def test_loop(model, inputs, targets,
sample_weights=None,
batch_size=None,
verbose=0,
steps=None):
"""Test function for eager execution.
Arguments:
model: Model instance that is being evaluated in Eager mode.
inputs: List of input arrays.
targets: List of target arrays.
sample_weights: Optional list of sample weight arrays.
batch_size: integer batch size or `None`.
verbose: verbosity mode.
steps: Total number of steps (batches of samples)
before declaring predictions finished.
Ignored with the default value of `None`.
Returns:
Scalar loss (if the model has a single output and no metrics)
or list of scalars (if the model has multiple outputs
and/or metrics). The attribute `model.metrics_names` will give you
the display labels for the scalar outputs.
"""
inputs, steps = training_utils.convert_to_iterator(
x=inputs,
y=targets,
sample_weights=sample_weights,
batch_size=batch_size,
steps_per_epoch=steps,
is_validation=True)
with backend.learning_phase_scope(0):
return iterator_test_loop(model, inputs, steps, verbose=verbose)
def predict_loop(model, inputs,
batch_size=32,
verbose=0,
steps=None):
"""Predict function for eager execution.
Arguments:
model: Instance of `Model`.
inputs: List of input arrays.
batch_size: integer batch size.
verbose: verbosity mode.
steps: Total number of steps (batches of samples)
before declaring `_predict_loop` finished.
Ignored with the default value of `None`.
Returns:
Array of predictions (if the model has a single output)
or list of arrays of predictions
(if the model has multiple outputs).
"""
with backend.learning_phase_scope(0):
if steps is not None:
return iterator_predict_loop(model, inputs, steps, verbose=verbose)
else:
return batch_predict_loop(
model, inputs, batch_size=batch_size, verbose=verbose)
def save(model, filepath, overwrite, include_optimizer, signatures=None):
"""Saves a model as a SavedModel to the filepath.
Args:
model: Keras model instance to be saved.
filepath: String path to save the model.
overwrite: whether to overwrite the existing filepath.
include_optimizer: If True, save the model's optimizer state.
signatures: Signatures to save with the SavedModel. Applicable to the 'tf'
format only. Please see the `signatures` argument in `tf.saved_model.save`
for details.
Raises:
ValueError: if the model's inputs have not been defined.
"""
# If file exists and should not be overwritten.
if not overwrite and os.path.exists(filepath):
proceed = ask_to_proceed_with_overwrite(filepath)
if not proceed:
return
if _should_skip_serialization(model):
saving_utils.raise_model_input_error(model)
if not include_optimizer:
orig_optimizer = model.optimizer
model.optimizer = None
# Trace all functions and signatures with `training=0` instead of using the
# default learning phase placeholder.
with K.learning_phase_scope(0):
save_lib.save(model, filepath, signatures)
if not include_optimizer:
model.optimizer = orig_optimizer
def predict_loop(model, inputs, batch_size=32, verbose=0, steps=None):
"""Predict function for eager execution.
Arguments:
model: Instance of `Model`.
inputs: List of input arrays.
batch_size: integer batch size.
verbose: verbosity mode.
steps: Total number of steps (batches of samples)
before declaring `_predict_loop` finished.
Ignored with the default value of `None`.
Returns:
Array of predictions (if the model has a single output)
or list of arrays of predictions
(if the model has multiple outputs).
"""
with backend.learning_phase_scope(0):
if steps is not None:
return iterator_predict_loop(model, inputs, steps, verbose=verbose)
else:
return batch_predict_loop(model,
inputs,
batch_size=batch_size,
verbose=verbose)
def test_loop(model,
inputs,
targets,
sample_weights=None,
batch_size=None,
verbose=0,
steps=None):
"""Test function for eager execution.
Arguments:
model: Model instance that is being evaluated in Eager mode.
inputs: List of input arrays.
targets: List of target arrays.
sample_weights: Optional list of sample weight arrays.
batch_size: integer batch size or `None`.
verbose: verbosity mode.
steps: Total number of steps (batches of samples)
before declaring predictions finished.
Ignored with the default value of `None`.
Returns:
Scalar loss (if the model has a single output and no metrics)
or list of scalars (if the model has multiple outputs
and/or metrics). The attribute `model.metrics_names` will give you
the display labels for the scalar outputs.
"""
inputs, steps = training_utils.convert_to_iterator(
x=inputs,
y=targets,
sample_weights=sample_weights,
batch_size=batch_size,
steps_per_epoch=steps,
is_validation=True)
with backend.learning_phase_scope(0):
return iterator_test_loop(model, inputs, steps, verbose=verbose)
def _process_single_batch(model,
inputs,
targets,
output_loss_metrics=None,
sample_weights=None,
training=False):
"""Calculate the loss and gradient for one input batch.
The model weights are updated if training is set to True.
Arguments:
model: Model whose loss has to be calculated.
inputs: List of input arrays.
targets: List of target arrays.
output_loss_metrics: List of metrics that are used to aggregated output
loss values.
sample_weights: Optional list of sample weight arrays.
training: The boolean represents if the weights of the model are updated.
'fit' methods will set this to True while 'evaluate' methods will
set this to False.
Returns:
output of the model, total loss, the loss and the mask
associated with each output.
Raises:
ValueError: If the model has no loss to optimize.
"""
with backend.learning_phase_scope(1 if training else 0):
with GradientTape() as tape:
outs, loss, loss_metrics, aggregated_loss_metrics, masks\
= _model_loss(
model,
inputs,
targets,
output_loss_metrics=output_loss_metrics,
sample_weights=sample_weights,
training=training)
if loss is None:
raise ValueError('The model cannot be run '
'because it has no loss to optimize.')
if training:
if not model._collected_trainable_weights:
logging.warning(
'The list of trainable weights is empty. Make sure that'
' you are not setting model.trainable to False before '
'compiling the model.')
else:
grads = tape.gradient(loss, model._collected_trainable_weights)
model.optimizer.apply_gradients(
zip(grads, model._collected_trainable_weights))
return outs, loss, loss_metrics, aggregated_loss_metrics, masks
def _process_single_batch(model,
inputs,
targets,
output_loss_metrics=None,
sample_weights=None,
training=False):
"""Calculate the loss and gradient for one input batch.
The model weights are updated if training is set to True.
Arguments:
model: Model whose loss has to be calculated.
inputs: List of input arrays.
targets: List of target arrays.
output_loss_metrics: List of metrics that are used to aggregated output
loss values.
sample_weights: Optional list of sample weight arrays.
training: The boolean represents if the weights of the model are updated.
'fit' methods will set this to True while 'evaluate' methods will
set this to False.
Returns:
output of the model, total loss, the loss and the mask
associated with each output.
Raises:
ValueError: If the model has no loss to optimize.
"""
with backend.learning_phase_scope(1 if training else 0):
with GradientTape() as tape:
outs, loss, loss_metrics, aggregated_loss_metrics, masks\
= _model_loss(
model,
inputs,
targets,
output_loss_metrics=output_loss_metrics,
sample_weights=sample_weights,
training=training)
if loss is None:
raise ValueError('The model cannot be run '
'because it has no loss to optimize.')
if training:
if not model._collected_trainable_weights:
logging.warning('The list of trainable weights is empty. Make sure that'
' you are not setting model.trainable to False before '
'compiling the model.')
else:
grads = tape.gradient(loss, model._collected_trainable_weights)
model.optimizer.apply_gradients(zip(grads,
model._collected_trainable_weights))
return outs, loss, loss_metrics, aggregated_loss_metrics, masks
def save(model,
filepath,
overwrite,
include_optimizer,
signatures=None,
options=None):
"""Saves a model as a SavedModel to the filepath.
Args:
model: Keras model instance to be saved.
filepath: String path to save the model.
overwrite: whether to overwrite the existing filepath.
include_optimizer: If True, save the model's optimizer state.
signatures: Signatures to save with the SavedModel. Applicable to the 'tf'
format only. Please see the `signatures` argument in `tf.saved_model.save`
for details.
options: Optional`tf.saved_model.SaveOptions` object that specifies
options for saving to SavedModel.
Raises:
ValueError: if the model's inputs have not been defined.
"""
# If file exists and should not be overwritten.
if not overwrite and os.path.exists(filepath):
proceed = ask_to_proceed_with_overwrite(filepath)
if not proceed:
return
if save_impl.should_skip_serialization(model):
saving_utils.raise_model_input_error(model)
if not include_optimizer:
orig_optimizer = model.optimizer
model.optimizer = None
# Trace all functions and signatures with `training=0` instead of using the
# default learning phase placeholder.
with K.learning_phase_scope(0):
# When saving a model involving batch norm layer within a strategy scope,
# the replica context is not available when calling `add_update()`, and thus
# we use the default replica context here.
with distribution_strategy_context._get_default_replica_context(): # pylint: disable=protected-access
save_lib.save(model, filepath, signatures, options)
if not include_optimizer:
model.optimizer = orig_optimizer
def fit_loop(model,
inputs,
targets,
sample_weights=None,
class_weight=None,
val_inputs=None,
val_targets=None,
val_sample_weights=None,
batch_size=None,
epochs=1,
verbose=1,
callbacks=None,
shuffle=True,
initial_epoch=0,
steps_per_epoch=None,
validation_steps=None):
"""Fit function for eager execution.
Arguments:
model: Instance of the model that is being executed in Eager mode.
inputs: List of input arrays.
targets: List of target arrays.
sample_weights: Optional list of sample weight arrays.
class_weight: Optional class-weight array to weight the importance of
samples in `inputs` based on the class they belong to, as conveyed by
`targets`.
val_inputs: Input data for validation.
val_targets: Target data for validation.
val_sample_weights: Sample weight data for validation.
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
shuffle: Whether to shuffle the data at the beginning of each epoch
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 default value of `None`.
Returns:
`History` object.
Raises:
ValueError: In case of invalid argument values.
"""
# Convert training inputs to an EagerIterator
inputs, steps_per_epoch = training_utils.convert_to_iterator(
x=inputs,
y=targets,
sample_weights=sample_weights,
batch_size=batch_size,
steps_per_epoch=steps_per_epoch,
epochs=epochs,
shuffle=shuffle)
# Required for eager execution
with backend.learning_phase_scope(1):
do_validation = val_inputs is not None
callbacks = cbks.configure_callbacks(
callbacks,
model,
do_validation=do_validation,
batch_size=batch_size,
epochs=epochs,
steps_per_epoch=steps_per_epoch,
val_inputs=val_inputs,
val_targets=val_targets,
val_sample_weights=val_sample_weights,
validation_steps=validation_steps,
verbose=verbose)
# Create metric wrapper for the losses.
output_loss_metrics = []
for i in range(len(model.outputs)):
loss_fn = model.loss_functions[i]
loss_name = loss_fn.name if isinstance(
loss_fn, losses_module.Loss) else loss_fn.__name__
mean_wrapped_loss = metrics_module.MeanMetricWrapper(
loss_fn, name=loss_name)
output_loss_metrics.append(mean_wrapped_loss)
callbacks.on_train_begin()
for epoch in range(initial_epoch, epochs):
if model._is_compiled: # Model may not be compiled the first time.
# Reset stateful metrics
for m in model.metrics:
m.reset_states()
for m in output_loss_metrics:
m.reset_states()
callbacks.on_epoch_begin(epoch)
epoch_logs = {}
iterator_fit_loop(model,
inputs,
class_weight,
steps_per_epoch=steps_per_epoch,
epoch_logs=epoch_logs,
val_inputs=val_inputs,
val_targets=val_targets,
val_sample_weights=val_sample_weights,
epochs=epochs,
verbose=verbose,
callbacks=callbacks,
validation_steps=validation_steps,
do_validation=do_validation,
batch_size=batch_size,
output_loss_metrics=output_loss_metrics)
callbacks.on_epoch_end(epoch, epoch_logs)
if callbacks.model.stop_training:
break
callbacks.on_train_end()
return model.history
def distributed_scope(strategy, learning_phase):
with strategy.scope(), backend.learning_phase_scope(learning_phase):
yield
def fit_loop(model,
inputs,
targets,
sample_weights=None,
class_weight=None,
val_inputs=None,
val_targets=None,
val_sample_weights=None,
batch_size=None,
epochs=1,
verbose=1,
callbacks=None,
shuffle=True,
initial_epoch=0,
steps_per_epoch=None,
validation_steps=None):
"""Fit function for eager execution.
Arguments:
model: Instance of the model that is being executed in Eager mode.
inputs: List of input arrays.
targets: List of target arrays.
sample_weights: Optional list of sample weight arrays.
class_weight: Optional class-weight array to weight the importance of
samples in `inputs` based on the class they belong to, as conveyed by
`targets`.
val_inputs: Input data for validation.
val_targets: Target data for validation.
val_sample_weights: Sample weight data for validation.
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
shuffle: Whether to shuffle the data at the beginning of each epoch
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 default value of `None`.
Returns:
`History` object.
Raises:
ValueError: In case of invalid argument values.
"""
# Convert training inputs to an EagerIterator
inputs, steps_per_epoch = training_utils.convert_to_iterator(
x=inputs,
y=targets,
sample_weights=sample_weights,
batch_size=batch_size,
steps_per_epoch=steps_per_epoch,
epochs=epochs,
shuffle=shuffle)
# Required for eager execution
with backend.learning_phase_scope(1):
do_validation = val_inputs is not None
callbacks = cbks.configure_callbacks(
callbacks,
model,
do_validation=do_validation,
batch_size=batch_size,
epochs=epochs,
steps_per_epoch=steps_per_epoch,
val_inputs=val_inputs,
val_targets=val_targets,
val_sample_weights=val_sample_weights,
validation_steps=validation_steps,
verbose=verbose)
callbacks.on_train_begin()
for epoch in range(initial_epoch, epochs):
if model._is_compiled: # Model may not be compiled the first time.
# Reset stateful metrics
for m in model.stateful_metric_functions:
m.reset_states()
callbacks.on_epoch_begin(epoch)
epoch_logs = {}
iterator_fit_loop(
model,
inputs,
class_weight,
steps_per_epoch=steps_per_epoch,
epoch_logs=epoch_logs,
val_inputs=val_inputs,
val_targets=val_targets,
val_sample_weights=val_sample_weights,
epochs=epochs,
verbose=verbose,
callbacks=callbacks,
validation_steps=validation_steps,
do_validation=do_validation,
batch_size=batch_size)
callbacks.on_epoch_end(epoch, epoch_logs)
if callbacks.model.stop_training:
break
callbacks.on_train_end()
return model.history
def _export_mode(
mode, has_saved_vars, builder, model, custom_objects, checkpoint_path,
input_signature):
"""Exports a model, and optionally saves new vars from the clone model.
Args:
mode: A `tf.estimator.ModeKeys` string.
has_saved_vars: A `boolean` indicating whether the SavedModel has already
exported variables.
builder: A `SavedModelBuilder` object.
model: A `tf.keras.Model` object.
custom_objects: A dictionary mapping string names to custom classes
or functions.
checkpoint_path: String path to checkpoint.
input_signature: Nested TensorSpec containing the expected inputs. Can be
`None`, in which case the signature will be inferred from the model.
Raises:
ValueError: If the train/eval mode is being exported, but the model does
not have an optimizer.
"""
compile_clone = (mode != mode_keys.ModeKeys.PREDICT)
if compile_clone and not model.optimizer:
raise ValueError(
'Model does not have an optimizer. Cannot export mode %s' % mode)
model_graph = ops.get_default_graph()
with ops.Graph().as_default() as g, K.learning_phase_scope(
mode == mode_keys.ModeKeys.TRAIN):
if input_signature is None:
input_tensors = None
else:
input_tensors = nest.map_structure(create_placeholder, input_signature)
# Clone the model into blank graph. This will create placeholders for inputs
# and targets.
clone = models_lib.clone_and_build_model(
model, input_tensors=input_tensors, custom_objects=custom_objects,
compile_clone=compile_clone)
# Make sure that iterations variable is added to the global step collection,
# to ensure that, when the SavedModel graph is loaded, the iterations
# variable is returned by `tf.compat.v1.train.get_global_step()`. This is
# required for compatibility with the SavedModelEstimator.
if compile_clone:
g.add_to_collection(ops.GraphKeys.GLOBAL_STEP, clone.optimizer.iterations)
# Extract update and train ops from train/test/predict functions.
train_op = None
if mode == mode_keys.ModeKeys.TRAIN:
clone._make_train_function() # pylint: disable=protected-access
train_op = clone.train_function.updates_op
elif mode == mode_keys.ModeKeys.TEST:
clone._make_test_function() # pylint: disable=protected-access
else:
clone._make_predict_function() # pylint: disable=protected-access
g.get_collection_ref(ops.GraphKeys.UPDATE_OPS).extend(clone.state_updates)
with session.Session().as_default():
clone_var_list = _get_var_list(clone)
if has_saved_vars:
# Confirm all variables in the clone have an entry in the checkpoint.
status = clone.load_weights(checkpoint_path)
status.assert_existing_objects_matched()
else:
# Confirm that variables between the clone and model match up exactly,
# not counting optimizer objects. Optimizer objects are ignored because
# if the model has not trained, the slot variables will not have been
# created yet.
# TODO(b/113179535): Replace with trackable equivalence.
_assert_same_non_optimizer_objects(model, model_graph, clone, g)
# TODO(b/113178242): Use value transfer for trackable objects.
clone.load_weights(checkpoint_path)
# Add graph and variables to SavedModel.
# TODO(b/113134168): Switch to add_meta_graph_and_variables.
clone.save_weights(checkpoint_path, save_format='tf', overwrite=True)
builder._has_saved_variables = True # pylint: disable=protected-access
# Add graph to the SavedModel builder.
builder.add_meta_graph(
model_utils.EXPORT_TAG_MAP[mode],
signature_def_map=_create_signature_def_map(clone, mode),
saver=saver_lib.Saver(
clone_var_list,
# Allow saving Models with no variables. This is somewhat odd, but
# it's not necessarily a bug.
allow_empty=True),
init_op=variables.local_variables_initializer(),
train_op=train_op)
return None
def _export_mode(
mode, has_saved_vars, builder, model, custom_objects, checkpoint_path,
input_signature):
"""Exports a model, and optionally saves new vars from the clone model.
Args:
mode: A `tf.estimator.ModeKeys` string.
has_saved_vars: A `boolean` indicating whether the SavedModel has already
exported variables.
builder: A `SavedModelBuilder` object.
model: A `tf.keras.Model` object.
custom_objects: A dictionary mapping string names to custom classes
or functions.
checkpoint_path: String path to checkpoint.
input_signature: Nested TensorSpec containing the expected inputs. Can be
`None`, in which case the signature will be inferred from the model.
Raises:
ValueError: If the train/eval mode is being exported, but the model does
not have an optimizer.
"""
from tensorflow.python.keras import models as models_lib # pylint: disable=g-import-not-at-top
compile_clone = (mode != mode_keys.ModeKeys.PREDICT)
if compile_clone and not model.optimizer:
raise ValueError(
'Model does not have an optimizer. Cannot export mode %s' % mode)
model_graph = ops.get_default_graph()
with ops.Graph().as_default() as g, K.learning_phase_scope(
mode == mode_keys.ModeKeys.TRAIN):
if input_signature is None:
input_tensors = None
else:
input_tensors = nest.map_structure(create_placeholder, input_signature)
# Clone the model into blank graph. This will create placeholders for inputs
# and targets.
clone = models_lib.clone_and_build_model(
model, input_tensors=input_tensors, custom_objects=custom_objects,
compile_clone=compile_clone)
# Make sure that iterations variable is added to the global step collection,
# to ensure that, when the SavedModel graph is loaded, the iterations
# variable is returned by `tf.train.get_global_step()`. This is required for
# compatibility with the SavedModelEstimator.
if compile_clone:
g.add_to_collection(ops.GraphKeys.GLOBAL_STEP, clone.optimizer.iterations)
# Extract update and train ops from train/test/predict functions.
train_op = None
if mode == mode_keys.ModeKeys.TRAIN:
clone._make_train_function()
train_op = clone.train_function.updates_op
elif mode == mode_keys.ModeKeys.TEST:
clone._make_test_function()
else:
clone._make_predict_function()
g.get_collection_ref(ops.GraphKeys.UPDATE_OPS).extend(clone.state_updates)
with session.Session().as_default():
clone_var_list = _get_var_list(clone)
if has_saved_vars:
# Confirm all variables in the clone have an entry in the checkpoint.
status = clone.load_weights(checkpoint_path)
status.assert_existing_objects_matched()
else:
# Confirm that variables between the clone and model match up exactly,
# not counting optimizer objects. Optimizer objects are ignored because
# if the model has not trained, the slot variables will not have been
# created yet.
# TODO(b/113179535): Replace with trackable equivalence.
_assert_same_non_optimizer_objects(model, model_graph, clone, g)
# TODO(b/113178242): Use value transfer for trackable objects.
clone.load_weights(checkpoint_path)
# Add graph and variables to SavedModel.
# TODO(b/113134168): Switch to add_meta_graph_and_variables.
clone.save_weights(checkpoint_path, save_format='tf', overwrite=True)
builder._has_saved_variables = True
# Add graph to the SavedModel builder.
builder.add_meta_graph(
model_utils.EXPORT_TAG_MAP[mode],
signature_def_map=_create_signature_def_map(clone, mode),
saver=saver_lib.Saver(clone_var_list),
init_op=variables.local_variables_initializer(),
train_op=train_op)
return None
def distributed_scope(strategy, learning_phase):
with strategy.scope(), K.learning_phase_scope(learning_phase):
yield
def fit_loop(model,
inputs,
targets,
sample_weights=None,
class_weight=None,
val_inputs=None,
val_targets=None,
val_sample_weights=None,
batch_size=None,
epochs=1,
verbose=1,
callbacks=None,
shuffle=True,
callback_metrics=None,
initial_epoch=0,
steps_per_epoch=None,
validation_steps=None):
"""Fit function for eager execution.
Arguments:
model: Instance of the model that is being executed in Eager mode.
inputs: List of input arrays.
targets: List of target arrays.
sample_weights: Optional list of sample weight arrays.
class_weight: Optional class-weight array to weight the importance of
samples in `inputs` based on the class they belong to, as conveyed by
`targets`.
val_inputs: Input data for validation.
val_targets: Target data for validation.
val_sample_weights: Sample weight data for validation.
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
shuffle: Whether to shuffle the data at the beginning of each epoch
callback_metrics: List of strings, the display names of the metrics
passed to the callbacks. They should be the
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 default value of `None`.
Returns:
`History` object.
Raises:
ValueError: In case of invalid argument values.
"""
# Required for eager execution
with backend.learning_phase_scope(1):
do_validation = False
if val_inputs:
do_validation = True
if (steps_per_epoch is None and verbose and inputs and
hasattr(inputs[0], 'shape') and hasattr(val_inputs[0], 'shape')):
print('Train on %d samples, validate on %d samples' %
(inputs[0].shape[0], val_inputs[0].shape[0]))
num_train_samples = None
out_labels = None
if steps_per_epoch is None or model._is_compiled:
out_labels = model.metrics_names
if do_validation:
callback_metrics = copy.copy(out_labels) + [
'val_' + n for n in out_labels
]
else:
callback_metrics = copy.copy(out_labels)
if steps_per_epoch is None:
if sample_weights:
feed_data = inputs + targets + sample_weights
else:
feed_data = inputs + targets
num_train_samples = training_utils.check_num_samples(
feed_data,
batch_size=batch_size,
steps=steps_per_epoch,
steps_name='steps_per_epoch')
if num_train_samples is not None:
index_array = np.arange(num_train_samples)
model.history = cbks.History()
callbacks = [cbks.BaseLogger()] + (callbacks or []) + [model.history]
if verbose:
if steps_per_epoch is not None:
count_mode = 'steps'
else:
count_mode = 'samples'
callbacks += [cbks.ProgbarLogger(count_mode)]
callbacks = cbks.CallbackList(callbacks)
# it's possible to callback a different model than self
# (used by Sequential models)
if hasattr(model, 'callback_model') and model.callback_model:
callback_model = model.callback_model
else:
callback_model = model
callbacks.set_model(callback_model)
callbacks.set_params({
'batch_size': batch_size,
'epochs': epochs,
'steps': steps_per_epoch,
'samples': num_train_samples,
'verbose': verbose,
'do_validation': do_validation,
'metrics': callback_metrics or [],
})
callbacks.on_train_begin()
callback_model.stop_training = False
for cbk in callbacks:
if not val_inputs:
cbk.validation_data = []
elif isinstance(val_inputs, iterator_ops.EagerIterator):
cbk.validation_data = val_inputs
elif val_sample_weights:
cbk.validation_data = val_inputs + val_targets + val_sample_weights
else:
cbk.validation_data = val_inputs + val_targets
for epoch in range(initial_epoch, epochs):
callbacks.on_epoch_begin(epoch)
epoch_logs = {}
if steps_per_epoch is not None:
iterator_fit_loop(
model,
inputs,
class_weight,
steps_per_epoch=steps_per_epoch,
callback_model=callback_model,
out_labels=out_labels,
epoch_logs=epoch_logs,
val_inputs=val_inputs,
val_targets=val_targets,
val_sample_weights=val_sample_weights,
epochs=epochs,
verbose=verbose,
callbacks=callbacks,
callback_metrics=callback_metrics,
validation_steps=validation_steps,
do_validation=do_validation)
else:
batch_fit_loop(
model,
inputs,
targets,
epoch_logs=epoch_logs,
index_array=index_array,
out_labels=out_labels,
callback_model=callback_model,
batch_size=batch_size,
sample_weights=sample_weights,
val_inputs=val_inputs,
val_targets=val_targets,
val_sample_weights=val_sample_weights,
callbacks=callbacks,
shuffle=shuffle,
num_train_samples=num_train_samples,
do_validation=do_validation)
callbacks.on_epoch_end(epoch, epoch_logs)
if callback_model.stop_training:
break
callbacks.on_train_end()
return model.history
def trace_with_training(value, fn=fn):
utils.set_training_arg(value, self._training_arg_index,
args, kwargs)
with K.learning_phase_scope(value):
fn.get_concrete_function(*args, **kwargs)
def fit_loop(model,
inputs,
targets,
sample_weights=None,
class_weight=None,
val_inputs=None,
val_targets=None,
val_sample_weights=None,
batch_size=None,
epochs=1,
verbose=1,
callbacks=None,
shuffle=True,
callback_metrics=None,
initial_epoch=0,
steps_per_epoch=None,
validation_steps=None):
"""Fit function for eager execution.
Arguments:
model: Instance of the model that is being executed in Eager mode.
inputs: List of input arrays.
targets: List of target arrays.
sample_weights: Optional list of sample weight arrays.
class_weight: Optional class-weight array to weight the importance of
samples in `inputs` based on the class they belong to, as conveyed by
`targets`.
val_inputs: Input data for validation.
val_targets: Target data for validation.
val_sample_weights: Sample weight data for validation.
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
shuffle: Whether to shuffle the data at the beginning of each epoch
callback_metrics: List of strings, the display names of the metrics
passed to the callbacks. They should be the
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 default value of `None`.
Returns:
`History` object.
Raises:
ValueError: In case of invalid argument values.
"""
# Convert training inputs to an EagerIterator
inputs, steps_per_epoch = training_utils.convert_to_iterator(
x=inputs,
y=targets,
sample_weights=sample_weights,
batch_size=batch_size,
steps_per_epoch=steps_per_epoch,
epochs=epochs,
shuffle=shuffle)
# Required for eager execution
with backend.learning_phase_scope(1):
do_validation = False
if val_inputs:
do_validation = True
num_train_samples = None
out_labels = None
if model._is_compiled:
out_labels = model.metrics_names
if do_validation:
callback_metrics = copy.copy(out_labels) + [
'val_' + n for n in out_labels
]
else:
callback_metrics = copy.copy(out_labels)
model.history = cbks.History()
callbacks = [cbks.BaseLogger()] + (callbacks or []) + [model.history]
if verbose:
callbacks += [cbks.ProgbarLogger('steps')]
callbacks = cbks.CallbackList(callbacks)
# it's possible to callback a different model than self
# (used by Sequential models)
if hasattr(model, 'callback_model') and model.callback_model:
callback_model = model.callback_model
else:
callback_model = model
callbacks.set_model(callback_model)
callback_params = {
'batch_size': batch_size,
'epochs': epochs,
'steps': steps_per_epoch,
'samples': num_train_samples,
'verbose': verbose,
'do_validation': do_validation,
'metrics': callback_metrics or [],
}
if validation_steps:
callback_params.update({'validation_steps': validation_steps})
callbacks.set_params(callback_params)
for cbk in callbacks:
if not val_inputs:
cbk.validation_data = []
elif isinstance(val_inputs, iterator_ops.EagerIterator):
cbk.validation_data = val_inputs
elif val_sample_weights:
cbk.validation_data = val_inputs + val_targets + val_sample_weights
else:
cbk.validation_data = val_inputs + val_targets
# validation_data must be set before on_train_begin() is called
# so that TensorboardCallback can validate its input
callbacks.on_train_begin()
callback_model.stop_training = False
for epoch in range(initial_epoch, epochs):
callbacks.on_epoch_begin(epoch)
epoch_logs = {}
iterator_fit_loop(model,
inputs,
class_weight,
steps_per_epoch=steps_per_epoch,
callback_model=callback_model,
out_labels=out_labels,
epoch_logs=epoch_logs,
val_inputs=val_inputs,
val_targets=val_targets,
val_sample_weights=val_sample_weights,
epochs=epochs,
verbose=verbose,
callbacks=callbacks,
callback_metrics=callback_metrics,
validation_steps=validation_steps,
do_validation=do_validation,
batch_size=batch_size)
callbacks.on_epoch_end(epoch, epoch_logs)
if callback_model.stop_training:
break
callbacks.on_train_end()
return model.history
