Source code for tensorlayer.layers.recurrent

#! /usr/bin/python
# -*- coding: utf-8 -*-

import tensorflow as tf

from tensorflow.python.ops import array_ops
from tensorflow.python.util.tf_inspect import getfullargspec
from tensorflow.contrib.rnn import stack_bidirectional_dynamic_rnn
from tensorflow.python.ops.rnn_cell import LSTMStateTuple

from tensorlayer.layers.core import Layer
from tensorlayer.layers.core import LayersConfig
from tensorlayer.layers.core import TF_GRAPHKEYS_VARIABLES

from tensorlayer import logging

from tensorlayer.decorators import deprecated_alias

__all__ = [
    'RNNLayer',
    'BiRNNLayer',
    'ConvRNNCell',
    'BasicConvLSTMCell',
    'ConvLSTMLayer',
    'advanced_indexing_op',
    'retrieve_seq_length_op',
    'retrieve_seq_length_op2',
    'retrieve_seq_length_op3',
    'target_mask_op',
    'DynamicRNNLayer',
    'BiDynamicRNNLayer',
    'Seq2Seq',
]


[docs]class RNNLayer(Layer): """ The :class:`RNNLayer` class is a fixed length recurrent layer for implementing vanilla RNN, LSTM, GRU and etc. Parameters ---------- prev_layer : :class:`Layer` Previous layer. cell_fn : TensorFlow cell function A TensorFlow core RNN cell - See `RNN Cells in TensorFlow <https://www.tensorflow.org/api_docs/python/>`__ - Note TF1.0+ and TF1.0- are different cell_init_args : dictionary The arguments for the cell function. n_hidden : int The number of hidden units in the layer. initializer : initializer The initializer for initializing the model parameters. n_steps : int The fixed sequence length. initial_state : None or RNN State If None, `initial_state` is zero state. return_last : boolean Whether return last output or all outputs in each step. - If True, return the last output, "Sequence input and single output" - If False, return all outputs, "Synced sequence input and output" - In other word, if you want to stack more RNNs on this layer, set to False. return_seq_2d : boolean Only consider this argument when `return_last` is `False` - If True, return 2D Tensor [n_example, n_hidden], for stacking DenseLayer after it. - If False, return 3D Tensor [n_example/n_steps, n_steps, n_hidden], for stacking multiple RNN after it. name : str A unique layer name. Attributes ---------- outputs : Tensor The output of this layer. final_state : Tensor or StateTuple The finial state of this layer. - When `state_is_tuple` is `False`, it is the final hidden and cell states, `states.get_shape() = [?, 2 * n_hidden]`. - When `state_is_tuple` is `True`, it stores two elements: `(c, h)`. - In practice, you can get the final state after each iteration during training, then feed it to the initial state of next iteration. initial_state : Tensor or StateTuple The initial state of this layer. - In practice, you can set your state at the begining of each epoch or iteration according to your training procedure. batch_size : int or Tensor It is an integer, if it is able to compute the `batch_size`; otherwise, tensor for dynamic batch size. Examples -------- - For synced sequence input and output, see `PTB example <https://github.com/tensorlayer/tensorlayer/blob/master/example/tutorial_ptb_lstm_state_is_tuple.py>`__ - For encoding see below. >>> import tensorflow as tf >>> import tensorlayer as tl >>> batch_size = 32 >>> num_steps = 5 >>> vocab_size = 3000 >>> hidden_size = 256 >>> keep_prob = 0.8 >>> is_train = True >>> input_data = tf.placeholder(tf.int32, [batch_size, num_steps]) >>> net = tl.layers.EmbeddingInputlayer(inputs=input_data, vocabulary_size=vocab_size, ... embedding_size=hidden_size, name='embed') >>> net = tl.layers.DropoutLayer(net, keep=keep_prob, is_fix=True, is_train=is_train, name='drop1') >>> net = tl.layers.RNNLayer(net, cell_fn=tf.contrib.rnn.BasicLSTMCell, ... n_hidden=hidden_size, n_steps=num_steps, return_last=False, name='lstm1') >>> net = tl.layers.DropoutLayer(net, keep=keep_prob, is_fix=True, is_train=is_train, name='drop2') >>> net = tl.layers.RNNLayer(net, cell_fn=tf.contrib.rnn.BasicLSTMCell, ... n_hidden=hidden_size, n_steps=num_steps, return_last=True, name='lstm2') >>> net = tl.layers.DropoutLayer(net, keep=keep_prob, is_fix=True, is_train=is_train, name='drop3') >>> net = tl.layers.DenseLayer(net, n_units=vocab_size, name='output') - For CNN+LSTM >>> image_size = 100 >>> batch_size = 10 >>> num_steps = 5 >>> x = tf.placeholder(tf.float32, shape=[batch_size, image_size, image_size, 1]) >>> net = tl.layers.InputLayer(x, name='in') >>> net = tl.layers.Conv2d(net, 32, (5, 5), (2, 2), tf.nn.relu, name='cnn1') >>> net = tl.layers.MaxPool2d(net, (2, 2), (2, 2), name='pool1') >>> net = tl.layers.Conv2d(net, 10, (5, 5), (2, 2), tf.nn.relu, name='cnn2') >>> net = tl.layers.MaxPool2d(net, (2, 2), (2, 2), name='pool2') >>> net = tl.layers.FlattenLayer(net, name='flatten') >>> net = tl.layers.ReshapeLayer(net, shape=[-1, num_steps, int(net.outputs._shape[-1])]) >>> rnn = tl.layers.RNNLayer(net, cell_fn=tf.contrib.rnn.BasicLSTMCell, n_hidden=200, n_steps=num_steps, return_last=False, return_seq_2d=True, name='rnn') >>> net = tl.layers.DenseLayer(rnn, 3, name='out') Notes ----- Input dimension should be rank 3 : [batch_size, n_steps, n_features], if no, please see :class:`ReshapeLayer`. References ---------- - `Neural Network RNN Cells in TensorFlow <https://www.tensorflow.org/api_docs/python/rnn_cell/>`__ - `tensorflow/python/ops/rnn.py <https://github.com/tensorflow/tensorflow/blob/master/tensorflow/python/ops/rnn.py>`__ - `tensorflow/python/ops/rnn_cell.py <https://github.com/tensorflow/tensorflow/blob/master/tensorflow/python/ops/rnn_cell.py>`__ - see TensorFlow tutorial ``ptb_word_lm.py``, TensorLayer tutorials ``tutorial_ptb_lstm*.py`` and ``tutorial_generate_text.py`` """ @deprecated_alias(layer='prev_layer', end_support_version=1.9) # TODO remove this line for the 1.9 release def __init__( self, prev_layer, cell_fn, cell_init_args=None, n_hidden=100, initializer=tf.random_uniform_initializer(-0.1, 0.1), n_steps=5, initial_state=None, return_last=False, return_seq_2d=False, name='rnn', ): if cell_fn is None: raise Exception("Please put in cell_fn") super(RNNLayer, self).__init__(prev_layer=prev_layer, cell_init_args=cell_init_args, name=name) if 'GRU' in cell_fn.__name__: try: self.cell_init_args.pop('state_is_tuple') except Exception: logging.warning('pop state_is_tuple fails.') logging.info( "RNNLayer %s: n_hidden: %d n_steps: %d in_dim: %d in_shape: %s cell_fn: %s " % (self.name, n_hidden, n_steps, self.inputs.get_shape().ndims, self.inputs.get_shape(), cell_fn.__name__) ) # You can get the dimension by .get_shape() or ._shape, and check the # dimension by .with_rank() as follow. # self.inputs.get_shape().with_rank(2) # self.inputs.get_shape().with_rank(3) # Input dimension should be rank 3 [batch_size, n_steps(max), n_features] try: self.inputs.get_shape().with_rank(3) except Exception: raise Exception("RNN : Input dimension should be rank 3 : [batch_size, n_steps, n_features]") # is_reshape : boolean (deprecate) # Reshape the inputs to 3 dimension tensor.\n # If input is´╝╗batch_size, n_steps, n_features], we do not need to reshape it.\n # If input is [batch_size * n_steps, n_features], we need to reshape it. # if is_reshape: # self.inputs = tf.reshape(self.inputs, shape=[-1, n_steps, int(self.inputs._shape[-1])]) fixed_batch_size = self.inputs.get_shape().with_rank_at_least(1)[0] if fixed_batch_size.value: batch_size = fixed_batch_size.value logging.info(" RNN batch_size (concurrent processes): %d" % batch_size) else: batch_size = array_ops.shape(self.inputs)[0] logging.info(" non specified batch_size, uses a tensor instead.") self.batch_size = batch_size # Simplified version of tensorflow.models.rnn.rnn.py's rnn(). # This builds an unrolled LSTM for tutorial purposes only. # In general, use the rnn() or state_saving_rnn() from rnn.py. # # The alternative version of the code below is: # # from tensorflow.models.rnn import rnn # inputs = [tf.squeeze(input_, [1]) # for input_ in tf.split(1, num_steps, inputs)] # outputs, state = rnn.rnn(cell, inputs, initial_state=self._initial_state) outputs = [] if 'reuse' in getfullargspec(cell_fn.__init__).args: self.cell = cell = cell_fn(num_units=n_hidden, reuse=tf.get_variable_scope().reuse, **self.cell_init_args) else: self.cell = cell = cell_fn(num_units=n_hidden, **self.cell_init_args) if initial_state is None: self.initial_state = cell.zero_state(batch_size, dtype=LayersConfig.tf_dtype) #dtype=tf.float32) # 1.2.3 state = self.initial_state with tf.variable_scope(name, initializer=initializer) as vs: for time_step in range(n_steps): if time_step > 0: tf.get_variable_scope().reuse_variables() (cell_output, state) = cell(self.inputs[:, time_step, :], state) outputs.append(cell_output) # Retrieve just the RNN variables. # rnn_variables = [v for v in tf.all_variables() if v.name.startswith(vs.name)] rnn_variables = tf.get_collection(TF_GRAPHKEYS_VARIABLES, scope=vs.name) logging.info(" n_params : %d" % (len(rnn_variables))) if return_last: # 2D Tensor [batch_size, n_hidden] self.outputs = outputs[-1] else: if return_seq_2d: # PTB tutorial: stack dense layer after that, or compute the cost from the output # 2D Tensor [n_example, n_hidden] self.outputs = tf.reshape(tf.concat(outputs, 1), [-1, n_hidden]) else: # <akara>: stack more RNN layer after that # 3D Tensor [n_example/n_steps, n_steps, n_hidden] self.outputs = tf.reshape(tf.concat(outputs, 1), [-1, n_steps, n_hidden]) self.final_state = state self._add_layers(self.outputs) self._add_params(rnn_variables)
[docs]class BiRNNLayer(Layer): """ The :class:`BiRNNLayer` class is a fixed length Bidirectional recurrent layer. Parameters ---------- prev_layer : :class:`Layer` Previous layer. cell_fn : TensorFlow cell function A TensorFlow core RNN cell. - See `RNN Cells in TensorFlow <https://www.tensorflow.org/api_docs/python/>`__. - Note TF1.0+ and TF1.0- are different. cell_init_args : dictionary or None The arguments for the cell function. n_hidden : int The number of hidden units in the layer. initializer : initializer The initializer for initializing the model parameters. n_steps : int The fixed sequence length. fw_initial_state : None or forward RNN State If None, `initial_state` is zero state. bw_initial_state : None or backward RNN State If None, `initial_state` is zero state. dropout : tuple of float or int The input and output keep probability (input_keep_prob, output_keep_prob). If one int, input and output keep probability are the same. n_layer : int The number of RNN layers, default is 1. return_last : boolean Whether return last output or all outputs in each step. - If True, return the last output, "Sequence input and single output" - If False, return all outputs, "Synced sequence input and output" - In other word, if you want to stack more RNNs on this layer, set to False. return_seq_2d : boolean Only consider this argument when `return_last` is `False` - If True, return 2D Tensor [n_example, n_hidden], for stacking DenseLayer after it. - If False, return 3D Tensor [n_example/n_steps, n_steps, n_hidden], for stacking multiple RNN after it. name : str A unique layer name. Attributes ---------- outputs : tensor The output of this layer. fw(bw)_final_state : tensor or StateTuple The finial state of this layer. - When `state_is_tuple` is `False`, it is the final hidden and cell states, `states.get_shape() = [?, 2 * n_hidden]`. - When `state_is_tuple` is `True`, it stores two elements: `(c, h)`. - In practice, you can get the final state after each iteration during training, then feed it to the initial state of next iteration. fw(bw)_initial_state : tensor or StateTuple The initial state of this layer. - In practice, you can set your state at the begining of each epoch or iteration according to your training procedure. batch_size : int or tensor It is an integer, if it is able to compute the `batch_size`; otherwise, tensor for dynamic batch size. Notes ----- Input dimension should be rank 3 : [batch_size, n_steps, n_features]. If not, please see :class:`ReshapeLayer`. For predicting, the sequence length has to be the same with the sequence length of training, while, for normal RNN, we can use sequence length of 1 for predicting. References ---------- `Source <https://github.com/akaraspt/deepsleep/blob/master/deepsleep/model.py>`__ """ @deprecated_alias(layer='prev_layer', end_support_version=1.9) # TODO remove this line for the 1.9 release def __init__( self, prev_layer, cell_fn, cell_init_args=None, n_hidden=100, initializer=tf.random_uniform_initializer(-0.1, 0.1), n_steps=5, fw_initial_state=None, bw_initial_state=None, dropout=None, n_layer=1, return_last=False, return_seq_2d=False, name='birnn', ): super(BiRNNLayer, self).__init__(prev_layer=prev_layer, cell_init_args=cell_init_args, name=name) if self.cell_init_args: self.cell_init_args['state_is_tuple'] = True # 'use_peepholes': True, if 'GRU' in cell_fn.__name__: try: self.cell_init_args.pop('state_is_tuple') except Exception: logging.warning("pop state_is_tuple fails.") if cell_fn is None: raise Exception("Please put in cell_fn") logging.info( "BiRNNLayer %s: n_hidden: %d n_steps: %d in_dim: %d in_shape: %s cell_fn: %s dropout: %s n_layer: %d " % ( self.name, n_hidden, n_steps, self.inputs.get_shape().ndims, self.inputs.get_shape(), cell_fn.__name__, dropout, n_layer ) ) fixed_batch_size = self.inputs.get_shape().with_rank_at_least(1)[0] if fixed_batch_size.value: self.batch_size = fixed_batch_size.value logging.info(" RNN batch_size (concurrent processes): %d" % self.batch_size) else: self.batch_size = array_ops.shape(self.inputs)[0] logging.info(" non specified batch_size, uses a tensor instead.") # Input dimension should be rank 3 [batch_size, n_steps(max), n_features] try: self.inputs.get_shape().with_rank(3) except Exception: raise Exception("RNN : Input dimension should be rank 3 : [batch_size, n_steps, n_features]") with tf.variable_scope(name, initializer=initializer) as vs: rnn_creator = lambda: cell_fn(num_units=n_hidden, **self.cell_init_args) # Apply dropout if dropout: if isinstance(dropout, (tuple, list)): # type(dropout) in [tuple, list]: in_keep_prob = dropout[0] out_keep_prob = dropout[1] elif isinstance(dropout, float): in_keep_prob, out_keep_prob = dropout, dropout else: raise Exception("Invalid dropout type (must be a 2-D tuple of " "float)") DropoutWrapper_fn = tf.contrib.rnn.DropoutWrapper cell_creator = lambda is_last=True: DropoutWrapper_fn( rnn_creator(), input_keep_prob=in_keep_prob, output_keep_prob=out_keep_prob if is_last else 1.0 ) else: cell_creator = rnn_creator self.fw_cell = cell_creator() self.bw_cell = cell_creator() # Apply multiple layers if n_layer > 1: MultiRNNCell_fn = tf.contrib.rnn.MultiRNNCell if dropout: try: self.fw_cell = MultiRNNCell_fn( [cell_creator(is_last=i == n_layer - 1) for i in range(n_layer)], state_is_tuple=True ) self.bw_cell = MultiRNNCell_fn( [cell_creator(is_last=i == n_layer - 1) for i in range(n_layer)], state_is_tuple=True ) except Exception: self.fw_cell = MultiRNNCell_fn([cell_creator(is_last=i == n_layer - 1) for i in range(n_layer)]) self.bw_cell = MultiRNNCell_fn([cell_creator(is_last=i == n_layer - 1) for i in range(n_layer)]) else: try: self.fw_cell = MultiRNNCell_fn([cell_creator() for _ in range(n_layer)], state_is_tuple=True) self.bw_cell = MultiRNNCell_fn([cell_creator() for _ in range(n_layer)], state_is_tuple=True) except Exception: self.fw_cell = MultiRNNCell_fn([cell_creator() for _ in range(n_layer)]) self.bw_cell = MultiRNNCell_fn([cell_creator() for _ in range(n_layer)]) # Initial state of RNN if fw_initial_state is None: self.fw_initial_state = self.fw_cell.zero_state( self.batch_size, dtype=LayersConfig.tf_dtype ) # dtype=tf.float32) else: self.fw_initial_state = fw_initial_state if bw_initial_state is None: self.bw_initial_state = self.bw_cell.zero_state( self.batch_size, dtype=LayersConfig.tf_dtype ) # dtype=tf.float32) else: self.bw_initial_state = bw_initial_state # exit() # Feedforward to MultiRNNCell list_rnn_inputs = tf.unstack(self.inputs, axis=1) bidirectional_rnn_fn = tf.contrib.rnn.static_bidirectional_rnn outputs, fw_state, bw_state = bidirectional_rnn_fn( # outputs, fw_state, bw_state = tf.contrib.rnn.static_bidirectional_rnn( cell_fw=self.fw_cell, cell_bw=self.bw_cell, inputs=list_rnn_inputs, initial_state_fw=self.fw_initial_state, initial_state_bw=self.bw_initial_state ) if return_last: raise Exception("Do not support return_last at the moment.") # self.outputs = outputs[-1] else: self.outputs = outputs if return_seq_2d: # 2D Tensor [n_example, n_hidden] self.outputs = tf.reshape(tf.concat(outputs, 1), [-1, n_hidden * 2]) else: # <akara>: stack more RNN layer after that # 3D Tensor [n_example/n_steps, n_steps, n_hidden] self.outputs = tf.reshape(tf.concat(outputs, 1), [-1, n_steps, n_hidden * 2]) self.fw_final_state = fw_state self.bw_final_state = bw_state # Retrieve just the RNN variables. rnn_variables = tf.get_collection(TF_GRAPHKEYS_VARIABLES, scope=vs.name) logging.info(" n_params : %d" % (len(rnn_variables))) self._add_layers(self.outputs) self._add_params(rnn_variables)
[docs]class ConvRNNCell(object): """Abstract object representing an Convolutional RNN Cell.""" def __call__(self, inputs, state, scope=None): """Run this RNN cell on inputs, starting from the given state.""" raise NotImplementedError("Abstract method") @property def state_size(self): """size(s) of state(s) used by this cell.""" raise NotImplementedError("Abstract method") @property def output_size(self): """Integer or TensorShape: size of outputs produced by this cell.""" raise NotImplementedError("Abstract method") def zero_state(self, batch_size, dtype=LayersConfig.tf_dtype): """Return zero-filled state tensor(s). Args: batch_size: int, float, or unit Tensor representing the batch size. Returns: tensor of shape '[batch_size x shape[0] x shape[1] x num_features] filled with zeros """ shape = self.shape num_features = self.num_features # TODO : TypeError: 'NoneType' object is not subscriptable zeros = tf.zeros([batch_size, shape[0], shape[1], num_features * 2], dtype=dtype) return zeros
[docs]class BasicConvLSTMCell(ConvRNNCell): """Basic Conv LSTM recurrent network cell. Parameters ----------- shape : tuple of int The height and width of the cell. filter_size : tuple of int The height and width of the filter num_features : int The hidden size of the cell forget_bias : float The bias added to forget gates (see above). input_size : int Deprecated and unused. state_is_tuple : boolen If True, accepted and returned states are 2-tuples of the `c_state` and `m_state`. If False, they are concatenated along the column axis. The latter behavior will soon be deprecated. act : activation function The activation function of this layer, tanh as default. """ def __init__( self, shape, filter_size, num_features, forget_bias=1.0, input_size=None, state_is_tuple=False, act=tf.nn.tanh ): """Initialize the basic Conv LSTM cell.""" # if not state_is_tuple: # logging.warn("%s: Using a concatenated state is slower and will soon be " # "deprecated. Use state_is_tuple=True.", self) if input_size is not None: logging.warn("%s: The input_size parameter is deprecated.", self) self.shape = shape self.filter_size = filter_size self.num_features = num_features self._forget_bias = forget_bias self._state_is_tuple = state_is_tuple self._activation = act @property def state_size(self): """State size of the LSTMStateTuple.""" return (LSTMStateTuple(self._num_units, self._num_units) if self._state_is_tuple else 2 * self._num_units) @property def output_size(self): """Number of units in outputs.""" return self._num_units def __call__(self, inputs, state, scope=None): """Long short-term memory cell (LSTM).""" with tf.variable_scope(scope or type(self).__name__): # "BasicLSTMCell" # Parameters of gates are concatenated into one multiply for efficiency. if self._state_is_tuple: c, h = state else: # print state # c, h = tf.split(3, 2, state) c, h = tf.split(state, 2, 3) concat = _conv_linear([inputs, h], self.filter_size, self.num_features * 4, True) # i = input_gate, j = new_input, f = forget_gate, o = output_gate # i, j, f, o = tf.split(3, 4, concat) i, j, f, o = tf.split(concat, 4, 3) new_c = (c * tf.nn.sigmoid(f + self._forget_bias) + tf.nn.sigmoid(i) * self._activation(j)) new_h = self._activation(new_c) * tf.nn.sigmoid(o) if self._state_is_tuple: new_state = LSTMStateTuple(new_c, new_h) else: new_state = tf.concat([new_c, new_h], 3) return new_h, new_state
def _conv_linear(args, filter_size, num_features, bias, bias_start=0.0, scope=None): """convolution: Parameters ---------- args : tensor 4D Tensor or a list of 4D, batch x n, Tensors. filter_size : tuple of int Filter height and width. num_features : int Nnumber of features. bias_start : float Starting value to initialize the bias; 0 by default. scope : VariableScope For the created subgraph; defaults to "Linear". Returns -------- - A 4D Tensor with shape [batch h w num_features] Raises ------- - ValueError : if some of the arguments has unspecified or wrong shape. """ # Calculate the total size of arguments on dimension 1. total_arg_size_depth = 0 shapes = [a.get_shape().as_list() for a in args] for shape in shapes: if len(shape) != 4: raise ValueError("Linear is expecting 4D arguments: %s" % str(shapes)) if not shape[3]: raise ValueError("Linear expects shape[4] of arguments: %s" % str(shapes)) else: total_arg_size_depth += shape[3] dtype = [a.dtype for a in args][0] # Now the computation. with tf.variable_scope(scope or "Conv"): matrix = tf.get_variable( "Matrix", [filter_size[0], filter_size[1], total_arg_size_depth, num_features], dtype=dtype ) if len(args) == 1: res = tf.nn.conv2d(args[0], matrix, strides=[1, 1, 1, 1], padding='SAME') else: res = tf.nn.conv2d(tf.concat(args, 3), matrix, strides=[1, 1, 1, 1], padding='SAME') if not bias: return res bias_term = tf.get_variable( "Bias", [num_features], dtype=dtype, initializer=tf.constant_initializer(bias_start, dtype=dtype) ) return res + bias_term
[docs]class ConvLSTMLayer(Layer): """A fixed length Convolutional LSTM layer. See this `paper <https://arxiv.org/abs/1506.04214>`__ . Parameters ---------- prev_layer : :class:`Layer` Previous layer cell_shape : tuple of int The shape of each cell width * height filter_size : tuple of int The size of filter width * height cell_fn : a convolutional RNN cell Cell function like :class:`BasicConvLSTMCell` feature_map : int The number of feature map in the layer. initializer : initializer The initializer for initializing the parameters. n_steps : int The sequence length. initial_state : None or ConvLSTM State If None, `initial_state` is zero state. return_last : boolean Whether return last output or all outputs in each step. - If True, return the last output, "Sequence input and single output". - If False, return all outputs, "Synced sequence input and output". - In other word, if you want to stack more RNNs on this layer, set to False. return_seq_2d : boolean Only consider this argument when `return_last` is `False` - If True, return 2D Tensor [n_example, n_hidden], for stacking DenseLayer after it. - If False, return 3D Tensor [n_example/n_steps, n_steps, n_hidden], for stacking multiple RNN after it. name : str A unique layer name. Attributes ---------- outputs : tensor The output of this RNN. return_last = False, outputs = all cell_output, which is the hidden state. cell_output.get_shape() = (?, h, w, c]) final_state : tensor or StateTuple The finial state of this layer. - When state_is_tuple = False, it is the final hidden and cell states, - When state_is_tuple = True, You can get the final state after each iteration during training, then feed it to the initial state of next iteration. initial_state : tensor or StateTuple It is the initial state of this ConvLSTM layer, you can use it to initialize your state at the beginning of each epoch or iteration according to your training procedure. batch_size : int or tensor Is int, if able to compute the batch_size, otherwise, tensor for ``?``. """ @deprecated_alias(layer='prev_layer', end_support_version=1.9) # TODO remove this line for the 1.9 release def __init__( self, prev_layer, cell_shape=None, feature_map=1, filter_size=(3, 3), cell_fn=BasicConvLSTMCell, initializer=tf.random_uniform_initializer(-0.1, 0.1), n_steps=5, initial_state=None, return_last=False, return_seq_2d=False, name='convlstm', ): super(ConvLSTMLayer, self).__init__(prev_layer=prev_layer, name=name) logging.info( "ConvLSTMLayer %s: feature_map: %d, n_steps: %d, " "in_dim: %d %s, cell_fn: %s " % (self.name, feature_map, n_steps, self.inputs.get_shape().ndims, self.inputs.get_shape(), cell_fn.__name__) ) # You can get the dimension by .get_shape() or ._shape, and check the # dimension by .with_rank() as follow. # self.inputs.get_shape().with_rank(2) # self.inputs.get_shape().with_rank(3) # Input dimension should be rank 5 [batch_size, n_steps(max), h, w, c] try: self.inputs.get_shape().with_rank(5) except Exception: raise Exception( "RNN : Input dimension should be rank 5 : [batch_size, n_steps, input_x, " "input_y, feature_map]" ) fixed_batch_size = self.inputs.get_shape().with_rank_at_least(1)[0] if fixed_batch_size.value: batch_size = fixed_batch_size.value logging.info(" RNN batch_size (concurrent processes): %d" % batch_size) else: batch_size = array_ops.shape(self.inputs)[0] logging.info(" non specified batch_size, uses a tensor instead.") self.batch_size = batch_size outputs = [] self.cell = cell = cell_fn(shape=cell_shape, filter_size=filter_size, num_features=feature_map) if initial_state is None: self.initial_state = cell.zero_state(batch_size, dtype=LayersConfig.tf_dtype) else: self.initial_state = initial_state state = self.initial_state # with tf.variable_scope("model", reuse=None, initializer=initializer): with tf.variable_scope(name, initializer=initializer) as vs: for time_step in range(n_steps): if time_step > 0: tf.get_variable_scope().reuse_variables() (cell_output, state) = cell(self.inputs[:, time_step, :, :, :], state) outputs.append(cell_output) # Retrieve just the RNN variables. # rnn_variables = [v for v in tf.all_variables() if v.name.startswith(vs.name)] rnn_variables = tf.get_collection(tf.GraphKeys.VARIABLES, scope=vs.name) logging.info(" n_params : %d" % (len(rnn_variables))) if return_last: # 2D Tensor [batch_size, n_hidden] self.outputs = outputs[-1] else: if return_seq_2d: # PTB tutorial: stack dense layer after that, or compute the cost from the output # 4D Tensor [n_example, h, w, c] self.outputs = tf.reshape(tf.concat(outputs, 1), [-1, cell_shape[0] * cell_shape[1] * feature_map]) else: # <akara>: stack more RNN layer after that # 5D Tensor [n_example/n_steps, n_steps, h, w, c] self.outputs = tf.reshape( tf.concat(outputs, 1), [-1, n_steps, cell_shape[0], cell_shape[1], feature_map] ) self.final_state = state self._add_layers(self.outputs) self._add_params(rnn_variables)
# Advanced Ops for Dynamic RNN
[docs]def advanced_indexing_op(inputs, index): """Advanced Indexing for Sequences, returns the outputs by given sequence lengths. When return the last output :class:`DynamicRNNLayer` uses it to get the last outputs with the sequence lengths. Parameters ----------- inputs : tensor for data With shape of [batch_size, n_step(max), n_features] index : tensor for indexing Sequence length in Dynamic RNN. [batch_size] Examples --------- >>> import numpy as np >>> import tensorflow as tf >>> import tensorlayer as tl >>> batch_size, max_length, n_features = 3, 5, 2 >>> z = np.random.uniform(low=-1, high=1, size=[batch_size, max_length, n_features]).astype(np.float32) >>> b_z = tf.constant(z) >>> sl = tf.placeholder(dtype=tf.int32, shape=[batch_size]) >>> o = advanced_indexing_op(b_z, sl) >>> >>> sess = tf.InteractiveSession() >>> tl.layers.initialize_global_variables(sess) >>> >>> order = np.asarray([1,1,2]) >>> print("real",z[0][order[0]-1], z[1][order[1]-1], z[2][order[2]-1]) >>> y = sess.run([o], feed_dict={sl:order}) >>> print("given",order) >>> print("out", y) real [-0.93021595 0.53820813] [-0.92548317 -0.77135968] [ 0.89952248 0.19149846] given [1 1 2] out [array([[-0.93021595, 0.53820813], [-0.92548317, -0.77135968], [ 0.89952248, 0.19149846]], dtype=float32)] References ----------- - Modified from TFlearn (the original code is used for fixed length rnn), `references <https://github.com/tflearn/tflearn/blob/master/tflearn/layers/recurrent.py>`__. """ batch_size = tf.shape(inputs)[0] # max_length = int(inputs.get_shape()[1]) # for fixed length rnn, length is given max_length = tf.shape(inputs)[1] # for dynamic_rnn, length is unknown dim_size = int(inputs.get_shape()[2]) index = tf.range(0, batch_size) * max_length + (index - 1) flat = tf.reshape(inputs, [-1, dim_size]) relevant = tf.gather(flat, index) return relevant
[docs]def retrieve_seq_length_op(data): """An op to compute the length of a sequence from input shape of [batch_size, n_step(max), n_features], it can be used when the features of padding (on right hand side) are all zeros. Parameters ----------- data : tensor [batch_size, n_step(max), n_features] with zero padding on right hand side. Examples --------- >>> data = [[[1],[2],[0],[0],[0]], ... [[1],[2],[3],[0],[0]], ... [[1],[2],[6],[1],[0]]] >>> data = np.asarray(data) >>> print(data.shape) (3, 5, 1) >>> data = tf.constant(data) >>> sl = retrieve_seq_length_op(data) >>> sess = tf.InteractiveSession() >>> tl.layers.initialize_global_variables(sess) >>> y = sl.eval() [2 3 4] Multiple features >>> data = [[[1,2],[2,2],[1,2],[1,2],[0,0]], ... [[2,3],[2,4],[3,2],[0,0],[0,0]], ... [[3,3],[2,2],[5,3],[1,2],[0,0]]] >>> print(sl) [4 3 4] References ------------ Borrow from `TFlearn <https://github.com/tflearn/tflearn/blob/master/tflearn/layers/recurrent.py>`__. """ with tf.name_scope('GetLength'): used = tf.sign(tf.reduce_max(tf.abs(data), 2)) length = tf.reduce_sum(used, 1) return tf.cast(length, tf.int32)
[docs]def retrieve_seq_length_op2(data): """An op to compute the length of a sequence, from input shape of [batch_size, n_step(max)], it can be used when the features of padding (on right hand side) are all zeros. Parameters ----------- data : tensor [batch_size, n_step(max)] with zero padding on right hand side. Examples -------- >>> data = [[1,2,0,0,0], ... [1,2,3,0,0], ... [1,2,6,1,0]] >>> o = retrieve_seq_length_op2(data) >>> sess = tf.InteractiveSession() >>> tl.layers.initialize_global_variables(sess) >>> print(o.eval()) [2 3 4] """ return tf.reduce_sum(tf.cast(tf.greater(data, tf.zeros_like(data)), tf.int32), 1)
[docs]def retrieve_seq_length_op3(data, pad_val=0): # HangSheng: return tensor for sequence length, if input is tf.string """Return tensor for sequence length, if input is ``tf.string``.""" data_shape_size = data.get_shape().ndims if data_shape_size == 3: return tf.reduce_sum(tf.cast(tf.reduce_any(tf.not_equal(data, pad_val), axis=2), dtype=tf.int32), 1) elif data_shape_size == 2: return tf.reduce_sum(tf.cast(tf.not_equal(data, pad_val), dtype=tf.int32), 1) elif data_shape_size == 1: raise ValueError("retrieve_seq_length_op3: data has wrong shape!") else: raise ValueError( "retrieve_seq_length_op3: handling data_shape_size %s hasn't been implemented!" % (data_shape_size) )
[docs]def target_mask_op(data, pad_val=0): # HangSheng: return tensor for mask,if input is tf.string """Return tensor for mask, if input is ``tf.string``.""" data_shape_size = data.get_shape().ndims if data_shape_size == 3: return tf.cast(tf.reduce_any(tf.not_equal(data, pad_val), axis=2), dtype=tf.int32) elif data_shape_size == 2: return tf.cast(tf.not_equal(data, pad_val), dtype=tf.int32) elif data_shape_size == 1: raise ValueError("target_mask_op: data has wrong shape!") else: raise ValueError("target_mask_op: handling data_shape_size %s hasn't been implemented!" % (data_shape_size))
[docs]class DynamicRNNLayer(Layer): """ The :class:`DynamicRNNLayer` class is a dynamic recurrent layer, see ``tf.nn.dynamic_rnn``. Parameters ---------- prev_layer : :class:`Layer` Previous layer cell_fn : TensorFlow cell function A TensorFlow core RNN cell - See `RNN Cells in TensorFlow <https://www.tensorflow.org/api_docs/python/>`__ - Note TF1.0+ and TF1.0- are different cell_init_args : dictionary or None The arguments for the cell function. n_hidden : int The number of hidden units in the layer. initializer : initializer The initializer for initializing the parameters. sequence_length : tensor, array or None The sequence length of each row of input data, see ``Advanced Ops for Dynamic RNN``. - If None, it uses ``retrieve_seq_length_op`` to compute the sequence length, i.e. when the features of padding (on right hand side) are all zeros. - If using word embedding, you may need to compute the sequence length from the ID array (the integer features before word embedding) by using ``retrieve_seq_length_op2`` or ``retrieve_seq_length_op``. - You can also input an numpy array. - More details about TensorFlow dynamic RNN in `Wild-ML Blog <http://www.wildml.com/2016/08/rnns-in-tensorflow-a-practical-guide-and-undocumented-features/>`__. initial_state : None or RNN State If None, `initial_state` is zero state. dropout : tuple of float or int The input and output keep probability (input_keep_prob, output_keep_prob). - If one int, input and output keep probability are the same. n_layer : int The number of RNN layers, default is 1. return_last : boolean or None Whether return last output or all outputs in each step. - If True, return the last output, "Sequence input and single output" - If False, return all outputs, "Synced sequence input and output" - In other word, if you want to stack more RNNs on this layer, set to False. return_seq_2d : boolean Only consider this argument when `return_last` is `False` - If True, return 2D Tensor [n_example, n_hidden], for stacking DenseLayer after it. - If False, return 3D Tensor [n_example/n_steps, n_steps, n_hidden], for stacking multiple RNN after it. dynamic_rnn_init_args : dictionary The arguments for ``tf.nn.dynamic_rnn``. name : str A unique layer name. Attributes ------------ outputs : tensor The output of this layer. final_state : tensor or StateTuple The finial state of this layer. - When `state_is_tuple` is `False`, it is the final hidden and cell states, `states.get_shape() = [?, 2 * n_hidden]`. - When `state_is_tuple` is `True`, it stores two elements: `(c, h)`. - In practice, you can get the final state after each iteration during training, then feed it to the initial state of next iteration. initial_state : tensor or StateTuple The initial state of this layer. - In practice, you can set your state at the begining of each epoch or iteration according to your training procedure. batch_size : int or tensor It is an integer, if it is able to compute the `batch_size`; otherwise, tensor for dynamic batch size. sequence_length : a tensor or array The sequence lengths computed by Advanced Opt or the given sequence lengths, [batch_size] Notes ----- Input dimension should be rank 3 : [batch_size, n_steps(max), n_features], if no, please see :class:`ReshapeLayer`. Examples -------- Synced sequence input and output, for loss function see ``tl.cost.cross_entropy_seq_with_mask``. >>> input_seqs = tf.placeholder(dtype=tf.int64, shape=[batch_size, None], name="input") >>> net = tl.layers.EmbeddingInputlayer( ... inputs=input_seqs, ... vocabulary_size=vocab_size, ... embedding_size=embedding_size, ... name='embedding') >>> net = tl.layers.DynamicRNNLayer(net, ... cell_fn=tf.contrib.rnn.BasicLSTMCell, # for TF0.2 use tf.nn.rnn_cell.BasicLSTMCell, ... n_hidden=embedding_size, ... dropout=(0.7 if is_train else None), ... sequence_length=tl.layers.retrieve_seq_length_op2(input_seqs), ... return_last=False, # for encoder, set to True ... return_seq_2d=True, # stack denselayer or compute cost after it ... name='dynamicrnn') >>> net = tl.layers.DenseLayer(net, n_units=vocab_size, name="output") References ---------- - `Wild-ML Blog <http://www.wildml.com/2016/08/rnns-in-tensorflow-a-practical-guide-and-undocumented-features/>`__ - `dynamic_rnn.ipynb <https://github.com/dennybritz/tf-rnn/blob/master/dynamic_rnn.ipynb>`__ - `tf.nn.dynamic_rnn <https://github.com/tensorflow/tensorflow/blob/master/tensorflow/g3doc/api_docs/python/functions_and_classes/shard8/tf.nn.dynamic_rnn.md>`__ - `tflearn rnn <https://github.com/tflearn/tflearn/blob/master/tflearn/layers/recurrent.py>`__ - ``tutorial_dynamic_rnn.py`` """ @deprecated_alias(layer='prev_layer', end_support_version=1.9) # TODO remove this line for the 1.9 release def __init__( self, prev_layer, cell_fn, #tf.nn.rnn_cell.LSTMCell, cell_init_args=None, n_hidden=256, initializer=tf.random_uniform_initializer(-0.1, 0.1), sequence_length=None, initial_state=None, dropout=None, n_layer=1, return_last=None, return_seq_2d=False, dynamic_rnn_init_args=None, name='dyrnn', ): if cell_fn is None: raise Exception("Please put in cell_fn") super(DynamicRNNLayer, self).__init__( prev_layer=prev_layer, cell_init_args=cell_init_args, dynamic_rnn_init_args=dynamic_rnn_init_args, name=name ) if self.cell_init_args: self.cell_init_args['state_is_tuple'] = True # 'use_peepholes': True if 'GRU' in cell_fn.__name__: try: self.cell_init_args.pop('state_is_tuple') except Exception: logging.warning("pop state_is_tuple fails.") if return_last is None: return_last = True logging.info( "DynamicRNNLayer %s: n_hidden: %d, in_dim: %d in_shape: %s cell_fn: %s dropout: %s n_layer: %d" % ( self.name, n_hidden, self.inputs.get_shape().ndims, self.inputs.get_shape(), cell_fn.__name__, dropout, n_layer ) ) # Input dimension should be rank 3 [batch_size, n_steps(max), n_features] try: self.inputs.get_shape().with_rank(3) except Exception: raise Exception("RNN : Input dimension should be rank 3 : [batch_size, n_steps(max), n_features]") # Get the batch_size fixed_batch_size = self.inputs.get_shape().with_rank_at_least(1)[0] if fixed_batch_size.value: batch_size = fixed_batch_size.value logging.info(" batch_size (concurrent processes): %d" % batch_size) else: batch_size = array_ops.shape(self.inputs)[0] logging.info(" non specified batch_size, uses a tensor instead.") self.batch_size = batch_size # Creats the cell function # cell_instance_fn=lambda: cell_fn(num_units=n_hidden, **self.cell_init_args) # HanSheng rnn_creator = lambda: cell_fn(num_units=n_hidden, **self.cell_init_args) # Apply dropout if dropout: if isinstance(dropout, (tuple, list)): in_keep_prob = dropout[0] out_keep_prob = dropout[1] elif isinstance(dropout, float): in_keep_prob, out_keep_prob = dropout, dropout else: raise Exception("Invalid dropout type (must be a 2-D tuple of " "float)") DropoutWrapper_fn = tf.contrib.rnn.DropoutWrapper # cell_instance_fn1=cell_instance_fn # HanSheng # cell_instance_fn=DropoutWrapper_fn( # cell_instance_fn1(), # input_keep_prob=in_keep_prob, # output_keep_prob=out_keep_prob) cell_creator = lambda is_last=True: DropoutWrapper_fn( rnn_creator(), input_keep_prob=in_keep_prob, output_keep_prob=out_keep_prob if is_last else 1.0 ) else: cell_creator = rnn_creator self.cell = cell_creator() # Apply multiple layers if n_layer > 1: try: MultiRNNCell_fn = tf.contrib.rnn.MultiRNNCell except Exception: MultiRNNCell_fn = tf.nn.rnn_cell.MultiRNNCell # cell_instance_fn2=cell_instance_fn # HanSheng if dropout: try: # cell_instance_fn=lambda: MultiRNNCell_fn([cell_instance_fn2() for _ in range(n_layer)], state_is_tuple=True) # HanSheng self.cell = MultiRNNCell_fn( [cell_creator(is_last=i == n_layer - 1) for i in range(n_layer)], state_is_tuple=True ) except Exception: # when GRU # cell_instance_fn=lambda: MultiRNNCell_fn([cell_instance_fn2() for _ in range(n_layer)]) # HanSheng self.cell = MultiRNNCell_fn([cell_creator(is_last=i == n_layer - 1) for i in range(n_layer)]) else: try: self.cell = MultiRNNCell_fn([cell_creator() for _ in range(n_layer)], state_is_tuple=True) except Exception: # when GRU self.cell = MultiRNNCell_fn([cell_creator() for _ in range(n_layer)]) # self.cell=cell_instance_fn() # HanSheng # Initialize initial_state if initial_state is None: self.initial_state = self.cell.zero_state(batch_size, dtype=LayersConfig.tf_dtype) # dtype=tf.float32) else: self.initial_state = initial_state # Computes sequence_length if sequence_length is None: sequence_length = retrieve_seq_length_op( self.inputs if isinstance(self.inputs, tf.Tensor) else tf.stack(self.inputs) ) # Main - Computes outputs and last_states with tf.variable_scope(name, initializer=initializer) as vs: outputs, last_states = tf.nn.dynamic_rnn( cell=self.cell, # inputs=X inputs=self.inputs, # dtype=tf.float64, sequence_length=sequence_length, initial_state=self.initial_state, **self.dynamic_rnn_init_args ) rnn_variables = tf.get_collection(TF_GRAPHKEYS_VARIABLES, scope=vs.name) # logging.info(" n_params : %d" % (len(rnn_variables))) # Manage the outputs if return_last: # [batch_size, n_hidden] # outputs = tf.transpose(tf.pack(outputs), [1, 0, 2]) self.outputs = advanced_indexing_op(outputs, sequence_length) else: # [batch_size, n_step(max), n_hidden] # self.outputs = result[0]["outputs"] # self.outputs = outputs # it is 3d, but it is a list if return_seq_2d: # PTB tutorial: # 2D Tensor [n_example, n_hidden] self.outputs = tf.reshape(tf.concat(outputs, 1), [-1, n_hidden]) else: # <akara>: # 3D Tensor [batch_size, n_steps(max), n_hidden] max_length = tf.shape(outputs)[1] batch_size = tf.shape(outputs)[0] self.outputs = tf.reshape(tf.concat(outputs, 1), [batch_size, max_length, n_hidden]) # self.outputs = tf.reshape(tf.concat(1, outputs), [-1, max_length, n_hidden]) # Final state self.final_state = last_states self.sequence_length = sequence_length self._add_layers(self.outputs) self._add_params(rnn_variables)
[docs]class BiDynamicRNNLayer(Layer): """ The :class:`BiDynamicRNNLayer` class is a RNN layer, you can implement vanilla RNN, LSTM and GRU with it. Parameters ---------- prev_layer : :class:`Layer` Previous layer. cell_fn : TensorFlow cell function A TensorFlow core RNN cell - See `RNN Cells in TensorFlow <https://www.tensorflow.org/api_docs/python/>`__. - Note TF1.0+ and TF1.0- are different. cell_init_args : dictionary The arguments for the cell initializer. n_hidden : int The number of hidden units in the layer. initializer : initializer The initializer for initializing the parameters. sequence_length : tensor, array or None The sequence length of each row of input data, see ``Advanced Ops for Dynamic RNN``. - If None, it uses ``retrieve_seq_length_op`` to compute the sequence length, i.e. when the features of padding (on right hand side) are all zeros. - If using word embedding, you may need to compute the sequence length from the ID array (the integer features before word embedding) by using ``retrieve_seq_length_op2`` or ``retrieve_seq_length_op``. - You can also input an numpy array. - More details about TensorFlow dynamic RNN in `Wild-ML Blog <http://www.wildml.com/2016/08/rnns-in-tensorflow-a-practical-guide-and-undocumented-features/>`__. fw_initial_state : None or forward RNN State If None, `initial_state` is zero state. bw_initial_state : None or backward RNN State If None, `initial_state` is zero state. dropout : tuple of float or int The input and output keep probability (input_keep_prob, output_keep_prob). - If one int, input and output keep probability are the same. n_layer : int The number of RNN layers, default is 1. return_last : boolean Whether return last output or all outputs in each step. - If True, return the last output, "Sequence input and single output" - If False, return all outputs, "Synced sequence input and output" - In other word, if you want to stack more RNNs on this layer, set to False. return_seq_2d : boolean Only consider this argument when `return_last` is `False` - If True, return 2D Tensor [n_example, 2 * n_hidden], for stacking DenseLayer after it. - If False, return 3D Tensor [n_example/n_steps, n_steps, 2 * n_hidden], for stacking multiple RNN after it. dynamic_rnn_init_args : dictionary The arguments for ``tf.nn.bidirectional_dynamic_rnn``. name : str A unique layer name. Attributes ----------------------- outputs : tensor The output of this layer. (?, 2 * n_hidden) fw(bw)_final_state : tensor or StateTuple The finial state of this layer. - When `state_is_tuple` is `False`, it is the final hidden and cell states, `states.get_shape() = [?, 2 * n_hidden]`. - When `state_is_tuple` is `True`, it stores two elements: `(c, h)`. - In practice, you can get the final state after each iteration during training, then feed it to the initial state of next iteration. fw(bw)_initial_state : tensor or StateTuple The initial state of this layer. - In practice, you can set your state at the begining of each epoch or iteration according to your training procedure. batch_size : int or tensor It is an integer, if it is able to compute the `batch_size`; otherwise, tensor for dynamic batch size. sequence_length : a tensor or array The sequence lengths computed by Advanced Opt or the given sequence lengths, [batch_size]. Notes ----- Input dimension should be rank 3 : [batch_size, n_steps(max), n_features], if no, please see :class:`ReshapeLayer`. References ---------- - `Wild-ML Blog <http://www.wildml.com/2016/08/rnns-in-tensorflow-a-practical-guide-and-undocumented-features/>`__ - `bidirectional_rnn.ipynb <https://github.com/dennybritz/tf-rnn/blob/master/bidirectional_rnn.ipynb>`__ """ @deprecated_alias(layer='prev_layer', end_support_version=1.9) # TODO remove this line for the 1.9 release def __init__( self, prev_layer, cell_fn, #tf.nn.rnn_cell.LSTMCell, cell_init_args=None, n_hidden=256, initializer=tf.random_uniform_initializer(-0.1, 0.1), sequence_length=None, fw_initial_state=None, bw_initial_state=None, dropout=None, n_layer=1, return_last=False, return_seq_2d=False, dynamic_rnn_init_args=None, name='bi_dyrnn_layer', ): super(BiDynamicRNNLayer, self).__init__( prev_layer=prev_layer, cell_init_args=cell_init_args, dynamic_rnn_init_args=dynamic_rnn_init_args, name=name ) if self.cell_init_args: self.cell_init_args['state_is_tuple'] = True # 'use_peepholes': True, if 'GRU' in cell_fn.__name__: try: self.cell_init_args.pop('state_is_tuple') except Exception: logging.warning("pop state_is_tuple fails.") if cell_fn is None: raise Exception("Please put in cell_fn") logging.info( "BiDynamicRNNLayer %s: n_hidden: %d in_dim: %d in_shape: %s cell_fn: %s dropout: %s n_layer: %d" % ( self.name, n_hidden, self.inputs.get_shape().ndims, self.inputs.get_shape(), cell_fn.__name__, dropout, n_layer ) ) # Input dimension should be rank 3 [batch_size, n_steps(max), n_features] try: self.inputs.get_shape().with_rank(3) except Exception: raise Exception("RNN : Input dimension should be rank 3 : [batch_size, n_steps(max), n_features]") # Get the batch_size fixed_batch_size = self.inputs.get_shape().with_rank_at_least(1)[0] if fixed_batch_size.value: batch_size = fixed_batch_size.value logging.info(" batch_size (concurrent processes): %d" % batch_size) else: batch_size = array_ops.shape(self.inputs)[0] logging.info(" non specified batch_size, uses a tensor instead.") self.batch_size = batch_size with tf.variable_scope(name, initializer=initializer) as vs: # Creats the cell function # cell_instance_fn=lambda: cell_fn(num_units=n_hidden, **self.cell_init_args) # HanSheng rnn_creator = lambda: cell_fn(num_units=n_hidden, **self.cell_init_args) # Apply dropout if dropout: if isinstance(dropout, (tuple, list)): in_keep_prob = dropout[0] out_keep_prob = dropout[1] elif isinstance(dropout, float): in_keep_prob, out_keep_prob = dropout, dropout else: raise Exception("Invalid dropout type (must be a 2-D tuple of " "float)") try: DropoutWrapper_fn = tf.contrib.rnn.DropoutWrapper except Exception: DropoutWrapper_fn = tf.nn.rnn_cell.DropoutWrapper # cell_instance_fn1=cell_instance_fn # HanSheng # cell_instance_fn=lambda: DropoutWrapper_fn( # cell_instance_fn1(), # input_keep_prob=in_keep_prob, # output_keep_prob=out_keep_prob) cell_creator = lambda is_last=True: DropoutWrapper_fn( rnn_creator(), input_keep_prob=in_keep_prob, output_keep_prob=out_keep_prob if is_last else 1.0 ) else: cell_creator = rnn_creator # if dropout: # self.fw_cell = DropoutWrapper_fn(self.fw_cell, input_keep_prob=1.0, output_keep_prob=out_keep_prob) # self.bw_cell = DropoutWrapper_fn(self.bw_cell, input_keep_prob=1.0, output_keep_prob=out_keep_prob) # self.fw_cell=cell_instance_fn() # self.bw_cell=cell_instance_fn() # Initial state of RNN self.fw_initial_state = fw_initial_state self.bw_initial_state = bw_initial_state # Computes sequence_length if sequence_length is None: sequence_length = retrieve_seq_length_op( self.inputs if isinstance(self.inputs, tf.Tensor) else tf.stack(self.inputs) ) if n_layer > 1: if dropout: self.fw_cell = [cell_creator(is_last=i == n_layer - 1) for i in range(n_layer)] self.bw_cell = [cell_creator(is_last=i == n_layer - 1) for i in range(n_layer)] else: self.fw_cell = [cell_creator() for _ in range(n_layer)] self.bw_cell = [cell_creator() for _ in range(n_layer)] outputs, states_fw, states_bw = stack_bidirectional_dynamic_rnn( cells_fw=self.fw_cell, cells_bw=self.bw_cell, inputs=self.inputs, sequence_length=sequence_length, initial_states_fw=self.fw_initial_state, initial_states_bw=self.bw_initial_state, dtype=LayersConfig.tf_dtype, **self.dynamic_rnn_init_args ) else: self.fw_cell = cell_creator() self.bw_cell = cell_creator() outputs, (states_fw, states_bw) = tf.nn.bidirectional_dynamic_rnn( cell_fw=self.fw_cell, cell_bw=self.bw_cell, inputs=self.inputs, sequence_length=sequence_length, initial_state_fw=self.fw_initial_state, initial_state_bw=self.bw_initial_state, dtype=LayersConfig.tf_dtype, **self.dynamic_rnn_init_args ) rnn_variables = tf.get_collection(TF_GRAPHKEYS_VARIABLES, scope=vs.name) logging.info(" n_params : %d" % (len(rnn_variables))) # Manage the outputs outputs = tf.concat(outputs, 2) if return_last: # [batch_size, 2 * n_hidden] raise NotImplementedError("Return last is not implemented yet.") # self.outputs = advanced_indexing_op(outputs, sequence_length) else: # [batch_size, n_step(max), 2 * n_hidden] if return_seq_2d: # PTB tutorial: # 2D Tensor [n_example, 2 * n_hidden] self.outputs = tf.reshape(tf.concat(outputs, 1), [-1, 2 * n_hidden]) else: # <akara>: # 3D Tensor [batch_size, n_steps(max), 2 * n_hidden] max_length = tf.shape(outputs)[1] batch_size = tf.shape(outputs)[0] self.outputs = tf.reshape(tf.concat(outputs, 1), [batch_size, max_length, 2 * n_hidden]) # Final state self.fw_final_states = states_fw self.bw_final_states = states_bw self.sequence_length = sequence_length self._add_layers(self.outputs) self._add_params(rnn_variables)
[docs]class Seq2Seq(Layer): """ The :class:`Seq2Seq` class is a simple :class:`DynamicRNNLayer` based Seq2seq layer without using `tl.contrib.seq2seq <https://www.tensorflow.org/api_guides/python/contrib.seq2seq>`__. See `Model <https://camo.githubusercontent.com/9e88497fcdec5a9c716e0de5bc4b6d1793c6e23f/687474703a2f2f73757269796164656570616e2e6769746875622e696f2f696d672f736571327365712f73657132736571322e706e67>`__ and `Sequence to Sequence Learning with Neural Networks <https://arxiv.org/abs/1409.3215>`__. - Please check this example `Chatbot in 200 lines of code <https://github.com/tensorlayer/seq2seq-chatbot>`__. - The Author recommends users to read the source code of :class:`DynamicRNNLayer` and :class:`Seq2Seq`. Parameters ---------- net_encode_in : :class:`Layer` Encode sequences, [batch_size, None, n_features]. net_decode_in : :class:`Layer` Decode sequences, [batch_size, None, n_features]. cell_fn : TensorFlow cell function A TensorFlow core RNN cell - see `RNN Cells in TensorFlow <https://www.tensorflow.org/api_docs/python/>`__ - Note TF1.0+ and TF1.0- are different cell_init_args : dictionary or None The arguments for the cell initializer. n_hidden : int The number of hidden units in the layer. initializer : initializer The initializer for the parameters. encode_sequence_length : tensor For encoder sequence length, see :class:`DynamicRNNLayer` . decode_sequence_length : tensor For decoder sequence length, see :class:`DynamicRNNLayer` . initial_state_encode : None or RNN state If None, `initial_state_encode` is zero state, it can be set by placeholder or other RNN. initial_state_decode : None or RNN state If None, `initial_state_decode` is the final state of the RNN encoder, it can be set by placeholder or other RNN. dropout : tuple of float or int The input and output keep probability (input_keep_prob, output_keep_prob). - If one int, input and output keep probability are the same. n_layer : int The number of RNN layers, default is 1. return_seq_2d : boolean Only consider this argument when `return_last` is `False` - If True, return 2D Tensor [n_example, 2 * n_hidden], for stacking DenseLayer after it. - If False, return 3D Tensor [n_example/n_steps, n_steps, 2 * n_hidden], for stacking multiple RNN after it. name : str A unique layer name. Attributes ------------ outputs : tensor The output of RNN decoder. initial_state_encode : tensor or StateTuple Initial state of RNN encoder. initial_state_decode : tensor or StateTuple Initial state of RNN decoder. final_state_encode : tensor or StateTuple Final state of RNN encoder. final_state_decode : tensor or StateTuple Final state of RNN decoder. Notes -------- - How to feed data: `Sequence to Sequence Learning with Neural Networks <https://arxiv.org/pdf/1409.3215v3.pdf>`__ - input_seqs : ``['how', 'are', 'you', '<PAD_ID>']`` - decode_seqs : ``['<START_ID>', 'I', 'am', 'fine', '<PAD_ID>']`` - target_seqs : ``['I', 'am', 'fine', '<END_ID>', '<PAD_ID>']`` - target_mask : ``[1, 1, 1, 1, 0]`` - related functions : tl.prepro <pad_sequences, precess_sequences, sequences_add_start_id, sequences_get_mask> Examples ---------- >>> from tensorlayer.layers import * >>> batch_size = 32 >>> encode_seqs = tf.placeholder(dtype=tf.int64, shape=[batch_size, None], name="encode_seqs") >>> decode_seqs = tf.placeholder(dtype=tf.int64, shape=[batch_size, None], name="decode_seqs") >>> target_seqs = tf.placeholder(dtype=tf.int64, shape=[batch_size, None], name="target_seqs") >>> target_mask = tf.placeholder(dtype=tf.int64, shape=[batch_size, None], name="target_mask") # tl.prepro.sequences_get_mask() >>> with tf.variable_scope("model"): >>> # for chatbot, you can use the same embedding layer, >>> # for translation, you may want to use 2 seperated embedding layers >>> with tf.variable_scope("embedding") as vs: >>> net_encode = EmbeddingInputlayer( ... inputs = encode_seqs, ... vocabulary_size = 10000, ... embedding_size = 200, ... name = 'seq_embedding') >>> vs.reuse_variables() >>> tl.layers.set_name_reuse(True) >>> net_decode = EmbeddingInputlayer( ... inputs = decode_seqs, ... vocabulary_size = 10000, ... embedding_size = 200, ... name = 'seq_embedding') >>> net = Seq2Seq(net_encode, net_decode, ... cell_fn = tf.contrib.rnn.BasicLSTMCell, ... n_hidden = 200, ... initializer = tf.random_uniform_initializer(-0.1, 0.1), ... encode_sequence_length = retrieve_seq_length_op2(encode_seqs), ... decode_sequence_length = retrieve_seq_length_op2(decode_seqs), ... initial_state_encode = None, ... dropout = None, ... n_layer = 1, ... return_seq_2d = True, ... name = 'seq2seq') >>> net_out = DenseLayer(net, n_units=10000, act=None, name='output') >>> e_loss = tl.cost.cross_entropy_seq_with_mask(logits=net_out.outputs, target_seqs=target_seqs, input_mask=target_mask, return_details=False, name='cost') >>> y = tf.nn.softmax(net_out.outputs) >>> net_out.print_params(False) """ def __init__( self, net_encode_in, net_decode_in, cell_fn, #tf.nn.rnn_cell.LSTMCell, cell_init_args=None, n_hidden=256, initializer=tf.random_uniform_initializer(-0.1, 0.1), encode_sequence_length=None, decode_sequence_length=None, initial_state_encode=None, initial_state_decode=None, dropout=None, n_layer=1, return_seq_2d=False, name='seq2seq', ): super(Seq2Seq, self).__init__(prev_layer=[net_encode_in, net_decode_in], cell_init_args=cell_init_args, name=name) if self.cell_init_args: self.cell_init_args['state_is_tuple'] = True # 'use_peepholes': True, if cell_fn is None: raise ValueError("cell_fn cannot be set to None") if 'GRU' in cell_fn.__name__: try: cell_init_args.pop('state_is_tuple') except Exception: logging.warning("pop state_is_tuple fails.") logging.info( "[*] Seq2Seq %s: n_hidden: %d cell_fn: %s dropout: %s n_layer: %d" % (self.name, n_hidden, cell_fn.__name__, dropout, n_layer) ) with tf.variable_scope(name): # tl.layers.set_name_reuse(reuse) # network = InputLayer(self.inputs, name=name+'/input') network_encode = DynamicRNNLayer( net_encode_in, cell_fn=cell_fn, cell_init_args=self.cell_init_args, n_hidden=n_hidden, initializer=initializer, initial_state=initial_state_encode, dropout=dropout, n_layer=n_layer, sequence_length=encode_sequence_length, return_last=False, return_seq_2d=True, name='encode' ) # vs.reuse_variables() # tl.layers.set_name_reuse(True) network_decode = DynamicRNNLayer( net_decode_in, cell_fn=cell_fn, cell_init_args=self.cell_init_args, n_hidden=n_hidden, initializer=initializer, initial_state=(network_encode.final_state if initial_state_decode is None else initial_state_decode), dropout=dropout, n_layer=n_layer, sequence_length=decode_sequence_length, return_last=False, return_seq_2d=return_seq_2d, name='decode' ) self.outputs = network_decode.outputs # rnn_variables = tf.get_collection(TF_GRAPHKEYS_VARIABLES, scope=vs.name) # Initial state self.initial_state_encode = network_encode.initial_state self.initial_state_decode = network_decode.initial_state # Final state self.final_state_encode = network_encode.final_state self.final_state_decode = network_decode.final_state # self.sequence_length = sequence_length self._add_layers(network_encode.all_layers) self._add_params(network_encode.all_params) self._add_dropout_layers(network_encode.all_drop) self._add_layers(network_decode.all_layers) self._add_params(network_decode.all_params) self._add_dropout_layers(network_decode.all_drop) self._add_layers(self.outputs)