def step_fn(inputs):
"""Per-Replica StepFn."""
# Note that we don't use tf.tile for labels here
images, labels = inputs
images = tf.tile(images, [FLAGS.ensemble_size, 1, 1, 1])
# get lambdas
lambdas = log_uniform_mean(lambda_parameters)
rep_lambdas = tf.repeat(lambdas, per_core_batch_size, axis=0)
# eval on testsets
logits = model([images, rep_lambdas], training=False)
if FLAGS.use_bfloat16:
logits = tf.cast(logits, tf.float32)
probs = tf.nn.softmax(logits)
per_probs = tf.split(probs,
num_or_size_splits=FLAGS.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):
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)
labels_tile = tf.tile(labels, [FLAGS.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, FLAGS.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'].update_state(labels, probs)
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)].update_state(labels, probs)
if dataset_name == 'clean':
per_probs_stacked = tf.stack(per_probs, axis=0)
diversity_results = um.average_pairwise_diversity(
per_probs_stacked, FLAGS.ensemble_size)
for k, v in diversity_results.items():
metrics['test/' + k].update_state(v)
def step_fn(inputs):
"""Per-Replica StepFn."""
images, labels = inputs
images = tf.tile(images, [FLAGS.ensemble_size, 1, 1, 1])
logits = model(images, training=False)
if FLAGS.use_bfloat16:
logits = tf.cast(logits, tf.float32)
probs = tf.nn.softmax(logits)
if dataset_name == 'clean':
per_probs_tensor = tf.reshape(
probs,
tf.concat([[FLAGS.ensemble_size, -1], probs.shape[1:]], 0))
diversity_results = um.average_pairwise_diversity(
per_probs_tensor, FLAGS.ensemble_size)
for k, v in diversity_results.items():
test_diversity['test/' + k].update_state(v)
per_probs = tf.split(probs,
num_or_size_splits=FLAGS.ensemble_size,
axis=0)
probs = tf.reduce_mean(per_probs, axis=0)
negative_log_likelihood = tf.reduce_mean(
tf.keras.losses.sparse_categorical_crossentropy(labels, probs))
for i in range(FLAGS.ensemble_size):
member_probs = per_probs[i]
if dataset_name == 'clean':
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)
metrics['test/member_accuracy_mean'].update_state(
labels, member_probs)
metrics['test/member_ece_mean'].update_state(
labels, member_probs)
elif dataset_name != 'confidence_validation':
corrupt_metrics['test/member_acc_mean_{}'.format(
dataset_name)].update_state(labels, member_probs)
corrupt_metrics['test/member_ece_mean_{}'.format(
dataset_name)].update_state(labels, member_probs)
if dataset_name == 'clean':
metrics['test/negative_log_likelihood'].update_state(
negative_log_likelihood)
metrics['test/accuracy'].update_state(labels, probs)
metrics['test/ece'].update_state(labels, probs)
elif dataset_name != 'confidence_validation':
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)].update_state(labels, probs)
if dataset_name == 'confidence_validation':
return tf.stack(per_probs, 0), labels
def step_fn(inputs):
"""Per-Replica StepFn."""
images, labels = inputs
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])
if FLAGS.use_bfloat16:
logits = tf.cast(logits, tf.float32)
all_probs = tf.nn.softmax(logits)
probs = tf.math.reduce_mean(all_probs, axis=[0, 1]) # marginalize
# 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)))
l2_loss = compute_l2_loss(model)
kl = sum(model.losses) / IMAGENET_VALIDATION_IMAGES
elbo = -(negative_log_likelihood + l2_loss + kl)
if dataset_name == 'clean':
if FLAGS.ensemble_size > 1:
per_probs = tf.reduce_mean(all_probs, axis=0) # marginalize samples
diversity_results = um.average_pairwise_diversity(
per_probs, FLAGS.ensemble_size)
for k, v in diversity_results.items():
test_diversity['test/' + k].update_state(v)
for i in range(FLAGS.ensemble_size):
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)
metrics['test/negative_log_likelihood'].update_state(
negative_log_likelihood)
metrics['test/kl'].update_state(kl)
metrics['test/elbo'].update_state(elbo)
metrics['test/accuracy'].update_state(labels, probs)
metrics['test/ece'].update_state(labels, probs)
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)].update_state(
labels, probs)
def testAveragePairwiseDiversity(self):
num_models = 3
batch_size = 2
num_classes = 5
logits = tf.random.normal([num_models, batch_size, num_classes])
probs = tf.nn.softmax(logits)
results = um.average_pairwise_diversity(probs, num_models=num_models)
self.assertLen(results, 3)
self.assertEqual(results['disagreement'].shape, [])
self.assertEqual(results['average_kl'].shape, [])
self.assertEqual(results['cosine_similarity'].shape, [])
def step_fn(inputs):
"""Per-Replica StepFn."""
images, labels = inputs
images = tf.tile(tf.expand_dims(images, 1),
[1, FLAGS.ensemble_size, 1, 1, 1])
logits = model(images, training=False)
if FLAGS.use_bfloat16:
logits = tf.cast(logits, tf.float32)
probs = tf.nn.softmax(logits)
if dataset_name == 'clean':
per_probs = tf.transpose(probs, perm=[1, 0, 2])
diversity_results = um.average_pairwise_diversity(
per_probs, FLAGS.ensemble_size)
for k, v in diversity_results.items():
test_diversity['test/' + k].update_state(v)
for i in range(FLAGS.ensemble_size):
member_probs = 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)
# Negative log marginal likelihood computed in a numerically-stable way.
labels_tiled = tf.tile(tf.expand_dims(labels, 1),
[1, FLAGS.ensemble_size])
log_likelihoods = -tf.keras.losses.sparse_categorical_crossentropy(
labels_tiled, logits, from_logits=True)
negative_log_likelihood = tf.reduce_mean(
-tf.reduce_logsumexp(log_likelihoods, axis=[1]) +
tf.math.log(float(FLAGS.ensemble_size)))
probs = tf.math.reduce_mean(probs, axis=1) # marginalize
if dataset_name == 'clean':
metrics['test/negative_log_likelihood'].update_state(
negative_log_likelihood)
metrics['test/accuracy'].update_state(labels, probs)
metrics['test/ece'].update_state(labels, probs)
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)].update_state(labels, probs)
def step_fn(inputs):
"""Per-Replica StepFn."""
images, labels = inputs
if FLAGS.adaptive_mixup:
images = tf.identity(images)
else:
images = tf.tile(images, [FLAGS.ensemble_size, 1, 1, 1])
if FLAGS.adaptive_mixup:
labels = tf.identity(labels)
elif FLAGS.mixup_alpha > 0:
labels = tf.tile(labels, [FLAGS.ensemble_size, 1])
else:
labels = tf.tile(labels, [FLAGS.ensemble_size])
with tf.GradientTape() as tape:
logits = model(images, training=True)
if FLAGS.use_bfloat16:
logits = tf.cast(logits, tf.float32)
probs = tf.nn.softmax(logits)
per_probs = tf.reshape(
probs,
tf.concat([[FLAGS.ensemble_size, -1], probs.shape[1:]], 0))
diversity_results = um.average_pairwise_diversity(
per_probs, FLAGS.ensemble_size)
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))
filtered_variables = []
for var in model.trainable_variables:
# Apply l2 on the slow weights and bias terms. This excludes BN
# parameters and fast weight approximate posterior/prior parameters,
# but pay caution to their naming scheme.
if 'kernel' 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))
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 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 weights. This excludes BN
# and slow weights, but pay caution to the naming scheme.
if ('batch_norm' not in var.name
and 'kernel' 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))
if FLAGS.mixup_alpha > 0:
labels = tf.argmax(labels, axis=-1)
metrics['train/ece'].update_state(labels, probs)
metrics['train/loss'].update_state(loss)
metrics['train/negative_log_likelihood'].update_state(
negative_log_likelihood)
metrics['train/accuracy'].update_state(labels, logits)
for k, v in diversity_results.items():
training_diversity['train/' + k].update_state(v)
def step_fn(inputs):
"""Per-Replica StepFn."""
if FLAGS.forget_mixup:
images, labels, idx = inputs
else:
images, labels = inputs
if FLAGS.adaptive_mixup or FLAGS.forget_mixup:
images = tf.identity(images)
elif FLAGS.augmix or FLAGS.random_augment:
images_shape = tf.shape(images)
images = tf.reshape(tf.transpose(
images, [1, 0, 2, 3, 4]), [-1, images_shape[2],
images_shape[3], images_shape[4]])
else:
images = tf.tile(images, [FLAGS.ensemble_size, 1, 1, 1])
# Augmix, adaptive mixup, forget mixup preprocessing gives tiled labels.
if FLAGS.mixup_alpha > 0 or FLAGS.label_smoothing > 0 or FLAGS.cutmix:
if FLAGS.augmix or FLAGS.adaptive_mixup or FLAGS.forget_mixup:
labels = tf.identity(labels)
else:
labels = tf.tile(labels, [FLAGS.ensemble_size, 1])
else:
labels = tf.tile(labels, [FLAGS.ensemble_size])
def _is_batch_norm(v):
"""Decide whether a variable belongs to `batch_norm`."""
keywords = ['batchnorm', 'batch_norm', 'bn']
return any([k in v.name.lower() for k in keywords])
def _normalize(x):
"""Normalize an input with l2 norm."""
l2 = tf.norm(x, ord=2, axis=-1)
return x / tf.expand_dims(l2, axis=-1)
# Taking the sum of upper triangular of XX^T and divided by ensemble size.
def pairwise_cosine_distance(x):
"""Compute the pairwise distance in a matrix."""
normalized_x = _normalize(x)
return (tf.reduce_sum(
tf.matmul(normalized_x, normalized_x, transpose_b=True)) -
FLAGS.ensemble_size) / (2.0 * FLAGS.ensemble_size)
with tf.GradientTape() as tape:
logits = model(images, training=True)
if FLAGS.use_bfloat16:
logits = tf.cast(logits, tf.float32)
if FLAGS.mixup_alpha > 0 or FLAGS.label_smoothing > 0 or FLAGS.cutmix:
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)
fast_weights = [var for var in model.trainable_variables if
not _is_batch_norm(var) and (
'alpha' in var.name or 'gamma' in var.name)]
pairwise_distance_loss = tf.add_n(
[pairwise_cosine_distance(var) for var in fast_weights])
diversity_start_iter = steps_per_epoch * FLAGS.diversity_start_epoch
diversity_iterations = optimizer.iterations - diversity_start_iter
if diversity_iterations > 0:
diversity_coeff = diversity_schedule(diversity_iterations)
diversity_loss = diversity_coeff * pairwise_distance_loss
loss = negative_log_likelihood + l2_loss + diversity_loss
else:
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 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 (not _is_batch_norm(var) and 'kernel' 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)
if FLAGS.ensemble_size > 1:
per_probs = tf.reshape(
probs, tf.concat([[FLAGS.ensemble_size, -1], probs.shape[1:]], 0))
diversity_results = um.average_pairwise_diversity(
per_probs, FLAGS.ensemble_size)
for k, v in diversity_results.items():
training_diversity['train/' + k].update_state(v)
if FLAGS.mixup_alpha > 0 or FLAGS.label_smoothing > 0 or FLAGS.cutmix:
labels = tf.argmax(labels, axis=-1)
metrics['train/ece'].update_state(labels, probs)
metrics['train/similarity'].update_state(pairwise_distance_loss)
metrics['train/l2'].update_state(l2_loss)
metrics['train/loss'].update_state(loss)
metrics['train/negative_log_likelihood'].update_state(
negative_log_likelihood)
metrics['train/accuracy'].update_state(labels, logits)
if FLAGS.forget_mixup:
train_predictions = tf.argmax(probs, -1)
labels = tf.cast(labels, train_predictions.dtype)
# For each ensemble member, we accumulate the accuracy counts.
accuracy_counts = tf.cast(tf.reshape(
(train_predictions == labels), [FLAGS.ensemble_size, -1]),
tf.float32)
return accuracy_counts, idx
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
dataset_input_fn = utils.load_input_fn(
split=tfds.Split.TEST,
name=FLAGS.dataset,
batch_size=FLAGS.per_core_batch_size,
use_bfloat16=FLAGS.use_bfloat16)
test_datasets = {'clean': dataset_input_fn()}
corruption_types, max_intensity = utils.load_corrupted_test_info(
FLAGS.dataset)
for name in corruption_types:
for intensity in range(1, max_intensity + 1):
dataset_name = '{0}_{1}'.format(name, intensity)
if FLAGS.dataset == 'cifar10':
load_c_dataset = utils.load_cifar10_c_input_fn
else:
load_c_dataset = functools.partial(
utils.load_cifar100_c_input_fn, path=FLAGS.cifar100_c_path)
corrupted_input_fn = load_c_dataset(
corruption_name=name,
corruption_intensity=intensity,
batch_size=FLAGS.per_core_batch_size,
use_bfloat16=FLAGS.use_bfloat16)
test_datasets[dataset_name] = corrupted_input_fn()
model = ub.models.wide_resnet(
input_shape=ds_info.features['image'].shape,
depth=28,
width_multiplier=10,
num_classes=num_classes,
l2=0.,
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())
# 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) # pytype: disable=attribute-error
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())
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': um.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)] = (
um.ExpectedCalibrationError(num_bins=FLAGS.num_bins))
for i in range(ensemble_size):
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 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) # pytype: disable=attribute-error
logits = logits_dataset[:, (step*batch_size):((step+1)*batch_size)]
labels = tf.cast(labels, tf.int32)
negative_log_likelihood = um.ensemble_cross_entropy(labels, logits)
per_probs = tf.nn.softmax(logits)
probs = tf.reduce_mean(per_probs, axis=0)
if name == 'clean':
gibbs_ce = um.gibbs_cross_entropy(labels, logits)
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'].update_state(labels, probs)
for i in range(ensemble_size):
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_results = um.average_pairwise_diversity(
per_probs, ensemble_size)
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)].update_state(
labels, probs)
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,
max_intensity)
total_results = {name: metric.result() for name, metric in metrics.items()}
total_results.update(corrupt_results)
logging.info('Metrics: %s', total_results)
def step_fn(inputs):
"""Per-Replica StepFn."""
images, labels = inputs
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)
if FLAGS.use_bfloat16:
logits = tf.cast(logits, tf.float32)
probs = tf.nn.softmax(logits)
if FLAGS.ensemble_size > 1:
per_probs = tf.reshape(
probs,
tf.concat([[FLAGS.ensemble_size, -1], probs.shape[1:]],
0))
diversity_results = um.average_pairwise_diversity(
per_probs, FLAGS.ensemble_size)
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) / APPROX_IMAGENET_TRAIN_IMAGES
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 weights. This excludes BN
# and slow weights, but pay caution to the naming scheme.
if ('batch_norm' not in var.name
and 'kernel' 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))
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, logits)
metrics['train/ece'].update_state(labels, probs)
if FLAGS.ensemble_size > 1:
for k, v in diversity_results.items():
training_diversity['train/' + k].update_state(v)
def step_fn(inputs):
"""Per-Replica StepFn."""
images, labels = inputs
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_bfloat16:
logits = tf.cast(logits, tf.float32)
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'].update_state(labels, probs)
metrics['train/loss'].update_state(loss)
metrics['train/negative_log_likelihood'].update_state(
negative_log_likelihood)
metrics['train/accuracy'].update_state(labels, logits)
diversity_results = um.average_pairwise_diversity(
per_probs_stacked, FLAGS.ensemble_size)
for k, v in diversity_results.items():
metrics['train/' + k].update_state(v)
if grads_and_vars:
grads, _ = zip(*grads_and_vars)
def step_fn(inputs):
"""Per-Replica StepFn."""
images, labels = inputs
if FLAGS.ensemble_size > 1:
images = tf.tile(images, [FLAGS.ensemble_size, 1, 1, 1])
if FLAGS.num_eval_samples > 1:
images = tf.tile(images, [FLAGS.num_eval_samples, 1, 1, 1])
logits = model(images, training=False)
probs = tf.nn.softmax(logits)
if FLAGS.num_eval_samples > 1:
probs = tf.reshape(probs,
tf.concat([[FLAGS.num_eval_samples, -1],
probs.shape[1:]], 0))
probs = tf.reduce_mean(probs, 0)
if FLAGS.ensemble_size > 1:
per_probs = tf.split(probs,
num_or_size_splits=FLAGS.ensemble_size,
axis=0)
if dataset_name == 'clean':
per_probs_tensor = tf.reshape(
probs, tf.concat([[FLAGS.ensemble_size, -1], probs.shape[1:]], 0))
diversity_results = um.average_pairwise_diversity(
per_probs_tensor, FLAGS.ensemble_size)
for k, v in diversity_results.items():
test_diversity['test/' + k].update_state(v)
for i in range(FLAGS.ensemble_size):
member_probs = per_probs[i]
member_nll = tf.keras.losses.sparse_categorical_crossentropy(
labels, member_probs)
metrics['test/nll_member_{}'.format(i)].update_state(member_nll)
metrics['test/accuracy_member_{}'.format(i)].update_state(
labels, member_probs)
probs = tf.reduce_mean(per_probs, axis=0)
negative_log_likelihood = tf.reduce_mean(
tf.keras.losses.sparse_categorical_crossentropy(labels, probs))
filtered_variables = []
for var in model.trainable_variables:
if 'kernel' in var.name or 'bias' in var.name:
filtered_variables.append(tf.reshape(var, (-1,)))
kl = sum(model.losses) / test_dataset_size
l2_loss = kl + FLAGS.l2 * 2 * tf.nn.l2_loss(
tf.concat(filtered_variables, axis=0))
loss = negative_log_likelihood + l2_loss
if dataset_name == 'clean':
metrics['test/negative_log_likelihood'].update_state(
negative_log_likelihood)
metrics['test/accuracy'].update_state(labels, probs)
metrics['test/ece'].update_state(labels, probs)
metrics['test/loss'].update_state(loss)
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)].update_state(
labels, probs)
def step_fn(inputs):
"""Per-Replica StepFn."""
images, labels = inputs
if FLAGS.version2 and FLAGS.ensemble_size > 1:
images = tf.tile(images, [FLAGS.ensemble_size, 1, 1, 1])
if not (FLAGS.member_sampling or FLAGS.expected_probs):
labels = tf.tile(labels, [FLAGS.ensemble_size])
if FLAGS.num_train_samples > 1:
images = tf.tile(images, [FLAGS.num_train_samples, 1, 1, 1])
with tf.GradientTape() as tape:
logits = model(images, training=True)
probs = tf.nn.softmax(logits)
# Diversity evaluation.
if FLAGS.version2 and FLAGS.ensemble_size > 1:
per_probs = tf.reshape(
probs, tf.concat([[FLAGS.ensemble_size, -1], probs.shape[1:]], 0))
diversity_results = um.average_pairwise_diversity(
per_probs, FLAGS.ensemble_size)
if FLAGS.num_train_samples > 1:
probs = tf.reshape(probs,
tf.concat([[FLAGS.num_train_samples, -1],
probs.shape[1:]], 0))
probs = tf.reduce_mean(probs, 0)
if FLAGS.member_sampling and FLAGS.version2 and FLAGS.ensemble_size > 1:
idx = tf.random.uniform([], maxval=FLAGS.ensemble_size,
dtype=tf.int64)
idx_one_hot = tf.expand_dims(tf.one_hot(idx, FLAGS.ensemble_size,
dtype=probs.dtype), 0)
probs_shape = probs.shape
probs = tf.reshape(probs, [FLAGS.ensemble_size, -1])
probs = tf.matmul(idx_one_hot, probs)
probs = tf.reshape(probs, tf.concat([[-1], probs_shape[1:]], 0))
elif FLAGS.expected_probs and FLAGS.version2 and FLAGS.ensemble_size > 1:
probs = tf.reshape(probs,
tf.concat([[FLAGS.ensemble_size, -1],
probs.shape[1:]], 0))
probs = tf.reduce_mean(probs, 0)
negative_log_likelihood = tf.reduce_mean(
tf.keras.losses.sparse_categorical_crossentropy(labels, probs))
filtered_variables = []
for var in model.trainable_variables:
# Apply l2 on the slow weights and bias terms. This excludes BN
# parameters and fast weight approximate posterior/prior parameters,
# but pay caution to their naming scheme.
if 'kernel' 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))
kl = sum(model.losses) / train_dataset_size
kl_scale = tf.cast(optimizer.iterations + 1, kl.dtype)
kl_scale /= FLAGS.kl_annealing_steps
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
grads = tape.gradient(scaled_loss, model.trainable_variables)
# Separate learning rate implementation.
grad_list = []
if FLAGS.fast_weight_lr_multiplier != 1.0:
grads_and_vars = list(zip(grads, model.trainable_variables))
for vec, var in grads_and_vars:
# 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 ('batch_norm' not in var.name and 'kernel' not in var.name):
grad_list.append((vec * FLAGS.fast_weight_lr_multiplier, var))
else:
grad_list.append((vec, var))
optimizer.apply_gradients(grad_list)
else:
optimizer.apply_gradients(zip(grads, model.trainable_variables))
metrics['train/ece'].update_state(labels, probs)
metrics['train/loss'].update_state(loss)
metrics['train/negative_log_likelihood'].update_state(
negative_log_likelihood)
metrics['train/accuracy'].update_state(labels, probs)
if FLAGS.version2 and FLAGS.ensemble_size > 1:
for k, v in diversity_results.items():
training_diversity['train/' + k].update_state(v)
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'].update_state(labels, probs)
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)].update_state(labels, probs)
if dataset_name == 'clean':
per_probs_stacked = tf.stack(per_probs, axis=0)
diversity_results = um.average_pairwise_diversity(
per_probs_stacked, ensemble_size)
for k, v in diversity_results.items():
metrics['test/' + k].update_state(v)
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
dataset = ub.datasets.get(
FLAGS.dataset,
split=tfds.Split.TEST).load(batch_size=batch_size)
validation_percent = 1. - FLAGS.train_proportion
val_dataset = ub.datasets.get(
dataset_name=FLAGS.dataset,
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}
extra_kwargs = {}
if FLAGS.dataset == 'cifar100':
extra_kwargs['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,
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(
input_shape=ds_info.features['image'].shape,
depth=28,
width_multiplier=10,
num_classes=num_classes,
l2=0.,
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())
# 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 = um.ensemble_cross_entropy(labels, logits)
per_probs = tf.nn.softmax(logits)
probs = tf.reduce_mean(per_probs, axis=0)
if name == 'clean':
gibbs_ce = um.gibbs_cross_entropy(labels, logits)
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_results = um.average_pairwise_diversity(
per_probs, len(per_probs))
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
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
dataset = ub.datasets.get(
FLAGS.dataset,
split=tfds.Split.TEST).load(batch_size=batch_size)
test_datasets = {'clean': dataset}
extra_kwargs = {}
if FLAGS.dataset == 'cifar100':
extra_kwargs['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,
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_heteroscedastic(
input_shape=ds_info.features['image'].shape,
depth=28,
width_multiplier=10,
num_classes=num_classes,
l2=0.,
version=2,
temperature=FLAGS.temperature,
num_factors=FLAGS.num_factors,
num_mc_samples=FLAGS.num_mc_samples)
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 = parse_checkpoint_dir(FLAGS.checkpoint_dir)
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.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())
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': um.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)] = (
um.ExpectedCalibrationError(num_bins=FLAGS.num_bins))
for i in range(ensemble_size):
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 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 = um.ensemble_cross_entropy(labels, logits)
per_probs = tf.nn.softmax(logits)
probs = tf.reduce_mean(per_probs, axis=0)
if name == 'clean':
gibbs_ce = um.gibbs_cross_entropy(labels, logits)
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)
for i in range(ensemble_size):
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_results = um.average_pairwise_diversity(
per_probs, ensemble_size)
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)
