def call(self, inputs, training=None, mask=None):
kwargs = {}
if has_arg(self.layer.call, 'training'):
kwargs['training'] = training
if has_arg(self.layer.call, 'mask'):
kwargs['mask'] = mask
y = self.forward_layer.call(inputs, **kwargs)
y_rev = self.backward_layer.call(inputs, **kwargs)
if self.return_sequences:
y_rev = K.reverse(y_rev, 1)
if self.merge_mode == 'concat':
output = K.concatenate([y, y_rev])
elif self.merge_mode == 'sum':
output = y + y_rev
elif self.merge_mode == 'ave':
output = (y + y_rev) / 2
elif self.merge_mode == 'mul':
output = y * y_rev
elif self.merge_mode is None:
output = [y, y_rev]
# Properly set learning phase
if (getattr(y, '_uses_learning_phase', False)
or getattr(y_rev, '_uses_learning_phase', False)):
if self.merge_mode is None:
for out in output:
out._uses_learning_phase = True
else:
output._uses_learning_phase = True
return output
def call(self, inputs, training=None, mask=None):
kwargs = {}
if has_arg(self.layer.call, 'training'):
kwargs['training'] = training
if has_arg(self.layer.call, 'mask'):
kwargs['mask'] = mask
y = self.forward_layer.call(inputs, **kwargs)
y_rev = self.backward_layer.call(inputs, **kwargs)
if self.return_sequences:
y_rev = K.reverse(y_rev, 1)
if self.merge_mode == 'concat':
output = K.concatenate([y, y_rev])
elif self.merge_mode == 'sum':
output = y + y_rev
elif self.merge_mode == 'ave':
output = (y + y_rev) / 2
elif self.merge_mode == 'mul':
output = y * y_rev
elif self.merge_mode is None:
output = [y, y_rev]
# Properly set learning phase
if 0 < self.layer.dropout + self.layer.recurrent_dropout:
if self.merge_mode is None:
for out in output:
out._uses_learning_phase = True
else:
output._uses_learning_phase = True
return output
def call(self, inputs, training=None, mask=None, initial_state=None):
kwargs = {}
if has_arg(self.layer.call, 'training'):
kwargs['training'] = training
if has_arg(self.layer.call, 'mask'):
kwargs['mask'] = mask
if initial_state is not None and has_arg(self.layer.call,
'initial_state'):
if not isinstance(initial_state, list):
raise ValueError(
'When passing `initial_state` to a Bidirectional RNN, the state '
'should be a list containing the states of the underlying RNNs. '
'Found: ' + str(initial_state))
forward_state = initial_state[:len(initial_state) // 2]
backward_state = initial_state[len(initial_state) // 2:]
y = self.forward_layer.call(inputs,
initial_state=forward_state,
**kwargs)
y_rev = self.backward_layer.call(inputs,
initial_state=backward_state,
**kwargs)
else:
y = self.forward_layer.call(inputs, **kwargs)
y_rev = self.backward_layer.call(inputs, **kwargs)
if self.return_state:
states = y[1:] + y_rev[1:]
y = y[0]
y_rev = y_rev[0]
if self.return_sequences:
y_rev = K.reverse(y_rev, 1)
if self.merge_mode == 'concat':
output = K.concatenate([y, y_rev])
elif self.merge_mode == 'sum':
output = y + y_rev
elif self.merge_mode == 'ave':
output = (y + y_rev) / 2
elif self.merge_mode == 'mul':
output = y * y_rev
elif self.merge_mode is None:
output = [y, y_rev]
# Properly set learning phase
if (getattr(y, '_uses_learning_phase', False)
or getattr(y_rev, '_uses_learning_phase', False)):
if self.merge_mode is None:
for out in output:
out._uses_learning_phase = True
else:
output._uses_learning_phase = True
if self.return_state:
if self.merge_mode is None:
return output + states
return [output] + states
return output
def call(self, inputs,
training=None,
mask=None,
initial_state=None,
constants=None):
"""`Bidirectional.call` implements the same API as the wrapped `RNN`."""
kwargs = {}
if generic_utils.has_arg(self.layer.call, 'training'):
kwargs['training'] = training
if generic_utils.has_arg(self.layer.call, 'mask'):
kwargs['mask'] = mask
if generic_utils.has_arg(self.layer.call, 'constants'):
kwargs['constants'] = constants
if initial_state is not None and generic_utils.has_arg(
self.layer.call, 'initial_state'):
forward_state = initial_state[:len(initial_state) // 2]
backward_state = initial_state[len(initial_state) // 2:]
y = self.forward_layer.call(inputs, initial_state=forward_state, **kwargs)
y_rev = self.backward_layer.call(
inputs, initial_state=backward_state, **kwargs)
else:
y = self.forward_layer.call(inputs, **kwargs)
y_rev = self.backward_layer.call(inputs, **kwargs)
if self.return_state:
states = y[1:] + y_rev[1:]
y = y[0]
y_rev = y_rev[0]
if self.return_sequences:
y_rev = K.reverse(y_rev, 1)
if self.merge_mode == 'concat':
output = K.concatenate([y, y_rev])
elif self.merge_mode == 'sum':
output = y + y_rev
elif self.merge_mode == 'ave':
output = (y + y_rev) / 2
elif self.merge_mode == 'mul':
output = y * y_rev
elif self.merge_mode is None:
output = [y, y_rev]
# Properly set learning phase
if (getattr(y, '_uses_learning_phase', False) or
getattr(y_rev, '_uses_learning_phase', False)):
if self.merge_mode is None:
for out in output:
out._uses_learning_phase = True
else:
output._uses_learning_phase = True
if self.return_state:
if self.merge_mode is None:
return output + states
return [output] + states
return output
def call(self, inputs, training=None, mask=None, initial_state=None):
kwargs = {}
if has_arg(self.layer.call, 'training'):
kwargs['training'] = training
if has_arg(self.layer.call, 'mask'):
kwargs['mask'] = mask
if initial_state is not None and has_arg(self.layer.call, 'initial_state'):
if not isinstance(initial_state, list):
raise ValueError(
'When passing `initial_state` to a Bidirectional RNN, the state '
'should be a list containing the states of the underlying RNNs. '
'Found: ' + str(initial_state))
forward_state = initial_state[:len(initial_state) // 2]
backward_state = initial_state[len(initial_state) // 2:]
y = self.forward_layer.call(inputs, initial_state=forward_state, **kwargs)
y_rev = self.backward_layer.call(
inputs, initial_state=backward_state, **kwargs)
else:
y = self.forward_layer.call(inputs, **kwargs)
y_rev = self.backward_layer.call(inputs, **kwargs)
if self.return_state:
states = y[1:] + y_rev[1:]
y = y[0]
y_rev = y_rev[0]
if self.return_sequences:
y_rev = K.reverse(y_rev, 1)
if self.merge_mode == 'concat':
output = K.concatenate([y, y_rev])
elif self.merge_mode == 'sum':
output = y + y_rev
elif self.merge_mode == 'ave':
output = (y + y_rev) / 2
elif self.merge_mode == 'mul':
output = y * y_rev
elif self.merge_mode is None:
output = [y, y_rev]
# Properly set learning phase
if (getattr(y, '_uses_learning_phase', False) or
getattr(y_rev, '_uses_learning_phase', False)):
if self.merge_mode is None:
for out in output:
out._uses_learning_phase = True
else:
output._uses_learning_phase = True
if self.return_state:
if self.merge_mode is None:
return output + states
return [output] + states
return output
def call(self, inputs, training=None, mask=None, initial_state=None):
kwargs = {}
if generic_utils.has_arg(self.layer.call, 'training'):
kwargs['training'] = training
if generic_utils.has_arg(self.layer.call, 'mask'):
kwargs['mask'] = mask
if initial_state is not None and generic_utils.has_arg(
self.layer.call, 'initial_state'):
forward_state = initial_state[:len(initial_state) // 2]
backward_state = initial_state[len(initial_state) // 2:]
y = self.forward_layer.call(inputs, initial_state=forward_state, **kwargs)
y_rev = self.backward_layer.call(
inputs, initial_state=backward_state, **kwargs)
else:
y = self.forward_layer.call(inputs, **kwargs)
y_rev = self.backward_layer.call(inputs, **kwargs)
if self.return_state:
states = y[1:] + y_rev[1:]
y = y[0]
y_rev = y_rev[0]
if self.return_sequences:
y_rev = K.reverse(y_rev, 1)
if self.merge_mode == 'concat':
output = K.concatenate([y, y_rev])
elif self.merge_mode == 'sum':
output = y + y_rev
elif self.merge_mode == 'ave':
output = (y + y_rev) / 2
elif self.merge_mode == 'mul':
output = y * y_rev
elif self.merge_mode is None:
output = [y, y_rev]
# Properly set learning phase
if (getattr(y, '_uses_learning_phase', False) or
getattr(y_rev, '_uses_learning_phase', False)):
if self.merge_mode is None:
for out in output:
out._uses_learning_phase = True
else:
output._uses_learning_phase = True
if self.return_state:
if self.merge_mode is None:
return output + states
return [output] + states
return output
def check_params(self, params):
"""Checks for user typos in `params`.
Arguments:
params: dictionary; the parameters to be checked
Raises:
ValueError: if any member of `params` is not a valid argument.
"""
legal_params_fns = [
Sequential.fit, Sequential.predict, Sequential.predict_classes,
Sequential.evaluate
]
if self.build_fn is None:
legal_params_fns.append(self.__call__)
elif (not isinstance(self.build_fn, types.FunctionType) and
not isinstance(self.build_fn, types.MethodType)):
legal_params_fns.append(self.build_fn.__call__)
else:
legal_params_fns.append(self.build_fn)
for params_name in params:
for fn in legal_params_fns:
if has_arg(fn, params_name):
break
else:
if params_name != 'nb_epoch':
raise ValueError('{} is not a legal parameter'.format(params_name))
def check_params(self, params):
"""Checks for user typos in `params`.
Arguments:
params: dictionary; the parameters to be checked
Raises:
ValueError: if any member of `params` is not a valid argument.
"""
legal_params_fns = [
Sequential.fit, Sequential.predict, Sequential.predict_classes,
Sequential.evaluate
]
if self.build_fn is None:
legal_params_fns.append(self.__call__)
elif (not isinstance(self.build_fn, types.FunctionType)
and not isinstance(self.build_fn, types.MethodType)):
legal_params_fns.append(self.build_fn.__call__)
else:
legal_params_fns.append(self.build_fn)
for params_name in params:
for fn in legal_params_fns:
if has_arg(fn, params_name):
break
else:
if params_name != 'nb_epoch':
raise ValueError(
'{} is not a legal parameter'.format(params_name))
def call(self, inputs, training=None, mask=None):
kwargs = {}
if generic_utils.has_arg(self.layer.call, 'training'):
kwargs['training'] = training
uses_learning_phase = False # pylint: disable=redefined-outer-name
input_shape = K.int_shape(inputs)
if input_shape[0]:
# batch size matters, use rnn-based implementation
def step(x, _):
global uses_learning_phase # pylint: disable=global-variable-undefined
output = self.layer.call(x, **kwargs)
if hasattr(output, '_uses_learning_phase'):
uses_learning_phase = (output._uses_learning_phase or
uses_learning_phase)
return output, []
_, outputs, _ = K.rnn(
step,
inputs,
initial_states=[],
input_length=input_shape[0],
unroll=False)
y = outputs
else:
# No batch size specified, therefore the layer will be able
# to process batches of any size.
# We can go with reshape-based implementation for performance.
input_length = input_shape[1]
if not input_length:
input_length = array_ops.shape(inputs)[1]
# Shape: (num_samples * timesteps, ...). And track the
# transformation in self._input_map.
input_uid = generic_utils.object_list_uid(inputs)
inputs = array_ops.reshape(inputs, (-1,) + input_shape[2:])
self._input_map[input_uid] = inputs
# (num_samples * timesteps, ...)
y = self.layer.call(inputs, **kwargs)
if hasattr(y, '_uses_learning_phase'):
uses_learning_phase = y._uses_learning_phase
# Shape: (num_samples, timesteps, ...)
output_shape = self.compute_output_shape(input_shape).as_list()
y = array_ops.reshape(y, (-1, input_length) + tuple(output_shape[2:]))
# Apply activity regularizer if any:
if (hasattr(self.layer, 'activity_regularizer') and
self.layer.activity_regularizer is not None):
regularization_loss = self.layer.activity_regularizer(y)
self.add_loss(regularization_loss, inputs)
if uses_learning_phase:
y._uses_learning_phase = True
return y
def call(self, inputs, training=None, mask=None):
kwargs = {}
if generic_utils.has_arg(self.layer.call, 'training'):
kwargs['training'] = training
uses_learning_phase = False # pylint: disable=redefined-outer-name
input_shape = K.int_shape(inputs)
if input_shape[0]:
# batch size matters, use rnn-based implementation
def step(x, _):
global uses_learning_phase # pylint: disable=global-variable-undefined
output = self.layer.call(x, **kwargs)
if hasattr(output, '_uses_learning_phase'):
uses_learning_phase = (output._uses_learning_phase
or uses_learning_phase)
return output, []
_, outputs, _ = K.rnn(step,
inputs,
initial_states=[],
input_length=input_shape[0],
unroll=False)
y = outputs
else:
# No batch size specified, therefore the layer will be able
# to process batches of any size.
# We can go with reshape-based implementation for performance.
input_length = input_shape[1]
if not input_length:
input_length = array_ops.shape(inputs)[1]
# Shape: (num_samples * timesteps, ...). And track the
# transformation in self._input_map.
input_uid = generic_utils.object_list_uid(inputs)
inputs = array_ops.reshape(inputs, (-1, ) + input_shape[2:])
self._input_map[input_uid] = inputs
# (num_samples * timesteps, ...)
y = self.layer.call(inputs, **kwargs)
if hasattr(y, '_uses_learning_phase'):
uses_learning_phase = y._uses_learning_phase
# Shape: (num_samples, timesteps, ...)
output_shape = self.compute_output_shape(input_shape).as_list()
y = array_ops.reshape(y,
(-1, input_length) + tuple(output_shape[2:]))
# Apply activity regularizer if any:
if (hasattr(self.layer, 'activity_regularizer')
and self.layer.activity_regularizer is not None):
regularization_loss = self.layer.activity_regularizer(y)
self.add_loss(regularization_loss, inputs)
if uses_learning_phase:
y._uses_learning_phase = True
return y
def filter_sk_params(self, fn, override=None):
"""Filters `sk_params` and returns those in `fn`'s arguments.
Arguments:
fn : arbitrary function
override: dictionary, values to override `sk_params`
Returns:
res : dictionary containing variables
in both `sk_params` and `fn`'s arguments.
"""
override = override or {}
res = {}
for name, value in self.sk_params.items():
if has_arg(fn, name):
res.update({name: value})
res.update(override)
return res
def filter_sk_params(self, fn, override=None):
"""Filters `sk_params` and returns those in `fn`'s arguments.
Arguments:
fn : arbitrary function
override: dictionary, values to override `sk_params`
Returns:
res : dictionary containing variables
in both `sk_params` and `fn`'s arguments.
"""
override = override or {}
res = {}
for name, value in self.sk_params.items():
if has_arg(fn, name):
res.update({name: value})
res.update(override)
return res
def call(self, inputs, mask=None):
arguments = self.arguments
if generic_utils.has_arg(self.function, 'mask'):
arguments['mask'] = mask
return self.function(inputs, **arguments)
def _clone_functional_model(model, input_tensors=None):
"""Clone a functional `Model` instance.
Model cloning is similar to calling a model on new inputs,
except that it creates new layers (and thus new weights) instead
of sharing the weights of the existing layers.
Arguments:
model: Instance of `Model`.
input_tensors: optional list of input tensors
to build the model upon. If not provided,
placeholders will be created.
Returns:
An instance of `Model` reproducing the behavior
of the original model, on top of new inputs tensors,
using newly instantiated weights.
Raises:
ValueError: in case of invalid `model` argument value.
"""
if not isinstance(model, Model):
raise ValueError('Expected `model` argument '
'to be a `Model` instance, got ', model)
if isinstance(model, Sequential):
raise ValueError('Expected `model` argument '
'to be a functional `Model` instance, '
'got a `Sequential` instance instead:', model)
layer_map = {} # Cache for created layers.
tensor_map = {} # Map {reference_tensor: (corresponding_tensor, mask)}
if input_tensors is None:
# Create placeholders to build the model on top of.
input_layers = []
input_tensors = []
for layer in model._input_layers:
input_tensor = Input(
batch_shape=layer._batch_input_shape,
dtype=layer.dtype,
sparse=layer.sparse,
name=layer.name)
input_tensors.append(input_tensor)
# Cache newly created input layer.
newly_created_input_layer = input_tensor._keras_history[0]
layer_map[layer] = newly_created_input_layer
for original_input_layer, cloned_input_layer in zip(model._input_layers,
input_layers):
layer_map[original_input_layer] = cloned_input_layer
else:
# Make sure that all input tensors come from a Keras layer.
# If tensor comes from an input layer: cache the input layer.
input_tensors = generic_utils.to_list(input_tensors)
input_tensors_ = []
for i, x in enumerate(input_tensors):
if not K.is_keras_tensor(x):
name = model._input_layers[i].name
input_tensor = Input(tensor=x, name='input_wrapper_for_' + name)
input_tensors_.append(input_tensor)
# Cache newly created input layer.
original_input_layer = x._keras_history[0]
newly_created_input_layer = input_tensor._keras_history[0]
layer_map[original_input_layer] = newly_created_input_layer
else:
input_tensors_.append(x)
input_tensors = input_tensors_
for x, y in zip(model.inputs, input_tensors):
tensor_map[x] = (y, None) # tensor, mask
# Iterated over every node in the reference model, in depth order.
depth_keys = list(model._nodes_by_depth.keys())
depth_keys.sort(reverse=True)
for depth in depth_keys:
nodes = model._nodes_by_depth[depth]
for node in nodes:
# Recover the corresponding layer.
layer = node.outbound_layer
# Get or create layer.
if layer not in layer_map:
# Clone layer.
new_layer = layer.__class__.from_config(layer.get_config())
layer_map[layer] = new_layer
layer = new_layer
else:
# Reuse previously cloned layer.
layer = layer_map[layer]
# Don't call InputLayer multiple times.
if isinstance(layer, InputLayer):
continue
# Gather inputs to call the new layer.
referenceinput_tensors_ = node.input_tensors
reference_output_tensors = node.output_tensors
# If all previous input tensors are available in tensor_map,
# then call node.inbound_layer on them.
computed_data = [] # List of tuples (input, mask).
for x in referenceinput_tensors_:
if x in tensor_map:
computed_data.append(tensor_map[x])
if len(computed_data) == len(referenceinput_tensors_):
# Call layer.
if node.arguments:
kwargs = node.arguments
else:
kwargs = {}
if len(computed_data) == 1:
computed_tensor, computed_mask = computed_data[0]
if has_arg(layer.call, 'mask'):
if 'mask' not in kwargs:
kwargs['mask'] = computed_mask
output_tensors = generic_utils.to_list(layer(computed_tensor,
**kwargs))
output_masks = generic_utils.to_list(
layer.compute_mask(computed_tensor, computed_mask))
computed_tensors = [computed_tensor]
computed_masks = [computed_mask]
else:
computed_tensors = [x[0] for x in computed_data]
computed_masks = [x[1] for x in computed_data]
if has_arg(layer.call, 'mask'):
if 'mask' not in kwargs:
kwargs['mask'] = computed_masks
output_tensors = generic_utils.to_list(layer(computed_tensors,
**kwargs))
output_masks = generic_utils.to_list(
layer.compute_mask(computed_tensors, computed_masks))
# Update tensor_map.
for x, y, mask in zip(reference_output_tensors, output_tensors,
output_masks):
tensor_map[x] = (y, mask)
# Check that we did compute the model outputs,
# then instantiate a new model from inputs and outputs.
output_tensors = []
for x in model.outputs:
assert x in tensor_map, 'Could not compute output ' + str(x)
tensor, _ = tensor_map[x]
output_tensors.append(tensor)
return Model(input_tensors, output_tensors, name=model.name)
def call(self,
inputs,
mask=None,
training=None,
initial_state=None,
constants=None):
# note that the .build() method of subclasses MUST define
# self.input_spec and self.state_spec with complete input shapes.
if isinstance(inputs, list):
inputs = inputs[0]
if initial_state is not None:
pass
elif self.stateful:
initial_state = self.states
else:
initial_state = self.get_initial_state(inputs)
if isinstance(mask, list):
mask = mask[0]
if len(initial_state) != len(self.states):
raise ValueError('Layer has ' + str(len(self.states)) +
' states but was passed ' +
str(len(initial_state)) + ' initial states.')
timesteps = K.int_shape(inputs)[1]
kwargs = {}
if generic_utils.has_arg(self.cell.call, 'training'):
kwargs['training'] = training
if constants:
if not generic_utils.has_arg(self.cell.call, 'constants'):
raise ValueError('RNN cell does not support constants')
def step(inputs, states):
constants = states[-self._num_constants:]
states = states[:-self._num_constants]
return self.cell.call(inputs,
states,
constants=constants,
**kwargs)
else:
def step(inputs, states):
return self.cell.call(inputs, states, **kwargs)
last_output, outputs, states = K.rnn(step,
inputs,
initial_state,
constants=constants,
go_backwards=self.go_backwards,
mask=mask,
input_length=timesteps)
if self.stateful:
updates = []
for i in range(len(states)):
updates.append(K.update(self.states[i], states[i]))
self.add_update(updates, inputs=True)
if self.return_sequences:
output = outputs
else:
output = last_output
# Properly set learning phase
if getattr(last_output, '_uses_learning_phase', False):
output._uses_learning_phase = True
if self.return_state:
if not isinstance(states, (list, tuple)):
states = [states]
else:
states = list(states)
return [output] + states
else:
return output
def call(self,
inputs,
mask=None,
training=None,
initial_state=None,
constants=None):
# note that the .build() method of subclasses MUST define
# self.input_spec and self.state_spec with complete input shapes.
if isinstance(inputs, list):
inputs = inputs[0]
if initial_state is not None:
pass
elif self.stateful:
initial_state = self.states
else:
initial_state = self.get_initial_state(inputs)
if isinstance(mask, list):
mask = mask[0]
if len(initial_state) != len(self.states):
raise ValueError('Layer has ' + str(len(self.states)) +
' states but was passed ' +
str(len(initial_state)) +
' initial states.')
timesteps = K.int_shape(inputs)[1]
kwargs = {}
if generic_utils.has_arg(self.cell.call, 'training'):
kwargs['training'] = training
if constants:
if not generic_utils.has_arg(self.cell.call, 'constants'):
raise ValueError('RNN cell does not support constants')
def step(inputs, states):
constants = states[-self._num_constants:]
states = states[:-self._num_constants]
return self.cell.call(inputs, states, constants=constants,
**kwargs)
else:
def step(inputs, states):
return self.cell.call(inputs, states, **kwargs)
last_output, outputs, states = K.rnn(step,
inputs,
initial_state,
constants=constants,
go_backwards=self.go_backwards,
mask=mask,
input_length=timesteps)
if self.stateful:
updates = []
for i in range(len(states)):
updates.append(K.update(self.states[i], states[i]))
self.add_update(updates, inputs=True)
if self.return_sequences:
output = outputs
else:
output = last_output
# Properly set learning phase
if getattr(last_output, '_uses_learning_phase', False):
output._uses_learning_phase = True
if self.return_state:
if not isinstance(states, (list, tuple)):
states = [states]
else:
states = list(states)
return [output] + states
else:
return output
def _clone_functional_model(model, input_tensors=None):
"""Clone a functional `Model` instance.
Model cloning is similar to calling a model on new inputs,
except that it creates new layers (and thus new weights) instead
of sharing the weights of the existing layers.
Arguments:
model: Instance of `Model`.
input_tensors: optional list of input tensors
to build the model upon. If not provided,
placeholders will be created.
Returns:
An instance of `Model` reproducing the behavior
of the original model, on top of new inputs tensors,
using newly instantiated weights.
Raises:
ValueError: in case of invalid `model` argument value.
"""
if not isinstance(model, Model):
raise ValueError(
'Expected `model` argument '
'to be a `Model` instance, got ', model)
if isinstance(model, Sequential):
raise ValueError(
'Expected `model` argument '
'to be a functional `Model` instance, '
'got a `Sequential` instance instead:', model)
layer_map = {} # Cache for created layers.
tensor_map = {} # Map {reference_tensor: (corresponding_tensor, mask)}
if input_tensors is None:
# Create placeholders to build the model on top of.
input_layers = []
input_tensors = []
for layer in model._input_layers:
input_tensor = Input(batch_shape=layer._batch_input_shape,
dtype=layer.dtype,
sparse=layer.sparse,
name=layer.name)
input_tensors.append(input_tensor)
# Cache newly created input layer.
newly_created_input_layer = input_tensor._keras_history[0]
layer_map[layer] = newly_created_input_layer
for original_input_layer, cloned_input_layer in zip(
model._input_layers, input_layers):
layer_map[original_input_layer] = cloned_input_layer
else:
# Make sure that all input tensors come from a Keras layer.
# If tensor comes from an input layer: cache the input layer.
input_tensors = generic_utils.to_list(input_tensors)
input_tensors_ = []
for i, x in enumerate(input_tensors):
if not K.is_keras_tensor(x):
name = model._input_layers[i].name
input_tensor = Input(tensor=x,
name='input_wrapper_for_' + name)
input_tensors_.append(input_tensor)
# Cache newly created input layer.
original_input_layer = x._keras_history[0]
newly_created_input_layer = input_tensor._keras_history[0]
layer_map[original_input_layer] = newly_created_input_layer
else:
input_tensors_.append(x)
input_tensors = input_tensors_
for x, y in zip(model.inputs, input_tensors):
tensor_map[x] = (y, None) # tensor, mask
# Iterated over every node in the reference model, in depth order.
depth_keys = list(model._nodes_by_depth.keys())
depth_keys.sort(reverse=True)
for depth in depth_keys:
nodes = model._nodes_by_depth[depth]
for node in nodes:
# Recover the corresponding layer.
layer = node.outbound_layer
# Get or create layer.
if layer not in layer_map:
# Clone layer.
new_layer = layer.__class__.from_config(layer.get_config())
layer_map[layer] = new_layer
layer = new_layer
else:
# Reuse previously cloned layer.
layer = layer_map[layer]
# Don't call InputLayer multiple times.
if isinstance(layer, InputLayer):
continue
# Gather inputs to call the new layer.
referenceinput_tensors_ = node.input_tensors
reference_output_tensors = node.output_tensors
# If all previous input tensors are available in tensor_map,
# then call node.inbound_layer on them.
computed_data = [] # List of tuples (input, mask).
for x in referenceinput_tensors_:
if x in tensor_map:
computed_data.append(tensor_map[x])
if len(computed_data) == len(referenceinput_tensors_):
# Call layer.
if node.arguments:
kwargs = node.arguments
else:
kwargs = {}
if len(computed_data) == 1:
computed_tensor, computed_mask = computed_data[0]
if has_arg(layer.call, 'mask'):
if 'mask' not in kwargs:
kwargs['mask'] = computed_mask
output_tensors = generic_utils.to_list(
layer(computed_tensor, **kwargs))
output_masks = generic_utils.to_list(
layer.compute_mask(computed_tensor, computed_mask))
computed_tensors = [computed_tensor]
computed_masks = [computed_mask]
else:
computed_tensors = [x[0] for x in computed_data]
computed_masks = [x[1] for x in computed_data]
if has_arg(layer.call, 'mask'):
if 'mask' not in kwargs:
kwargs['mask'] = computed_masks
output_tensors = generic_utils.to_list(
layer(computed_tensors, **kwargs))
output_masks = generic_utils.to_list(
layer.compute_mask(computed_tensors, computed_masks))
# Update tensor_map.
for x, y, mask in zip(reference_output_tensors, output_tensors,
output_masks):
tensor_map[x] = (y, mask)
# Check that we did compute the model outputs,
# then instantiate a new model from inputs and outputs.
output_tensors = []
for x in model.outputs:
assert x in tensor_map, 'Could not compute output ' + str(x)
tensor, _ = tensor_map[x]
output_tensors.append(tensor)
return Model(input_tensors, output_tensors, name=model.name)
def call(self, inputs, mask=None):
arguments = self.arguments
if has_arg(self.function, 'mask'):
arguments['mask'] = mask
return self.function(inputs, **arguments)
