExpectedCalibrationError(
num_bins=FLAGS.num_bins))
corrupt_metrics['test/nll_weighted_moe_{}'.format(
dataset_name)] = (tf.keras.metrics.Mean())
corrupt_metrics['test/accuracy_weighted_moe_{}'.format(
dataset_name)] = (
tf.keras.metrics.SparseCategoricalAccuracy())
corrupt_metrics['test/ece_weighted_moe_{}'.format(
dataset_name)] = (rm.metrics.ExpectedCalibrationError(
num_bins=FLAGS.num_bins))
checkpoint = tf.train.Checkpoint(model=model, optimizer=optimizer)
latest_checkpoint = tf.train.latest_checkpoint(FLAGS.output_dir)
initial_epoch = 0
if latest_checkpoint:
# checkpoint.restore must be within a strategy.scope() so that optimizer
# slot variables are mirrored.
checkpoint.restore(latest_checkpoint)
logging.info('Loaded checkpoint %s', latest_checkpoint)
initial_epoch = optimizer.iterations.numpy() // steps_per_epoch
def _process_3d_logits(logits, routing_weights, labels):
routing_weights_3d = tf.expand_dims(routing_weights, axis=-1)
weighted_logits = tf.math.reduce_mean(routing_weights_3d * logits,
axis=1)
unweighted_logits = tf.math.reduce_mean(logits, axis=1)
probs = tf.nn.softmax(logits)
unweighted_probs = tf.math.reduce_mean(probs, axis=1)
weighted_probs = tf.math.reduce_sum(routing_weights_3d * probs, axis=1)
labels_broadcasted = tf.tile(tf.reshape(labels, (-1, 1)),
(1, FLAGS.num_experts))
neg_log_likelihoods = tf.keras.losses.sparse_categorical_crossentropy(
labels_broadcasted, logits, from_logits=True)
unweighted_gibbs_ce = tf.math.reduce_mean(neg_log_likelihoods)
weighted_gibbs_ce = tf.math.reduce_mean(
tf.math.reduce_sum(routing_weights * neg_log_likelihoods, axis=1))
return {
'weighted_logits': weighted_logits,
'unweighted_logits': unweighted_logits,
'unweighted_probs': unweighted_probs,
'weighted_probs': weighted_probs,
'neg_log_likelihoods': neg_log_likelihoods,
'unweighted_gibbs_ce': unweighted_gibbs_ce,
'weighted_gibbs_ce': weighted_gibbs_ce
}
def _process_3d_logits_train(logits, routing_weights, labels):
processing_results = _process_3d_logits(logits, routing_weights,
labels)
if FLAGS.loss == 'gibbs_ce':
probs = processing_results['weighted_probs']
negative_log_likelihood = processing_results['weighted_gibbs_ce']
elif FLAGS.loss == 'unweighted_gibbs_ce':
probs = processing_results['unweighted_probs']
negative_log_likelihood = processing_results['unweighted_gibbs_ce']
elif FLAGS.loss == 'moe':
probs = processing_results['weighted_probs']
negative_log_likelihood = tf.math.reduce_mean(
tf.keras.losses.sparse_categorical_crossentropy(
labels, probs, from_logits=False))
elif FLAGS.loss == 'unweighted_moe':
probs = processing_results['unweighted_probs']
negative_log_likelihood = tf.math.reduce_mean(
tf.keras.losses.sparse_categorical_crossentropy(
labels, probs, from_logits=False))
elif FLAGS.loss == 'poe':
probs = tf.softmax(processing_results['weighted_logits'])
negative_log_likelihood = tf.math.reduce_mean(
tf.keras.losses.sparse_categorical_crossentropy(
labels,
processing_results['weighted_logits'],
from_logits=True))
elif FLAGS.loss == 'unweighted_poe':
probs = tf.softmax(processing_results['unweighted_logits'])
negative_log_likelihood = tf.math.reduce_mean(
tf.keras.losses.sparse_categorical_crossentropy(
labels,
processing_results['unweighted_logits'],
from_logits=True))
return probs, negative_log_likelihood
def _process_3d_logits_test(routing_weights, logits, labels):
processing_results = _process_3d_logits(logits, routing_weights,
labels)
nll_poe = tf.math.reduce_mean(
tf.keras.losses.sparse_categorical_crossentropy(
labels,
processing_results['weighted_logits'],
from_logits=True))
nll_unweighted_poe = tf.math.reduce_mean(
tf.keras.losses.sparse_categorical_crossentropy(
labels,
processing_results['unweighted_logits'],
from_logits=True))
nll_moe = tf.math.reduce_mean(
tf.keras.losses.sparse_categorical_crossentropy(
labels,
processing_results['weighted_probs'],
from_logits=False))
nll_unweighted_moe = tf.math.reduce_mean(
tf.keras.losses.sparse_categorical_crossentropy(
labels,
processing_results['unweighted_probs'],
from_logits=False))
return {
'nll_poe': nll_poe,
'nll_moe': nll_moe,
'nll_unweighted_poe': nll_unweighted_poe,
'nll_unweighted_moe': nll_unweighted_moe,
'unweighted_gibbs_ce': processing_results['unweighted_gibbs_ce'],
'weighted_gibbs_ce': processing_results['weighted_gibbs_ce'],
'weighted_probs': processing_results['weighted_probs'],
'unweighted_probs': processing_results['unweighted_probs'],
'weighted_logits': processing_results['weighted_logits'],
'unweighted_logits': processing_results['unweighted_logits']
}
@tf.function
def train_step(iterator):
"""Training StepFn."""
def step_fn(inputs):
"""Per-Replica StepFn."""
images = inputs['features']
labels = inputs['labels']
with tf.GradientTape() as tape:
logits = model(images, training=True)
if FLAGS.use_bfloat16:
logits = tf.cast(logits, tf.float32)
# if not FLAGS.reduce_dense_outputs and FLAGS.use_cond_dense:
if not isinstance(logits, (list, tuple)):
raise ValueError('Logits are not a tuple.')
# logits is a `Tensor` of shape [batch_size, num_experts, num_classes]
logits, all_routing_weights = logits
# routing_weights is a `Tensor` of shape [batch_size, num_experts]
routing_weights = all_routing_weights[-1]
if not FLAGS.reduce_dense_outputs and FLAGS.use_cond_dense:
probs, negative_log_likelihood = _process_3d_logits_train(
logits, routing_weights, labels)
else:
probs = tf.nn.softmax(logits)
# Prior to reduce_mean the NLLs are of the shape [batch, num_experts].
negative_log_likelihood = tf.reduce_mean(
tf.keras.losses.sparse_categorical_crossentropy(
labels, logits, from_logits=True))
l2_loss = sum(model.losses)
loss = negative_log_likelihood + l2_loss
# Scale the loss given the TPUStrategy will reduce sum all gradients.
scaled_loss = loss / strategy.num_replicas_in_sync
grads = tape.gradient(scaled_loss, model.trainable_variables)
optimizer.apply_gradients(zip(grads, model.trainable_variables))
metrics['train/ece'].add_batch(probs, label=labels)
metrics['train/loss'].update_state(loss)
metrics['train/negative_log_likelihood'].update_state(
negative_log_likelihood)
metrics['train/accuracy'].update_state(labels, probs)
for _ in tf.range(tf.cast(steps_per_epoch, tf.int32)):
strategy.run(step_fn, args=(next(iterator), ))
@tf.function
def test_step(iterator, dataset_split, dataset_name, num_steps):
"""Evaluation StepFn."""
def step_fn(inputs):
"""Per-Replica StepFn."""
images = inputs['features']
labels = inputs['labels']
logits = model(images, training=False)
if FLAGS.use_bfloat16:
logits = tf.cast(logits, tf.float32)
if not isinstance(logits, (list, tuple)):
raise ValueError('Logits not a tuple')
# logits is a `Tensor` of shape [batch_size, num_experts, num_classes]
# routing_weights is a `Tensor` of shape [batch_size, num_experts]
logits, all_routing_weights = logits
routing_weights = all_routing_weights[-1]
if not FLAGS.reduce_dense_outputs and FLAGS.use_cond_dense:
results = _process_3d_logits_test(routing_weights, logits,
labels)
else:
probs = tf.nn.softmax(logits)
negative_log_likelihood = tf.reduce_mean(
tf.keras.losses.sparse_categorical_crossentropy(
labels, probs))
if dataset_name == 'clean':
if not FLAGS.reduce_dense_outputs and FLAGS.use_cond_dense:
metrics[f'{dataset_split}/nll_poe'].update_state(
results['nll_poe'])
metrics[f'{dataset_split}/nll_moe'].update_state(
results['nll_moe'])
metrics[
f'{dataset_split}/nll_unweighted_poe'].update_state(
results['nll_unweighted_poe'])
metrics[
f'{dataset_split}/nll_unweighted_moe'].update_state(
results['nll_unweighted_moe'])
metrics[
f'{dataset_split}/unweighted_gibbs_ce'].update_state(
results['unweighted_gibbs_ce'])
metrics[
f'{dataset_split}/negative_log_likelihood'].update_state(
results['weighted_gibbs_ce'])
metrics[f'{dataset_split}/ece'].add_batch(
results['weighted_probs'], label=labels)
metrics[f'{dataset_split}/accuracy'].update_state(
labels, results['weighted_probs'])
metrics[f'{dataset_split}/ece_unweighted_moe'].add_batch(
results['unweighted_probs'], label=labels)
metrics[
f'{dataset_split}/accuracy_unweighted_moe'].update_state(
labels, results['unweighted_probs'])
metrics[f'{dataset_split}/ece_poe'].add_batch(
results['weighted_logits'], label=labels)
metrics[f'{dataset_split}/accuracy_poe'].update_state(
labels, results['weighted_logits'])
metrics[f'{dataset_split}/ece_unweighted_poe'].add_batch(
results['unweighted_logits'], label=labels)
metrics[
f'{dataset_split}/accuracy_unweighted_poe'].update_state(
labels, results['unweighted_logits'])
# TODO(ghassen): summarize all routing weights not only last layer's.
average_routing_weights = tf.math.reduce_mean(
routing_weights, axis=0)
routing_weights_sum = tf.math.reduce_sum(
average_routing_weights)
for idx in range(FLAGS.num_experts):
metrics[
f'{dataset_split}/dense_routing_weight_{idx}'].update_state(
average_routing_weights[idx])
key = f'{dataset_split}/dense_routing_weight_normalized_{idx}'
metrics[key].update_state(
average_routing_weights[idx] / routing_weights_sum)
# TODO(ghassen): add more metrics for expert utilization,
# load loss and importance/balance loss.
else:
metrics[
f'{dataset_split}/negative_log_likelihood'].update_state(
negative_log_likelihood)
metrics[f'{dataset_split}/accuracy'].update_state(
labels, probs)
metrics[f'{dataset_split}/ece'].add_batch(probs,
label=labels)
else:
# TODO(ghassen): figure out how to aggregate probs for the OOD case.
if not FLAGS.reduce_dense_outputs and FLAGS.use_cond_dense:
corrupt_metrics['test/nll_{}'.format(
dataset_name)].update_state(
results['unweighted_gibbs_ce'])
corrupt_metrics['test/accuracy_{}'.format(
dataset_name)].update_state(
labels, results['unweighted_probs'])
corrupt_metrics['test/ece_{}'.format(
dataset_name)].add_batch(results['unweighted_probs'],
label=labels)
corrupt_metrics['test/nll_weighted_moe{}'.format(
dataset_name)].update_state(
results['weighted_gibbs_ce'])
corrupt_metrics['test/accuracy_weighted_moe_{}'.format(
dataset_name)].update_state(labels,
results['weighted_probs'])
corrupt_metrics['test/ece_weighted_moe{}'.format(
dataset_name)].add_batch(results['weighted_probs'],
label=labels)
else:
corrupt_metrics['test/nll_{}'.format(
dataset_name)].update_state(negative_log_likelihood)
corrupt_metrics['test/accuracy_{}'.format(
dataset_name)].update_state(labels, probs)
corrupt_metrics['test/ece_{}'.format(
dataset_name)].add_batch(probs, label=labels)
for _ in tf.range(tf.cast(num_steps, tf.int32)):
strategy.run(step_fn, args=(next(iterator), ))
metrics.update({'test/ms_per_example': tf.keras.metrics.Mean()})
train_iterator = iter(train_dataset)
start_time = time.time()
for epoch in range(initial_epoch, FLAGS.train_epochs):
logging.info('Starting to run epoch: %s', epoch)
train_step(train_iterator)
current_step = (epoch + 1) * steps_per_epoch
max_steps = steps_per_epoch * FLAGS.train_epochs
time_elapsed = time.time() - start_time
steps_per_sec = float(current_step) / time_elapsed
eta_seconds = (max_steps - current_step) / steps_per_sec
message = ('{:.1%} completion: epoch {:d}/{:d}. {:.1f} steps/s. '
'ETA: {:.0f} min. Time elapsed: {:.0f} min'.format(
current_step / max_steps, epoch + 1, FLAGS.train_epochs,
steps_per_sec, eta_seconds / 60, time_elapsed / 60))
logging.info(message)
if validation_dataset:
validation_iterator = iter(validation_dataset)
test_step(validation_iterator, 'validation', 'clean',
steps_per_validation)
datasets_to_evaluate = {'clean': test_datasets['clean']}
if (FLAGS.corruptions_interval > 0
and (epoch + 1) % FLAGS.corruptions_interval == 0):
datasets_to_evaluate = test_datasets
for dataset_name, test_dataset in datasets_to_evaluate.items():
test_iterator = iter(test_dataset)
logging.info('Testing on dataset %s', dataset_name)
logging.info('Starting to run eval at epoch: %s', epoch)
test_start_time = time.time()
test_step(test_iterator, 'test', dataset_name, steps_per_eval)
ms_per_example = (time.time() - test_start_time) * 1e6 / batch_size
metrics['test/ms_per_example'].update_state(ms_per_example)
logging.info('Done with testing on %s', dataset_name)
corrupt_results = {}
if (FLAGS.corruptions_interval > 0
and (epoch + 1) % FLAGS.corruptions_interval == 0):
corrupt_results = utils.aggregate_corrupt_metrics(
corrupt_metrics, corruption_types, max_intensity)
logging.info('Train Loss: %.4f, Accuracy: %.2f%%',
metrics['train/loss'].result(),
metrics['train/accuracy'].result() * 100)
logging.info('Test NLL: %.4f, Accuracy: %.2f%%',
metrics['test/negative_log_likelihood'].result(),
metrics['test/accuracy'].result() * 100)
total_results = {
name: metric.result()
for name, metric in metrics.items()
}
total_results.update(corrupt_results)
# Metrics from Robustness Metrics (like ECE) will return a dict with a
# single key/value, instead of a scalar.
total_results = {
k: (list(v.values())[0] if isinstance(v, dict) else v)
for k, v in total_results.items()
}
with summary_writer.as_default():
for name, result in total_results.items():
tf.summary.scalar(name, result, step=epoch + 1)
for metric in metrics.values():
metric.reset_states()
if (FLAGS.checkpoint_interval > 0
and (epoch + 1) % FLAGS.checkpoint_interval == 0):
checkpoint_name = checkpoint.save(
os.path.join(FLAGS.output_dir, 'checkpoint'))
logging.info('Saved checkpoint to %s', checkpoint_name)
final_checkpoint_name = checkpoint.save(
os.path.join(FLAGS.output_dir, 'checkpoint'))
logging.info('Saved last checkpoint to %s', final_checkpoint_name)
with summary_writer.as_default():
hp.hparams({
'base_learning_rate':
FLAGS.base_learning_rate,
'one_minus_momentum':
FLAGS.one_minus_momentum,
'l2':
FLAGS.l2,
'dropout_rate':
FLAGS.dropout_rate,
'num_dropout_samples':
FLAGS.num_dropout_samples,
'num_dropout_samples_training':
FLAGS.num_dropout_samples_training,
})
def main(argv):
del argv # unused arg
tf.io.gfile.makedirs(FLAGS.output_dir)
logging.info('Saving checkpoints at %s', FLAGS.output_dir)
tf.random.set_seed(FLAGS.seed)
# Split the seed into a 2-tuple, for passing into dataset builder.
dataset_seed = (FLAGS.seed, FLAGS.seed + 1)
data_dir = utils.get_data_dir_from_flags(FLAGS)
if FLAGS.use_gpu:
logging.info('Use GPU')
strategy = tf.distribute.MirroredStrategy()
else:
logging.info('Use TPU at %s',
FLAGS.tpu if FLAGS.tpu is not None else 'local')
resolver = tf.distribute.cluster_resolver.TPUClusterResolver(
tpu=FLAGS.tpu)
tf.config.experimental_connect_to_cluster(resolver)
tf.tpu.experimental.initialize_tpu_system(resolver)
strategy = tf.distribute.TPUStrategy(resolver)
batch_size = (FLAGS.per_core_batch_size * FLAGS.num_cores //
FLAGS.num_dropout_samples_training)
test_batch_size = FLAGS.per_core_batch_size * FLAGS.num_cores
num_classes = 10 if FLAGS.dataset == 'cifar10' else 100
aug_params = {
'augmix': FLAGS.augmix,
'aug_count': FLAGS.aug_count,
'augmix_depth': FLAGS.augmix_depth,
'augmix_prob_coeff': FLAGS.augmix_prob_coeff,
'augmix_width': FLAGS.augmix_width,
'ensemble_size': 1,
'mixup_alpha': FLAGS.mixup_alpha,
}
validation_proportion = 1. - FLAGS.train_proportion
use_validation_set = validation_proportion > 0.
if FLAGS.dataset == 'cifar10':
dataset_builder_class = ub.datasets.Cifar10Dataset
else:
dataset_builder_class = ub.datasets.Cifar100Dataset
train_dataset_builder = dataset_builder_class(
data_dir=data_dir,
download_data=FLAGS.download_data,
split=tfds.Split.TRAIN,
use_bfloat16=FLAGS.use_bfloat16,
aug_params=aug_params,
validation_percent=validation_proportion,
seed=dataset_seed)
train_dataset = train_dataset_builder.load(batch_size=batch_size)
train_sample_size = train_dataset_builder.num_examples
if validation_proportion > 0.:
validation_dataset_builder = dataset_builder_class(
data_dir=data_dir,
download_data=FLAGS.download_data,
split=tfds.Split.VALIDATION,
use_bfloat16=FLAGS.use_bfloat16,
validation_percent=validation_proportion)
validation_dataset = validation_dataset_builder.load(
batch_size=batch_size)
validation_dataset = strategy.experimental_distribute_dataset(
validation_dataset)
val_sample_size = validation_dataset_builder.num_examples
steps_per_val = steps_per_epoch = int(val_sample_size / batch_size)
clean_test_dataset_builder = dataset_builder_class(
data_dir=data_dir,
download_data=FLAGS.download_data,
split=tfds.Split.TEST,
use_bfloat16=FLAGS.use_bfloat16)
clean_test_dataset = clean_test_dataset_builder.load(
batch_size=test_batch_size)
steps_per_epoch = int(train_sample_size / batch_size)
steps_per_epoch = train_dataset_builder.num_examples // batch_size
steps_per_eval = clean_test_dataset_builder.num_examples // batch_size
train_dataset = strategy.experimental_distribute_dataset(train_dataset)
test_datasets = {
'clean': strategy.experimental_distribute_dataset(clean_test_dataset),
}
if FLAGS.corruptions_interval > 0:
if FLAGS.dataset == 'cifar10':
load_c_dataset = utils.load_cifar10_c
else:
load_c_dataset = functools.partial(utils.load_cifar100_c,
path=FLAGS.cifar100_c_path)
corruption_types, max_intensity = utils.load_corrupted_test_info(
FLAGS.dataset)
for corruption in corruption_types:
for intensity in range(1, max_intensity + 1):
dataset = load_c_dataset(corruption_name=corruption,
corruption_intensity=intensity,
batch_size=test_batch_size,
data_dir=data_dir,
download_data=FLAGS.download_data,
use_bfloat16=FLAGS.use_bfloat16)
test_datasets['{0}_{1}'.format(corruption, intensity)] = (
strategy.experimental_distribute_dataset(dataset))
if FLAGS.use_bfloat16:
policy = tf.keras.mixed_precision.experimental.Policy('mixed_bfloat16')
tf.keras.mixed_precision.experimental.set_policy(policy)
summary_writer = tf.summary.create_file_writer(
os.path.join(FLAGS.output_dir, 'summaries'))
with strategy.scope():
logging.info('Building ResNet model')
if FLAGS.use_spec_norm:
logging.info('Use Spectral Normalization with norm bound %.2f',
FLAGS.spec_norm_bound)
if FLAGS.use_gp_layer:
logging.info('Use GP layer with hidden units %d',
FLAGS.gp_hidden_dim)
model = ub.models.wide_resnet_sngp(
input_shape=(32, 32, 3),
batch_size=batch_size,
depth=28,
width_multiplier=10,
num_classes=num_classes,
l2=FLAGS.l2,
use_mc_dropout=FLAGS.use_mc_dropout,
use_filterwise_dropout=FLAGS.use_filterwise_dropout,
dropout_rate=FLAGS.dropout_rate,
use_gp_layer=FLAGS.use_gp_layer,
gp_input_dim=FLAGS.gp_input_dim,
gp_hidden_dim=FLAGS.gp_hidden_dim,
gp_scale=FLAGS.gp_scale,
gp_bias=FLAGS.gp_bias,
gp_input_normalization=FLAGS.gp_input_normalization,
gp_random_feature_type=FLAGS.gp_random_feature_type,
gp_cov_discount_factor=FLAGS.gp_cov_discount_factor,
gp_cov_ridge_penalty=FLAGS.gp_cov_ridge_penalty,
use_spec_norm=FLAGS.use_spec_norm,
spec_norm_iteration=FLAGS.spec_norm_iteration,
spec_norm_bound=FLAGS.spec_norm_bound)
logging.info('Model input shape: %s', model.input_shape)
logging.info('Model output shape: %s', model.output_shape)
logging.info('Model number of weights: %s', model.count_params())
# Linearly scale learning rate and the decay epochs by vanilla settings.
base_lr = FLAGS.base_learning_rate * batch_size / 128
lr_decay_epochs = [(int(start_epoch_str) * FLAGS.train_epochs) // 200
for start_epoch_str in FLAGS.lr_decay_epochs]
lr_schedule = ub.schedules.WarmUpPiecewiseConstantSchedule(
steps_per_epoch,
base_lr,
decay_ratio=FLAGS.lr_decay_ratio,
decay_epochs=lr_decay_epochs,
warmup_epochs=FLAGS.lr_warmup_epochs)
optimizer = tf.keras.optimizers.SGD(lr_schedule,
momentum=1.0 -
FLAGS.one_minus_momentum,
nesterov=True)
metrics = {
'train/negative_log_likelihood':
tf.keras.metrics.Mean(),
'train/accuracy':
tf.keras.metrics.SparseCategoricalAccuracy(),
'train/loss':
tf.keras.metrics.Mean(),
'train/ece':
rm.metrics.ExpectedCalibrationError(num_bins=FLAGS.num_bins),
'test/negative_log_likelihood':
tf.keras.metrics.Mean(),
'test/accuracy':
tf.keras.metrics.SparseCategoricalAccuracy(),
'test/ece':
rm.metrics.ExpectedCalibrationError(num_bins=FLAGS.num_bins),
'test/stddev':
tf.keras.metrics.Mean(),
}
if use_validation_set:
metrics.update({
'val/negative_log_likelihood':
tf.keras.metrics.Mean(),
'val/accuracy':
tf.keras.metrics.SparseCategoricalAccuracy(),
'val/ece':
rm.metrics.ExpectedCalibrationError(num_bins=FLAGS.num_bins),
'val/stddev':
tf.keras.metrics.Mean(),
})
if FLAGS.corruptions_interval > 0:
corrupt_metrics = {}
for intensity in range(1, max_intensity + 1):
for corruption in corruption_types:
dataset_name = '{0}_{1}'.format(corruption, intensity)
corrupt_metrics['test/nll_{}'.format(dataset_name)] = (
tf.keras.metrics.Mean())
corrupt_metrics['test/accuracy_{}'.format(
dataset_name)] = (
tf.keras.metrics.SparseCategoricalAccuracy())
corrupt_metrics['test/ece_{}'.format(dataset_name)] = (
rm.metrics.ExpectedCalibrationError(
num_bins=FLAGS.num_bins))
corrupt_metrics['test/stddev_{}'.format(dataset_name)] = (
tf.keras.metrics.Mean())
checkpoint = tf.train.Checkpoint(model=model, optimizer=optimizer)
latest_checkpoint = tf.train.latest_checkpoint(FLAGS.output_dir)
initial_epoch = 0
if latest_checkpoint:
# checkpoint.restore must be within a strategy.scope() so that optimizer
# slot variables are mirrored.
checkpoint.restore(latest_checkpoint)
logging.info('Loaded checkpoint %s', latest_checkpoint)
initial_epoch = optimizer.iterations.numpy() // steps_per_epoch
@tf.function
def train_step(iterator, step):
"""Training StepFn."""
def step_fn(inputs, step):
"""Per-Replica StepFn."""
images = inputs['features']
labels = inputs['labels']
if tf.equal(step, 0) and FLAGS.gp_cov_discount_factor < 0:
# Resetting covaraince estimator at the begining of a new epoch.
model.layers[-1].reset_covariance_matrix()
if FLAGS.augmix and FLAGS.aug_count >= 1:
# Index 0 at augmix preprocessing is the unperturbed image.
images = images[:, 1, ...]
# This is for the case of combining AugMix and Mixup.
if FLAGS.mixup_alpha > 0:
labels = tf.split(labels, FLAGS.aug_count + 1, axis=0)[1]
images = tf.tile(images,
[FLAGS.num_dropout_samples_training, 1, 1, 1])
if FLAGS.mixup_alpha > 0:
labels = tf.tile(labels,
[FLAGS.num_dropout_samples_training, 1])
else:
labels = tf.tile(labels, [FLAGS.num_dropout_samples_training])
with tf.GradientTape() as tape:
logits = model(images, training=True)
if isinstance(logits, (list, tuple)):
# If model returns a tuple of (logits, covmat), extract logits
logits, _ = logits
if FLAGS.use_bfloat16:
logits = tf.cast(logits, tf.float32)
if FLAGS.mixup_alpha > 0:
negative_log_likelihood = tf.reduce_mean(
tf.keras.losses.categorical_crossentropy(
labels, logits, from_logits=True))
else:
negative_log_likelihood = tf.reduce_mean(
tf.keras.losses.sparse_categorical_crossentropy(
labels, logits, from_logits=True))
l2_loss = sum(model.losses)
loss = negative_log_likelihood + l2_loss
# Scale the loss given the TPUStrategy will reduce sum all gradients.
scaled_loss = loss / strategy.num_replicas_in_sync
grads = tape.gradient(scaled_loss, model.trainable_variables)
optimizer.apply_gradients(zip(grads, model.trainable_variables))
probs = tf.nn.softmax(logits)
if FLAGS.mixup_alpha > 0:
labels = tf.argmax(labels, axis=-1)
metrics['train/ece'].add_batch(probs, label=labels)
metrics['train/loss'].update_state(loss)
metrics['train/negative_log_likelihood'].update_state(
negative_log_likelihood)
metrics['train/accuracy'].update_state(labels, logits)
strategy.run(step_fn, args=(next(iterator), step))
@tf.function
def test_step(iterator, dataset_name):
"""Evaluation StepFn."""
def step_fn(inputs):
"""Per-Replica StepFn."""
images = inputs['features']
labels = inputs['labels']
logits_list = []
stddev_list = []
for _ in range(FLAGS.num_dropout_samples):
logits = model(images, training=False)
if isinstance(logits, (list, tuple)):
# If model returns a tuple of (logits, covmat), extract both
logits, covmat = logits
else:
covmat = tf.eye(FLAGS.per_core_batch_size)
if FLAGS.use_bfloat16:
logits = tf.cast(logits, tf.float32)
logits = ed.layers.utils.mean_field_logits(
logits,
covmat,
mean_field_factor=FLAGS.gp_mean_field_factor)
stddev = tf.sqrt(tf.linalg.diag_part(covmat))
stddev_list.append(stddev)
logits_list.append(logits)
# Logits dimension is (num_samples, batch_size, num_classes).
logits_list = tf.stack(logits_list, axis=0)
stddev_list = tf.stack(stddev_list, axis=0)
stddev = tf.reduce_mean(stddev_list, axis=0)
probs_list = tf.nn.softmax(logits_list)
probs = tf.reduce_mean(probs_list, axis=0)
labels_broadcasted = tf.broadcast_to(
labels, [FLAGS.num_dropout_samples, labels.shape[0]])
log_likelihoods = -tf.keras.losses.sparse_categorical_crossentropy(
labels_broadcasted, logits_list, from_logits=True)
negative_log_likelihood = tf.reduce_mean(
-tf.reduce_logsumexp(log_likelihoods, axis=[0]) +
tf.math.log(float(FLAGS.num_dropout_samples)))
if dataset_name == 'clean':
metrics['test/negative_log_likelihood'].update_state(
negative_log_likelihood)
metrics['test/accuracy'].update_state(labels, probs)
metrics['test/ece'].add_batch(probs, label=labels)
metrics['test/stddev'].update_state(stddev)
elif dataset_name == 'val':
metrics['val/negative_log_likelihood'].update_state(
negative_log_likelihood)
metrics['val/accuracy'].update_state(labels, probs)
metrics['val/ece'].add_batch(probs, label=labels)
metrics['val/stddev'].update_state(stddev)
else:
corrupt_metrics['test/nll_{}'.format(
dataset_name)].update_state(negative_log_likelihood)
corrupt_metrics['test/accuracy_{}'.format(
dataset_name)].update_state(labels, probs)
corrupt_metrics['test/ece_{}'.format(dataset_name)].add_batch(
probs, label=labels)
corrupt_metrics['test/stddev_{}'.format(
dataset_name)].update_state(stddev)
for _ in tf.range(tf.cast(steps_per_eval, tf.int32)):
strategy.run(step_fn, args=(next(iterator), ))
metrics.update({'test/ms_per_example': tf.keras.metrics.Mean()})
step_variable = tf.Variable(0, dtype=tf.int32)
train_iterator = iter(train_dataset)
start_time = time.time()
for epoch in range(initial_epoch, FLAGS.train_epochs):
logging.info('Starting to run epoch: %s', epoch)
for step in range(steps_per_epoch):
step_variable.assign(step)
# Pass `step` as a tf.Variable to train_step to prevent the tf.function
# train_step() re-compiling itself at each function call.
train_step(train_iterator, step_variable)
current_step = epoch * steps_per_epoch + (step + 1)
max_steps = steps_per_epoch * FLAGS.train_epochs
time_elapsed = time.time() - start_time
steps_per_sec = float(current_step) / time_elapsed
eta_seconds = (max_steps - current_step) / steps_per_sec
message = ('{:.1%} completion: epoch {:d}/{:d}. {:.1f} steps/s. '
'ETA: {:.0f} min. Time elapsed: {:.0f} min'.format(
current_step / max_steps, epoch + 1,
FLAGS.train_epochs, steps_per_sec, eta_seconds / 60,
time_elapsed / 60))
if step % 20 == 0:
logging.info(message)
datasets_to_evaluate = {'clean': test_datasets['clean']}
if use_validation_set:
datasets_to_evaluate['val'] = validation_dataset
if (FLAGS.corruptions_interval > 0
and (epoch + 1) % FLAGS.corruptions_interval == 0):
datasets_to_evaluate = test_datasets
for dataset_name, test_dataset in datasets_to_evaluate.items():
test_iterator = iter(test_dataset)
logging.info('Testing on dataset %s', dataset_name)
steps_per_eval = steps_per_val if dataset_name == 'val' else steps_per_eval
logging.info('Starting to run eval at epoch: %s', epoch)
test_start_time = time.time()
test_step(test_iterator, dataset_name)
ms_per_example = (time.time() - test_start_time) * 1e6 / batch_size
metrics['test/ms_per_example'].update_state(ms_per_example)
logging.info('Done with testing on %s', dataset_name)
corrupt_results = {}
if (FLAGS.corruptions_interval > 0
and (epoch + 1) % FLAGS.corruptions_interval == 0):
corrupt_results = utils.aggregate_corrupt_metrics(
corrupt_metrics, corruption_types, max_intensity)
logging.info('Train Loss: %.4f, Accuracy: %.2f%%',
metrics['train/loss'].result(),
metrics['train/accuracy'].result() * 100)
if use_validation_set:
logging.info('Val NLL: %.4f, Accuracy: %.2f%%',
metrics['val/negative_log_likelihood'].result(),
metrics['val/accuracy'].result() * 100)
logging.info('Test NLL: %.4f, Accuracy: %.2f%%',
metrics['test/negative_log_likelihood'].result(),
metrics['test/accuracy'].result() * 100)
total_results = {
name: metric.result()
for name, metric in metrics.items()
}
total_results.update(corrupt_results)
# Metrics from Robustness Metrics (like ECE) will return a dict with a
# single key/value, instead of a scalar.
total_results = {
k: (list(v.values())[0] if isinstance(v, dict) else v)
for k, v in total_results.items()
}
with summary_writer.as_default():
for name, result in total_results.items():
tf.summary.scalar(name, result, step=epoch + 1)
for metric in metrics.values():
metric.reset_states()
if (FLAGS.checkpoint_interval > 0
and (epoch + 1) % FLAGS.checkpoint_interval == 0):
checkpoint_name = checkpoint.save(
os.path.join(FLAGS.output_dir, 'checkpoint'))
logging.info('Saved checkpoint to %s', checkpoint_name)
final_checkpoint_name = checkpoint.save(
os.path.join(FLAGS.output_dir, 'checkpoint'))
logging.info('Saved last checkpoint to %s', final_checkpoint_name)
final_save_name = os.path.join(FLAGS.output_dir, 'model')
model.save(final_save_name)
logging.info('Saved model to %s', final_save_name)
with summary_writer.as_default():
hp.hparams({
'base_learning_rate': FLAGS.base_learning_rate,
'one_minus_momentum': FLAGS.one_minus_momentum,
'l2': FLAGS.l2,
'gp_mean_field_factor': FLAGS.gp_mean_field_factor,
})
def main(argv):
del argv # unused arg
if not FLAGS.use_gpu:
raise ValueError('Only GPU is currently supported.')
if FLAGS.num_cores > 1:
raise ValueError('Only a single accelerator is currently supported.')
tf.random.set_seed(FLAGS.seed)
tf.io.gfile.makedirs(FLAGS.output_dir)
ds_info = tfds.builder(FLAGS.dataset).info
batch_size = FLAGS.per_core_batch_size * FLAGS.num_cores
steps_per_eval = ds_info.splits['test'].num_examples // batch_size
num_classes = ds_info.features['label'].num_classes
data_dir = utils.get_data_dir_from_flags(FLAGS)
dataset = ub.datasets.get(
FLAGS.dataset,
data_dir=data_dir,
download_data=FLAGS.download_data,
split=tfds.Split.TEST).load(batch_size=batch_size)
test_datasets = {'clean': dataset}
extra_kwargs = {}
if FLAGS.dataset == 'cifar100':
data_dir = FLAGS.cifar100_c_path
corruption_types, _ = utils.load_corrupted_test_info(FLAGS.dataset)
for corruption_type in corruption_types:
for severity in range(1, 6):
dataset = ub.datasets.get(
f'{FLAGS.dataset}_corrupted',
corruption_type=corruption_type,
data_dir=data_dir,
severity=severity,
split=tfds.Split.TEST,
**extra_kwargs).load(batch_size=batch_size)
test_datasets[f'{corruption_type}_{severity}'] = dataset
model = ub.models.wide_resnet_sngp(
input_shape=ds_info.features['image'].shape,
batch_size=FLAGS.per_core_batch_size,
depth=28,
width_multiplier=10,
num_classes=num_classes,
l2=0.,
use_mc_dropout=FLAGS.use_mc_dropout,
use_filterwise_dropout=FLAGS.use_filterwise_dropout,
dropout_rate=FLAGS.dropout_rate,
use_gp_layer=FLAGS.use_gp_layer,
gp_input_dim=FLAGS.gp_input_dim,
gp_hidden_dim=FLAGS.gp_hidden_dim,
gp_scale=FLAGS.gp_scale,
gp_bias=FLAGS.gp_bias,
gp_input_normalization=FLAGS.gp_input_normalization,
gp_random_feature_type=FLAGS.gp_random_feature_type,
gp_cov_discount_factor=FLAGS.gp_cov_discount_factor,
gp_cov_ridge_penalty=FLAGS.gp_cov_ridge_penalty,
use_spec_norm=FLAGS.use_spec_norm,
spec_norm_iteration=FLAGS.spec_norm_iteration,
spec_norm_bound=FLAGS.spec_norm_bound)
logging.info('Model input shape: %s', model.input_shape)
logging.info('Model output shape: %s', model.output_shape)
logging.info('Model number of weights: %s', model.count_params())
# Search for checkpoints from their index file; then remove the index suffix.
ensemble_filenames = tf.io.gfile.glob(
os.path.join(FLAGS.checkpoint_dir, '**/*.index'))
ensemble_filenames = [filename[:-6] for filename in ensemble_filenames]
ensemble_size = len(ensemble_filenames)
logging.info('Ensemble size: %s', ensemble_size)
logging.info('Ensemble number of weights: %s',
ensemble_size * model.count_params())
logging.info('Ensemble filenames: %s', str(ensemble_filenames))
checkpoint = tf.train.Checkpoint(model=model)
# Write model predictions to files.
num_datasets = len(test_datasets)
for m, ensemble_filename in enumerate(ensemble_filenames):
checkpoint.restore(ensemble_filename)
for n, (name, test_dataset) in enumerate(test_datasets.items()):
filename = '{dataset}_{member}.npy'.format(dataset=name, member=m)
filename = os.path.join(FLAGS.output_dir, filename)
if not tf.io.gfile.exists(filename):
logits = []
test_iterator = iter(test_dataset)
for _ in range(steps_per_eval):
features = next(test_iterator)['features'] # pytype: disable=unsupported-operands
logits_member = model(features, training=False)
if isinstance(logits_member, (list, tuple)):
# If model returns a tuple of (logits, covmat), extract both
logits_member, covmat_member = logits_member
else:
covmat_member = tf.eye(FLAGS.per_core_batch_size)
logits_member = ed.layers.utils.mean_field_logits(
logits_member, covmat_member,
FLAGS.gp_mean_field_factor_ensemble)
logits.append(logits_member)
logits = tf.concat(logits, axis=0)
with tf.io.gfile.GFile(filename, 'w') as f:
np.save(f, logits.numpy())
percent = (m * num_datasets +
(n + 1)) / (ensemble_size * num_datasets)
message = (
'{:.1%} completion for prediction: ensemble member {:d}/{:d}. '
'Dataset {:d}/{:d}'.format(percent, m + 1, ensemble_size,
n + 1, num_datasets))
logging.info(message)
metrics = {
'test/negative_log_likelihood': tf.keras.metrics.Mean(),
'test/gibbs_cross_entropy': tf.keras.metrics.Mean(),
'test/accuracy': tf.keras.metrics.SparseCategoricalAccuracy(),
'test/ece':
rm.metrics.ExpectedCalibrationError(num_bins=FLAGS.num_bins),
}
corrupt_metrics = {}
for name in test_datasets:
corrupt_metrics['test/nll_{}'.format(name)] = tf.keras.metrics.Mean()
corrupt_metrics['test/accuracy_{}'.format(name)] = (
tf.keras.metrics.SparseCategoricalAccuracy())
corrupt_metrics['test/ece_{}'.format(name)] = (
rm.metrics.ExpectedCalibrationError(num_bins=FLAGS.num_bins))
# Evaluate model predictions.
for n, (name, test_dataset) in enumerate(test_datasets.items()):
logits_dataset = []
for m in range(ensemble_size):
filename = '{dataset}_{member}.npy'.format(dataset=name, member=m)
filename = os.path.join(FLAGS.output_dir, filename)
with tf.io.gfile.GFile(filename, 'rb') as f:
logits_dataset.append(np.load(f))
logits_dataset = tf.convert_to_tensor(logits_dataset)
test_iterator = iter(test_dataset)
for step in range(steps_per_eval):
labels = next(test_iterator)['labels'] # pytype: disable=unsupported-operands
logits = logits_dataset[:, (step * batch_size):((step + 1) *
batch_size)]
labels = tf.cast(labels, tf.int32)
negative_log_likelihood_metric = rm.metrics.EnsembleCrossEntropy()
negative_log_likelihood_metric.add_batch(logits, labels=labels)
negative_log_likelihood = list(
negative_log_likelihood_metric.result().values())[0]
per_probs = tf.nn.softmax(logits)
probs = tf.reduce_mean(per_probs, axis=0)
if name == 'clean':
gibbs_ce_metric = rm.metrics.GibbsCrossEntropy()
gibbs_ce_metric.add_batch(logits, labels=labels)
gibbs_ce = list(gibbs_ce_metric.result().values())[0]
metrics['test/negative_log_likelihood'].update_state(
negative_log_likelihood)
metrics['test/gibbs_cross_entropy'].update_state(gibbs_ce)
metrics['test/accuracy'].update_state(labels, probs)
metrics['test/ece'].add_batch(probs, label=labels)
else:
corrupt_metrics['test/nll_{}'.format(name)].update_state(
negative_log_likelihood)
corrupt_metrics['test/accuracy_{}'.format(name)].update_state(
labels, probs)
corrupt_metrics['test/ece_{}'.format(name)].add_batch(
probs, label=labels)
message = (
'{:.1%} completion for evaluation: dataset {:d}/{:d}'.format(
(n + 1) / num_datasets, n + 1, num_datasets))
logging.info(message)
corrupt_results = utils.aggregate_corrupt_metrics(corrupt_metrics,
corruption_types)
total_results = {name: metric.result() for name, metric in metrics.items()}
total_results.update(corrupt_results)
# Metrics from Robustness Metrics (like ECE) will return a dict with a
# single key/value, instead of a scalar.
total_results = {
k: (list(v.values())[0] if isinstance(v, dict) else v)
for k, v in total_results.items()
}
logging.info('Metrics: %s', total_results)