def predict(self,
model,
x,
batch_size=None,
verbose=0,
steps=None,
callbacks=None,
**kwargs):
"""Predict loop for Distribution Strategies."""
dist_utils.validate_inputs(x=x, y=None)
batch_size, steps = dist_utils.process_batch_and_step_size(
model._distribution_strategy, x, batch_size, steps, ModeKeys.PREDICT)
batch_size = model._validate_or_infer_batch_size(batch_size, steps, x)
dataset = model._distribution_standardize_user_data(
x,
batch_size=batch_size,
allow_partial_batch=True)
if dist_utils.is_tpu_strategy(model._distribution_strategy):
steps = training_utils.infer_steps_for_dataset(
model, dataset, steps, steps_name='steps')
if steps is None:
raise ValueError('Number of steps could not be inferred from the data, '
'please pass the steps argument.')
if not context.executing_eagerly():
return experimental_tpu_predict_loop(
model, dataset, verbose=verbose, steps=steps, callbacks=callbacks)
return training_arrays.predict_loop(
model,
dataset,
batch_size=batch_size,
verbose=verbose,
steps=steps,
callbacks=callbacks)
def evaluate(self,
model,
x=None,
y=None,
batch_size=None,
verbose=1,
sample_weight=None,
steps=None,
callbacks=None,
**kwargs):
"""Evaluate loop for Distribution Strategies."""
dist_utils.validate_inputs(x, y)
batch_size, steps = dist_utils.process_batch_and_step_size(
model._distribution_strategy, x, batch_size, steps, ModeKeys.TEST)
batch_size = model._validate_or_infer_batch_size(batch_size, steps, x)
dataset = model._distribution_standardize_user_data(
x,
y,
sample_weight=sample_weight,
batch_size=batch_size,
allow_partial_batch=True)
if dist_utils.is_tpu_strategy(model._distribution_strategy):
steps = training_utils.infer_steps_for_dataset(model,
dataset,
steps,
steps_name='steps')
if steps is None:
raise ValueError(
'Number of steps could not be inferred from the data, '
'please pass the steps argument.')
if not context.executing_eagerly():
# Run TPU evaluation in a custom loop in graph mode.
return experimental_tpu_test_loop(model,
dataset,
verbose=verbose,
steps=steps,
callbacks=callbacks)
return training_arrays_v1.test_loop(model,
inputs=dataset,
batch_size=batch_size,
verbose=verbose,
steps=steps,
callbacks=callbacks)
def _model_iteration(
self, model, mode, x=None, y=None, batch_size=None, verbose=1,
sample_weight=None, steps=None, callbacks=None, max_queue_size=10,
workers=1, use_multiprocessing=False, **kwargs):
batch_size = model._validate_or_infer_batch_size(
batch_size, steps, x)
strategy = _get_distribution_strategy(model)
batch_size, steps = dist_utils.process_batch_and_step_size(
strategy, x, batch_size, steps, mode)
dist_utils.validate_callbacks(input_callbacks=callbacks,
optimizer=model.optimizer)
# Enter tf.distribute.Strategy scope.
with strategy.scope():
adapter = _process_inputs(
model,
mode,
x,
y,
batch_size=batch_size,
sample_weights=sample_weight,
steps=steps,
distribution_strategy=strategy,
max_queue_size=max_queue_size,
workers=workers,
use_multiprocessing=use_multiprocessing)
total_samples = _get_total_number_of_samples(adapter)
use_sample = total_samples is not None
dataset = adapter.get_dataset()
if not steps:
# Raise an error if `steps` isn't specified but the dataset
# is infinite.
steps = adapter.get_size() or training_utils.infer_steps_for_dataset(
model, dataset, steps, steps_name='steps')
# tf.print('{} on {} steps.'.format(ModeKeys.TRAIN, steps_per_epoch))
training_context = TrainingContext()
dataset = strategy.experimental_distribute_dataset(dataset)
execution_function = training_v2_utils._get_or_make_execution_function(
model, mode)
data_iterator = iter(dataset)
callbacks = cbks.configure_callbacks(
callbacks,
model,
do_validation=False,
batch_size=batch_size,
epochs=1,
steps_per_epoch=steps,
samples=use_sample,
count_mode='samples' if use_sample else 'steps',
verbose=0, # Handle ProgBarLogger separately in this loop.
mode=mode)
with training_context.on_start(
model, callbacks, use_sample, verbose, mode):
with training_context.on_epoch(0, mode) as epoch_logs:
model.reset_metrics()
result = run_one_epoch(
model,
data_iterator,
execution_function,
dataset_size=adapter.get_size(),
batch_size=adapter.batch_size(),
strategy=strategy,
steps_per_epoch=steps,
num_samples=total_samples,
mode=mode,
training_context=training_context,
total_epochs=1)
cbks.make_logs(model, epoch_logs, result, mode)
if len(result) == 1:
result = result[0]
return result
def fit(
self, model, x=None, y=None, batch_size=None, epochs=1, verbose=1,
callbacks=None, validation_split=0., validation_data=None, shuffle=True,
class_weight=None, sample_weight=None, initial_epoch=0,
steps_per_epoch=None, validation_steps=None, validation_freq=1,
max_queue_size=10, workers=1, use_multiprocessing=False, **kwargs):
batch_size = model._validate_or_infer_batch_size(
batch_size, steps_per_epoch, x)
strategy = _get_distribution_strategy(model)
batch_size, steps_per_epoch = dist_utils.process_batch_and_step_size(
strategy,
x,
batch_size,
steps_per_epoch,
ModeKeys.TRAIN,
validation_split=validation_split)
dist_utils.validate_callbacks(input_callbacks=callbacks,
optimizer=model.optimizer)
# Enter tf.distribute.Strategy scope.
with strategy.scope():
training_data_adapter, validation_adapter = _process_training_inputs(
model,
x,
y,
batch_size=batch_size,
epochs=epochs,
sample_weights=sample_weight,
class_weights=class_weight,
validation_split=validation_split,
steps_per_epoch=steps_per_epoch,
shuffle=shuffle,
validation_data=validation_data,
validation_steps=validation_steps,
distribution_strategy=strategy,
max_queue_size=max_queue_size,
workers=workers,
use_multiprocessing=use_multiprocessing)
total_samples = _get_total_number_of_samples(training_data_adapter)
use_sample = total_samples is not None
do_validation = (validation_adapter is not None)
recreate_training_iterator = (
training_data_adapter.should_recreate_iterator(steps_per_epoch))
if not steps_per_epoch:
# TODO(b/139762795): Add step inference for when steps is None to
# prevent end of sequence warning message.
steps_per_epoch = training_data_adapter.get_size()
# tf.print('{} on {} steps.'.format(ModeKeys.TRAIN, steps_per_epoch))
training_context = TrainingContext()
training_dataset = training_data_adapter.get_dataset()
# Raise an error if steps_per_epoch isn't specified but the dataset
# is infinite.
# TODO(scottzhu): This check should probably happen in the adapter
inferred_steps = training_utils.infer_steps_for_dataset(
model,
training_dataset,
steps_per_epoch,
steps_name='steps_per_epoch',
epochs=0)
steps_per_epoch = (
inferred_steps if steps_per_epoch is None else steps_per_epoch)
training_dataset = strategy.experimental_distribute_dataset(
training_dataset)
training_function = training_v2_utils._get_or_make_execution_function(
model, ModeKeys.TRAIN)
training_data_iter = None
if do_validation:
validation_dataset = validation_adapter.get_dataset()
if not validation_steps:
# Raise an error if validation_steps isn't specified but the
# validation dataset is infinite.
validation_steps = (
validation_adapter.get_size() or
training_utils.infer_steps_for_dataset(
model,
validation_dataset,
validation_steps,
steps_name='validation_steps'))
eval_function = training_v2_utils._get_or_make_execution_function(
model, ModeKeys.TEST)
eval_data_iter = None
validation_dataset = strategy.experimental_distribute_dataset(
validation_dataset)
val_total_samples = _get_total_number_of_samples(validation_adapter)
else:
val_total_samples = None
if verbose and (total_samples or steps_per_epoch):
_print_train_info(total_samples, steps_per_epoch, val_total_samples,
validation_steps)
training_callbacks = cbks.configure_callbacks(
callbacks,
model,
do_validation=do_validation,
batch_size=batch_size,
epochs=epochs,
steps_per_epoch=steps_per_epoch,
samples=total_samples or steps_per_epoch,
count_mode='samples' if use_sample else 'steps',
verbose=0, # Handle ProgBarLogger separately in this loop.
mode=ModeKeys.TRAIN)
with training_context.on_start(model, training_callbacks, use_sample,
verbose, ModeKeys.TRAIN):
initial_epoch = model._maybe_load_initial_epoch_from_ckpt(
initial_epoch, ModeKeys.TRAIN)
for epoch in range(initial_epoch, epochs):
if training_context.callbacks.model.stop_training:
break
# Training
with training_context.on_epoch(epoch, ModeKeys.TRAIN) as epoch_logs:
model.reset_metrics()
if training_data_iter is None or recreate_training_iterator:
if (training_data_iter is not None and
distribution_strategy_context.has_strategy()):
# TODO(kaftan): remove this when MultiDeviceIterator is a
## compositetensor (unless this is more efficient)
training_data_iter._initializer # pylint: disable=pointless-statement
else:
training_data_iter = iter(training_dataset)
training_result = run_one_epoch(
model,
training_data_iter,
training_function,
dataset_size=training_data_adapter.get_size(),
batch_size=training_data_adapter.batch_size(),
strategy=strategy,
steps_per_epoch=steps_per_epoch,
num_samples=total_samples,
mode=ModeKeys.TRAIN,
training_context=training_context,
total_epochs=epochs)
cbks.make_logs(model, epoch_logs, training_result, ModeKeys.TRAIN)
# In the case of steps_per_epoch = None, the final cardinality will
# be determined when the inputs are fully consumed (eg dataset or
# generator). Update the steps_per_epoch to the new value.
if (steps_per_epoch is None
and training_context.progbar.progbar.target is not None):
steps_per_epoch = training_context.progbar.progbar.target
# Evaluation
if (do_validation and
training_utils.should_run_validation(validation_freq, epoch) and
not training_callbacks.model.stop_training):
if (eval_data_iter is not None and
distribution_strategy_context.has_strategy()):
# TODO(kaftan): remove this when MultiDeviceIterator is a
## compositetensor (unless this is more efficient)
eval_data_iter._initializer # pylint: disable=pointless-statement
else:
eval_data_iter = iter(validation_dataset)
validation_callbacks = cbks.configure_callbacks(
training_callbacks,
model,
batch_size=batch_size,
epochs=1,
steps_per_epoch=validation_steps,
samples=val_total_samples or validation_steps,
count_mode='samples' if use_sample else 'steps',
verbose=0, # Handle ProgBarLogger separately in this loop.
mode=ModeKeys.TEST)
eval_context = TrainingContext()
with eval_context.on_start(
model,
validation_callbacks,
use_sample,
verbose=0,
mode=ModeKeys.TEST):
with eval_context.on_epoch(epoch, ModeKeys.TEST):
model.reset_metrics()
eval_result = run_one_epoch(
model,
eval_data_iter,
eval_function,
dataset_size=validation_adapter.get_size(),
batch_size=validation_adapter.batch_size(),
strategy=strategy,
steps_per_epoch=validation_steps,
num_samples=val_total_samples,
mode=ModeKeys.TEST,
training_context=eval_context,
total_epochs=1)
cbks.make_logs(model, epoch_logs, eval_result, ModeKeys.TEST,
prefix='val_')
return model.history
def fit(self,
model,
x=None,
y=None,
batch_size=None,
epochs=1,
verbose=1,
callbacks=None,
validation_split=0.,
validation_data=None,
shuffle=True,
class_weight=None,
sample_weight=None,
initial_epoch=0,
steps_per_epoch=None,
validation_steps=None,
validation_freq=1,
**kwargs):
batch_size = model._validate_or_infer_batch_size(
batch_size, steps_per_epoch, x)
strategy = _get_distribution_strategy(model)
batch_size, steps_per_epoch = dist_utils.process_batch_and_step_size(
strategy, x, batch_size, steps_per_epoch, ModeKeys.TRAIN)
dist_utils.validate_callbacks(input_callbacks=callbacks,
optimizer=model.optimizer)
# Enter tf.distribute.Strategy scope.
with strategy.scope():
training_data_adapter, validation_adapter = _process_training_inputs(
model,
x,
y,
batch_size=batch_size,
sample_weights=sample_weight,
class_weights=class_weight,
validation_split=validation_split,
steps_per_epoch=steps_per_epoch,
shuffle=shuffle,
validation_data=validation_data,
validation_steps=validation_steps,
distribution_strategy=strategy)
total_samples = _get_total_number_of_samples(training_data_adapter)
use_sample = total_samples is not None
do_validation = (validation_adapter is not None)
if not steps_per_epoch:
steps_per_epoch = training_data_adapter.get_size()
# tf.print('{} on {} steps.'.format(ModeKeys.TRAIN, steps_per_epoch))
training_context = TrainingContext()
initial_epoch = model._maybe_load_initial_epoch_from_ckpt(
initial_epoch, ModeKeys.TRAIN)
training_dataset = training_data_adapter.get_dataset()
# Raise an error if steps_per_epoch isn't specified but the dataset
# is infinite.
# TODO(scottzhu): This check should probably happen in the adapter
training_utils.infer_steps_for_dataset(
training_dataset,
steps_per_epoch,
steps_name='steps_per_epoch',
epochs=0)
training_dataset = strategy.experimental_distribute_dataset(
training_dataset)
_update_sample_weight_mode(model, ModeKeys.TRAIN, training_dataset)
training_function = training_v2_utils._get_or_make_execution_function(
model, ModeKeys.TRAIN)
training_data_iter = None
# Only recreate iterator when the data has a fixed length, which will be
# fully consumed every epoch, or has a unknown length (dataset, generator)
# and will be fully consumed (steps_per_epoch is None)
recreate_training_iterator = (training_data_adapter.get_size()
is not None
or steps_per_epoch is None)
if do_validation:
if not validation_steps:
validation_steps = validation_adapter.get_size()
eval_function = training_v2_utils._get_or_make_execution_function(
model, ModeKeys.TEST)
eval_data_iter = None
validation_dataset = validation_adapter.get_dataset()
# Raise an error if validation_steps isn't specified but the validation
# dataset is infinite.
# TODO(scottzhu): This check should probably happen in the adapter
training_utils.infer_steps_for_dataset(
validation_dataset,
validation_steps,
steps_name='validation_steps',
epochs=0)
validation_dataset = strategy.experimental_distribute_dataset(
validation_dataset)
callbacks = cbks.configure_callbacks(
callbacks,
model,
do_validation=do_validation,
batch_size=batch_size,
epochs=epochs,
steps_per_epoch=steps_per_epoch,
samples=total_samples,
count_mode='samples' if use_sample else 'steps',
verbose=0, # Handle ProgBarLogger separately in this loop.
mode=ModeKeys.TRAIN)
with training_context.on_start(model, callbacks, use_sample,
verbose, ModeKeys.TRAIN):
# TODO(scottzhu): Handle TPUStrategy training loop
for epoch in range(initial_epoch, epochs):
if training_context.callbacks.model.stop_training:
break
# Training
with training_context.on_epoch(
epoch, ModeKeys.TRAIN) as epoch_logs:
model.reset_metrics()
if training_data_iter is None or recreate_training_iterator:
if (training_data_iter is not None
and distribution_strategy_context.
has_strategy()):
# TODO(kaftan): remove this when MultiDeviceIterator is a
## compositetensor (unless this is more efficient)
training_data_iter._initializer # pylint: disable=pointless-statement
else:
training_data_iter = iter(training_dataset)
training_result = run_one_epoch(
model,
training_data_iter,
training_function,
dataset_size=training_data_adapter.get_size(),
batch_size=training_data_adapter.batch_size(),
strategy=strategy,
steps_per_epoch=steps_per_epoch,
num_samples=total_samples,
mode=ModeKeys.TRAIN,
training_context=training_context,
total_epochs=epochs)
cbks.make_logs(model, epoch_logs, training_result,
ModeKeys.TRAIN)
# Evaluation
if (do_validation
and training_utils.should_run_validation(
validation_freq, epoch)
and not callbacks.model.stop_training):
if (eval_data_iter is not None
and distribution_strategy_context.
has_strategy()):
# TODO(kaftan): remove this when MultiDeviceIterator is a
## compositetensor (unless this is more efficient)
eval_data_iter._initializer # pylint: disable=pointless-statement
else:
eval_data_iter = iter(validation_dataset)
val_total_samples = _get_total_number_of_samples(
validation_adapter)
eval_context = TrainingContext()
with eval_context.on_start(model,
callbacks,
use_sample,
verbose=0,
mode=ModeKeys.TEST):
with eval_context.on_epoch(
epoch, ModeKeys.TEST):
model.reset_metrics()
eval_result = run_one_epoch(
model,
eval_data_iter,
eval_function,
dataset_size=validation_adapter.
get_size(),
batch_size=validation_adapter.
batch_size(),
strategy=strategy,
steps_per_epoch=validation_steps,
num_samples=val_total_samples,
mode=ModeKeys.TEST,
training_context=eval_context,
total_epochs=1)
cbks.make_logs(model,
epoch_logs,
eval_result,
ModeKeys.TEST,
prefix='val_')
return model.history
def fit(self,
model,
x=None,
y=None,
batch_size=None,
epochs=1,
verbose=1,
callbacks=None,
validation_split=0.,
validation_data=None,
shuffle=True,
class_weight=None,
sample_weight=None,
initial_epoch=0,
steps_per_epoch=None,
validation_steps=None,
validation_freq=1,
**kwargs):
"""Fit loop for Distribution Strategies."""
dist_utils.validate_callbacks(input_callbacks=callbacks,
optimizer=model.optimizer)
dist_utils.validate_inputs(x, y)
batch_size, steps_per_epoch = dist_utils.process_batch_and_step_size(
model._distribution_strategy, x, batch_size, steps_per_epoch,
ModeKeys.TRAIN)
batch_size = model._validate_or_infer_batch_size(
batch_size, steps_per_epoch, x)
dataset = model._distribution_standardize_user_data(
x,
y,
sample_weight=sample_weight,
class_weight=class_weight,
batch_size=batch_size,
validation_split=validation_split,
shuffle=shuffle,
epochs=epochs)
if not dist_utils.is_distributing_by_cloning(model):
with model._distribution_strategy.scope():
(dataset, _, _) = model._standardize_user_data(
dataset,
sample_weight=sample_weight,
class_weight=class_weight,
batch_size=batch_size,
validation_split=validation_split,
shuffle=shuffle)
val_dataset = None
if validation_data:
val_x, val_y, val_sample_weights = training_utils.unpack_validation_data(
validation_data)
dist_utils.validate_inputs(val_x, val_y)
_, validation_steps = dist_utils.process_batch_and_step_size(
model._distribution_strategy, val_x, batch_size,
validation_steps, ModeKeys.TEST)
val_dataset = model._distribution_standardize_user_data(
val_x,
val_y,
sample_weight=val_sample_weights,
class_weight=None,
batch_size=batch_size,
validation_split=validation_split,
shuffle=shuffle,
allow_partial_batch=True)
elif validation_split:
raise ValueError('validation_split argument is not supported with '
'distribution strategies.')
if dist_utils.is_tpu_strategy(model._distribution_strategy):
steps_per_epoch = training_utils.infer_steps_for_dataset(
dataset, steps_per_epoch, epochs, steps_name='steps_per_epoch')
if steps_per_epoch is None:
raise ValueError(
'Number of steps could not be inferred from the data, '
'please pass the steps_per_epoch argument.')
if not context.executing_eagerly():
# Run TPU training in a custom loop in graph mode.
return experimental_tpu_fit_loop(
model,
dataset,
epochs=epochs,
verbose=verbose,
callbacks=callbacks,
val_dataset=val_dataset,
initial_epoch=initial_epoch,
steps_per_epoch=steps_per_epoch,
validation_steps=validation_steps,
validation_freq=validation_freq)
return training_arrays.fit_loop(model,
dataset,
batch_size=batch_size,
epochs=epochs,
verbose=verbose,
callbacks=callbacks,
val_inputs=val_dataset,
shuffle=shuffle,
initial_epoch=initial_epoch,
steps_per_epoch=steps_per_epoch,
validation_steps=validation_steps,
validation_freq=validation_freq,
steps_name='steps_per_epoch')
def _model_iteration(self,
model,
mode,
x=None,
y=None,
batch_size=None,
verbose=1,
sample_weight=None,
steps=None,
callbacks=None,
**kwargs):
batch_size = model._validate_or_infer_batch_size(batch_size, steps, x)
strategy = _get_distribution_strategy(model)
if strategy:
batch_size, steps = dist_utils.process_batch_and_step_size(
strategy, x, batch_size, steps, mode)
dist_utils.validate_callbacks(input_callbacks=callbacks,
optimizer=model.optimizer)
# Enter tf.distribute.Strategy scope.
scope = dist_utils.distributed_scope(strategy=strategy,
learning_phase=0)
scope.__enter__()
adapter = _process_inputs(model,
x,
y,
batch_size=batch_size,
sample_weights=sample_weight,
steps=steps,
distribution_strategy=strategy)
if not steps:
steps = adapter.get_size()
# tf.print('{} on {} steps.'.format(ModeKeys.TRAIN, steps_per_epoch))
training_context = TrainingContext()
_update_sample_weight_mode(model, mode, adapter)
execution_function = _make_execution_function(model, mode)
data_iterator = _create_dataset_iterator(strategy,
adapter.get_dataset())
callbacks = cbks.configure_callbacks(
callbacks,
model,
do_validation=False,
batch_size=batch_size,
epochs=1,
steps_per_epoch=steps,
samples=None,
verbose=0, # Handle ProgBarLogger separately in this loop.
mode=mode)
with training_context.on_start(model, callbacks, verbose, mode):
# TODO(scottzhu): Handle TPUStrategy training loop
with training_context.on_epoch(0, mode) as epoch_logs:
model.reset_metrics()
result = run_one_epoch(model,
data_iterator,
execution_function,
dataset_size=adapter.get_size(),
strategy=strategy,
steps_per_epoch=steps,
mode=mode,
training_context=training_context,
current_epoch=1)
cbks.make_logs(model, epoch_logs, result, mode)
if strategy:
scope.__exit__(None, None, None)
if len(result) == 1:
result = result[0]
return result
def fit(self,
model,
x=None,
y=None,
batch_size=None,
epochs=1,
verbose=1,
callbacks=None,
validation_split=0.,
validation_data=None,
shuffle=True,
class_weight=None,
sample_weight=None,
initial_epoch=0,
steps_per_epoch=None,
validation_steps=None,
validation_freq=1,
**kwargs):
batch_size = model._validate_or_infer_batch_size(
batch_size, steps_per_epoch, x)
strategy = _get_distribution_strategy(model)
if strategy:
batch_size, steps_per_epoch = dist_utils.process_batch_and_step_size(
strategy, x, batch_size, steps_per_epoch, ModeKeys.TRAIN)
dist_utils.validate_callbacks(input_callbacks=callbacks,
optimizer=model.optimizer)
# Enter tf.distribute.Strategy scope.
scope = dist_utils.distributed_scope(strategy=strategy,
learning_phase=1)
scope.__enter__()
training_data_adapter, validation_adapter = _process_training_inputs(
model,
x,
y,
batch_size=batch_size,
sample_weights=sample_weight,
class_weights=class_weight,
validation_split=validation_split,
steps_per_epoch=steps_per_epoch,
shuffle=shuffle,
validation_data=validation_data,
validation_steps=validation_steps,
distribution_strategy=strategy)
do_validation = (validation_adapter is not None)
if not steps_per_epoch:
steps_per_epoch = training_data_adapter.get_size()
# tf.print('{} on {} steps.'.format(ModeKeys.TRAIN, steps_per_epoch))
training_context = TrainingContext()
initial_epoch = model._maybe_load_initial_epoch_from_ckpt(
initial_epoch, ModeKeys.TRAIN)
_update_sample_weight_mode(model, ModeKeys.TRAIN,
training_data_adapter)
training_function = _make_execution_function(model, ModeKeys.TRAIN)
training_data_iter = None
# Only recreate iterator when the data has a fixed length, which will be
# fully consumed every epoch, or has a unknown length (dataset, generator)
# and will be fully consumed (steps_per_epoch is None)
recreate_training_iterator = (training_data_adapter.get_size()
is not None or steps_per_epoch is None)
if do_validation:
if not validation_steps:
validation_steps = validation_adapter.get_size()
eval_function = _make_execution_function(model, ModeKeys.TEST)
eval_data_iter = None
recreate_eval_iterator = (validation_adapter.get_size() is not None
or validation_steps is None)
callbacks = cbks.configure_callbacks(
callbacks,
model,
do_validation=do_validation,
batch_size=batch_size,
epochs=epochs,
steps_per_epoch=steps_per_epoch,
samples=None,
verbose=0, # Handle ProgBarLogger separately in this loop.
mode=ModeKeys.TRAIN)
with training_context.on_start(model, callbacks, verbose,
ModeKeys.TRAIN):
# TODO(scottzhu): Handle TPUStrategy training loop
for epoch in range(initial_epoch, epochs):
if training_context.callbacks.model.stop_training:
break
# Training
with training_context.on_epoch(epoch,
ModeKeys.TRAIN) as epoch_logs:
model.reset_metrics()
if training_data_iter is None or recreate_training_iterator:
training_data_iter = _create_dataset_iterator(
strategy, training_data_adapter.get_dataset())
training_result = run_one_epoch(
model,
training_data_iter,
training_function,
dataset_size=training_data_adapter.get_size(),
strategy=strategy,
steps_per_epoch=steps_per_epoch,
mode=ModeKeys.TRAIN,
training_context=training_context,
current_epoch=epoch)
cbks.make_logs(model, epoch_logs, training_result,
ModeKeys.TRAIN)
# Evaluation
if (do_validation and training_utils.should_run_validation(
validation_freq, epoch)
and not callbacks.model.stop_training):
if eval_data_iter is None or recreate_eval_iterator:
eval_data_iter = _create_dataset_iterator(
strategy, validation_adapter.get_dataset())
eval_context = TrainingContext()
with eval_context.on_start(model,
callbacks,
verbose=0,
mode=ModeKeys.TEST):
with eval_context.on_epoch(epoch, ModeKeys.TEST):
model.reset_metrics()
eval_result = run_one_epoch(
model,
eval_data_iter,
eval_function,
dataset_size=validation_adapter.get_size(),
strategy=strategy,
steps_per_epoch=validation_steps,
mode=ModeKeys.TEST,
training_context=eval_context,
current_epoch=epochs)
cbks.make_logs(model,
epoch_logs,
eval_result,
ModeKeys.TRAIN,
prefix='val_')
if strategy:
scope.__exit__(None, None, None)
return model.history
def _model_iteration(
self, model, mode, x=None, y=None, batch_size=None, verbose=1,
sample_weight=None, steps=None, callbacks=None, **kwargs):
batch_size = model._validate_or_infer_batch_size(
batch_size, steps, x)
strategy = _get_distribution_strategy(model)
batch_size, steps = dist_utils.process_batch_and_step_size(
strategy, x, batch_size, steps, mode)
dist_utils.validate_callbacks(input_callbacks=callbacks,
optimizer=model.optimizer)
# Enter tf.distribute.Strategy scope.
with dist_utils.distributed_scope(
strategy=strategy, learning_phase=0):
adapter = _process_inputs(
model,
x,
y,
batch_size=batch_size,
sample_weights=sample_weight,
steps=steps,
distribution_strategy=strategy)
if not steps:
steps = adapter.get_size()
# tf.print('{} on {} steps.'.format(ModeKeys.TRAIN, steps_per_epoch))
training_context = TrainingContext()
dataset = adapter.get_dataset()
# Raise an error if `steps` isn't specified but the dataset
# is infinite.
# TODO(scottzhu): This check should probably happen in the adapter
training_utils.infer_steps_for_dataset(
dataset, steps, steps_name='steps', epochs=0)
dataset = strategy.experimental_distribute_dataset(dataset)
_update_sample_weight_mode(model, mode, dataset)
execution_function = training_v2_utils._get_or_make_execution_function(
model, mode)
data_iterator = iter(dataset)
callbacks = cbks.configure_callbacks(
callbacks,
model,
do_validation=False,
batch_size=batch_size,
epochs=1,
steps_per_epoch=steps,
samples=None,
verbose=0, # Handle ProgBarLogger separately in this loop.
mode=mode)
with training_context.on_start(model, callbacks, verbose, mode):
# TODO(scottzhu): Handle TPUStrategy training loop
with training_context.on_epoch(0, mode) as epoch_logs:
model.reset_metrics()
result = run_one_epoch(
model,
data_iterator,
execution_function,
dataset_size=adapter.get_size(),
strategy=strategy,
steps_per_epoch=steps,
mode=mode,
training_context=training_context,
total_epochs=1)
cbks.make_logs(model, epoch_logs, result, mode)
if len(result) == 1:
result = result[0]
return result
