def _apply_delete_mask(self, node, inbound_masks):
"""Apply the inbound delete mask and return the outbound delete mask
When specific channels in a layer or layer instance are deleted, the
mask propagates information about which channels are affected to
downstream layers.
If the layer contains weights, those which were previously connected
to the deleted channels are deleted and outbound masks are set to None
since further downstream layers aren't affected.
If the layer does not contain weights, its output mask is calculated to
reflect any transformations performed by the layer to ensure that
information about the deleted channels is propagated downstream.
Arguments:
node(Node): The node where the delete mask is applied.
inbound_masks: Mask(s) from inbound node(s).
Returns:
new_layer: Pass through `layer` if it has no weights, otherwise a
new `Layer` object with weights corresponding to the
inbound mask deleted.
outbound_mask: Mask corresponding to `new_layer`.
"""
# TODO: This breaks layer sharing. Write a test for this.
# if delete_mask is None or all values are True, it does not affect
# this layer or any layers above/downstream from it
print(node, "node")
print(inbound_masks, "inbound_masks")
layer = node.outbound_layer
print(layer, "outbound layer")
if all(mask is None for mask in inbound_masks):
new_layer = layer
outbound_mask = None
print(node, "node if return")
return new_layer, outbound_mask
elif any(mask is None for mask in inbound_masks):
inbound_masks = [
np.ones(shape[1:], dtype=bool)
if inbound_masks[i] is None else inbound_masks[i]
for i, shape in enumerate(node.input_shapes)
]
output_shape = utils.single_element(node.output_shapes)
input_shape = utils.single_element(node.input_shapes)
data_format = getattr(layer, 'data_format', 'channels_last')
inbound_masks = utils.single_element(inbound_masks)
print(node, "node")
# otherwise, delete_mask.shape should be: layer.input_shape[1:]
layer_class = layer.__class__.__name__
if layer_class == 'InputLayer':
raise RuntimeError('This should never get here!')
elif layer_class == 'Dense':
if np.all(inbound_masks):
new_layer = layer
else:
weights = layer.get_weights()
weights[0] = weights[0][np.where(inbound_masks)[0], :]
config = layer.get_config()
config['weights'] = weights
new_layer = type(layer).from_config(config)
outbound_mask = None
elif layer_class == 'Flatten':
outbound_mask = np.reshape(inbound_masks, [
-1,
])
new_layer = layer
elif layer_class in ('Conv1D', 'Conv2D', 'Conv3D'):
if np.all(inbound_masks):
new_layer = layer
print("npall conv1d")
else:
if data_format == 'channels_first':
inbound_masks = np.swapaxes(inbound_masks, 0, -1)
# Conv layer: trim down inbound_masks to filter shape
k_size = layer.kernel_size
index = [slice(None, dim_size, None) for dim_size in k_size]
inbound_masks = inbound_masks[index + [slice(None)]]
# Delete unused weights to obtain new_weights
weights = layer.get_weights()
# Each deleted channel was connected to all of the channels
# in layer; therefore, the mask must be repeated for each
# channel.
# `delete_mask`'s size: size(inbound_mask)+[layer.filters]
# TODO: replace repeat with tile
delete_mask = np.repeat(inbound_masks[..., np.newaxis],
weights[0].shape[-1],
axis=-1)
new_shape = list(weights[0].shape)
new_shape[-2] = -1 # Weights always have channels_last
print(weights[0].shape, "weights[0]")
print(delete_mask.shape, "deletemask")
print(new_shape, "new_shape")
weights[0] = np.reshape(weights[0][delete_mask], new_shape)
# Instantiate new layer with new_weights
config = layer.get_config()
config['weights'] = weights
new_layer = type(layer).from_config(config)
outbound_mask = None
elif layer_class in ('Cropping1D', 'Cropping2D', 'Cropping3D',
'MaxPooling1D', 'MaxPooling2D', 'MaxPooling3D',
'AveragePooling1D', 'AveragePooling2D',
'AveragePooling3D'):
index = [slice(None, x, None) for x in output_shape[1:]]
if data_format == 'channels_first':
index[0] = slice(None)
elif data_format == 'channels_last':
index[-1] = slice(None)
else:
raise ValueError('Invalid data format')
outbound_mask = inbound_masks[index]
new_layer = layer
elif layer_class in ('UpSampling1D', 'UpSampling2D', 'UpSampling3D',
'ZeroPadding1D', 'ZeroPadding2D',
'ZeroPadding3D'):
# Get slice of mask with all singleton dimensions except
# channels dimension
index = [slice(1)] * (len(input_shape) - 1)
tile_shape = list(output_shape[1:])
if data_format == 'channels_first':
index[0] = slice(None)
tile_shape[0] = 1
elif data_format == 'channels_last':
index[-1] = slice(None)
tile_shape[-1] = 1
else:
raise ValueError('Invalid data format')
channels_vector = inbound_masks[index]
# Tile this slice to create the outbound mask
outbound_mask = np.tile(channels_vector, tile_shape)
new_layer = layer
elif layer_class in ('GlobalMaxPooling1D', 'GlobalMaxPooling2D',
'GlobalAveragePooling1D',
'GlobalAveragePooling2D'):
# Get slice of mask with all singleton dimensions except
# channels dimension
index = [0] * (len(input_shape) - 1)
if data_format == 'channels_first':
index[0] = slice(None)
elif data_format == 'channels_last':
index[-1] = slice(None)
else:
raise ValueError('Invalid data format')
channels_vector = inbound_masks[index]
# Tile this slice to create the outbound mask
outbound_mask = channels_vector
new_layer = layer
elif layer_class in ('Dropout', 'Activation', 'SpatialDropout1D',
'SpatialDropout2D', 'SpatialDropout3D',
'ActivityRegularization', 'Masking', 'LeakyReLU',
'ELU', 'ThresholdedReLU', 'GaussianNoise',
'GaussianDropout', 'AlphaDropout'):
# Pass-through layers
outbound_mask = inbound_masks
new_layer = layer
elif layer_class == 'Reshape':
outbound_mask = np.reshape(inbound_masks, layer.target_shape)
new_layer = layer
elif layer_class == 'Permute':
outbound_mask = np.transpose(inbound_masks,
[x - 1 for x in layer.dims])
new_layer = layer
elif layer_class == 'RepeatVector':
outbound_mask = np.repeat(np.expand_dims(inbound_masks, 0),
layer.n,
axis=0)
new_layer = layer
elif layer_class == 'Embedding':
# Embedding will always be the first layer so it doesn't need
# to consider the inbound_delete_mask
if inbound_masks is not None:
raise ValueError('Channels cannot be deleted bedore Embedding '
'layers because they change the number of '
'channels.')
outbound_mask = None
new_layer = layer
elif layer_class in ('Add', 'Multiply', 'Average', 'Maximum'):
# The inputs must be the same size
if not utils.all_equal(inbound_masks):
ValueError(
'{0} layers must have the same size inputs. All '
'inbound nodes must have the same channels deleted'.format(
layer_class))
outbound_mask = inbound_masks[1]
new_layer = layer
elif layer_class == 'Concatenate':
axis = layer.axis
if layer.axis < 0:
axis = axis % len(layer.input_shape[0])
# Below: axis=axis-1 because the mask excludes the batch dimension
outbound_mask = np.concatenate(inbound_masks, axis=axis - 1)
new_layer = layer
elif layer_class in ('SimpleRNN', 'GRU', 'LSTM'):
if np.all(inbound_masks):
new_layer = layer
else:
weights = layer.get_weights()
weights[0] = weights[0][np.where(inbound_masks[0, :])[0], :]
config = layer.get_config()
config['weights'] = weights
new_layer = type(layer).from_config(config)
outbound_mask = None
elif layer_class == 'BatchNormalization':
outbound_mask = inbound_masks
# Get slice of mask with all singleton dimensions except
# channels dimension
index = [0] * (len(input_shape))
index[layer.axis] = slice(None)
index = index[1:]
# TODO: Maybe use channel indices everywhere instead of masks?
channel_indices = np.where(inbound_masks[index] == False)[0]
weights = [
np.delete(w, channel_indices, axis=-1)
for w in layer.get_weights()
]
new_layer = BatchNormalization.from_config(layer.get_config())
new_input_shape = list(input_shape)
new_input_shape[new_layer.axis] -= len(channel_indices)
new_layer.build(new_input_shape)
new_layer.set_weights(weights)
else:
# Not implemented:
# - Lambda
# - SeparableConv2D
# - Conv2DTranspose
# - LocallyConnected1D
# - LocallyConnected2D
# - TimeDistributed
# - Bidirectional
# - Dot
# - PReLU
# Warning/error needed for Reshape if channels axis is split
raise ValueError('"{0}" layers are currently '
'unsupported.'.format(layer_class))
print(node, "node return")
return new_layer, outbound_mask
def _apply_delete_mask(self, node, inbound_masks):
"""Apply the inbound delete mask and return the outbound delete mask
When specific channels in a layer or layer instance are deleted, the
mask propagates information about which channels are affected to
downstream layers.
If the layer contains weights, those which were previously connected
to the deleted channels are deleted and outbound masks are set to None
since further downstream layers aren't affected.
If the layer does not contain weights, its output mask is calculated to
reflect any transformations performed by the layer to ensure that
information about the deleted channels is propagated downstream.
Arguments:
node(Node): The node where the delete mask is applied.
inbound_masks: Mask(s) from inbound node(s).
Returns:
new_layer: Pass through `layer` if it has no weights, otherwise a
new `Layer` object with weights corresponding to the
inbound mask deleted.
outbound_mask: Mask corresponding to `new_layer`.
"""
# if delete_mask is None or all values are True, it does not affect
# this layer or any layers above/downstream from it
layer = node.outbound_layer
if all(mask is None for mask in inbound_masks):
new_layer = layer
outbound_mask = None
return new_layer, outbound_mask
# If one or more of the masks are None, replace them with ones.
if any(mask is None for mask in inbound_masks):
inbound_masks = [
np.ones(shape[1:], dtype=bool)
if inbound_masks[i] is None else inbound_masks[i]
for i, shape in enumerate(node.input_shapes)
]
# If the layer is shared and has already been affected by this
# operation, use the cached new layer.
if (len(get_inbound_nodes(layer)) > 1
and layer in self._replace_layers_map.keys()):
return self._replace_layers_map[layer]
output_shape = utils.single_element(node.output_shapes)
input_shape = utils.single_element(node.input_shapes)
data_format = getattr(layer, "data_format", "channels_last")
inbound_masks = utils.single_element(inbound_masks)
# otherwise, delete_mask.shape should be: layer.input_shape[1:]
layer_class = layer.__class__.__name__
if layer_class == "InputLayer":
raise RuntimeError("This should never get here!")
elif layer_class == "Dense":
if np.all(inbound_masks):
new_layer = layer
else:
weights = layer.get_weights()
weights[0] = weights[0][np.where(inbound_masks)[0], :]
config = layer.get_config()
config["weights"] = weights
new_layer = type(layer).from_config(config)
outbound_mask = None
elif layer_class == "Flatten":
outbound_mask = np.reshape(inbound_masks, [
-1,
])
new_layer = layer
elif layer_class in ("Conv1D", "Conv2D", "Conv3D"):
if np.all(inbound_masks):
new_layer = layer
else:
if data_format == "channels_first":
inbound_masks = np.swapaxes(inbound_masks, 0, -1)
# Conv layer: trim down inbound_masks to filter shape
k_size = layer.kernel_size
index = [slice(None, 1, None) for _ in k_size]
inbound_masks = inbound_masks[tuple(index + [slice(None)])]
weights = layer.get_weights()
# Delete unused weights to obtain new_weights
# Each deleted channel was connected to all of the channels
# in layer; therefore, the mask must be repeated for each
# channel.
# `delete_mask`'s size: size(weights[0])
delete_mask = np.tile(
inbound_masks[..., np.newaxis],
list(k_size) + [1, weights[0].shape[-1]],
)
new_shape = list(weights[0].shape)
new_shape[-2] = -1 # Weights always have channels_last
weights[0] = np.reshape(weights[0][delete_mask], new_shape)
# Instantiate new layer with new_weights
config = layer.get_config()
config["weights"] = weights
new_layer = type(layer).from_config(config)
outbound_mask = None
elif layer_class in (
"Cropping1D",
"Cropping2D",
"Cropping3D",
"MaxPooling1D",
"MaxPooling2D",
"MaxPooling3D",
"AveragePooling1D",
"AveragePooling2D",
"AveragePooling3D",
):
index = [slice(None, x, None) for x in output_shape[1:]]
if data_format == "channels_first":
index[0] = slice(None)
elif data_format == "channels_last":
index[-1] = slice(None)
else:
raise ValueError("Invalid data format")
outbound_mask = inbound_masks[tuple(index)]
new_layer = layer
elif layer_class in (
"UpSampling1D",
"UpSampling2D",
"UpSampling3D",
"ZeroPadding1D",
"ZeroPadding2D",
"ZeroPadding3D",
):
# Get slice of mask with all singleton dimensions except
# channels dimension
index = [slice(1)] * (len(input_shape) - 1)
tile_shape = list(output_shape[1:])
if data_format == "channels_first":
index[0] = slice(None)
tile_shape[0] = 1
elif data_format == "channels_last":
index[-1] = slice(None)
tile_shape[-1] = 1
else:
raise ValueError("Invalid data format")
channels_vector = inbound_masks[tuple(index)]
# Tile this slice to create the outbound mask
outbound_mask = np.tile(channels_vector, tile_shape)
new_layer = layer
elif layer_class in (
"GlobalMaxPooling1D",
"GlobalMaxPooling2D",
"GlobalAveragePooling1D",
"GlobalAveragePooling2D",
):
# Get slice of mask with all singleton dimensions except
# channels dimension
index = [0] * (len(input_shape) - 1)
if data_format == "channels_first":
index[0] = slice(None)
elif data_format == "channels_last":
index[-1] = slice(None)
else:
raise ValueError("Invalid data format")
channels_vector = inbound_masks[tuple(index)]
# Tile this slice to create the outbound mask
outbound_mask = channels_vector
new_layer = layer
elif layer_class in (
"Dropout",
"Activation",
"SpatialDropout1D",
"SpatialDropout2D",
"SpatialDropout3D",
"ActivityRegularization",
"Masking",
"LeakyReLU",
"ELU",
"ThresholdedReLU",
"GaussianNoise",
"GaussianDropout",
"AlphaDropout",
"Rename",
) or (layer_class == "TensorFlowOpLayer"
and layer.node_def.op == "ResizeBilinear"):
# Pass-through layers
outbound_mask = inbound_masks
new_layer = layer
elif layer_class == "Reshape":
outbound_mask = np.reshape(inbound_masks, layer.target_shape)
new_layer = layer
elif layer_class == "Permute":
outbound_mask = np.transpose(inbound_masks,
[x - 1 for x in layer.dims])
new_layer = layer
elif layer_class == "RepeatVector":
outbound_mask = np.repeat(np.expand_dims(inbound_masks, 0),
layer.n,
axis=0)
new_layer = layer
elif layer_class == "Embedding":
# Embedding will always be the first layer so it doesn't need
# to consider the inbound_delete_mask
if inbound_masks is not None:
raise ValueError("Channels cannot be deleted bedore Embedding "
"layers because they change the number of "
"channels.")
outbound_mask = None
new_layer = layer
elif layer_class in ("Add", "Multiply", "Average", "Maximum"):
# The inputs must be the same size
if not utils.all_equal(inbound_masks):
ValueError(
"{0} layers must have the same size inputs. All "
"inbound nodes must have the same channels deleted".format(
layer_class))
outbound_mask = inbound_masks[1]
new_layer = layer
elif layer_class == "Concatenate":
axis = layer.axis
if layer.axis < 0:
axis = axis % len(layer.input_shape[0])
# Below: axis=axis-1 because the mask excludes the batch dimension
outbound_mask = np.concatenate(inbound_masks, axis=axis - 1)
new_layer = layer
elif layer_class in ("SimpleRNN", "GRU", "LSTM"):
if np.all(inbound_masks):
new_layer = layer
else:
weights = layer.get_weights()
weights[0] = weights[0][np.where(inbound_masks[0, :])[0], :]
config = layer.get_config()
config["weights"] = weights
new_layer = type(layer).from_config(config)
outbound_mask = None
elif layer_class == "BatchNormalization":
outbound_mask = inbound_masks
# Get slice of mask with all singleton dimensions except
# channels dimension
index = [0] * (len(input_shape))
index[layer.axis] = slice(None)
index = index[1:]
# TODO: Maybe use channel indices everywhere instead of masks?
channel_indices = np.where(inbound_masks[tuple(index)] == False)[0]
weights = [
np.delete(w, channel_indices, axis=-1)
for w in layer.get_weights()
]
new_layer = BatchNormalization.from_config(layer.get_config())
new_input_shape = list(input_shape)
new_input_shape[new_layer.axis] -= len(channel_indices)
new_layer.build(new_input_shape)
new_layer.set_weights(weights)
else:
# Not implemented:
# - Lambda
# - SeparableConv2D
# - Conv2DTranspose
# - LocallyConnected1D
# - LocallyConnected2D
# - TimeDistributed
# - Bidirectional
# - Dot
# - PReLU
# Warning/error needed for Reshape if channels axis is split
raise ValueError('"{0}" layers are currently '
"unsupported.".format(layer_class))
if len(get_inbound_nodes(layer)) > 1 and new_layer != layer:
self._replace_layers_map[layer] = (new_layer, outbound_mask)
return new_layer, outbound_mask