def test_concat_single_batch(self):
aggregator = training_utils.OutputsAggregator(use_steps=True)
data = _TEST_DATA.copy()
aggregator.create(data)
assert len(aggregator.results) == 1
assert isinstance(aggregator.results[0],
training_utils.ConcatAggregator)
aggregator.aggregate(data)
aggregator.finalize()
assert aggregator.results is data # No copy.
def test_slice_single_batch(self):
aggregator = training_utils.OutputsAggregator(use_steps=False,
num_samples=6)
data = _TEST_DATA.copy()
aggregator.create(data)
assert len(aggregator.results) == 1
assert isinstance(aggregator.results[0],
training_utils.SliceAggregator)
aggregator.aggregate(data, 0, 6)
aggregator.finalize()
assert aggregator.results is data # No copy.
def _run_with_steps(self):
aggregator = training_utils.OutputsAggregator(use_steps=True)
for i, batch in enumerate(np.array_split(_TEST_DATA, 4)):
if i == 0:
aggregator.create(batch)
aggregator.aggregate(batch)
assert len(aggregator.results) == 1
assert isinstance(aggregator.results[0],
training_utils.ConcatAggregator)
aggregator.finalize()
return aggregator.results
def test_nested_aggregation(self):
aggregator = training_utils.OutputsAggregator(use_steps=False,
num_samples=6)
batches = np.array_split(_TEST_DATA, 4)
batch_start = 0
for i, batch in enumerate(zip(batches, batches)):
if i == 0:
aggregator.create(batch)
batch_end = batch_start + batch[0].shape[0]
aggregator.aggregate(batch, batch_start, batch_end)
batch_start = batch_end
assert len(aggregator.results) == 2
aggregator.finalize()
self.assertAllEqual(aggregator.results, (_TEST_DATA, _TEST_DATA))
def _run_without_steps(self):
aggregator = training_utils.OutputsAggregator(use_steps=False,
num_samples=6)
batch_start = 0
for i, batch in enumerate(np.array_split(_TEST_DATA, 4)):
if i == 0:
aggregator.create(batch)
batch_end = batch_start + batch.shape[0]
aggregator.aggregate(batch, batch_start, batch_end)
batch_start = batch_end
assert len(aggregator.results) == 1
assert isinstance(aggregator.results[0],
training_utils.SliceAggregator)
aggregator.finalize()
return aggregator.results
def run_one_epoch(model,
iterator,
execution_function,
dataset_size=None,
strategy=None,
steps_per_epoch=None,
mode=ModeKeys.TRAIN,
training_context=None,
current_epoch=1):
"""Run the execution function with the data from iterator.
Given the dataset iterator and execution function, get the data from iterator
and call it with the execution function to get the result (metric/loss).
It will run for steps_per_epoch or until to the iterator is fully consumed.
Args:
model: The keras model to run.
iterator: the dataset iterator to fetch the data.
execution_function: a tf.function that can be called with data.
dataset_size: the size of iterator, None when unknown.
strategy: the distribution strategy instance from the model.
steps_per_epoch: the number of steps to run for the epoch.
mode: the mode for the current epoch.
training_context: the context that contains callbacks and progress bar.
current_epoch: the epoch number. Used when throw error when the
the iterator is unexpected reach its end.
Returns:
The loss and metric value from the model.
"""
if mode == ModeKeys.PREDICT:
aggregator = training_utils.OutputsAggregator(
use_steps=True, num_samples_or_steps=steps_per_epoch)
else:
aggregator = training_utils.MetricsAggregator(
use_steps=True, num_samples_or_steps=steps_per_epoch)
callbacks = training_context.callbacks
progbar = training_context.progbar
if callbacks.model.stop_training:
return
target_steps = steps_per_epoch or np.inf
step = 0
while step < target_steps:
with training_context.on_batch(step, mode=mode) as batch_logs:
try:
batch_ins = create_batch_inputs(iterator, mode, model,
strategy)
batch_outs = execution_function(batch_ins)
except StopIteration:
# The only acceptable case here is that the input has a unknown
# length, and configured to fully consume it.
if (dataset_size is None and steps_per_epoch is None
and step > 0):
# The input passed by the user ran out of batches.
# Now we know the cardinality of the input(dataset or generator).
steps_per_epoch = step
aggregator.num_samples_or_steps = steps_per_epoch
progbar.params['steps'] = steps_per_epoch
progbar.progbar.target = steps_per_epoch
else:
callbacks.model.stop_training = True
logging.warning(
'Your input ran out of data; interrupting training. '
'Make sure that your dataset or generator can generate at '
'least {} batches. You may need to use the repeat() function '
'when building your dataset.'.format(current_epoch *
steps_per_epoch))
# In either case, break out the loop for training batch.
break
if not isinstance(batch_outs, list):
batch_outs = [batch_outs]
if strategy:
batch_outs = dist_utils._per_replica_aggregate_batch(
batch_outs, model, mode)
if step == 0:
aggregator.create(batch_outs)
aggregator.aggregate(batch_outs)
cbks.make_logs(model, batch_logs, batch_outs, mode)
step += 1
if callbacks.model.stop_training:
break
# End of an epoch.
aggregator.finalize()
results = aggregator.results
return results
def model_iteration(model,
inputs,
targets=None,
sample_weights=None,
batch_size=None,
epochs=1,
verbose=1,
callbacks=None,
val_inputs=None,
val_targets=None,
val_sample_weights=None,
shuffle=True,
initial_epoch=0,
steps_per_epoch=None,
validation_steps=None,
mode='train',
validation_in_fit=False,
**kwargs):
"""Loop function for arrays of data with modes 'train'/'test'/'predict'.
Arguments:
model: Keras Model instance.
inputs: Either a list of arrays or a dictionary.
targets: List of target arrays.
sample_weights: Optional list of sample weight arrays.
batch_size: Integer batch size or None if unknown.
epochs: Number of times to iterate over the data
verbose: Verbosity mode, 0, 1 or 2
callbacks: List of callbacks to be called during training
val_inputs: List of input arrays.
val_targets: List of target arrays.
val_sample_weights: Optional list of sample weight arrays.
shuffle: Whether to shuffle the data at the beginning of each epoch
concatenation of list the display names of the outputs of `f` and the
list of display names of the outputs of `f_val`.
initial_epoch: Epoch at which to start training (useful for resuming a
previous training run)
steps_per_epoch: Total number of steps (batches of samples) before
declaring one epoch finished and starting the next epoch. Ignored with
the default value of `None`.
validation_steps: Number of steps to run validation for (only if doing
validation from data tensors). Ignored with the default value of `None`.
mode: One of 'train'/'test'/'predict'.
validation_in_fit: if true, then this method is invoked from within
training iteration (for validation). In this case, do not copy weights
when using a tf.distribute.Strategy.
**kwargs: Additional arguments for backwards compatibility.
Returns:
- In 'train' mode: `History` object.
- In 'test' mode: Evaluation metrics.
- In 'predict' mode: Outputs of the Model called on inputs.
Raises:
ValueError: in case of invalid arguments.
"""
# Backwards compatibility.
if 'steps' in kwargs:
steps_per_epoch = kwargs['steps']
_validate_arguments(steps_per_epoch, validation_steps, kwargs)
if mode == 'train':
_print_train_info(inputs, val_inputs, steps_per_epoch, verbose)
# Enter DistributionStrategy scope.
if model._distribution_strategy:
scope = model._distribution_strategy.scope()
scope.__enter__()
# Get step function and loop type.
f = _make_execution_function(model, mode)
use_steps = steps_per_epoch is not None
do_validation = val_inputs is not None
# Prepare input data.
ins = _prepare_feed_values(model, inputs, targets, sample_weights, mode)
num_samples_or_steps = _get_num_samples_or_steps(ins, batch_size,
steps_per_epoch)
# Configure callbacks.
count_mode = 'steps' if use_steps else 'samples'
callbacks = cbks.configure_callbacks(
callbacks,
model,
do_validation=do_validation,
batch_size=batch_size,
epochs=epochs,
steps_per_epoch=steps_per_epoch,
samples=num_samples_or_steps,
verbose=0, # Handle ProgBarLogger separately in this loop.
mode=mode)
# TODO(omalleyt): Handle ProgBar as part of Callbacks once hooks are ready.
progbar = training_utils.get_progbar(model, count_mode)
progbar.params = callbacks.params
progbar.params['verbose'] = verbose
# Find beforehand arrays that need sparse-to-dense conversion.
if issparse is not None and not use_steps:
indices_for_conversion_to_dense = []
feed = _get_model_feed(model, mode)
for i, (input_data, feed_tensor) in enumerate(zip(ins, feed)):
if issparse(input_data) and not K.is_sparse(feed_tensor):
indices_for_conversion_to_dense.append(i)
# Select aggregation method.
if mode == 'predict':
aggregator = training_utils.OutputsAggregator(use_steps,
num_samples_or_steps)
else:
aggregator = training_utils.MetricsAggregator(use_steps,
num_samples_or_steps)
if model._distribution_strategy and not validation_in_fit:
training_distributed._copy_weights_to_distributed_model(
model, model._grouped_model)
callbacks.model.stop_training = False
callbacks._call_begin_hook(mode)
progbar.on_train_begin()
for epoch in range(initial_epoch, epochs):
if callbacks.model.stop_training:
break
# Setup work for each epoch
epoch_logs = {}
model.reset_metrics()
callbacks.on_epoch_begin(epoch, epoch_logs, mode=mode)
progbar.on_epoch_begin(epoch, epoch_logs)
if use_steps:
# Step-wise loop.
for step in range(steps_per_epoch):
batch_logs = {'batch': step, 'size': 1}
callbacks._call_batch_hook(mode, 'begin', step, batch_logs)
progbar.on_batch_begin(step, batch_logs)
# Get outputs.
try:
# `ins` can be callable in DistributionStrategy + eager case.
actual_inputs = ins() if callable(ins) else ins
batch_outs = f(actual_inputs)
except errors.OutOfRangeError:
logging.warning(
'Your dataset iterator ran out of data; '
'interrupting training. Make sure that your dataset '
'can generate at least `steps_per_epoch * epochs` '
'batches (in this case, %d batches). You may need to'
'use the repeat() function when building your '
'dataset.' % steps_per_epoch * epochs)
break
if not isinstance(batch_outs, list):
batch_outs = [batch_outs]
if model._distribution_strategy:
batch_outs = training_distributed._per_device_aggregate_batch(
batch_outs, model, mode)
# Aggregate results.
if step == 0:
aggregator.create(batch_outs)
aggregator.aggregate(batch_outs)
# Callbacks batch end.
batch_logs = cbks.make_logs(model, batch_logs, batch_outs,
mode)
callbacks._call_batch_hook(mode, 'end', step, batch_logs)
progbar.on_batch_end(step, batch_logs)
if callbacks.model.stop_training:
break
else:
# Sample-wise loop.
index_array = np.arange(num_samples_or_steps)
if shuffle == 'batch':
index_array = training_utils.batch_shuffle(
index_array, batch_size)
elif shuffle:
np.random.shuffle(index_array)
batches = make_batches(num_samples_or_steps, batch_size)
for batch_index, (batch_start, batch_end) in enumerate(batches):
batch_ids = index_array[batch_start:batch_end]
# Slice into a batch.
try:
if ins and isinstance(ins[-1], int):
# Do not slice the training phase flag.
ins_batch = slice_arrays(ins[:-1],
batch_ids) + [ins[-1]]
else:
ins_batch = slice_arrays(ins, batch_ids)
except TypeError:
raise TypeError('TypeError while preparing batch. '
'If using HDF5 input data, '
'pass shuffle="batch".')
# Sparse to dense conversion.
if issparse is not None:
for i in indices_for_conversion_to_dense:
ins_batch[i] = ins_batch[i].toarray()
# Callbacks batch_begin.
batch_logs = {'batch': batch_index, 'size': len(batch_ids)}
callbacks._call_batch_hook(mode, 'begin', batch_index,
batch_logs)
progbar.on_batch_begin(batch_index, batch_logs)
# Get outputs.
batch_outs = f(ins_batch)
if not isinstance(batch_outs, list):
batch_outs = [batch_outs]
# Aggregate results.
if batch_index == 0:
aggregator.create(batch_outs)
aggregator.aggregate(batch_outs, batch_start, batch_end)
# Callbacks batch end.
batch_logs = cbks.make_logs(model, batch_logs, batch_outs,
mode)
callbacks._call_batch_hook(mode, 'end', batch_index,
batch_logs)
progbar.on_batch_end(batch_index, batch_logs)
if callbacks.model.stop_training:
break
aggregator.finalize()
results = aggregator.results
epoch_logs = cbks.make_logs(model, epoch_logs, results, mode)
if len(results) == 1:
results = results[0]
# Run the test loop every epoch during training.
if do_validation and not callbacks.model.stop_training:
val_results = model_iteration(model,
val_inputs,
targets=val_targets,
sample_weights=val_sample_weights,
batch_size=batch_size,
steps_per_epoch=validation_steps,
callbacks=callbacks,
verbose=0,
mode='test',
validation_in_fit=True)
if not isinstance(val_results, list):
val_results = [val_results]
epoch_logs = cbks.make_logs(model,
epoch_logs,
val_results,
mode,
prefix='val_')
if mode == 'train':
# Epochs only apply to `fit`.
callbacks.on_epoch_end(epoch, epoch_logs, mode=mode)
progbar.on_epoch_end(epoch, epoch_logs)
callbacks._call_end_hook(mode)
if model._distribution_strategy:
# TODO(priyag, psv): Copy back metrics to the original model as well?
if not validation_in_fit:
training_distributed._copy_weights_to_original_model(
model, model._grouped_model, mode)
scope.__exit__(None, None, None)
if mode == 'train':
return model.history
return results
def model_iteration(
model,
inputs,
targets=None,
batch_size=2,
epochs=1,
verbose=1,
callbacks=None,
validation_data=None,
exchange_data=None,
shuffle=False,
validation_split=0.0,
exchange_split=0.0,
validation_freq=1,
random_data_split_state=0,
mode=ModeKeys.TRAIN,
):
"""Loop function for arrays of data with modes TRAIN/TEST/PREDICT.
Args:
model: `EnsembleModel` instance.
inputs: Either a list or dictionary of arrays, or a dataset instance.
targets: List/dictionary of input arrays.
batch_size: Integer batch size or None if unknown.
epochs: Number of times to iterate over the data
verbose: 0, 1, or 2. Verbosity mode.
0 = silent, 1 = progress bar, 2 = one line per epoch.
Note that the progress bar is not particularly useful when
logged to a file, so verbose=2 is recommended when not running
interactively (eg, in a production environment).
callbacks: List of callbacks to be called during training
validation_data:
shuffle: Whether to shuffle the data at the beginning of each epoch
concatenation of list the display names of the outputs of `f` and the
list of display names of the outputs of `f_val`.
validation_freq: Only relevant if validation data is provided. Integer or
`collections_abc.Container` instance (e.g. list, tuple, etc.). If an
integer, specifies how many training epochs to run before a new
validation run is performed, e.g. `validation_freq=2` runs
validation every 2 epochs. If a Container, specifies the epochs on
which to run validation, e.g. `validation_freq=[1, 2, 10]` runs
validation at the end of the 1st, 2nd, and 10th epochs.
mode: One of ModeKeys.TRAIN/ModeKeys.TEST/ModeKeys.PREDICT.
Returns:
- In TRAIN mode: `History` object.
- In TEST mode: Evaluation metrics.
- In PREDICT mode: Outputs of the Model called on inputs.
Raises:
ValueError: in case of invalid arguments.
"""
datasets = training_utils.prepare_data_iterables(
inputs,
targets,
validation_split=validation_split,
validation_data=validation_data,
exchange_data=exchange_data,
batch_size=batch_size,
shuffle=shuffle,
exchange_split=exchange_split,
random_state=random_data_split_state)
val_samples_or_steps = None
exchange_data = None
if (isinstance(datasets, training_utils.DataIterable)
or len(datasets) == 3 and datasets[1] is None):
# TEST, PREDICT modes or TRAIN mode without validation data
do_validation = False
if isinstance(datasets, training_utils.DataIterable):
train_dataset = datasets
else:
train_dataset = datasets[0]
exchange_data = datasets[2]
else:
# TRAIN mode with validation data
do_validation = True
train_dataset, test_dataset, exchange_data = datasets
val_samples_or_steps = len(test_dataset)
num_samples_or_steps = len(train_dataset)
f = _make_execution_function(model,
mode) #whether to train, test or predict
if mode == ModeKeys.PREDICT:
aggregator = keras_train_utils.OutputsAggregator(
use_steps=False, num_samples=num_samples_or_steps)
else:
aggregator = training_utils.MetricsAggregator(
n_replicas=model.n_replicas, num_samples=len(train_dataset))
if mode == ModeKeys.TRAIN and verbose:
_print_train_info(num_samples_or_steps,
val_samples_or_steps,
replicas=model.n_replicas,
increment='samples')
# Configure callbacks
callbacks = cbks.configure_callbacks(
callbacks,
model,
do_validation=do_validation,
batch_size=batch_size,
samples=num_samples_or_steps,
epochs=epochs,
verbose=verbose,
mode=mode,
exchange_data=exchange_data,
)
callbacks.model.stop_training = False
callbacks._call_begin_hook(mode)
for epoch in range(epochs):
if callbacks.model.stop_training:
break
# Setup work for each epoch
epoch_logs = {}
if mode != ModeKeys.PREDICT:
# Collecting and resetting metrics has non-zero cost and will needlessly
# slow down model.predict.
model.reset_metrics()
callbacks._call_epoch_hook(mode, 'begin', epoch, epoch_logs)
# batch_start and batch_end are added so we can use the
# Keras' aggregator. It accepts it as args to compute
# weighted batch size average of the overall losses.
batch_start = 0
for batch_index, batch_data in enumerate(train_dataset):
# Callbacks batch_begin.
if mode == ModeKeys.PREDICT:
x, y = batch_data, None
else:
x, y = batch_data
batch_end = batch_start + x.shape[0]
batch_logs = {'batch': batch_index, 'size': x.shape[0]}
callbacks._call_batch_hook(mode, 'begin', batch_index, batch_logs)
# Get outputs.
batch_outs = f(x, y)
if not isinstance(batch_outs, list):
batch_outs = [batch_outs]
# Aggregate results.
if batch_index == 0:
aggregator.create(batch_outs)
aggregator.aggregate(batch_outs, batch_start, batch_end)
# Callbacks batch end.
batch_logs = cbks.make_logs(model, batch_logs, batch_outs, mode)
callbacks._call_batch_hook(mode, 'end', batch_index, batch_logs)
batch_start = batch_end
if callbacks.model.stop_training:
break
aggregator.finalize()
results = aggregator.results
epoch_logs = cbks.make_logs(model, epoch_logs, results, mode)
if len(results) == 1:
results = results[0]
if (do_validation and keras_train_utils.should_run_validation(
validation_freq, epochs)):
val_results = model_iteration(model,
test_dataset,
targets=None,
batch_size=batch_size,
callbacks=callbacks,
verbose=0,
mode=ModeKeys.TEST)
if not isinstance(val_results, list):
val_results = [val_results]
epoch_logs = cbks.make_logs(model,
epoch_logs,
val_results,
mode,
prefix='val_')
callbacks._call_epoch_hook(mode, 'end', epoch, epoch_logs)
callbacks._call_end_hook(mode)
callbacks.on_train_end() # TODO: move this to CallbackListWrap
if mode == ModeKeys.TRAIN:
return model.history
return results
def model_iteration(model,
inputs,
targets=None,
sample_weights=None,
batch_size=None,
epochs=1,
verbose=1,
callbacks=None,
val_inputs=None,
val_targets=None,
val_sample_weights=None,
shuffle=True,
initial_epoch=0,
steps_per_epoch=None,
validation_steps=None,
mode=ModeKeys.TRAIN,
validation_in_fit=False,
steps_name='steps',
**kwargs):
"""Loop function for arrays of data with modes TRAIN/TEST/PREDICT.
Arguments:
model: Keras Model instance.
inputs: Either a list or dictionary of arrays, or a dataset instance.
targets: List/dictionary of input arrays.
sample_weights: Optional list of sample weight arrays.
batch_size: Integer batch size or None if unknown.
epochs: Number of times to iterate over the data
verbose: Verbosity mode, 0, 1 or 2
callbacks: List of callbacks to be called during training
val_inputs: Either a list or dictionary of arrays, or a dataset instance.
val_targets: List/dictionary of target arrays.
val_sample_weights: Optional list of sample weight arrays.
shuffle: Whether to shuffle the data at the beginning of each epoch
concatenation of list the display names of the outputs of `f` and the
list of display names of the outputs of `f_val`.
initial_epoch: Epoch at which to start training (useful for resuming a
previous training run)
steps_per_epoch: Total number of steps (batches of samples) before
declaring one epoch finished and starting the next epoch. Ignored with
the default value of `None`.
validation_steps: Number of steps to run validation for (only if doing
validation from data tensors). Ignored with the default value of `None`.
mode: One of ModeKeys.TRAIN/ModeKeys.TEST/ModeKeys.PREDICT.
validation_in_fit: DEPRECATED: if true, then this method is invoked from
within training iteration (for validation). In this case, do not copy
weights when using a tf.distribute.Strategy. The input is deprecated as
it is not required if the user creates a distributed model under the
distribution strategy scope rather than passing it to compile.
steps_name: The string name of the steps argument, either `steps`,
`validation_steps`, or `steps_per_epoch`. Only used for error message
formatting.
**kwargs: Additional arguments for backwards compatibility.
Returns:
- In TRAIN mode: `History` object.
- In TEST mode: Evaluation metrics.
- In PREDICT mode: Outputs of the Model called on inputs.
Raises:
ValueError: in case of invalid arguments.
"""
# Backwards compatibility.
if 'steps' in kwargs:
steps_per_epoch = kwargs.pop('steps')
if kwargs:
raise TypeError('Unknown arguments: %s' % (kwargs, ))
# In case we were passed a dataset, we extract symbolic tensors from it.
reset_dataset_after_each_epoch = False
original_dataset = None
is_dataset = isinstance(inputs,
(dataset_ops.DatasetV1, dataset_ops.DatasetV2))
# TODO(fchollet): consider moving `steps_per_epoch` inference to
# _standardize_user_data and set reset_dataset_after_each_epoch as an
# attribute on the dataset instance.
if is_dataset:
original_dataset = inputs
if steps_per_epoch is None:
reset_dataset_after_each_epoch = True
steps_per_epoch = training_utils.infer_steps_for_dataset(
inputs, steps_per_epoch, epochs=epochs, steps_name=steps_name)
if mode == ModeKeys.TRAIN:
_print_train_info(inputs, val_inputs, steps_per_epoch, verbose)
# Enter DistributionStrategy scope.
if model._distribution_strategy:
scope = model._distribution_strategy.scope()
scope.__enter__()
# Get step function and loop type.
f = _make_execution_function(model, mode)
use_steps = is_dataset or steps_per_epoch is not None
do_validation = val_inputs is not None
# Convert Eager Tensors to NumPy arrays to support batching/shuffling.
inputs, targets, sample_weights = training_utils. \
convert_eager_tensors_to_numpy((inputs, targets, sample_weights))
# Prepare input data.
ins = _prepare_feed_values(model, inputs, targets, sample_weights, mode)
if not is_dataset:
num_samples_or_steps = _get_num_samples_or_steps(
ins, batch_size, steps_per_epoch)
else:
num_samples_or_steps = steps_per_epoch
# Configure callbacks.
count_mode = 'steps' if use_steps else 'samples'
callbacks = cbks.configure_callbacks(
callbacks,
model,
do_validation=do_validation,
batch_size=batch_size,
epochs=epochs,
steps_per_epoch=steps_per_epoch,
samples=num_samples_or_steps,
verbose=0, # Handle ProgBarLogger separately in this loop.
mode=mode)
# TODO(omalleyt): Handle ProgBar as part of Callbacks once hooks are ready.
progbar = training_utils.get_progbar(model, count_mode)
progbar.params = callbacks.params
progbar.params['verbose'] = verbose
# Find beforehand arrays that need sparse-to-dense conversion.
if issparse is not None and not use_steps:
indices_for_conversion_to_dense = []
feed = _get_model_feed(model, mode)
for i, (input_data, feed_tensor) in enumerate(zip(ins, feed)):
if issparse(input_data) and not K.is_sparse(feed_tensor):
indices_for_conversion_to_dense.append(i)
# Select aggregation method.
if mode == ModeKeys.PREDICT:
aggregator = training_utils.OutputsAggregator(use_steps,
num_samples_or_steps)
else:
aggregator = training_utils.MetricsAggregator(use_steps,
num_samples_or_steps)
if model._compile_distribution and not validation_in_fit:
distributed_training_utils._copy_weights_to_distributed_model(
model, model._distributed_model)
callbacks.model.stop_training = False
callbacks._call_begin_hook(mode)
progbar.on_train_begin()
for epoch in range(initial_epoch, epochs):
if callbacks.model.stop_training:
break
# Setup work for each epoch
epoch_logs = {}
model.reset_metrics()
if mode == ModeKeys.TRAIN:
callbacks.on_epoch_begin(epoch, epoch_logs)
progbar.on_epoch_begin(epoch, epoch_logs)
if use_steps:
# Step-wise loop.
if steps_per_epoch is None:
# Loop over dataset until `OutOfRangeError` is raised.
target_steps = np.inf
else:
# Loop over dataset for the specified number of steps.
target_steps = steps_per_epoch
step = 0
while step < target_steps:
batch_logs = {'batch': step, 'size': 1}
callbacks._call_batch_hook(mode, 'begin', step, batch_logs)
progbar.on_batch_begin(step, batch_logs)
# Get outputs.
try:
# `ins` can be callable in DistributionStrategy + eager case.
actual_inputs = ins() if callable(ins) else ins
batch_outs = f(actual_inputs)
except errors.OutOfRangeError:
if original_dataset is None:
# We ran out of batches while the user passed an iterator (legacy).
logging.warning(
'Your dataset iterator ran out of data; '
'interrupting training. Make sure that your iterator '
'can generate at least `%s * epochs` '
'batches (in this case, %d batches). You may need to'
'use the repeat() function when building your '
'dataset.' %
(steps_name, steps_per_epoch * epochs))
callbacks.model.stop_training = True
else:
# The dataset passed by the user ran out of batches.
# Now we know the cardinality of the dataset.
if step > 0:
steps_per_epoch = step
aggregator.num_samples_or_steps = steps_per_epoch
progbar.params['steps'] = steps_per_epoch
progbar.progbar.target = steps_per_epoch
break
if not isinstance(batch_outs, list):
batch_outs = [batch_outs]
if model._distribution_strategy:
batch_outs = distributed_training_utils._per_device_aggregate_batch(
batch_outs, model, mode)
# Aggregate results.
if step == 0:
aggregator.create(batch_outs)
aggregator.aggregate(batch_outs)
# Callbacks batch end.
batch_logs = cbks.make_logs(model, batch_logs, batch_outs,
mode)
callbacks._call_batch_hook(mode, 'end', step, batch_logs)
progbar.on_batch_end(step, batch_logs)
step += 1
if callbacks.model.stop_training:
break
else:
# Sample-wise loop.
index_array = np.arange(num_samples_or_steps)
if shuffle == 'batch':
index_array = training_utils.batch_shuffle(
index_array, batch_size)
elif shuffle:
np.random.shuffle(index_array)
batches = make_batches(num_samples_or_steps, batch_size)
for batch_index, (batch_start, batch_end) in enumerate(batches):
batch_ids = index_array[batch_start:batch_end]
# Slice into a batch.
try:
if ins and isinstance(ins[-1], int):
# Do not slice the training phase flag.
ins_batch = slice_arrays(ins[:-1],
batch_ids) + [ins[-1]]
else:
ins_batch = slice_arrays(ins, batch_ids)
except TypeError:
raise TypeError('TypeError while preparing batch. '
'If using HDF5 input data, '
'pass shuffle="batch".')
# Sparse to dense conversion.
if issparse is not None:
for i in indices_for_conversion_to_dense:
ins_batch[i] = ins_batch[i].toarray()
# Callbacks batch_begin.
batch_logs = {'batch': batch_index, 'size': len(batch_ids)}
callbacks._call_batch_hook(mode, 'begin', batch_index,
batch_logs)
progbar.on_batch_begin(batch_index, batch_logs)
# Get outputs.
batch_outs = f(ins_batch)
if not isinstance(batch_outs, list):
batch_outs = [batch_outs]
# Aggregate results.
if batch_index == 0:
aggregator.create(batch_outs)
aggregator.aggregate(batch_outs, batch_start, batch_end)
# Callbacks batch end.
batch_logs = cbks.make_logs(model, batch_logs, batch_outs,
mode)
callbacks._call_batch_hook(mode, 'end', batch_index,
batch_logs)
progbar.on_batch_end(batch_index, batch_logs)
if callbacks.model.stop_training:
break
aggregator.finalize()
results = aggregator.results
epoch_logs = cbks.make_logs(model, epoch_logs, results, mode)
if len(results) == 1:
results = results[0]
# Run the test loop every epoch during training.
if do_validation and not callbacks.model.stop_training:
val_results = model_iteration(model,
val_inputs,
targets=val_targets,
sample_weights=val_sample_weights,
batch_size=batch_size,
steps_per_epoch=validation_steps,
callbacks=callbacks,
verbose=0,
mode=ModeKeys.TEST,
validation_in_fit=True,
steps_name='validation_steps')
if not isinstance(val_results, list):
val_results = [val_results]
epoch_logs = cbks.make_logs(model,
epoch_logs,
val_results,
mode,
prefix='val_')
if mode == ModeKeys.TRAIN:
# Epochs only apply to `fit`.
callbacks.on_epoch_end(epoch, epoch_logs)
progbar.on_epoch_end(epoch, epoch_logs)
# Recreate dataset iterator for the next epoch.
if reset_dataset_after_each_epoch and epoch < epochs - 1:
ins = _prepare_feed_values(model, original_dataset, None, None,
mode)
callbacks._call_end_hook(mode)
if model._distribution_strategy:
if model._compile_distribution and not validation_in_fit:
# TODO(priyag, psv): Copy back metrics to the original model as well?
distributed_training_utils._copy_weights_to_original_model(
model, model._distributed_model, mode)
scope.__exit__(None, None, None)
if mode == ModeKeys.TRAIN:
return model.history
return results
def run_one_epoch(model,
iterator,
execution_function,
dataset_size=None,
strategy=None,
steps_per_epoch=None,
mode=ModeKeys.TRAIN,
training_context=None,
total_epochs=None):
"""Run the execution function with the data from iterator.
Given the dataset iterator and execution function, get the data from iterator
and call it with the execution function to get the result (metric/loss).
It will run for steps_per_epoch or until to the iterator is fully consumed.
Args:
model: The keras model to run.
iterator: the dataset iterator to fetch the data.
execution_function: a tf.function that can be called with data.
dataset_size: the size of iterator, None when unknown.
strategy: the distribution strategy instance from the model.
steps_per_epoch: the number of steps to run for the epoch.
mode: the mode for the current epoch.
training_context: the context that contains callbacks and progress bar.
total_epochs: the total number of epochs that will be run.
Used when throw error when the iterator unexpectedly
reaches its end.
Returns:
The loss and metric value from the model.
"""
if mode == ModeKeys.PREDICT:
aggregator = training_utils.OutputsAggregator(
use_steps=True, num_samples_or_steps=steps_per_epoch)
else:
aggregator = training_utils.MetricsAggregator(
use_steps=True, num_samples_or_steps=steps_per_epoch)
callbacks = training_context.callbacks
progbar = training_context.progbar
if callbacks.model.stop_training:
return
target_steps = steps_per_epoch or np.inf
step = 0
while step < target_steps:
# TODO(scottzhu): Maybe update the training context to take into account
# whether a batch of training happens. Then it could still use a
# context manager
batch_logs = {'batch': step, 'size': 1}
training_context.callbacks._call_batch_hook(
mode, 'begin', step, batch_logs)
training_context.progbar.on_batch_begin(step, batch_logs)
try:
batch_outs = execution_function(iterator)
except (StopIteration, errors.OutOfRangeError):
# TODO(kaftan): File bug about tf function and errors.OutOfRangeError?
# Are there any other C++ errors tf function should recapture?
# The only acceptable case here is that the input has a unknown
# length, and configured to fully consume it.
if (dataset_size is None
and steps_per_epoch is None
and step > 0):
# The input passed by the user ran out of batches.
# Now we know the cardinality of the input(dataset or generator).
steps_per_epoch = step
aggregator.num_samples_or_steps = steps_per_epoch
progbar.params['steps'] = steps_per_epoch
progbar.progbar.target = steps_per_epoch
else:
callbacks.model.stop_training = True
logging.warning(
'Your input ran out of data; interrupting training. '
'Make sure that your dataset or generator can generate at '
'least `steps_per_epoch * epochs` batches (in this case, '
'{} batches). You may need to use the repeat() function '
'when building your dataset.'.format(
total_epochs * steps_per_epoch))
# In either case, break out the loop for training batch.
break
if not isinstance(batch_outs, list):
batch_outs = [batch_outs]
if strategy:
batch_outs = dist_utils._per_replica_aggregate_batch(
batch_outs, model, mode)
if step == 0:
aggregator.create(batch_outs)
aggregator.aggregate(batch_outs)
cbks.make_logs(model, batch_logs, batch_outs, mode)
training_context.callbacks._call_batch_hook(
mode, 'end', step, batch_logs)
training_context.progbar.on_batch_end(step, batch_logs)
step += 1
if callbacks.model.stop_training:
break
# End of an epoch.
aggregator.finalize()
results = aggregator.results
return results
def model_iteration(model,
data,
steps_per_epoch=None,
epochs=1,
verbose=1,
callbacks=None,
validation_data=None,
validation_steps=None,
class_weight=None,
max_queue_size=10,
workers=1,
use_multiprocessing=False,
shuffle=False,
initial_epoch=0,
mode='train',
batch_size=None,
**kwargs):
"""Loop function for arrays of data with modes 'train'/'test'/'predict'.
Arguments:
model: Keras Model instance.
data: Either a tuple of NumPy/Tensor inputs (i.e. `(x,)` or `(x, y)` or
`(x, y, sample_weights)`) or a generator or
`keras.utils.data_utils.Sequence` object or Eager Iterator or Dataset.
steps_per_epoch: Total number of steps (batches of samples) before
declaring one epoch finished and starting the next epoch. Ignored with
the default value of `None`.
epochs: Number of times to iterate over the data.
verbose: Verbosity mode, 0, 1 or 2.
callbacks: List of callbacks to be called during training.
validation_data: Either a tuple of NumPy/Tensor inputs (i.e. `(x,)` or
`(x, y)` or `(x, y, sample_weights)`) or a generator or
`keras.utils.data_utils.Sequence` object or Eager Iterator or Dataset.
validation_steps: Total number of steps (batches of samples) before
declaring validation finished.
class_weight: Dictionary mapping class indices to a weight for the class.
max_queue_size: Integer. Maximum size for the generator queue. If
unspecified, `max_queue_size` will default to 10.
workers: Integer. Maximum number of processes to spin up when using
process-based threading. If unspecified, `workers` will default to 1. If
0, will execute the generator on the main thread.
use_multiprocessing: Boolean. If `True`, use process-based threading. If
unspecified, `use_multiprocessing` will default to `False`. Note that
because this implementation relies on multiprocessing, you should not
pass non-picklable arguments to the generator as they can't be passed
easily to children processes.
shuffle: Boolean. Whether to shuffle the order of the batches at the
beginning of each epoch. Only used with instances of `Sequence`
(`keras.utils.Sequence`). Has no effect when `steps_per_epoch` is not
`None`.
initial_epoch: Epoch at which to start training (useful for resuming a
previous training run).
mode: One of 'train'/'test'/'predict'.
batch_size: Integer batch size or None if unknown. Will only be used if
`data` is in NumPy/Tensor format.
**kwargs: Additional arguments for backwards compatibility. `steps` is
accepted as an alias for `steps_per_epoch`.
Returns:
- In 'train' mode: `History` object.
- In 'test' mode: Evaluation metrics.
- In 'predict' mode: Outputs of the Model called on inputs.
Raises:
ValueError: in case of invalid arguments.
"""
if 'steps' in kwargs:
steps_per_epoch = kwargs['steps']
# Convert to a format that supports `next(generator)`.
generator, steps_per_epoch = convert_to_generator_like(
data,
steps_per_epoch=steps_per_epoch,
batch_size=batch_size,
epochs=epochs - initial_epoch,
shuffle=shuffle)
do_validation = validation_data is not None
should_set_learning_phase = context.executing_eagerly(
) and model.run_eagerly
is_sequence = isinstance(generator, data_utils.Sequence)
_validate_arguments(is_sequence, use_multiprocessing, workers,
steps_per_epoch, validation_data, validation_steps,
mode, kwargs)
batch_function = _make_execution_function(model,
mode,
class_weight=class_weight)
# Create the queue for the generator.
output_generator, enqueuer = _make_enqueued_generator(
generator,
workers=workers,
use_multiprocessing=use_multiprocessing,
max_queue_size=max_queue_size,
shuffle=shuffle)
num_samples_or_steps, use_steps = _get_num_samples_or_steps(
data, steps_per_epoch)
count_mode = 'steps' if use_steps else 'samples'
callbacks = cbks.configure_callbacks(
callbacks,
model,
do_validation=do_validation,
epochs=epochs,
steps_per_epoch=steps_per_epoch,
batch_size=batch_size,
samples=num_samples_or_steps,
verbose=0, # Handle ProgBar as part of Callbacks once hooks are ready.
mode=mode)
# TODO(omalleyt): Handle ProgBar as part of Callbacks once hooks are ready.
progbar = training_utils.get_progbar(model, count_mode)
progbar.params = callbacks.params
progbar.params['verbose'] = verbose
if mode == 'predict':
aggregator = training_utils.OutputsAggregator(True, steps_per_epoch)
else:
aggregator = training_utils.MetricsAggregator(True, steps_per_epoch)
if should_set_learning_phase:
old_learning_phase = backend.learning_phase()
backend.set_learning_phase(1 if mode == 'train' else 0)
callbacks.model.stop_training = False
callbacks._call_begin_hook(mode)
progbar.on_train_begin()
for epoch in range(initial_epoch, epochs):
if callbacks.model.stop_training:
break
# Setup work for each epoch.
model.reset_metrics()
epoch_logs = {}
callbacks.on_epoch_begin(epoch, epoch_logs, mode=mode)
progbar.on_epoch_begin(epoch, epoch_logs)
for step in range(steps_per_epoch):
batch_data = _get_next_batch(output_generator, mode)
if batch_data is None:
callbacks.model.stop_training = True
break
# `batch_size` used for validation data if validation
# data is NumPy/EagerTensors.
batch_size = int(nest.flatten(batch_data)[0].shape[0])
# Callbacks batch begin.
batch_logs = {'batch': step, 'size': batch_size}
callbacks._call_batch_hook(mode, 'begin', step, batch_logs)
progbar.on_batch_begin(step, batch_logs)
batch_outs = batch_function(*batch_data)
if not isinstance(batch_outs, list):
batch_outs = [batch_outs]
# Aggregate results.
if step == 0:
aggregator.create(batch_outs)
aggregator.aggregate(batch_outs)
# Callbacks batch end.
batch_logs = cbks.make_logs(model, batch_logs, batch_outs, mode)
callbacks._call_batch_hook(mode, 'end', step, batch_logs)
progbar.on_batch_end(step, batch_logs)
if callbacks.model.stop_training:
break
aggregator.finalize()
results = aggregator.results
epoch_logs = cbks.make_logs(model, epoch_logs, results, mode)
if len(results) == 1:
results = results[0]
# Run the test loop every epoch during training.
if do_validation and not callbacks.model.stop_training:
val_results = model_iteration(
model,
validation_data,
steps_per_epoch=validation_steps,
batch_size=batch_size,
class_weight=class_weight,
workers=workers,
use_multiprocessing=use_multiprocessing,
max_queue_size=max_queue_size,
callbacks=callbacks,
verbose=0,
mode='test')
if not isinstance(val_results, list):
val_results = [val_results]
epoch_logs = cbks.make_logs(model,
epoch_logs,
val_results,
mode,
prefix='val_')
if mode == 'train':
# Epochs only apply to `fit`.
callbacks.on_epoch_end(epoch, epoch_logs, mode=mode)
progbar.on_epoch_end(epoch, epoch_logs)
callbacks._call_end_hook(mode)
if enqueuer is not None:
enqueuer.stop()
if should_set_learning_phase:
backend.set_learning_phase(old_learning_phase)
if mode == 'train':
return model.history
return results
def model_iteration(model,
data,
steps_per_epoch=None,
epochs=1,
verbose=1,
callbacks=None,
validation_data=None,
validation_steps=None,
validation_freq=1,
train_class_weight=None,
val_class_weight=None,
max_queue_size=10,
workers=1,
use_multiprocessing=False,
shuffle=False,
initial_epoch=0,
mode=ModeKeys.TRAIN,
batch_size=None,
steps_name='steps',
**kwargs):
if 'steps' in kwargs:
steps_per_epoch = kwargs['steps']
# Determine the number of steps per epoch and whether we should reset the
# dataset at the end of each epoch.
reset_dataset_after_each_epoch = False
original_dataset = None
is_dataset = isinstance(data,
(dataset_ops.DatasetV2, dataset_ops.DatasetV1))
if is_dataset:
original_dataset = data
if steps_per_epoch is None:
reset_dataset_after_each_epoch = True
steps_per_epoch = training_utils.infer_steps_for_dataset(
data, steps_per_epoch, epochs=epochs, steps_name=steps_name)
# Convert to a format that supports `next(generator)`.
generator, steps_per_epoch = convert_to_generator_like(
data,
steps_per_epoch=steps_per_epoch,
batch_size=batch_size,
epochs=epochs - initial_epoch,
shuffle=shuffle)
do_validation = validation_data is not None
is_sequence = isinstance(generator, data_utils.Sequence)
_validate_arguments(is_sequence, is_dataset, use_multiprocessing, workers,
steps_per_epoch, validation_data, validation_steps,
mode, kwargs)
# print(train_class_weight, 'before make execution')
######################################################################
batch_function = _make_execution_function(
model,
mode,
train_class_weight=train_class_weight,
val_class_weight=val_class_weight)
######################################################################
# Create the queue for the generator.
enqueuer = None
if not is_dataset:
generator, enqueuer = _make_enqueued_generator(
generator,
workers=workers,
use_multiprocessing=use_multiprocessing,
max_queue_size=max_queue_size,
shuffle=shuffle)
num_samples_or_steps, use_steps = _get_num_samples_or_steps(
data, steps_per_epoch)
count_mode = 'steps' if use_steps else 'samples'
callbacks = cbks.configure_callbacks(callbacks,
model,
do_validation=do_validation,
epochs=epochs,
steps_per_epoch=steps_per_epoch,
batch_size=batch_size,
samples=num_samples_or_steps,
verbose=verbose,
count_mode=count_mode,
mode=mode)
if mode == ModeKeys.PREDICT:
aggregator = training_utils.OutputsAggregator(True,
steps=steps_per_epoch)
else:
aggregator = training_utils.MetricsAggregator(True,
steps=steps_per_epoch)
should_set_learning_phase = context.executing_eagerly(
) and model.run_eagerly
if should_set_learning_phase:
learning_phase_scope = backend.eager_learning_phase_scope(
1 if mode == ModeKeys.TRAIN else 0)
learning_phase_scope.__enter__()
callbacks.model.stop_training = False
callbacks._call_begin_hook(mode)
print(initial_epoch, mode)
# TODO: mode is a bug?
# https://github.com/tensorflow/tensorflow/blob/r2.2/tensorflow/python/keras/engine/training.py
initial_epoch = model._maybe_load_initial_epoch_from_ckpt(initial_epoch)
for epoch in range(initial_epoch, epochs):
if callbacks.model.stop_training:
break
# Setup work for each epoch.
model.reset_metrics()
epoch_logs = {}
if mode == ModeKeys.TRAIN:
callbacks.on_epoch_begin(epoch, epoch_logs)
if steps_per_epoch is None:
# Loop over dataset until `OutOfRangeError` is raised.
target_steps = np.inf
else:
# Loop over dataset for the specified number of steps.
target_steps = steps_per_epoch
step = 0
while step < target_steps:
batch_data = _get_next_batch(generator)
if batch_data is None:
if is_dataset:
# The dataset passed by the user ran out of batches.
# Now we know the cardinality of the dataset.
# If steps_per_epoch was specified, then running out of data is
# unexpected, so we stop training and inform the user.
if steps_per_epoch:
callbacks.model.stop_training = True
logging.warning(
'Your dataset ran out of data; interrupting training. '
'Make sure that your dataset can generate at least '
'`%s * epochs` batches (in this case, %d batches). '
'You may need to use the repeat() function when '
'building your dataset.' %
(steps_name, steps_per_epoch * epochs))
elif step > 0:
steps_per_epoch = step
aggregator.steps = steps_per_epoch
else:
# We ran out of batches while the user passed an iterator (legacy).
callbacks.model.stop_training = True
logging.warning(
'Your dataset iterator ran out of data; '
'interrupting training. Make sure that your iterator '
'can generate at least `%s * epochs` '
'batches (in this case, %d batches). You may need to'
'use the repeat() function when building your '
'dataset.' % (steps_name, steps_per_epoch * epochs))
break
# `batch_size` used for validation data if validation
# data is NumPy/EagerTensors.
batch_size = int(nest.flatten(batch_data)[0].shape[0])
# Callbacks batch begin.
batch_logs = {'batch': step, 'size': batch_size}
callbacks._call_batch_hook(mode, 'begin', step, batch_logs)
is_deferred = not model._is_compiled
######################################################
batch_outs = batch_function(*batch_data)
######################################################
if not isinstance(batch_outs, list):
batch_outs = [batch_outs]
if step == 0:
aggregator.create(batch_outs)
if is_deferred:
# Set callbacks params. We do this here when model is compiled only
# in the first iteration of this loop (deferred build scenario).
cbks.set_callback_parameters(
callbacks,
model,
do_validation=do_validation,
batch_size=batch_size,
epochs=epochs,
steps_per_epoch=steps_per_epoch,
samples=num_samples_or_steps,
verbose=verbose,
mode=mode)
# Aggregate results.
aggregator.aggregate(batch_outs)
# Callbacks batch end.
batch_logs = cbks.make_logs(model, batch_logs, batch_outs, mode)
callbacks._call_batch_hook(mode, 'end', step, batch_logs)
step += 1
if callbacks.model.stop_training:
break
aggregator.finalize()
results = aggregator.results
epoch_logs = cbks.make_logs(model, epoch_logs, results, mode)
if len(results) == 1:
results = results[0]
# Run the test loop every epoch during training.
if (do_validation and training_utils.should_run_validation(
validation_freq, epoch) and not callbacks.model.stop_training):
############################################################################
val_results = model_iteration(
model,
validation_data,
steps_per_epoch=validation_steps,
batch_size=batch_size,
val_class_weight=val_class_weight, ######## HACK
workers=workers,
use_multiprocessing=use_multiprocessing,
max_queue_size=max_queue_size,
callbacks=callbacks,
verbose=0,
mode=ModeKeys.TEST,
steps_name='validation_steps')
############################################################################
if not isinstance(val_results, list):
val_results = [val_results]
epoch_logs = cbks.make_logs(model,
epoch_logs,
val_results,
mode,
prefix='val_')
if mode == ModeKeys.TRAIN:
# Epochs only apply to `fit`.
callbacks.on_epoch_end(epoch, epoch_logs)
# Recreate dataset iterator for the next epoch.
if reset_dataset_after_each_epoch and epoch < epochs - 1:
generator = dataset_ops.make_one_shot_iterator(original_dataset)
callbacks._call_end_hook(mode)
if enqueuer is not None:
enqueuer.stop()
if should_set_learning_phase:
learning_phase_scope.__exit__(None, None, None)
if mode == ModeKeys.TRAIN:
return model.history
return results
def model_iteration(model,
inputs,
targets=None,
sample_weights=None,
batch_size=None,
epochs=1,
verbose=1,
callbacks=None,
val_inputs=None,
val_targets=None,
val_sample_weights=None,
shuffle=True,
initial_epoch=0,
steps_per_epoch=None,
validation_steps=None,
validation_freq=1,
mode=ModeKeys.TRAIN,
validation_in_fit=False,
prepared_feed_values_from_dataset=False,
steps_name='steps',
**kwargs):
"""Loop function for arrays of data with modes TRAIN/TEST/PREDICT.
Arguments:
model: Keras Model instance.
inputs: Either a list or dictionary of arrays, or a dataset instance.
targets: List/dictionary of input arrays.
sample_weights: Optional list of sample weight arrays.
batch_size: Integer batch size or None if unknown.
epochs: Number of times to iterate over the data
verbose: Verbosity mode, 0, 1 or 2
callbacks: List of callbacks to be called during training
val_inputs: Either a list or dictionary of arrays, or a dataset instance.
val_targets: List/dictionary of target arrays.
val_sample_weights: Optional list of sample weight arrays.
shuffle: Whether to shuffle the data at the beginning of each epoch
concatenation of list the display names of the outputs of `f` and the
list of display names of the outputs of `f_val`.
initial_epoch: Epoch at which to start training (useful for resuming a
previous training run)
steps_per_epoch: Total number of steps (batches of samples) before
declaring one epoch finished and starting the next epoch. Ignored with
the default value of `None`.
validation_steps: Number of steps to run validation for (only if doing
validation from data tensors). Ignored with the default value of `None`.
validation_freq: Only relevant if validation data is provided. Integer or
`collections.Container` instance (e.g. list, tuple, etc.). If an
integer, specifies how many training epochs to run before a new
validation run is performed, e.g. `validation_freq=2` runs
validation every 2 epochs. If a Container, specifies the epochs on
which to run validation, e.g. `validation_freq=[1, 2, 10]` runs
validation at the end of the 1st, 2nd, and 10th epochs.
mode: One of ModeKeys.TRAIN/ModeKeys.TEST/ModeKeys.PREDICT.
validation_in_fit: if true, then this method is invoked from within
training iteration (for validation). In the case where `val_inputs` is a
dataset, this flag indicates that its iterator and feed values are
already created so should properly reuse resources.
prepared_feed_values_from_dataset: if True, `inputs` is a list of feed
tensors returned from `_prepare_feed_values` call on the validation
dataset, so do not call it again on `inputs`. Should only be used for
inline validation (i.e., only if `validation_in_fit` is also True).
steps_name: The string name of the steps argument, either `steps`,
`validation_steps`, or `steps_per_epoch`. Only used for error message
formatting.
**kwargs: Additional arguments for backwards compatibility.
Returns:
- In TRAIN mode: `History` object.
- In TEST mode: Evaluation metrics.
- In PREDICT mode: Outputs of the Model called on inputs.
Raises:
ValueError: in case of invalid arguments.
"""
# Backwards compatibility.
if 'steps' in kwargs:
steps_per_epoch = kwargs.pop('steps')
if kwargs:
raise TypeError('Unknown arguments: %s' % (kwargs,))
# In case we were passed a dataset, we extract symbolic tensors from it.
reset_dataset_after_each_epoch = False
input_iterator = None
is_dataset = isinstance(inputs,
(dataset_ops.DatasetV1, dataset_ops.DatasetV2))
# TODO(fchollet): consider moving `steps_per_epoch` inference to
# _standardize_user_data and set reset_dataset_after_each_epoch as an
# attribute on the dataset instance.
if is_dataset:
if steps_per_epoch is None:
reset_dataset_after_each_epoch = True
steps_per_epoch = training_utils.infer_steps_for_dataset(
inputs, steps_per_epoch, epochs=epochs, steps_name=steps_name)
input_iterator = _get_iterator(inputs, model._distribution_strategy)
if mode == ModeKeys.TRAIN:
_print_train_info(inputs, val_inputs, steps_per_epoch, verbose)
# Enter DistributionStrategy scope.
if model._distribution_strategy:
scope = distributed_training_utils.distributed_scope(
strategy=model._distribution_strategy,
learning_phase=(1 if mode == ModeKeys.TRAIN else 0))
scope.__enter__()
# Get step function and loop type.
f = _make_execution_function(model, mode)
use_steps = is_dataset or steps_per_epoch is not None
do_validation = val_inputs is not None
# Convert Eager Tensors to NumPy arrays to support batching/shuffling.
inputs, targets, sample_weights = training_utils. \
convert_eager_tensors_to_numpy((inputs, targets, sample_weights))
# Prepare input data.
inputs = input_iterator or inputs
if validation_in_fit and prepared_feed_values_from_dataset:
# When invoking validation in training loop, avoid creating iterator and
# list of feed values for the same validation dataset multiple times (which
# essentially would call `iterator.get_next()` that slows down execution and
# leads to OOM errors eventually.
ins = inputs
else:
ins = _prepare_feed_values(model, inputs, targets, sample_weights, mode)
if not is_dataset:
num_samples_or_steps = _get_num_samples_or_steps(ins, batch_size,
steps_per_epoch)
else:
num_samples_or_steps = steps_per_epoch
# Prepare validation data. Hold references to the iterator and the input list
# to properly reinitialize and reuse in multiple validation passes.
val_iterator = None
if isinstance(val_inputs, (dataset_ops.DatasetV1, dataset_ops.DatasetV2)):
if validation_steps is None:
# Because we pass an iterator feed instead of a Dataset to the eval
# model_iteration() call, it will not trigger the dataset-input path
# that determines the number of steps required. To avoid this issue,
# set validation_steps here if validation_steps is None.
validation_steps = training_utils.infer_steps_for_dataset(
val_inputs,
validation_steps,
epochs=epochs,
steps_name='validation_steps')
val_iterator = _get_iterator(val_inputs, model._distribution_strategy)
val_inputs = _prepare_feed_values(
model, val_iterator, val_targets, val_sample_weights, ModeKeys.TEST)
# Configure callbacks.
count_mode = 'steps' if use_steps else 'samples'
callbacks = cbks.configure_callbacks(
callbacks,
model,
do_validation=do_validation,
val_inputs=val_inputs,
val_targets=val_targets,
val_sample_weights=val_sample_weights,
batch_size=batch_size,
epochs=epochs,
steps_per_epoch=steps_per_epoch,
samples=num_samples_or_steps,
verbose=0, # Handle ProgBarLogger separately in this loop.
mode=mode)
# TODO(omalleyt): Handle ProgBar as part of Callbacks once hooks are ready.
progbar = training_utils.get_progbar(model, count_mode)
progbar.params = callbacks.params
progbar.params['verbose'] = verbose
# Find beforehand arrays that need sparse-to-dense conversion.
if issparse is not None and not use_steps:
indices_for_conversion_to_dense = []
feed = _get_model_feed(model, mode)
for i, (input_data, feed_tensor) in enumerate(zip(ins, feed)):
if issparse(input_data) and not K.is_sparse(feed_tensor):
indices_for_conversion_to_dense.append(i)
# Select aggregation method.
if mode == ModeKeys.PREDICT:
aggregator = training_utils.OutputsAggregator(use_steps,
num_samples_or_steps)
else:
aggregator = training_utils.MetricsAggregator(use_steps,
num_samples_or_steps)
if model._compile_distribution:
distributed_training_utils._copy_weights_to_distributed_model(model, mode)
callbacks.model.stop_training = False
callbacks._call_begin_hook(mode)
progbar.on_train_begin()
for epoch in range(initial_epoch, epochs):
# Reset stateful metrics
for m in model.stateful_metric_functions:
m.reset_states()
# Update callbacks
callbacks.on_epoch_begin(epoch)
epoch_logs = {}
model.reset_metrics()
if mode == ModeKeys.TRAIN:
callbacks.on_epoch_begin(epoch, epoch_logs)
progbar.on_epoch_begin(epoch, epoch_logs)
if use_steps:
# Step-wise loop.
if steps_per_epoch is None:
# Loop over dataset until `OutOfRangeError` is raised.
target_steps = np.inf
else:
# Loop over dataset for the specified number of steps.
target_steps = steps_per_epoch
step = 0
while step < target_steps:
batch_logs = {'batch': step, 'size': 1}
callbacks._call_batch_hook(mode, 'begin', step, batch_logs)
progbar.on_batch_begin(step, batch_logs)
# Get outputs.
try:
outs = f(ins)
except errors.OutOfRangeError:
if is_dataset:
# The dataset passed by the user ran out of batches.
# Now we know the cardinality of the dataset.
# If steps_per_epoch was specified, then running out of data is
# unexpected, so we stop training and inform the user.
if steps_per_epoch:
callbacks.model.stop_training = True
logging.warning(
'Your dataset ran out of data; interrupting training. '
'Make sure that your dataset can generate at least '
'`%s * epochs` batches (in this case, %d batches). '
'You may need to use the repeat() function when '
'building your dataset.'
% (steps_name, steps_per_epoch * epochs))
elif step > 0:
steps_per_epoch = step
aggregator.num_samples_or_steps = steps_per_epoch
if mode == ModeKeys.TRAIN:
progbar.params['steps'] = steps_per_epoch
progbar.progbar.target = steps_per_epoch
else:
# We ran out of batches while the user passed an iterator (legacy).
callbacks.model.stop_training = True
logging.warning(
'Your dataset iterator ran out of data; '
'interrupting training. Make sure that your iterator '
'can generate at least `%s * epochs` '
'batches (in this case, %d batches). You may need to'
'use the repeat() function when building your '
'dataset.' % (steps_name, steps_per_epoch * epochs))
break
if not isinstance(batch_outs, list):
batch_outs = [batch_outs]
if model._distribution_strategy:
batch_outs = distributed_training_utils._per_device_aggregate_batch(
batch_outs, model, mode)
# Aggregate results.
if step == 0:
aggregator.create(batch_outs)
aggregator.aggregate(batch_outs)
# Callbacks batch end.
batch_logs = cbks.make_logs(model, batch_logs, batch_outs, mode)
callbacks._call_batch_hook(mode, 'end', step, batch_logs)
progbar.on_batch_end(step, batch_logs)
step += 1
callbacks.on_batch_end(step_index, batch_logs)
if callbacks.model.stop_training:
break
if do_validation:
val_outs = test_loop(
model,
val_inputs,
val_targets,
sample_weights=val_sample_weights,
steps=validation_steps,
verbose=0)
if not isinstance(val_outs, list):
val_outs = [val_outs]
# Same labels assumed.
for l, o in zip(model.metrics_names, val_outs):
epoch_logs['val_' + l] = o
else:
# Sample-wise fit loop.
if shuffle == 'batch':
index_array = training_utils.batch_shuffle(index_array, batch_size)
elif shuffle:
np.random.shuffle(index_array)
batches = make_batches(num_train_samples, batch_size)
for batch_index, (batch_start, batch_end) in enumerate(batches):
batch_ids = index_array[batch_start:batch_end]
try:
if isinstance(ins[-1], int):
# Do not slice the training phase flag.
ins_batch = slice_arrays(ins[:-1], batch_ids) + [ins[-1]]
else:
ins_batch = slice_arrays(ins, batch_ids)
except TypeError:
raise TypeError('TypeError while preparing batch. '
'If using HDF5 input data, '
'pass shuffle="batch".')
batch_logs = {}
batch_logs['batch'] = batch_index
batch_logs['size'] = len(batch_ids)
callbacks.on_batch_begin(batch_index, batch_logs)
for i in indices_for_conversion_to_dense:
ins_batch[i] = ins_batch[i].toarray()
outs = f(ins_batch)
if not isinstance(outs, list):
outs = [outs]
for l, o in zip(model.metrics_names, outs):
batch_logs[l] = o
callbacks.on_batch_end(batch_index, batch_logs)
if callbacks.model.stop_training:
break
if batch_index == len(batches) - 1: # Last batch.
if do_validation:
val_outs = test_loop(
model,
val_inputs,
val_targets,
sample_weights=val_sample_weights,
batch_size=batch_size,
verbose=0)
if not isinstance(val_outs, list):
val_outs = [val_outs]
# Same labels assumed.
for l, o in zip(model.metrics_names, val_outs):
epoch_logs['val_' + l] = o
callbacks.on_epoch_end(epoch, epoch_logs)
if callbacks.model.stop_training:
break
callbacks.on_train_end()
return model.history
def model_iteration(model,
data,
steps_per_epoch=None,
epochs=1,
verbose=1,
callbacks=None,
validation_data=None,
validation_steps=None,
validation_freq=1,
class_weight=None,
max_queue_size=10,
workers=1,
use_multiprocessing=False,
shuffle=False,
initial_epoch=0,
mode=ModeKeys.TRAIN,
batch_size=None,
steps_name='steps',
**kwargs):
"""Loop function for arrays of data with modes TRAIN/TEST/PREDICT.
Arguments:
model: Keras Model instance.
data: Either a tuple of NumPy/Tensor inputs (i.e. `(x,)` or `(x, y)` or
`(x, y, sample_weights)`) or a generator or
`keras.utils.data_utils.Sequence` object or Eager Iterator or Dataset.
steps_per_epoch: Total number of steps (batches of samples) before
declaring one epoch finished and starting the next epoch. Ignored with
the default value of `None`.
epochs: Number of times to iterate over the data.
verbose: 0, 1, or 2. Verbosity mode.
0 = silent, 1 = progress bar, 2 = one line per epoch.
Note that the progress bar is not particularly useful when
logged to a file, so verbose=2 is recommended when not running
interactively (eg, in a production environment).
callbacks: List of callbacks to be called during training.
validation_data: Either a tuple of NumPy/Tensor inputs (i.e. `(x,)` or
`(x, y)` or `(x, y, sample_weights)`) or a generator or
`keras.utils.data_utils.Sequence` object or Eager Iterator or Dataset.
validation_steps: Total number of steps (batches of samples) before
declaring validation finished.
validation_freq: Only relevant if validation data is provided. Integer or
`collections.abc.Container` instance (e.g. list, tuple, etc.). If an
integer, specifies how many training epochs to run before a new
validation run is performed, e.g. `validation_freq=2` runs
validation every 2 epochs. If a Container, specifies the epochs on
which to run validation, e.g. `validation_freq=[1, 2, 10]` runs
validation at the end of the 1st, 2nd, and 10th epochs.
class_weight: Dictionary mapping class indices to a weight for the class.
max_queue_size: Integer. Maximum size for the generator queue. If
unspecified, `max_queue_size` will default to 10.
workers: Integer. Maximum number of processes to spin up when using
process-based threading. If unspecified, `workers` will default to 1. If
0, will execute the generator on the main thread.
use_multiprocessing: Boolean. If `True`, use process-based threading. If
unspecified, `use_multiprocessing` will default to `False`. Note that
because this implementation relies on multiprocessing, you should not
pass non-picklable arguments to the generator as they can't be passed
easily to children processes.
shuffle: Boolean. Whether to shuffle the order of the batches at the
beginning of each epoch. Only used with instances of `Sequence`
(`keras.utils.Sequence`). Has no effect when `steps_per_epoch` is not
`None`.
initial_epoch: Epoch at which to start training (useful for resuming a
previous training run).
mode: One of ModeKeys.TRAIN/ModeKeys.TEST/ModeKeys.PREDICT.
batch_size: Integer batch size or None if unknown. Will only be used if
`data` is in NumPy/Tensor format.
steps_name: The string name of the steps argument, either `steps`,
`validation_steps`, or `steps_per_epoch`. Only used for error message
formatting.
**kwargs: Additional arguments for backwards compatibility. `steps` is
accepted as an alias for `steps_per_epoch`.
Returns:
- In TRAIN mode: `History` object.
- In TEST mode: Evaluation metrics.
- In PREDICT mode: Outputs of the Model called on inputs.
Raises:
ValueError: in case of invalid arguments.
"""
if 'steps' in kwargs:
steps_per_epoch = kwargs['steps']
# Determine the number of steps per epoch and whether we should reset the
# dataset at the end of each epoch.
reset_dataset_after_each_epoch = False
original_dataset = None
is_dataset = isinstance(data,
(dataset_ops.DatasetV2, dataset_ops.DatasetV1))
if is_dataset:
original_dataset = data
if steps_per_epoch is None:
reset_dataset_after_each_epoch = True
steps_per_epoch = training_utils.infer_steps_for_dataset(
model,
data,
steps_per_epoch,
epochs=epochs,
steps_name=steps_name)
# Convert to a format that supports `next(generator)`.
generator, steps_per_epoch = convert_to_generator_like(
data,
steps_per_epoch=steps_per_epoch,
batch_size=batch_size,
epochs=epochs - initial_epoch,
shuffle=shuffle)
do_validation = validation_data is not None
is_sequence = isinstance(generator, data_utils.Sequence)
_validate_arguments(is_sequence, is_dataset, use_multiprocessing, workers,
steps_per_epoch, validation_data, validation_steps,
mode, kwargs)
batch_function = _make_execution_function(model,
mode,
class_weight=class_weight)
# Create the queue for the generator.
enqueuer = None
if not is_dataset:
generator, enqueuer = _make_enqueued_generator(
generator,
workers=workers,
use_multiprocessing=use_multiprocessing,
max_queue_size=max_queue_size,
shuffle=shuffle)
num_samples_or_steps, use_steps = _get_num_samples_or_steps(
data, steps_per_epoch)
count_mode = 'steps' if use_steps else 'samples'
callbacks = cbks.configure_callbacks(callbacks,
model,
do_validation=do_validation,
epochs=epochs,
steps_per_epoch=steps_per_epoch,
batch_size=batch_size,
samples=num_samples_or_steps,
count_mode=count_mode,
verbose=verbose,
mode=mode)
if mode == ModeKeys.PREDICT:
aggregator = training_utils.OutputsAggregator(True,
steps=steps_per_epoch)
else:
aggregator = training_utils.MetricsAggregator(True,
steps=steps_per_epoch)
should_set_learning_phase = context.executing_eagerly(
) and model.run_eagerly
if should_set_learning_phase:
learning_phase_scope = backend.eager_learning_phase_scope(
1 if mode == ModeKeys.TRAIN else 0)
learning_phase_scope.__enter__()
callbacks.model.stop_training = False
callbacks._call_begin_hook(mode)
initial_epoch = model._maybe_load_initial_epoch_from_ckpt(
initial_epoch, mode)
for epoch in range(initial_epoch, epochs):
if callbacks.model.stop_training:
break
# Setup work for each epoch.
model.reset_metrics()
epoch_logs = {}
if mode == ModeKeys.TRAIN:
callbacks.on_epoch_begin(epoch, epoch_logs)
if steps_per_epoch is None:
# Loop over dataset until `OutOfRangeError` is raised.
target_steps = np.inf
else:
# Loop over dataset for the specified number of steps.
target_steps = steps_per_epoch
step = 0
while step < target_steps:
batch_data = _get_next_batch(generator)
if batch_data is None:
if is_dataset:
# The dataset passed by the user ran out of batches.
# Now we know the cardinality of the dataset.
# If steps_per_epoch was specified, then running out of data is
# unexpected, so we stop training and inform the user.
if steps_per_epoch:
callbacks.model.stop_training = True
logging.warning(
'Your dataset ran out of data; interrupting training. '
'Make sure that your dataset can generate at least '
'`%s * epochs` batches (in this case, %d batches). '
'You may need to use the repeat() function when '
'building your dataset.' %
(steps_name, steps_per_epoch * epochs))
elif step > 0:
steps_per_epoch = step
aggregator.steps = steps_per_epoch
else:
# We ran out of batches while the user passed an iterator (legacy).
callbacks.model.stop_training = True
logging.warning(
'Your dataset iterator ran out of data; '
'interrupting training. Make sure that your iterator '
'can generate at least `%s * epochs` '
'batches (in this case, %d batches). You may need to'
'use the repeat() function when building your '
'dataset.' % (steps_name, steps_per_epoch * epochs))
break
# `batch_size` used for validation data if validation
# data is NumPy/EagerTensors.
batch_size = int(nest.flatten(batch_data)[0].shape[0])
# Callbacks batch begin.
batch_logs = {'batch': step, 'size': batch_size}
callbacks._call_batch_hook(mode, 'begin', step, batch_logs)
is_deferred = not model._is_compiled
batch_outs = batch_function(*batch_data)
if not isinstance(batch_outs, list):
batch_outs = [batch_outs]
if step == 0:
aggregator.create(batch_outs)
if is_deferred:
# Set callbacks params. We do this here when model is compiled only
# in the first iteration of this loop (deferred build scenario).
cbks.set_callback_parameters(
callbacks,
model,
do_validation=do_validation,
batch_size=batch_size,
epochs=epochs,
steps_per_epoch=steps_per_epoch,
samples=num_samples_or_steps,
verbose=verbose,
mode=mode)
# Aggregate results.
aggregator.aggregate(batch_outs)
# Callbacks batch end.
batch_logs = cbks.make_logs(model, batch_logs, batch_outs, mode)
callbacks._call_batch_hook(mode, 'end', step, batch_logs)
step += 1
if callbacks.model.stop_training:
break
aggregator.finalize()
results = aggregator.results
epoch_logs = cbks.make_logs(model, epoch_logs, results, mode)
if len(results) == 1:
results = results[0]
# Run the test loop every epoch during training.
if (do_validation and training_utils.should_run_validation(
validation_freq, epoch) and not callbacks.model.stop_training):
val_results = model_iteration(
model,
validation_data,
steps_per_epoch=validation_steps,
batch_size=batch_size,
class_weight=class_weight,
workers=workers,
use_multiprocessing=use_multiprocessing,
max_queue_size=max_queue_size,
callbacks=callbacks,
verbose=verbose,
mode=ModeKeys.TEST,
steps_name='validation_steps')
if not isinstance(val_results, list):
val_results = [val_results]
epoch_logs = cbks.make_logs(model,
epoch_logs,
val_results,
mode,
prefix='val_')
if mode == ModeKeys.TRAIN:
# Epochs only apply to `fit`.
callbacks.on_epoch_end(epoch, epoch_logs)
# Recreate dataset iterator for the next epoch.
if reset_dataset_after_each_epoch and epoch < epochs - 1:
generator = dataset_ops.make_one_shot_iterator(original_dataset)
model._successful_loop_finish = True
callbacks._call_end_hook(mode)
if enqueuer is not None:
enqueuer.stop()
if should_set_learning_phase:
learning_phase_scope.__exit__(None, None, None)
if mode == ModeKeys.TRAIN:
return model.history
return results
def model_iteration(model,
inputs,
targets=None,
sample_weights=None,
batch_size=None,
epochs=1,
verbose=1,
callbacks=None,
val_inputs=None,
val_targets=None,
val_sample_weights=None,
shuffle=True,
initial_epoch=0,
steps_per_epoch=None,
validation_steps=None,
validation_freq=1,
mode=ModeKeys.TRAIN,
validation_in_fit=False,
prepared_feed_values_from_dataset=False,
steps_name='steps',
**kwargs):
"""Loop function for arrays of data with modes TRAIN/TEST/PREDICT.
Arguments:
model: Keras Model instance.
inputs: Either a list or dictionary of arrays, or a dataset instance.
targets: List/dictionary of input arrays.
sample_weights: Optional list of sample weight arrays.
batch_size: Integer batch size or None if unknown.
epochs: Number of times to iterate over the data
verbose: 0, 1, or 2. Verbosity mode.
0 = silent, 1 = progress bar, 2 = one line per epoch.
Note that the progress bar is not particularly useful when
logged to a file, so verbose=2 is recommended when not running
interactively (eg, in a production environment).
callbacks: List of callbacks to be called during training
val_inputs: Either a list or dictionary of arrays, or a dataset instance.
val_targets: List/dictionary of target arrays.
val_sample_weights: Optional list of sample weight arrays.
shuffle: Whether to shuffle the data at the beginning of each epoch
concatenation of list the display names of the outputs of `f` and the
list of display names of the outputs of `f_val`.
initial_epoch: Epoch at which to start training (useful for resuming a
previous training run)
steps_per_epoch: Total number of steps (batches of samples) before
declaring one epoch finished and starting the next epoch. Ignored with
the default value of `None`.
validation_steps: Number of steps to run validation for (only if doing
validation from data tensors). Ignored with the default value of
`None`.
validation_freq: Only relevant if validation data is provided. Integer or
`collections_abc.Container` instance (e.g. list, tuple, etc.). If an
integer, specifies how many training epochs to run before a new
validation run is performed, e.g. `validation_freq=2` runs
validation every 2 epochs. If a Container, specifies the epochs on
which to run validation, e.g. `validation_freq=[1, 2, 10]` runs
validation at the end of the 1st, 2nd, and 10th epochs.
mode: One of ModeKeys.TRAIN/ModeKeys.TEST/ModeKeys.PREDICT.
validation_in_fit: if true, then this method is invoked from within
training iteration (for validation). In the case where `val_inputs` is
a dataset, this flag indicates that its iterator and feed values are
already created so should properly reuse resources.
prepared_feed_values_from_dataset: if True, `inputs` is a list of feed
tensors returned from `_prepare_feed_values` call on the validation
dataset, so do not call it again on `inputs`. Should only be used for
inline validation (i.e., only if `validation_in_fit` is also True).
steps_name: The string name of the steps argument, either `steps`,
`validation_steps`, or `steps_per_epoch`. Only used for error message
formatting.
**kwargs: Additional arguments for backwards compatibility.
Returns:
- In TRAIN mode: `History` object.
- In TEST mode: Evaluation metrics.
- In PREDICT mode: Outputs of the Model called on inputs.
Raises:
ValueError: in case of invalid arguments.
"""
# Backwards compatibility.
if 'steps' in kwargs:
steps_per_epoch = kwargs.pop('steps')
if kwargs:
raise TypeError('Unknown arguments: %s' % (kwargs, ))
# In case we were passed a dataset, we extract symbolic tensors from it.
reset_dataset_after_each_epoch = False
input_iterator = None
is_dataset = isinstance(inputs,
(dataset_ops.DatasetV1, dataset_ops.DatasetV2))
# TODO(fchollet): consider moving `steps_per_epoch` inference to
# _standardize_user_data and set reset_dataset_after_each_epoch as an
# attribute on the dataset instance.
if is_dataset:
if steps_per_epoch is None:
reset_dataset_after_each_epoch = True
steps_per_epoch = training_utils.infer_steps_for_dataset(
model,
inputs,
steps_per_epoch,
epochs=epochs,
steps_name=steps_name)
input_iterator = _get_iterator(inputs, model._distribution_strategy)
# Enter tf.distribute.Strategy scope.
if model._distribution_strategy:
scope = distributed_training_utils.distributed_scope(
strategy=model._distribution_strategy,
learning_phase=(1 if mode == ModeKeys.TRAIN else 0))
scope.__enter__()
use_steps = is_dataset or steps_per_epoch is not None
do_validation = val_inputs is not None
# Convert Eager Tensors to NumPy arrays to support batching/shuffling.
inputs, targets, sample_weights = training_utils. \
convert_eager_tensors_to_numpy((inputs, targets, sample_weights))
# Prepare input data.
inputs = input_iterator or inputs
if validation_in_fit and prepared_feed_values_from_dataset:
# When invoking validation in training loop, avoid creating iterator and
# list of feed values for the same validation dataset multiple times (which
# essentially would call `iterator.get_next()` that slows down execution and
# leads to OOM errors eventually.
ins = inputs
else:
ins = _prepare_feed_values(model, inputs, targets, sample_weights,
mode)
# `ins` is a function when a distribute strategy is used in Eager mode. In
# that case `is_dataset` is True. The code branches that have requirements
# about the type of `ins` do not trigger in the distributed case.
if not is_dataset:
num_samples_or_steps = _get_num_samples_or_steps(
ins, batch_size, steps_per_epoch)
else:
num_samples_or_steps = steps_per_epoch
# Update sample_weight_mode of the model if sample_weights is specified by the
# user. We need to call this function after we have a handle on the inputs
# (both numpy arrays and datasets) in order to determine if the user has
# specified sample_weights.
_update_sample_weight_mode(model, mode, ins)
# Get step function and loop type. As part of building the execution
# function we recompile the metrics based on the updated
# sample_weight_mode value.
f = _make_execution_function(model, mode)
# Prepare validation data. Hold references to the iterator and the input list
# to properly reinitialize and reuse in multiple validation passes.
val_iterator = None
if isinstance(val_inputs, (dataset_ops.DatasetV1, dataset_ops.DatasetV2)):
if validation_steps is None:
# Because we pass an iterator feed instead of a Dataset to the eval
# model_iteration() call, it will not trigger the dataset-input path
# that determines the number of steps required. To avoid this issue,
# set validation_steps here if validation_steps is None.
validation_steps = training_utils.infer_steps_for_dataset(
model,
val_inputs,
validation_steps,
epochs=epochs,
steps_name='validation_steps')
val_iterator = _get_iterator(val_inputs, model._distribution_strategy)
val_inputs = _prepare_feed_values(model, val_iterator, val_targets,
val_sample_weights, ModeKeys.TEST)
# Get num steps for printing.
val_samples_or_steps = validation_steps
else:
# Get num samples for printing.
val_samples_or_steps = val_inputs and nest.flatten(
val_inputs)[0].shape[0] or None
if mode == ModeKeys.TRAIN and verbose:
_print_train_info(num_samples_or_steps, val_samples_or_steps,
is_dataset)
# Configure callbacks.
count_mode = 'steps' if use_steps else 'samples'
callbacks = cbks.configure_callbacks(
callbacks,
model,
do_validation=do_validation,
batch_size=batch_size,
epochs=epochs,
steps_per_epoch=steps_per_epoch,
samples=num_samples_or_steps,
verbose=0, # Handle ProgBarLogger separately in this loop.
mode=mode)
# TODO(omalleyt): Handle ProgBar as part of Callbacks once hooks are ready.
progbar = training_utils.get_progbar(model, count_mode,
mode != ModeKeys.PREDICT)
progbar.params = callbacks.params
progbar.params['verbose'] = verbose
# Find beforehand arrays that need sparse-to-dense conversion.
if issparse is not None and not use_steps:
indices_for_conversion_to_dense = []
feed = _get_model_feed(model, mode)
for i, (input_data, feed_tensor) in enumerate(zip(ins, feed)):
if issparse(input_data) and not K.is_sparse(feed_tensor):
indices_for_conversion_to_dense.append(i)
# Select aggregation method.
if mode == ModeKeys.PREDICT:
aggregator = training_utils.OutputsAggregator(
use_steps,
num_samples=None if steps_per_epoch else num_samples_or_steps,
steps=steps_per_epoch)
else:
aggregator = training_utils.MetricsAggregator(
use_steps,
num_samples=None if steps_per_epoch else num_samples_or_steps,
steps=steps_per_epoch)
if model._compile_distribution:
distributed_training_utils._copy_weights_to_distributed_model(
model, mode)
callbacks.model.stop_training = False
callbacks._call_begin_hook(mode)
progbar.on_train_begin()
initial_epoch = model._maybe_load_initial_epoch_from_ckpt(
initial_epoch, mode)
for epoch in range(initial_epoch, epochs):
if callbacks.model.stop_training:
break
# Setup work for each epoch
epoch_logs = {}
if mode != ModeKeys.PREDICT:
# Collecting and resetting metrics has non-zero cost and will needlessly
# slow down model.predict.
model.reset_metrics()
if mode == ModeKeys.TRAIN:
callbacks.on_epoch_begin(epoch, epoch_logs)
progbar.on_epoch_begin(epoch, epoch_logs)
if use_steps:
# Step-wise loop.
if steps_per_epoch is None:
# Loop over dataset until `OutOfRangeError` is raised.
target_steps = np.inf
else:
# Loop over dataset for the specified number of steps.
target_steps = steps_per_epoch
step = 0
while step < target_steps:
batch_logs = {'batch': step, 'size': 1}
callbacks._call_batch_hook(mode, 'begin', step, batch_logs)
progbar.on_batch_begin(step, batch_logs)
# Get outputs.
try:
# `ins` can be callable in tf.distribute.Strategy + eager case.
if not callable(ins) or (
model._distribution_strategy
and not distributed_training_utils.
is_distributing_by_cloning(model)):
actual_inputs = ins
else:
actual_inputs = ins()
batch_outs = f(actual_inputs)
except errors.OutOfRangeError:
if is_dataset:
# The dataset passed by the user ran out of batches.
# Now we know the cardinality of the dataset.
# If steps_per_epoch was specified, then running out of data is
# unexpected, so we stop training and inform the user.
if steps_per_epoch:
callbacks.model.stop_training = True
logging.warning(
'Your dataset ran out of data; interrupting training. '
'Make sure that your dataset can generate at least '
'`%s * epochs` batches (in this case, %d batches). '
'You may need to use the repeat() function when '
'building your dataset.' %
(steps_name, steps_per_epoch * epochs))
elif step > 0:
steps_per_epoch = step
aggregator.steps = steps_per_epoch
if mode == ModeKeys.TRAIN:
progbar.params['steps'] = steps_per_epoch
progbar.progbar.target = steps_per_epoch
else:
# We ran out of batches while the user passed an iterator (legacy).
callbacks.model.stop_training = True
logging.warning(
'Your dataset iterator ran out of data; '
'interrupting training. Make sure that your iterator '
'can generate at least `%s * epochs` '
'batches (in this case, %d batches). You may need to'
'use the repeat() function when building your '
'dataset.' %
(steps_name, steps_per_epoch * epochs))
break
if not isinstance(batch_outs, list):
batch_outs = [batch_outs]
if model._distribution_strategy:
batch_outs = distributed_training_utils._per_replica_aggregate_batch(
model._distribution_strategy, batch_outs, model, mode)
# Aggregate results.
if step == 0:
aggregator.create(batch_outs)
aggregator.aggregate(batch_outs)
# Callbacks batch end.
batch_logs = cbks.make_logs(model, batch_logs, batch_outs,
mode)
callbacks._call_batch_hook(mode, 'end', step, batch_logs)
progbar.on_batch_end(step, batch_logs)
step += 1
if callbacks.model.stop_training:
break
else:
# Sample-wise loop.
index_array = np.arange(num_samples_or_steps)
if shuffle == 'batch':
index_array = training_utils.batch_shuffle(
index_array, batch_size)
elif shuffle:
np.random.shuffle(index_array)
batches = make_batches(num_samples_or_steps, batch_size)
for batch_index, (batch_start, batch_end) in enumerate(batches):
batch_ids = index_array[batch_start:batch_end]
# Slice into a batch.
if len(batches) == 1:
# If we only have one batch, do not slice. This takes care of
# composite tensors in non-Dataset modes; we currently don't support
# slicing them.
# TODO(b/133517906): Add slicing support.
ins_batch = ins
else:
try:
if ins and isinstance(ins[-1], int):
# Do not slice the training phase flag.
ins_batch = slice_arrays(ins[:-1],
batch_ids) + [ins[-1]]
else:
ins_batch = slice_arrays(ins, batch_ids)
except TypeError:
raise TypeError('TypeError while preparing batch. '
'If using HDF5 input data, '
'pass shuffle="batch".')
# Sparse to dense conversion.
if issparse is not None:
for i in indices_for_conversion_to_dense:
ins_batch[i] = ins_batch[i].toarray()
# Callbacks batch_begin.
batch_logs = {'batch': batch_index, 'size': len(batch_ids)}
callbacks._call_batch_hook(mode, 'begin', batch_index,
batch_logs)
progbar.on_batch_begin(batch_index, batch_logs)
# Get outputs.
batch_outs = f(ins_batch)
if not isinstance(batch_outs, list):
batch_outs = [batch_outs]
# Aggregate results.
if batch_index == 0:
aggregator.create(batch_outs)
aggregator.aggregate(batch_outs, batch_start, batch_end)
# Callbacks batch end.
batch_logs = cbks.make_logs(model, batch_logs, batch_outs,
mode)
callbacks._call_batch_hook(mode, 'end', batch_index,
batch_logs)
progbar.on_batch_end(batch_index, batch_logs)
if callbacks.model.stop_training:
break
aggregator.finalize()
results = aggregator.results
epoch_logs = cbks.make_logs(model, epoch_logs, results, mode)
if len(results) == 1:
results = results[0]
# Run the test loop every `validation_freq` epochs during training.
if (do_validation and training_utils.should_run_validation(
validation_freq, epoch) and not callbacks.model.stop_training):
if model._compile_distribution:
# Since we create a new clone from the original model we need to copy
# the weights back to the original model before we can run validation.
distributed_training_utils._copy_weights_to_original_model(
model, ModeKeys.TRAIN)
val_results = model_iteration(
model,
val_inputs,
targets=val_targets,
sample_weights=val_sample_weights,
batch_size=batch_size,
steps_per_epoch=validation_steps,
callbacks=callbacks,
verbose=0,
mode=ModeKeys.TEST,
validation_in_fit=True,
prepared_feed_values_from_dataset=(val_iterator is not None),
steps_name='validation_steps')
if not isinstance(val_results, list):
val_results = [val_results]
epoch_logs = cbks.make_logs(model,
epoch_logs,
val_results,
mode,
prefix='val_')
if val_iterator and epoch < epochs - 1:
_reinitialize_iterator(val_iterator,
model._distribution_strategy)
if mode == ModeKeys.TRAIN:
# Epochs only apply to `fit`.
callbacks.on_epoch_end(epoch, epoch_logs)
progbar.on_epoch_end(epoch, epoch_logs)
# Reinitialize dataset iterator for the next epoch.
if reset_dataset_after_each_epoch and epoch < epochs - 1:
_reinitialize_iterator(input_iterator,
model._distribution_strategy)
callbacks._call_end_hook(mode)
if model._distribution_strategy:
if model._compile_distribution:
# TODO(priyag, psv): Copy back metrics to the original model as well?
distributed_training_utils._copy_weights_to_original_model(
model, mode)
scope.__exit__(None, None, None)
if mode == ModeKeys.TRAIN:
return model.history
return results
def run_one_epoch(model,
iterator,
execution_function,
dataset_size=None,
batch_size=None,
strategy=None,
steps_per_epoch=None,
num_samples=None,
mode=ModeKeys.TRAIN,
training_context=None,
total_epochs=None):
"""Run the execution function with the data from iterator.
Given the dataset iterator and execution function, get the data from iterator
and call it with the execution function to get the result (metric/loss).
It will run for steps_per_epoch or until to the iterator is fully consumed.
Args:
model: The keras model to run.
iterator: the dataset iterator to fetch the data.
execution_function: a tf.function that can be called with data.
dataset_size: the size of iterator, None when unknown.
batch_size: The size of the current batch.
strategy: the distribution strategy instance from the model.
steps_per_epoch: the number of steps to run for the epoch.
num_samples: the number of samples for the whole epoch if known. This can be
used to calculate the final partial batch, and scale the loss.
mode: the mode for the current epoch.
training_context: the context that contains callbacks and progress bar.
total_epochs: the total number of epochs that will be run.
Used when throw error when the iterator unexpectedly
reaches its end.
Returns:
The loss and metric value from the model.
"""
# Only use the sample to count if there is a partial batch at the end.
use_steps = num_samples is None
if mode == ModeKeys.PREDICT:
aggregator = training_utils.OutputsAggregator(
use_steps=use_steps,
steps=steps_per_epoch,
num_samples=num_samples,
batch_size=batch_size)
else:
aggregator = training_utils.MetricsAggregator(
use_steps=use_steps, steps=steps_per_epoch, num_samples=num_samples)
callbacks = training_context.callbacks
progbar = training_context.progbar
if callbacks.model.stop_training:
return
target_steps = steps_per_epoch or np.inf
step = 0
while step < target_steps:
if use_steps:
current_batch_size = 1
elif step < target_steps - 1:
current_batch_size = batch_size
else:
current_batch_size = num_samples - step * batch_size
with training_context.on_batch(
step=step, mode=mode, size=current_batch_size) as batch_logs:
try:
batch_outs = execution_function(iterator)
except (StopIteration, errors.OutOfRangeError):
# TODO(kaftan): File bug about tf function and errors.OutOfRangeError?
# Are there any other C++ errors tf function should recapture?
# The only acceptable case here is that the input has a unknown
# length, and configured to fully consume it.
if (dataset_size is None
and steps_per_epoch is None
and step > 0):
# The input passed by the user ran out of batches.
# Now we know the cardinality of the input(dataset or generator).
steps_per_epoch = step
aggregator.steps = steps_per_epoch
if mode == ModeKeys.TRAIN:
progbar.params['steps'] = steps_per_epoch
progbar.progbar.target = steps_per_epoch
else:
callbacks.model.stop_training = True
logging.warning(
'Your input ran out of data; interrupting training. '
'Make sure that your dataset or generator can generate at '
'least `steps_per_epoch * epochs` batches (in this case, '
'{} batches). You may need to use the repeat() function '
'when building your dataset.'.format(
total_epochs * steps_per_epoch))
# In either case, break out the loop for training batch.
# Also note the training_context that data inputs are exhausted, so all
# the post batch hooks can be skipped.
batch_logs['data_exhausted'] = True
break
if mode != ModeKeys.PREDICT:
data_batch_size = batch_outs['batch_size']
batch_outs = (batch_outs['total_loss'] + batch_outs['output_losses']
+ batch_outs['metrics'])
if current_batch_size != data_batch_size:
batch_logs['size'] = data_batch_size
current_batch_size = data_batch_size
else:
batch_outs = _aggregate_predict_results(strategy, batch_outs, model)
if step == 0:
aggregator.create(batch_outs)
if use_steps:
aggregator.aggregate(batch_outs)
else:
aggregator.aggregate(
batch_outs,
batch_start=step * batch_size,
batch_end=step * batch_size + current_batch_size)
cbks.make_logs(model, batch_logs, batch_outs, mode)
step += 1
if callbacks.model.stop_training:
break
# End of an epoch.
aggregator.finalize()
return aggregator.results
def model_iteration(model,
data,
steps_per_epoch=None,
epochs=1,
verbose=1,
callbacks=None,
validation_data=None,
validation_steps=None,
validation_freq=1,
class_weight=None,
max_queue_size=10,
workers=1,
use_multiprocessing=False,
shuffle=False,
initial_epoch=0,
mode=ModeKeys.TRAIN,
batch_size=None,
steps_name='steps',
**kwargs):
"""Loop function for arrays of data with modes TRAIN/TEST/PREDICT.
Arguments:
model: Keras Model instance.
data: Either a tuple of NumPy/Tensor inputs (i.e. `(x,)` or `(x, y)` or
`(x, y, sample_weights)`) or a generator or
`keras.utils.data_utils.Sequence` object or Eager Iterator or Dataset.
steps_per_epoch: Total number of steps (batches of samples) before
declaring one epoch finished and starting the next epoch. Ignored with
the default value of `None`.
epochs: Number of times to iterate over the data.
verbose: Verbosity mode, 0, 1 or 2.
callbacks: List of callbacks to be called during training.
validation_data: Either a tuple of NumPy/Tensor inputs (i.e. `(x,)` or
`(x, y)` or `(x, y, sample_weights)`) or a generator or
`keras.utils.data_utils.Sequence` object or Eager Iterator or Dataset.
validation_steps: Total number of steps (batches of samples) before
declaring validation finished.
validation_freq: Only relevant if validation data is provided. Integer or
`collections.Container` instance (e.g. list, tuple, etc.). If an
integer, specifies how many training epochs to run before a new
validation run is performed, e.g. `validation_freq=2` runs
validation every 2 epochs. If a Container, specifies the epochs on
which to run validation, e.g. `validation_freq=[1, 2, 10]` runs
validation at the end of the 1st, 2nd, and 10th epochs.
class_weight: Dictionary mapping class indices to a weight for the class.
max_queue_size: Integer. Maximum size for the generator queue. If
unspecified, `max_queue_size` will default to 10.
workers: Integer. Maximum number of processes to spin up when using
process-based threading. If unspecified, `workers` will default to 1. If
0, will execute the generator on the main thread.
use_multiprocessing: Boolean. If `True`, use process-based threading. If
unspecified, `use_multiprocessing` will default to `False`. Note that
because this implementation relies on multiprocessing, you should not
pass non-picklable arguments to the generator as they can't be passed
easily to children processes.
shuffle: Boolean. Whether to shuffle the order of the batches at the
beginning of each epoch. Only used with instances of `Sequence`
(`keras.utils.Sequence`). Has no effect when `steps_per_epoch` is not
`None`.
initial_epoch: Epoch at which to start training (useful for resuming a
previous training run).
mode: One of ModeKeys.TRAIN/ModeKeys.TEST/ModeKeys.PREDICT.
batch_size: Integer batch size or None if unknown. Will only be used if
`data` is in NumPy/Tensor format.
steps_name: The string name of the steps argument, either `steps`,
`validation_steps`, or `steps_per_epoch`. Only used for error message
formatting.
**kwargs: Additional arguments for backwards compatibility. `steps` is
accepted as an alias for `steps_per_epoch`.
Returns:
- In TRAIN mode: `History` object.
- In TEST mode: Evaluation metrics.
- In PREDICT mode: Outputs of the Model called on inputs.
Raises:
ValueError: in case of invalid arguments.
"""
if 'steps' in kwargs:
steps_per_epoch = kwargs['steps']
# Determine the number of steps per epoch and whether we should reset the
# dataset at the end of each epoch.
reset_dataset_after_each_epoch = False
original_dataset = None
is_dataset = isinstance(data,
(dataset_ops.DatasetV2, dataset_ops.DatasetV1))
if is_dataset:
original_dataset = data
if steps_per_epoch is None:
reset_dataset_after_each_epoch = True
steps_per_epoch = training_utils.infer_steps_for_dataset(
data, steps_per_epoch, epochs=epochs, steps_name=steps_name)
# Convert to a format that supports `next(generator)`.
generator, steps_per_epoch = convert_to_generator_like(
data,
steps_per_epoch=steps_per_epoch,
batch_size=batch_size,
epochs=epochs - initial_epoch,
shuffle=shuffle)
do_validation = validation_data is not None
is_sequence = isinstance(generator, data_utils.Sequence)
_validate_arguments(is_sequence, is_dataset, use_multiprocessing, workers,
steps_per_epoch, validation_data, validation_steps,
mode, kwargs)
batch_function = _make_execution_function(model,
mode,
class_weight=class_weight)
# Create the queue for the generator.
enqueuer = None
if not is_dataset:
generator, enqueuer = _make_enqueued_generator(
generator,
workers=workers,
use_multiprocessing=use_multiprocessing,
max_queue_size=max_queue_size,
shuffle=shuffle)
num_samples_or_steps, use_steps = _get_num_samples_or_steps(
data, steps_per_epoch)
count_mode = 'steps' if use_steps else 'samples'
callbacks = cbks.configure_callbacks(
callbacks,
model,
do_validation=do_validation,
epochs=epochs,
steps_per_epoch=steps_per_epoch,
batch_size=batch_size,
samples=num_samples_or_steps,
verbose=0, # Handle ProgBar as part of Callbacks once hooks are ready.
mode=mode)
# TODO(omalleyt): Handle ProgBar as part of Callbacks once hooks are ready.
progbar = training_utils.get_progbar(model, count_mode)
progbar.params = callbacks.params
progbar.params['verbose'] = verbose
if mode == ModeKeys.PREDICT:
aggregator = training_utils.OutputsAggregator(True, steps_per_epoch)
else:
aggregator = training_utils.MetricsAggregator(True, steps_per_epoch)
should_set_learning_phase = context.executing_eagerly(
) and model.run_eagerly
if should_set_learning_phase:
old_learning_phase = backend.learning_phase()
backend.set_eager_learning_phase(1 if mode == ModeKeys.TRAIN else 0)
callbacks.model.stop_training = False
callbacks._call_begin_hook(mode)
progbar.on_train_begin()
for epoch in range(initial_epoch, epochs):
if callbacks.model.stop_training:
break
# Setup work for each epoch.
model.reset_metrics()
epoch_logs = {}
if mode == ModeKeys.TRAIN:
callbacks.on_epoch_begin(epoch, epoch_logs)
progbar.on_epoch_begin(epoch, epoch_logs)
if steps_per_epoch is None:
# Loop over dataset until `OutOfRangeError` is raised.
target_steps = np.inf
else:
# Loop over dataset for the specified number of steps.
target_steps = steps_per_epoch
step = 0
while step < target_steps:
batch_data = _get_next_batch(generator, mode)
if batch_data is None:
if is_dataset:
# The dataset passed by the user ran out of batches.
# Now we know the cardinality of the dataset.
# If steps_per_epoch was specified, then running out of data is
# unexpected, so we stop training and inform the user.
if steps_per_epoch:
callbacks.model.stop_training = True
logging.warning(
'Your dataset ran out of data; interrupting training. '
'Make sure that your dataset can generate at least '
'`%s * epochs` batches (in this case, %d batches). '
'You may need to use the repeat() function when '
'building your dataset.' %
(steps_name, steps_per_epoch * epochs))
elif step > 0:
steps_per_epoch = step
aggregator.num_samples_or_steps = steps_per_epoch
if mode == ModeKeys.TRAIN:
progbar.params['steps'] = steps_per_epoch
progbar.progbar.target = steps_per_epoch
else:
# We ran out of batches while the user passed an iterator (legacy).
callbacks.model.stop_training = True
logging.warning(
'Your dataset iterator ran out of data; '
'interrupting training. Make sure that your iterator '
'can generate at least `%s * epochs` '
'batches (in this case, %d batches). You may need to'
'use the repeat() function when building your '
'dataset.' % (steps_name, steps_per_epoch * epochs))
break
