class Im2LatexModelParams(dlc.HyperParams):
proto = GlobalParams.proto + (
### Training Parameters ####
PD(
'assert_whole_batch',
'(boolean): Disallow batch size that is not integral factor '
'of the bin-size',
boolean,
),
PD(
'squash_input_seq',
'(boolean): Remove whitespace from target sequences',
boolean,
),
PD('input_queue_capacity', 'Capacity of input queue.', integer(1),
LambdaVal(lambda _, d: d.num_towers * 1)),
PD(
'DecodingSlack',
"Since we ignore blanks/spaces in loss and accuracy measurement, the network is free "
"to insert blanks into the decoded/predicted sequence. Therefore the predicted sequence "
"can be arbitrarily long. However, we need to limit the max decoded sequence length. We "
"do so by determining the extra slack to give to the network - the more slack we give it "
"presumably that much easier the learning will be. This parameter includes that slack. In "
"other words, MaxDecodeLen = MaxSeqLen + DecodingSlack",
integer(0), 20),
PD('MaxDecodeLen',
"See the description for MaxSeqLen and DecodingSlack", integer(151),
LambdaVal(lambda _, p: p.MaxSeqLen + p.DecodingSlack)),
PD(
'SFactor',
'Applicable to Scanning LSTM only: Multiplier to derive MaxS from MaxSeqLen',
decimal(1.0),
LambdaVal(lambda _, p: 1.5 if p.build_scanning_RNN else None)),
PD(
'MaxS',
'Applicable to Scanning LSTM only: Max value of S for the given data-set',
integer(1),
LambdaVal(lambda _, p: int(p.MaxSeqLen * p.SFactor)
if p.build_scanning_RNN else None)),
PD(
'no_ctc_merge_repeated',
"(boolean): Negated value of ctc_merge_repeated beamsearch_length_penatly for ctc operations",
boolean, True),
PD(
'ctc_beam_width',
'Beam Width to use for ctc_beamsearch_decoder, which is different from the seq2seq.BeamSearchDecoder',
integer(1)),
PD(
'seq2seq_beam_width',
'Beam Width to use for seq2seq.BeamSearchDecoder, which is different from the ctc_beamsearch_decoder',
integer(1)),
PD(
'beamsearch_length_penalty',
'length_penalty_weight used by beamsearch decoder. Same as alpha value of length-penalty described in https://arxiv.org/pdf/1609.08144.pdf'
'In the paper they used a value of alpha in the range [0.6,0.7]. A value of 0 turns length-penalty off.',
decimal(0., 1.),
# 0.6
),
PD('swap_memory', 'swap_memory option to tf.scan', boolean, False),
PD(
'tf_session_allow_growth',
'tf ConfigProto.gpu_option_allow_growth. Setting this will allow the gpu memory to be allocated incrementally instead of all at once.',
boolean,
# False
),
PD(
'adam_alpha',
'(float or None): alpha value (step, learning_rate) of adam optimizer.',
instanceof(float),
# 0.0001 # default in tf.train.AdamOptimizer is 0.001
),
PD(
'adam_beta1',
'beta1 value of adam-optimizer. If undefined here, the default in tf.train.AdamOptimizer is is 0.9.',
decimal(0., 1.),
),
PD(
'adam_beta2',
'beta2 value of adam-optimizer. If undefined here, the default in tf.train.AdamOptimizer is is 0.999.',
decimal(0., 1.),
# 0.9
),
PD('optimizer', 'tensorflow optimizer function (e.g. AdamOptimizer).',
('adam', ), 'adam'),
PD(
'no_towers',
'Should be always set to False. Indicates code-switch to build without towers which will not work',
(False, ), False),
PD('num_gpus', 'Number of GPUs employed in parallel', integer(1)),
PD(
'towers_per_gpu', """
Number of towers per GPU running concurrently. Multiple towers per gpu are
needed in order to circumvent OOM errors.""", integer(1)),
PD(
'num_towers', """
Number of towers per GPU running concurrently. Multiple towers per gpu are
needed in order to circumvent OOM errors.""", integer(1),
LambdaVal(lambda _, p: p.num_gpus * p.towers_per_gpu)),
PD('data_reader_B', 'batch_size for the data_reader', integer(1),
LambdaVal(lambda _, d: d.B * d.num_towers)),
### Embedding Layer ###
PD(
'embeddings_initializer',
'Initializer for embedding weights',
iscallable(),
## tf.contrib.layers.xavier_initializer()
equalto('weights_initializer')),
PD('embeddings_regularizer', 'L1 / L2 norm regularization',
iscallableOrNone(), equalto('weights_regularizer')),
### ConvNet Params ###
PD(
'CONVNET',
'ConvStackParams for the convent',
instanceofOrNone(ConvStackParams),
## Value is set dynamically inside make_hyper
),
PD('image_frame_width',
'Width of an extra padding frame around the (possibly already padded) image. This extra padding is used '
'in order to ensure that there is enough whites-space around the edges of the image, so as to enable VALID padding '
'in the first conv-net layer without losing any information. The effect of doing this is to simulate SAME padding '
'but using custom padding values (background color in this case) instead of zeroes (which is what SAME padding would do). '
'This value should be equal to (kernel_size)//2 using kernel_size of the first convolution layer.',
integer(),
LambdaVal(lambda _, p: 0 if (p.build_image_context != 2) else
(p.CONVNET.layers[0].kernel_shape[0]) // 2)
## Dynamically set to = (kernel_size-1)/2 given kernel_size of first conv-net layer
),
PD('image_shape', 'Shape of input images. Should be a python sequence.'
'= image_shape_unpadded + image_frame_width around it',
issequenceof(int),
LambdaVal(lambda _, p: pad_image_shape(p.image_shape_unframed, p.
image_frame_width))
## = get_image_shape(raw_data_folder, num_channels, image_frame_width)
),
### Decoder CALSTM Params ###
PD(
'CALSTM_STACK',
'sequence of CALSTMParams, one for each CALSTM layer in the stack. The paper '
"has code for more than one layer, but mentions that it is not well-tested. I take that to mean "
"that the published results are based on one layer alone.",
issequenceof(CALSTMParams)),
### Output MLP
PD(
'output_reuse_embeddings',
'(boolean): Output layer in the paper has a special first layer which considers embedding weights as part of the first-layer weight matrix.'
'Setting this value to True (default) will follow the paper"s logic. Otherwise'
"a straight MLP will be used wherein all inputs (including Ey(t-1)) are first concatenated and fed into an MLP."
"Including the softmax layer, the paper uses a minimum of 2 layers.",
boolean,
# True
),
PD(
'outputMLP_skip_connections',
'(boolean): Applicable only when output_reuse_embeddings==False. Setting this value to False will cause'
'image context (z_t) and sequence input (Ex_t) to not be fed into the output MLP. If True (Default), the'
'output MLP receives a concatenation of Ex_t, h_t and z_t as input. If set to False, only h_t is input.',
boolean, True),
PD('output_first_layer',
"Some params of first layer of output MLP if output_reuse_embeddings==True",
instanceof(Properties)
## Value set dynamically inside self._trickledown() iff output_reuse_embeddings==True
),
PD(
'output_layers',
"(MLPParams): Parameters for the output MLP. The last layer outputs the logits and therefore "
"must have num_units = K. If output_reuse_embeddings==True, an additional initial layer is created "
"with num_units = m and activtion tanh. Therefore the min number of layers is 2 in that case. "
"Note: In the paper all layers have num_units=m except the last(softmax) layer.",
instanceof(MLPParams),
## Value set dynamically inside self._trickledown()
),
### Initializer MLP ###
PD(
'build_init_model', """
Boolean parameter specifying whether or not to build the LSTM init_state model. If set to False zero-state
will be used for init-state, otherwise a init-state model will be created based on other init_model_*
params.
""", boolean),
PD(
'init_model_input_transform', """
Transform to apply to the image-context input to the init model. Only applies if build_init_model == True.
'mean' implies take a mean across the 'L' image-locations and produce an input of size (batchsize, D).
'full' implies take in all the 'L' features and produce an input tensor of shape (batchsize, L*D).
Note that with this option the # of parameters in the first layer will go up by a factor of L i.e.
around 100x.
""", ('mean', 'full')),
PD(
'init_model_hidden',
'MLP stack for hidden layers of the init_state model. In addition to the stack specified here, an additional FC '
"layer will be forked off at the top for each 'c' and 'h' state in the RNN Im2LatexDecoderRNN state."
"Hence, this is a 'multi-headed' MLP because it has multiple top-layers."
"By default their implementation has num_hidden_layers==0 (i.e. n_layers_init==1).",
instanceof(MLPParams),
## Value set dynamically inside self._trickledown()
),
PD(
'init_model_final_layers',
'',
instanceof(FCLayerParams),
## Value set dynamically inside self._trickledown()
),
### Loss / Cost Layer ###decoder_lstm
PD(
'sum_logloss',
'Whether to normalize log-loss per sample as in standard log perplexity '
'calculation or whether to just sum up log-losses as in the paper. Defaults'
'to True in conformance with the paper.',
boolean,
# True
),
PD(
'MeanSumAlphaEquals1',
'(boolean): When calculating the alpha penalty, the paper uses the term: '
'square{1 - sum_over_t{alpha_t_i}}). This assumes that the mean sum_over_t should be 1. '
"However, that's not true, since the mean of sum_over_t term should be C/L. This "
"variable if set to True, causes the term to change to square{C/L - sum_over_t{alpha_t_i}}). "
"The default value is True in conformance with the paper.",
boolean,
# True
),
PD(
'pLambda',
'Lambda value for alpha penalty, Setting this to zero turns off alpha_penalty.',
(0.0, 0.0005, 0.005, 0.0001, 0.05),
# LambdaVal(lambda _, p: 0.005 if p.build_scanning_RNN else 0.000)
), # default in the show-and-tell paper is .00001?
PD(
'target_aae',
"""
Target mean_norm_AAE value to shoot for. Varies with data-set. Value discovered by experimentation.
""",
(0., 51.42, 51.79),
# LambdaVal(lambda _, p: None if (p.pLambda == 0) else 51.42)
),
PD(
'target_ase',
"""
Target mean_norm_ASE value to shoot for. Varies with data-set. Value discovered by experimentation.
""",
(0.0, 5.27, 5.35, 10.0),
# LambdaVal(lambda _, p: None if (p.pLambda == 0) else (10.0 if p.build_scanning_RNN else 5.27))
LambdaVal(lambda _, p: None if (p.pLambda == 0) else 5.27)),
PD(
'k',
'Number of top-scoring beams to consider for best-of-k metrics.',
integer(1),
# Value specified in run.py
))
def __init__(self, initVals):
dlc.HyperParams.__init__(self, self.proto, initVals, seal=False)
self._trickledown()
def _trickledown(self):
"""
Trickle changes down to dependant parameters in sub-tree(s).
(For same level dependencies use LambdaFunctions instead.)
Call at the end of __init__ and end of update.
"""
######## Output Model ########
if self.output_reuse_embeddings:
assert not self.build_scanning_RNN, 'Scanning RNN cannot reuse-embeddings because there are no embeddings'
self.output_first_layer = FCLayerParams(self).updated({
'num_units':
self.m,
'activation_fn':
tf.nn.tanh, # Shouldn't this be None?
# dropout imported from outer scope
}).freeze()
self.output_layers = MLPParams(self).updated({
# One layer with num_units = m is added if output_reuse_embeddings == True
'op_name':
'yLogits_MLP',
# dropout imported from outer scope
'layers': (
## paper has activation set to relu for all but the softmax layer
## paper has all hidden layers with num_units = m.
# TODO: num_units should probably be self.K otherwise the model is a reverse pyramid
FCLayerParams(self).updated({
'num_units': 64,
'activation_fn': tf.nn.relu
}).freeze(),
## Last layer must have num_units = K and activation_fn=None because it outputs logits.
FCLayerParams(self).updated({
'num_units': self.K,
'activation_fn': None,
'dropout': None
}).freeze(),
)
}).freeze()
else:
self.output_layers = MLPParams(self).updated({
'op_name':
'yLogits_MLP',
'layers': (
# paper has activation set to relu for all but the softmax layer
# paper has all hidden layers with num_units = m.
FCLayerParams(self).updated({
'num_units': 358,
'activation_fn': tf.nn.tanh
}).freeze(),
FCLayerParams(self).updated({
'num_units': 358,
'activation_fn': tf.nn.tanh
}).freeze(),
# Last layer must have num_units = K and activation_fn=None because it outputs logits.
FCLayerParams(self).updated({
'num_units': self.K,
'activation_fn': None,
'dropout': None
}).freeze(),
)
}).freeze()
assert self.output_layers.layers[-2].num_units >= self.K
assert self.output_layers.layers[
-1].activation_fn == None, 'The last layer must have linear activation because softmax is added later (since we need logits for efficient cross-entropy calculation)'
if (not self.output_reuse_embeddings):
assert len(
self.output_layers.layers
) >= 2, "Need one hidden layer at least to match the paper's complexity."
######## Init Model ########
if self.build_init_model:
# Note: There are no hidden init layers by default in the Show&Tell paper
self.init_model_hidden = MLPParams(self).updated({
'layers': (
# Show&Tell paper sets hidden activations=relu
# The Show&Tell paper's source sets all hidden units to D
FCLayerParams(self).updated({
'num_units': min(self.D, 100),
'activation_fn': tf.nn.tanh
}).freeze(), )
}).freeze()
self.init_model_final_layers = FCLayerParams(self).updated({
# Show&Tell paper sets final=tanh
'activation_fn':
tf.nn.tanh,
'dropout':
None
}).freeze()
def __copy__(self):
## Shallow copy
return self.__class__(self)
def copy(self, override_vals={}):
## Shallow copy
return self.__class__(self).updated(override_vals)
class GlobalParams(dlc.HyperParams):
""" Common Properties to trickle down. """
proto = (
## Data-set Properties ##
PD(
'raw_data_dir',
'Filesystem path of raw_data_folder from where the pre-processed data is stored.',
dlc.instanceof(str)),
PD(
'image_shape_unframed',
'Shape of input images. Should be a python sequence.'
'This is superseded by image_shape which optionally includes an extra padding frame around the input image'
'Value is loaded from the dataset and is not configurable.',
issequenceof(int),
# Set dynamically based on dataset.
),
PD(
'MaxSeqLen',
"Max sequence length including the end-of-sequence marker token. Is used to "
"limit the number of decoding steps. Value is loaded from the dataset and is not configurable.",
integer(151),
# Set dynamically based on dataset.
),
PD(
'K',
'Vocabulary size including zero. Value is loaded from the dataset and is not configurable.',
(358, 557, 339),
# Set dynamically based on dataset.
# LambdaVal(lambda _, d: 557+1 if d.use_ctc_loss else 557) #get_vocab_size(data_folder) + 1 for Blank-Token
),
PD(
'CTCBlankTokenID',
'ID of the space/blank token. By tf.nn.ctc requirement, blank token should be == K-1,'
'Value is loaded from the dataset and is not configurable.',
integerOrNone(),
# Set dynamically based on dataset.
),
PD(
'SpaceTokenID',
'Space Token ID if present in the dataset.',
integerOrNone(),
# Set dynamically based on dataset.
),
PD(
'NullTokenID',
'ID of the EOS token == Null Token. Must be zero. Its value is loaded from the dataset and is not configurable.',
(0, ),
# Set dynamically based on dataset.
),
PD(
'StartTokenID',
'ID of the begin-sequence token. The value is loaded from the dataset and is not configurable.',
(1, ),
# Set dynamically based on dataset.
),
###############################
PD(
'build_image_context', """
(enum): Type of decoder conv-net model to use:
0 => Do not build decoder conv-net. Use pre-generated image features instead.
1 => Use VGG16 Conv-Net model (imported from Keras).
2 => Use a custom conv-net (defined in make_hyper)
""", (0, 1, 2)),
PD(
'build_scanning_RNN',
'(boolean): Whether to build a regular RNN or a scanning RNN',
boolean,
),
PD(
'B',
'(integer): Size of mini-batch for training, validation and testing graphs/towers. '
'NOTE: Batch-size for the data-reader is different and set under property "data_reader_B"',
integer(1),
),
PD(
'n',
"The variable n in the paper. The number of units in the decoder_lstm cell(s). "
"The paper uses a value of 1000.", (1000, 1500), 1500),
PD(
'm', '(integer): dimensionality of the embedded input vector (Ex).'
"Note: For a stacked CALSTM, the upper layers will be fed output of the previous CALSTM, "
"therefore their input dimensionality will not be equal to the embedding dimensionality, rather "
" it will be equal to output_size of the previous CALSTM. That's why this value needs to be "
"appropriately adjusted for upper CALSTM layers.", (64, 3),
LambdaVal(lambda _, p: 3 if p.build_scanning_RNN else 64)),
PD(
'REGROUP_IMAGE',
"""
Specifies how the image feature vectors should be grouped together
along Height and Width axes. For e.g. if the original dimension of the context feature map was (3,33,512)
- i.e. original H=3, original W=33 and D=512- and if REGROUP_IMAGE was (3,3) then the new
context-map would have shape (1, 11, 512*3*3) resulting in H=1, W=33, D=4608 and L=33.
A None value implies no regrouping.
""",
issequenceofOrNone(int),
),
PD('image_size', 'Older image-size was "small". Newer one is "big"',
('small', 'big'), 'big'),
PD('H0',
'Height of feature-map produced by conv-net. Specific to the dataset image size.',
integer(1),
LambdaVal(lambda _, p: 4 if (p.image_size == 'big') else 3)
# LambdaVal(lambda _, p: 8 if (p.build_image_context == 2) else (4 if p.dataset == 3 else 3))
),
PD('W0',
'Width of feature-map produced by conv-net. Specific to the dataset image size.',
integer(1),
LambdaVal(lambda _, p: 34 if (p.image_size == 'big') else 33)
# LambdaVal(lambda _, p: 68 if (p.build_image_context == 2) else (34 if p.dataset == 3 else 33))
),
PD(
'L0',
'(integer): number of pixels in an image feature-map coming out of conv-net = H0xW0 (see paper or model description)',
integer(1), LambdaVal(lambda _, p: p.H0 * p.W0)),
PD(
'D0',
'(integer): number of features coming out of the conv-net. Depth/channels of the last conv-net layer.'
'See paper or model description.', integer(1), 512),
PD(
'H', 'Height of feature-map produced fed to the decoder.',
integer(1),
LambdaVal(lambda _, p: p.H0 if (p.REGROUP_IMAGE is None) else p.H0
// p.REGROUP_IMAGE[0])),
PD(
'W', 'Width of feature-map fed to the decoder.', integer(1),
LambdaVal(lambda _, p: p.W0 if (p.REGROUP_IMAGE is None) else p.W0
// p.REGROUP_IMAGE[1])),
PD(
'L',
'(integer): number of pixels in an image feature-map fed to the decoder = HxW (see paper or model description)',
integer(1), LambdaVal(lambda _, p: p.H * p.W)),
PD(
'D',
'(integer): number of image-features fed to the decoder. Depth/channels of the last conv-net layer.'
'See paper or model description.', integer(1),
LambdaVal(lambda _, p: p.D0 if (p.REGROUP_IMAGE is None) else p.D0
* p.REGROUP_IMAGE[0] * p.REGROUP_IMAGE[1])),
PD(
'tb',
"Tensorboard Params.",
instanceof(TensorboardParams),
),
PD(
'dropout',
'Dropout parameters if any - global. Absence of this property '
'signals no dropouts. If this is non-None, then weights regularizer should be None.',
instanceofOrNone(DropoutParams)),
PD('dtype', 'tensorflow float type for the entire model.',
(tf.float32, tf.float64), tf.float32),
PD('dtype_np', 'dtype for the entire model.', (np.float32, np.float64),
np.float32),
PD('int_type', 'tensorflow int type for the entire model.',
(tf.int32, tf.int64), tf.int32),
PD('int_type_np', 'numpy inttype for the entire model.',
(np.int32, np.int64), np.int32),
PD(
'weights_initializer',
'Tensorflow weights initializer function',
iscallable(),
tf.contrib.layers.xavier_initializer(
uniform=True, dtype=tf.float32) ## = glorot_uniform
# tf.contrib.layers.variance_scaling_initializer()
),
PD(
'biases_initializer',
'Tensorflow biases initializer function, e.g. tf.zeros_initializer(). ',
iscallable(), tf.zeros_initializer()),
PD(
'rLambda',
'Lambda value (scale) for regularizer.',
decimal(),
),
PD(
'weights_regularizer',
'L1 / L2 norm regularization. If this is non-None then dropout should be None.',
iscallableOrNone(),
# tf.contrib.layers.l2_regularizer(scale=1.0, scope='L2_Regularizer')
# tf.contrib.layers.l1_regularizer(scale=1.0, scope="L1_Regularizer")
),
PD(
'use_ctc_loss',
"Whether to train using ctc_loss or cross-entropy/log-loss/log-likelihood. In either case "
"ctc_loss will be logged. Also, use_ctc_loss must be turned on if building scanning-RNN.",
boolean, LambdaVal(lambda _, p: p.build_scanning_RNN)),
PD('biases_regularizer', 'L1 / L2 norm regularization',
iscallable(noneokay=True), None),
PD(
'use_peephole',
'(boolean): whether to employ peephole connections in the decoder LSTM',
(True, False), True),
PD('logger', 'Python logger object for logging.',
instanceof(logging.Logger)),
)
def __init__(self, initVals=None):
dlc.HyperParams.__init__(self, self.proto, initVals)
self._trickledown()
def _trickledown(self):
with open(os.path.join(self.raw_data_dir, 'data_props.pkl'),
'rb') as pickle_file:
data_props = np.load(pickle_file,
encoding="latin1",
allow_pickle=True)
num_channels = 1 if (self.build_image_context == 2) else 3
self.image_shape_unframed = (data_props['padded_image_dim']['height'],
data_props['padded_image_dim']['width'],
num_channels)
self.SpaceTokenID = data_props['SpaceTokenID']
self.NullTokenID = data_props['NullTokenID']
self.StartTokenID = data_props['StartTokenID']
self.MaxSeqLen = int(data_props['MaxSeqLen'])
if self.SpaceTokenID is not None:
if False: # self.use_ctc_loss:
self.K = int(data_props['K']) + 1
self.CTCBlankTokenID = self.K - 1
else:
self.K = int(data_props['K'])
self.CTCBlankTokenID = None
else:
self.K = int(data_props['K']) + 1
self.CTCBlankTokenID = self.K - 1
def __copy__(self):
## Shallow copy
return self.__class__(self)
def copy(self, override_vals={}):
## Shallow copy
return self.__class__(self).updated(override_vals)
class CALSTMParams(dlc.HyperParams):
proto = GlobalParams.proto + (
### Attention Model Params ###
PD(
'att_layers',
'MLP or Convnet parameters for attention model',
dlc.either(instanceof(MLPParams), instanceof(ConvStackParams)),
## Set dynamically in self._trickledown()
),
PD(
'att_model',
'Whether the attention model should share weights across the "L" image locations - i.e. perform a 1x1 convolution - or use a straight MLP.'
'Choosing "MLP_shared" conforms to the paper resulting in a (D+n,att_1_n) kernel (similar to 1x1 convolution but implemented as an MLPStack).'
'Choosing "1x1_conv" results in a 1x1 convolution-stack implementation instead of shared-MLP as above. The model should be identical to that obtained'
'by setting att_model=MLP_shared (plus equivalent num_units and same activation functions)'
'Choosing "MLP_full" will result in a standard MLP whose input is the entire flattened image feature vector concatenated with h(t-1), resulting '
'in a vector size (L*D + n) and a weight matrix of size (L*D+n,att_1_n). That is, the kernel will receive input from all the "L" '
"locations of image feature-map (in addition to h(t-1)) as against only one location in the MLP_shared or 1x1_conv cases.",
('MLP_shared', '1x1_conv', 'MLP_full'),
),
PD(
'att_modulator',
'A neural-network whose scalar output modulates the soft context signal "z_t" in comparison to the embedded-label signal fed into the decoder LSTM.'
'Serves as an "equalizer knob" that either amplifies or attenuates the context input signal versus the embedded-label input signal to the LSTM.'
'In the paper this scalar-value is called "beta" and in their code it is called the "selector". They implemented it as the output of a sigmoid and hence a value between 0 and 1.'
"We'll use a generic MLP stack with either a sigmoid activation in the last layer or a relu (in wchich case the modulator can take values greater than 1). "
"Input to this MLP is the h(t-1) - the previous LSTM output.",
instanceof(MLPParams),
),
PD('build_att_modulator',
'(boolean): Turns on/off the att_modulator function.', boolean),
PD(
'feed_clock_to_att',
'Turns on/off feeding scanning clock into the attention model. Only applicable for scanning-RNN.',
boolean,
LambdaVal(lambda _, p: True if p.build_scanning_RNN else None)),
PD(
'no_clock_to_lstm',
'Turns on/off feeding scanning clock into the decoder-LSTM. Only applicable for scanning-RNN.',
boolean,
LambdaVal(lambda _, p: True if p.build_scanning_RNN else None)),
### Decoder LSTM Params ###
PD(
'decoder_lstm',
'Decoder LSTM parameters. Multiple LSTM layers are supported.',
instanceof(RNNParams),
## Set dynamically in self._trickledown()
))
def __init__(self, initVals):
## "Note: For a stacked CALSTM, the upper layers will be fed output of the previous CALSTM, "
## "therefore their input dimensionality will not be equal to the embedding dimensionality, rather "
## " it will be equal to output_size of the previous CALSTM. That's why the value of m needs to be "
## "appropriately adjusted for upper CALSTM layers."
assert initVals['m'] is not None
dlc.HyperParams.__init__(self, self.proto, initVals, seal=False)
## No dropout within CALSTM
self.dropout = None
self._trickledown()
def _trickledown(self):
"""
Trickle down changes onto parameters in sub-tree(s) if needed.
(For same level dependencies use LambdaFunctions instead.)
Call at the end of __init__ and end of update.
"""
#### Attention Model ####
if self.att_model == '1x1_conv':
self.att_layers = ConvStackParams({
'op_name':
'1x1Conv',
'tb':
self.tb,
# 'activation_fn': tf.nn.relu,
# 'weights_initializer': self.weights_initializer,
# 'biases_initializer': self.biases_initializer,
# 'weights_regularizer': self.weights_regularizer,
# 'biases_regularizer': self.biases_regularizer,
# 'padding': 'VALID',
'layers': (
## TODO: Try with relu activation
ConvLayerParams(self).updated({
'output_channels': self.D,
'kernel_shape': (1, 1),
'stride': (1, 1),
'padding': 'VALID',
'activation_fn': tf.nn.tanh
}).freeze(),
ConvLayerParams(self).updated({
'output_channels': self.D,
'kernel_shape': (1, 1),
'stride': (1, 1),
'padding': 'VALID',
'activation_fn': tf.nn.tanh
}).freeze(),
ConvLayerParams(self).updated({
'output_channels': 1,
'kernel_shape': (1, 1),
'stride': (1, 1),
'padding': 'VALID',
'activation_fn': None
}).freeze())
}).freeze()
assert self.att_layers.layers[
-1].output_channels == 1, 'num output_channels of the final layer of the att_convnet should equal 1'
assert self.att_layers.layers[
-1].activation_fn == None ## Softmax activation will be added after squeezing dims
elif self.att_model == 'MLP_shared':
self.att_layers = MLPParams(self).updated({
'op_name':
'MLP_shared',
# Number of units in all layers of the attention model = D in the Show and Tell paper"s source-code.
'layers': (
FCLayerParams(self).updated({
'num_units': self.D,
'activation_fn': tf.nn.tanh,
'dropout': self.dropout
}).freeze(),
FCLayerParams(self).updated({
'num_units': self.D,
'activation_fn': tf.nn.tanh,
'dropout': self.dropout
}).freeze(),
FCLayerParams(self).updated({
'num_units': 1,
'activation_fn': None,
'dropout': None
}).freeze(),
)
}).freeze()
assert self.att_layers.layers[
-1].num_units == 1, 'num_units of the final layer of the att_kernel should equal 1'
assert self.att_layers.layers[
-1].activation_fn == None ## Softmax activation will be added after squeezing dims
assert self.att_layers.layers[
-1].dropout == None ## No droput in the softmax layer
elif self.att_model == 'MLP_full':
self.att_layers = MLPParams(self).updated({
'op_name':
'MLP_full',
'layers': (
FCLayerParams(self).updated({
'num_units': max(self.L, 256),
'activation_fn': tf.nn.tanh,
'dropout': self.dropout
}).freeze(),
FCLayerParams(self).updated({
'num_units': max(self.L, 128),
'activation_fn': tf.nn.tanh,
'dropout': self.dropout
}).freeze(),
FCLayerParams(self).updated({
'num_units': self.L,
'activation_fn': None,
'dropout': None
}).freeze(),
)
}).freeze()
assert self.att_layers.layers[
-1].num_units == self.L, 'num_units of the final layer of the att_MLP should equal L(%d)' % self.L
assert self.att_layers.layers[
-1].activation_fn == None ## softmax activation will be added in code for consistency
assert self.att_layers.layers[
-1].dropout == None ## No droput before/after softmax activation
#### Attention Modulator ####
if self.build_att_modulator:
self.att_modulator = MLPParams(self).updated({
'op_name':
'beta_MLP',
## paper's code uses 1 layer only. The last-layer must have only one neuron os that the output is scalar.
'layers': (FCLayerParams(self).updated({
'num_units': 1,
'activation_fn': tf.nn.sigmoid,
'dropout': None
}).freeze(), )
}).freeze()
#### LSTM-Stack ####
self.decoder_lstm = RNNParams(self).updated({
'B':
self.B,
'i':
self.D if
(self.build_scanning_RNN and self.no_clock_to_lstm) else self.m +
self.D, # size of Ex_t + size of z_t.
# show-and-tell paper uses a value of n=1000
'layers_units': (self.n, self.n),
## 'dropout': None # No dropout in LSTM
}).freeze()
self.seal()
def __copy__(self):
## Shallow copy
return self.__class__(self)
def copy(self, override_vals={}):
## Shallow copy
return self.__class__(self).updated(override_vals)