Python tensorflow.python.ops.array_ops.concat() Examples

The following are 30 code examples of tensorflow.python.ops.array_ops.concat(). You can vote up the ones you like or vote down the ones you don't like, and go to the original project or source file by following the links above each example. You may also want to check out all available functions/classes of the module tensorflow.python.ops.array_ops , or try the search function .
Example #1
Source File: laplace.py    From lambda-packs with MIT License 6 votes vote down vote up
def _sample_n(self, n, seed=None):
    shape = array_ops.concat([[n], self.batch_shape_tensor()], 0)
    # Uniform variates must be sampled from the open-interval `(-1, 1)` rather
    # than `[-1, 1)`. In the case of `(0, 1)` we'd use
    # `np.finfo(self.dtype.as_numpy_dtype).tiny` because it is the smallest,
    # positive, "normal" number. However, the concept of subnormality exists
    # only at zero; here we need the smallest usable number larger than -1,
    # i.e., `-1 + eps/2`.
    uniform_samples = random_ops.random_uniform(
        shape=shape,
        minval=np.nextafter(self.dtype.as_numpy_dtype(-1.),
                            self.dtype.as_numpy_dtype(0.)),
        maxval=1.,
        dtype=self.dtype,
        seed=seed)
    return (self.loc - self.scale * math_ops.sign(uniform_samples) *
            math_ops.log1p(-math_ops.abs(uniform_samples))) 
Example #2
Source File: rnn_cell_impl.py    From lambda-packs with MIT License 6 votes vote down vote up
def call(self, inputs, state):
    """Run this multi-layer cell on inputs, starting from state."""
    cur_state_pos = 0
    cur_inp = inputs
    new_states = []
    for i, cell in enumerate(self._cells):
      with vs.variable_scope("cell_%d" % i):
        if self._state_is_tuple:
          if not nest.is_sequence(state):
            raise ValueError(
                "Expected state to be a tuple of length %d, but received: %s" %
                (len(self.state_size), state))
          cur_state = state[i]
        else:
          cur_state = array_ops.slice(state, [0, cur_state_pos],
                                      [-1, cell.state_size])
          cur_state_pos += cell.state_size
        cur_inp, new_state = cell(cur_inp, cur_state)
        new_states.append(new_state)

    new_states = (tuple(new_states) if self._state_is_tuple else
                  array_ops.concat(new_states, 1))

    return cur_inp, new_states 
Example #3
Source File: nn_ops.py    From lambda-packs with MIT License 6 votes vote down vote up
def _flatten_outer_dims(logits):
  """Flattens logits' outer dimensions and keep its last dimension."""
  rank = array_ops.rank(logits)
  last_dim_size = array_ops.slice(
      array_ops.shape(logits), [math_ops.subtract(rank, 1)], [1])
  output = array_ops.reshape(logits, array_ops.concat([[-1], last_dim_size], 0))

  # Set output shape if known.
  shape = logits.get_shape()
  if shape is not None and shape.dims is not None:
    shape = shape.as_list()
    product = 1
    product_valid = True
    for d in shape[:-1]:
      if d is None:
        product_valid = False
        break
      else:
        product *= d
    if product_valid:
      output_shape = [product, shape[-1]]
      output.set_shape(output_shape)

  return output 
Example #4
Source File: rnn_cell_impl.py    From lambda-packs with MIT License 6 votes vote down vote up
def call(self, inputs, state):
    """Long short-term memory cell (LSTM)."""
    sigmoid = math_ops.sigmoid
    # Parameters of gates are concatenated into one multiply for efficiency.
    if self._state_is_tuple:
      c, h = state
    else:
      c, h = array_ops.split(value=state, num_or_size_splits=2, axis=1)

    concat = _linear([inputs, h], 4 * self._num_units, True)

    # i = input_gate, j = new_input, f = forget_gate, o = output_gate
    i, j, f, o = array_ops.split(value=concat, num_or_size_splits=4, axis=1)

    new_c = (
        c * sigmoid(f + self._forget_bias) + sigmoid(i) * self._activation(j))
    new_h = self._activation(new_c) * sigmoid(o)

    if self._state_is_tuple:
      new_state = LSTMStateTuple(new_c, new_h)
    else:
      new_state = array_ops.concat([new_c, new_h], 1)
    return new_h, new_state 
Example #5
Source File: beam_search_decoder.py    From lambda-packs with MIT License 6 votes vote down vote up
def _tile_batch(t, multiplier):
  """Core single-tensor implementation of tile_batch."""
  t = ops.convert_to_tensor(t, name="t")
  shape_t = array_ops.shape(t)
  if t.shape.ndims is None or t.shape.ndims < 1:
    raise ValueError("t must have statically known rank")
  tiling = [1] * (t.shape.ndims + 1)
  tiling[1] = multiplier
  tiled_static_batch_size = (
      t.shape[0].value * multiplier if t.shape[0].value is not None else None)
  tiled = array_ops.tile(array_ops.expand_dims(t, 1), tiling)
  tiled = array_ops.reshape(
      tiled, array_ops.concat(([shape_t[0] * multiplier], shape_t[1:]), 0))
  tiled.set_shape(
      tensor_shape.TensorShape(
          [tiled_static_batch_size]).concatenate(t.shape[1:]))
  return tiled 
Example #6
Source File: dynamic_decoder.py    From tensorflow_end2end_speech_recognition with MIT License 6 votes vote down vote up
def _transpose_batch_time(x):
    """Transpose the batch and time dimensions of a Tensor.
    Retains as much of the static shape information as possible.
    Args:
        x: A tensor of rank 2 or higher.
    Returns:
        x transposed along the first two dimensions.
    Raises:
        ValueError: if `x` is rank 1 or lower.
    """
    x_static_shape = x.get_shape()
    if x_static_shape.ndims is not None and x_static_shape.ndims < 2:
        raise ValueError(
            "Expected input tensor %s to have rank at least 2, but saw shape: %s" %
            (x, x_static_shape))
    x_rank = array_ops.rank(x)
    x_t = array_ops.transpose(
        x, array_ops.concat(
            ([1, 0], math_ops.range(2, x_rank)), axis=0))
    x_t.set_shape(
        tensor_shape.TensorShape([
            x_static_shape[1].value, x_static_shape[0].value
        ]).concatenate(x_static_shape[2:]))
    return x_t 
Example #7
Source File: layers.py    From tensornets with MIT License 6 votes vote down vote up
def _dense_inner_flatten(inputs, new_rank):
  """Helper function for `inner_flatten`."""
  rank_assertion = check_ops.assert_rank_at_least(
      inputs, new_rank, message='inputs has rank less than new_rank')
  with ops.control_dependencies([rank_assertion]):
    outer_dimensions = array_ops.strided_slice(
        array_ops.shape(inputs), [0], [new_rank - 1])
    new_shape = array_ops.concat((outer_dimensions, [-1]), 0)
    reshaped = array_ops.reshape(inputs, new_shape)

  # if `new_rank` is an integer, try to calculate new shape.
  if isinstance(new_rank, six.integer_types):
    static_shape = inputs.get_shape()
    if static_shape is not None and static_shape.dims is not None:
      static_shape = static_shape.as_list()
      static_outer_dims = static_shape[:new_rank - 1]
      static_inner_dims = static_shape[new_rank - 1:]
      flattened_dimension = 1
      for inner_dim in static_inner_dims:
        if inner_dim is None:
          flattened_dimension = None
          break
        flattened_dimension *= inner_dim
      reshaped.set_shape(static_outer_dims + [flattened_dimension])
  return reshaped 
Example #8
Source File: sequence_queueing_state_saver.py    From lambda-packs with MIT License 6 votes vote down vote up
def _move_sparse_tensor_in_context(context, sequences):
  sparse_tensor_keys = [
      k for k in sorted(sequences) if k.startswith(_SPARSE_CONTEXT_PREFIX_KEY)]
  for key in sparse_tensor_keys:
    new_key = key[len(_SPARSE_CONTEXT_PREFIX_KEY):]
    sp_tensor = sequences[key]
    # Take out time dimension.
    sp_tensor = sparse_tensor.SparseTensor(
        sp_tensor.indices,  # with only 0s at column 1 representing time.
        sp_tensor.values,
        array_ops.concat(
            [[sp_tensor.dense_shape[0]],  # batch
             [1],  # time
             sp_tensor.dense_shape[2:]],  # SparseTensor shape prior to batching
            0))
    new_shape = array_ops.concat(
        [[sp_tensor.dense_shape[0]], sp_tensor.dense_shape[2:]], 0)
    context[new_key] = sparse_ops.sparse_reshape(sp_tensor, new_shape)
    del sequences[key] 
Example #9
Source File: nn_ops.py    From lambda-packs with MIT License 6 votes vote down vote up
def crelu(features, name=None):
  """Computes Concatenated ReLU.

  Concatenates a ReLU which selects only the positive part of the activation
  with a ReLU which selects only the *negative* part of the activation.
  Note that as a result this non-linearity doubles the depth of the activations.
  Source: [Understanding and Improving Convolutional Neural Networks via Concatenated Rectified Linear Units. W. Shang, et al.](https://arxiv.org/abs/1603.05201) 

  Args:
    features: A `Tensor` with type `float`, `double`, `int32`, `int64`, `uint8`,
      `int16`, or `int8`.
    name: A name for the operation (optional).

  Returns:
    A `Tensor` with the same type as `features`.
  """
  with ops.name_scope(name, "CRelu", [features]) as name:
    features = ops.convert_to_tensor(features, name="features")
    c = array_ops.concat([features, -features], -1, name=name)
    return gen_nn_ops.relu(c) 
Example #10
Source File: lstm2d.py    From lambda-packs with MIT License 6 votes vote down vote up
def horizontal_lstm(images, num_filters_out, scope=None):
  """Run an LSTM bidirectionally over all the rows of each image.

  Args:
    images: (num_images, height, width, depth) tensor
    num_filters_out: output depth
    scope: optional scope name

  Returns:
    (num_images, height, width, num_filters_out) tensor, where
    num_steps is width and new num_batches is num_image_batches * height
  """
  with variable_scope.variable_scope(scope, "HorizontalLstm", [images]):
    batch_size, _, _, _ = _shape(images)
    sequence = images_to_sequence(images)
    with variable_scope.variable_scope("lr"):
      hidden_sequence_lr = lstm1d.ndlstm_base(sequence, num_filters_out // 2)
    with variable_scope.variable_scope("rl"):
      hidden_sequence_rl = (lstm1d.ndlstm_base(
          sequence, num_filters_out - num_filters_out // 2, reverse=1))
    output_sequence = array_ops.concat([hidden_sequence_lr, hidden_sequence_rl],
                                       2)
    output = sequence_to_images(output_sequence, batch_size)
    return output 
Example #11
Source File: fully_connected.py    From lambda-packs with MIT License 6 votes vote down vote up
def inference_graph(self, data):
    with ops.device(self.device_assigner):
      # Compute activations for the neural network.
      nn_activations = [layers.fully_connected(data, self.params.layer_size)]

      for _ in range(1, self.params.num_layers):
        # pylint: disable=W0106
        nn_activations.append(
            layers.fully_connected(
                nn_activations[-1],
                self.params.layer_size))

      nn_activations_tensor = array_ops.concat(
          nn_activations, 1, name="flattened_nn_activations")

      return nn_activations_tensor 
Example #12
Source File: backend.py    From lambda-packs with MIT License 6 votes vote down vote up
def concatenate(tensors, axis=-1):
  """Concatenates a list of tensors alongside the specified axis.

  Arguments:
      tensors: list of tensors to concatenate.
      axis: concatenation axis.

  Returns:
      A tensor.
  """
  if axis < 0:
    rank = ndim(tensors[0])
    if rank:
      axis %= rank
    else:
      axis = 0

  if py_all([is_sparse(x) for x in tensors]):
    return sparse_ops.sparse_concat(axis, tensors)
  else:
    return array_ops.concat([to_dense(x) for x in tensors], axis) 
Example #13
Source File: gmm_ops.py    From lambda-packs with MIT License 6 votes vote down vote up
def _define_partial_maximization_operation(self, shard_id, shard):
    """Computes the partial statistics of the means and covariances.

    Args:
      shard_id: current shard id.
      shard: current data shard, 1 X num_examples X dimensions.
    """
    # Soft assignment of each data point to each of the two clusters.
    self._points_in_k[shard_id] = math_ops.reduce_sum(
        self._w[shard_id], 0, keep_dims=True)
    # Partial means.
    w_mul_x = array_ops.expand_dims(
        math_ops.matmul(
            self._w[shard_id], array_ops.squeeze(shard, [0]), transpose_a=True),
        1)
    self._w_mul_x.append(w_mul_x)
    # Partial covariances.
    x = array_ops.concat([shard for _ in range(self._num_classes)], 0)
    x_trans = array_ops.transpose(x, perm=[0, 2, 1])
    x_mul_w = array_ops.concat([
        array_ops.expand_dims(x_trans[k, :, :] * self._w[shard_id][:, k], 0)
        for k in range(self._num_classes)
    ], 0)
    self._w_mul_x2.append(math_ops.matmul(x_mul_w, x)) 
Example #14
Source File: tfexample_decoder.py    From lambda-packs with MIT License 6 votes vote down vote up
def tensors_to_item(self, keys_to_tensors):
    indices = keys_to_tensors[self._indices_key]
    values = keys_to_tensors[self._values_key]
    if self._shape_key:
      shape = keys_to_tensors[self._shape_key]
      if isinstance(shape, sparse_tensor.SparseTensor):
        shape = sparse_ops.sparse_tensor_to_dense(shape)
    elif self._shape:
      shape = self._shape
    else:
      shape = indices.dense_shape
    indices_shape = array_ops.shape(indices.indices)
    rank = indices_shape[1]
    ids = math_ops.to_int64(indices.values)
    indices_columns_to_preserve = array_ops.slice(
        indices.indices, [0, 0], array_ops.stack([-1, rank - 1]))
    new_indices = array_ops.concat(
        [indices_columns_to_preserve, array_ops.reshape(ids, [-1, 1])], 1)

    tensor = sparse_tensor.SparseTensor(new_indices, values.values, shape)
    if self._densify:
      tensor = sparse_ops.sparse_tensor_to_dense(tensor, self._default_value)
    return tensor 
Example #15
Source File: tfexample_decoder.py    From lambda-packs with MIT License 6 votes vote down vote up
def tensors_to_item(self, keys_to_tensors):
    """Maps the given dictionary of tensors to a contatenated list of bboxes.

    Args:
      keys_to_tensors: a mapping of TF-Example keys to parsed tensors.

    Returns:
      [num_boxes, 4] tensor of bounding box coordinates,
        i.e. 1 bounding box per row, in order [y_min, x_min, y_max, x_max].
    """
    sides = []
    for key in self._full_keys:
      side = array_ops.expand_dims(keys_to_tensors[key].values, 0)
      sides.append(side)

    bounding_box = array_ops.concat(sides, 0)
    return array_ops.transpose(bounding_box) 
Example #16
Source File: resource_variable_ops.py    From lambda-packs with MIT License 6 votes vote down vote up
def _GatherGrad(op, grad):
  """Gradient for gather op."""
  # Build appropriately shaped IndexedSlices
  # Walk graph back until the original handle is found.
  # TODO(apassos): more robust way of getting the shape.
  handle = op.inputs[0]
  while handle.op.type != "VarHandleOp":
    handle = handle.op.inputs[0]
  params_shape = ops.convert_to_tensor(
      tensor_shape.TensorShape(handle.op.get_attr("shape")))
  indices = op.inputs[1]
  size = array_ops.expand_dims(array_ops.size(indices), 0)
  values_shape = array_ops.concat([size, params_shape[1:]], 0)
  values = array_ops.reshape(grad, values_shape)
  indices = array_ops.reshape(indices, size)
  return [ops.IndexedSlices(values, indices, params_shape), None] 
Example #17
Source File: multinomial.py    From lambda-packs with MIT License 6 votes vote down vote up
def _sample_n(self, n, seed=None):
    n_draws = math_ops.cast(self.total_count, dtype=dtypes.int32)
    if self.total_count.get_shape().ndims is not None:
      if self.total_count.get_shape().ndims != 0:
        raise NotImplementedError(
            "Sample only supported for scalar number of draws.")
    elif self.validate_args:
      is_scalar = check_ops.assert_rank(
          n_draws, 0,
          message="Sample only supported for scalar number of draws.")
      n_draws = control_flow_ops.with_dependencies([is_scalar], n_draws)
    k = self.event_shape_tensor()[0]
    # Flatten batch dims so logits has shape [B, k],
    # where B = reduce_prod(self.batch_shape_tensor()).
    draws = random_ops.multinomial(
        logits=array_ops.reshape(self.logits, [-1, k]),
        num_samples=n * n_draws,
        seed=seed)
    draws = array_ops.reshape(draws, shape=[-1, n, n_draws])
    x = math_ops.reduce_sum(array_ops.one_hot(draws, depth=k),
                            axis=-2)  # shape: [B, n, k]
    x = array_ops.transpose(x, perm=[1, 0, 2])
    final_shape = array_ops.concat([[n], self.batch_shape_tensor(), [k]], 0)
    return array_ops.reshape(x, final_shape) 
Example #18
Source File: exponential.py    From lambda-packs with MIT License 6 votes vote down vote up
def _sample_n(self, n, seed=None):
    shape = array_ops.concat([[n], array_ops.shape(self._rate)], 0)
    # Uniform variates must be sampled from the open-interval `(0, 1)` rather
    # than `[0, 1)`. To do so, we use `np.finfo(self.dtype.as_numpy_dtype).tiny`
    # because it is the smallest, positive, "normal" number. A "normal" number
    # is such that the mantissa has an implicit leading 1. Normal, positive
    # numbers x, y have the reasonable property that, `x + y >= max(x, y)`. In
    # this case, a subnormal number (i.e., np.nextafter) can cause us to sample
    # 0.
    sampled = random_ops.random_uniform(
        shape,
        minval=np.finfo(self.dtype.as_numpy_dtype).tiny,
        maxval=1.,
        seed=seed,
        dtype=self.dtype)
    return -math_ops.log(sampled) / self._rate 
Example #19
Source File: dirichlet_multinomial.py    From lambda-packs with MIT License 6 votes vote down vote up
def _sample_n(self, n, seed=None):
    n_draws = math_ops.cast(self.total_count, dtype=dtypes.int32)
    k = self.event_shape_tensor()[0]
    unnormalized_logits = array_ops.reshape(
        math_ops.log(random_ops.random_gamma(
            shape=[n],
            alpha=self.concentration,
            dtype=self.dtype,
            seed=seed)),
        shape=[-1, k])
    draws = random_ops.multinomial(
        logits=unnormalized_logits,
        num_samples=n_draws,
        seed=distribution_util.gen_new_seed(seed, salt="dirichlet_multinomial"))
    x = math_ops.reduce_sum(array_ops.one_hot(draws, depth=k), -2)
    final_shape = array_ops.concat([[n], self.batch_shape_tensor(), [k]], 0)
    return array_ops.reshape(x, final_shape) 
Example #20
Source File: rnn_cell.py    From lambda-packs with MIT License 6 votes vote down vote up
def call(self, inputs, state):
    """LSTM cell with layer normalization and recurrent dropout."""
    c, h = state
    args = array_ops.concat([inputs, h], 1)
    concat = self._linear(args)

    i, j, f, o = array_ops.split(value=concat, num_or_size_splits=4, axis=1)
    if self._layer_norm:
      i = self._norm(i, "input")
      j = self._norm(j, "transform")
      f = self._norm(f, "forget")
      o = self._norm(o, "output")

    g = self._activation(j)
    if (not isinstance(self._keep_prob, float)) or self._keep_prob < 1:
      g = nn_ops.dropout(g, self._keep_prob, seed=self._seed)

    new_c = (c * math_ops.sigmoid(f + self._forget_bias)
             + math_ops.sigmoid(i) * g)
    if self._layer_norm:
      new_c = self._norm(new_c, "state")
    new_h = self._activation(new_c) * math_ops.sigmoid(o)

    new_state = rnn_cell_impl.LSTMStateTuple(new_c, new_h)
    return new_h, new_state 
Example #21
Source File: array_grad.py    From lambda-packs with MIT License 6 votes vote down vote up
def _MatrixSetDiagGrad(op, grad):
  """Gradient for MatrixSetDiag."""
  input_shape = op.inputs[0].get_shape().merge_with(grad.get_shape())
  diag_shape = op.inputs[1].get_shape()
  batch_shape = input_shape[:-2].merge_with(diag_shape[:-1])
  matrix_shape = input_shape[-2:]
  if batch_shape.is_fully_defined() and matrix_shape.is_fully_defined():
    diag_shape = batch_shape.as_list() + [min(matrix_shape.as_list())]
  else:
    with ops.colocate_with(grad):
      grad_shape = array_ops.shape(grad)
      grad_rank = array_ops.rank(grad)
      batch_shape = array_ops.slice(grad_shape, [0], [grad_rank - 2])
      matrix_shape = array_ops.slice(grad_shape, [grad_rank - 2], [2])
      min_dim = math_ops.reduce_min(matrix_shape)
      diag_shape = array_ops.concat([batch_shape, [min_dim]], 0)
  grad_input = array_ops.matrix_set_diag(
      grad, array_ops.zeros(
          diag_shape, dtype=grad.dtype))
  grad_diag = array_ops.matrix_diag_part(grad)
  return (grad_input, grad_diag) 
Example #22
Source File: feature_column.py    From lambda-packs with MIT License 6 votes vote down vote up
def _get_dense_tensor(self, inputs, weight_collections=None, trainable=None):
    """Returns a `Tensor`.

    The output of this function will be used by model-builder-functions. For
    example the pseudo code of `input_layer` will be like:

    ```python
    def input_layer(features, feature_columns, ...):
      outputs = [fc._get_dense_tensor(...) for fc in feature_columns]
      return tf.concat(outputs)
    ```

    Args:
      inputs: A `_LazyBuilder` object to access inputs.
      weight_collections: List of graph collections to which Variables (if any
        will be created) are added.
      trainable: If `True` also add variables to the graph collection
        `GraphKeys.TRAINABLE_VARIABLES` (see ${tf.Variable}).

    Returns:
      `Tensor` of shape [batch_size] + `_variable_shape`.
    """
    pass 
Example #23
Source File: layers.py    From lambda-packs with MIT License 6 votes vote down vote up
def _dense_inner_flatten(inputs, new_rank):
  """Helper function for `inner_flatten`."""
  rank_assertion = check_ops.assert_rank_at_least(
      inputs, new_rank, message='inputs has rank less than new_rank')
  with ops.control_dependencies([rank_assertion]):
    outer_dimensions = array_ops.strided_slice(
        array_ops.shape(inputs), [0], [new_rank - 1])
    new_shape = array_ops.concat((outer_dimensions, [-1]), 0)
    reshaped = array_ops.reshape(inputs, new_shape)

  # if `new_rank` is an integer, try to calculate new shape.
  if isinstance(new_rank, six.integer_types):
    static_shape = inputs.get_shape()
    if static_shape is not None and static_shape.dims is not None:
      static_shape = static_shape.as_list()
      static_outer_dims = static_shape[:new_rank - 1]
      static_inner_dims = static_shape[new_rank - 1:]
      flattened_dimension = 1
      for inner_dim in static_inner_dims:
        if inner_dim is None:
          flattened_dimension = None
          break
        flattened_dimension *= inner_dim
      reshaped.set_shape(static_outer_dims + [flattened_dimension])
  return reshaped 
Example #24
Source File: init_ops.py    From lambda-packs with MIT License 5 votes vote down vote up
def __call__(self, shape, dtype=None, partition_info=None):
    if dtype is None:
      dtype = self.dtype
    # Check the shape
    if len(shape) < 2:
      raise ValueError("The tensor to initialize must be "
                       "at least two-dimensional")
    # Flatten the input shape with the last dimension remaining
    # its original shape so it works for conv2d
    num_rows = 1
    for dim in shape[:-1]:
      num_rows *= dim
    num_cols = shape[-1]
    flat_shape = (num_rows, num_cols)

    # Generate a random matrix
    a = random_ops.random_normal(flat_shape, dtype=dtype, seed=self.seed)
    # Compute the qr factorization
    q, r = linalg_ops.qr(a, full_matrices=False)
    # Make Q uniform
    square_len = math_ops.minimum(num_rows, num_cols)
    d = array_ops.diag_part(r[:square_len, :square_len])
    ph = d / math_ops.abs(d)
    q *= ph
    # Pad zeros to Q (if rows smaller than cols)
    if num_rows < num_cols:
      padding = array_ops.zeros([num_rows, num_cols - num_rows], dtype=dtype)
      q = array_ops.concat([q, padding], 1)
    return self.gain * array_ops.reshape(q, shape) 
Example #25
Source File: my_attention_decoder_fn.py    From SentenceFunction with Apache License 2.0 5 votes vote down vote up
def _create_attention_construct_fn(name, num_units, attention_score_fn, reuse):
  """Function to compute attention vectors.

  Args:
    name: to label variables.
    num_units: hidden state dimension.
    attention_score_fn: to compute similarity between key and target states.
    reuse: whether to reuse variable scope.

  Returns:
    attention_construct_fn: to build attention states.
  """
  with variable_scope.variable_scope(name, reuse=reuse) as scope:

    def construct_fn(attention_query, attention_keys, attention_values):
      context = attention_score_fn(attention_query, attention_keys,
                                   attention_values)
      concat_input = array_ops.concat([attention_query, context], 1)
      attention = layers.linear(
          concat_input, num_units, biases_initializer=None, scope=scope)
      return attention

    return construct_fn


# keys: [batch_size, attention_length, attn_size]
# query: [batch_size, 1, attn_size]
# return weights [batch_size, attention_length] 
Example #26
Source File: math_grad.py    From lambda-packs with MIT License 5 votes vote down vote up
def _SegmentMeanGrad(op, grad):
  """Gradient for SegmentMean."""
  input_rank = array_ops.rank(op.inputs[0])
  ones_shape = array_ops.concat([
      array_ops.shape(op.inputs[1]),
      array_ops.fill(array_ops.expand_dims(input_rank - 1, 0), 1)
  ], 0)
  ones = array_ops.fill(ones_shape,
                        constant_op.constant(1, dtype=grad.dtype))
  scaled_grad = math_ops.div(grad, math_ops.segment_sum(ones, op.inputs[1]))
  return array_ops.gather(scaled_grad, op.inputs[1]), None 
Example #27
Source File: feature_column.py    From lambda-packs with MIT License 5 votes vote down vote up
def _transform_feature(self, inputs):
    """Returns dense `Tensor` representing feature.

    Args:
      inputs: A `_LazyBuilder` object to access inputs.

    Returns:
      Transformed feature `Tensor`.
    """
    id_weight_pair = self.categorical_column._get_sparse_tensors(inputs)  # pylint: disable=protected-access
    id_tensor = id_weight_pair.id_tensor
    weight_tensor = id_weight_pair.weight_tensor

    # If the underlying column is weighted, return the input as a dense tensor.
    if weight_tensor is not None:
      weighted_column = sparse_ops.sparse_merge(
          sp_ids=id_tensor,
          sp_values=weight_tensor,
          vocab_size=self._variable_shape[-1])
      return sparse_ops.sparse_tensor_to_dense(weighted_column)

    dense_id_tensor = sparse_ops.sparse_tensor_to_dense(
        id_tensor, default_value=-1)

    # One hot must be float for tf.concat reasons since all other inputs to
    # input_layer are float32.
    one_hot_id_tensor = array_ops.one_hot(
        dense_id_tensor,
        depth=self._variable_shape[-1],
        on_value=1.0,
        off_value=0.0)

    # Reduce to get a multi-hot per example.
    return math_ops.reduce_sum(one_hot_id_tensor, axis=[1]) 
Example #28
Source File: rnn_cell.py    From lambda-packs with MIT License 5 votes vote down vote up
def call(self, inputs, state):
    """Run one step of LSTM.

    Args:
      inputs: input Tensor, 2D, [batch, feature_size].
      state: Tensor or tuple of Tensors, 2D, [batch, state_size], depends on the
        flag self._state_is_tuple.

    Returns:
      A tuple containing:
      - A 2D, [batch, output_dim], Tensor representing the output of the LSTM
        after reading "inputs" when previous state was "state".
        Here output_dim is num_units.
      - A 2D, [batch, state_size], Tensor representing the new state of LSTM
        after reading "inputs" when previous state was "state".
    Raises:
      ValueError: if an input_size was specified and the provided inputs have
        a different dimension.
    """
    batch_size = inputs.shape[0].value or array_ops.shape(inputs)[0]
    freq_inputs = self._make_tf_features(inputs)
    m_out_lst = []
    state_out_lst = []
    for block in range(len(freq_inputs)):
      m_out_lst_current, state_out_lst_current = self._compute(
          freq_inputs[block], block, state, batch_size,
          state_is_tuple=self._state_is_tuple)
      m_out_lst.extend(m_out_lst_current)
      state_out_lst.extend(state_out_lst_current)
    if self._state_is_tuple:
      state_out = self._state_tuple_type(*state_out_lst)
    else:
      state_out = array_ops.concat(state_out_lst, 1)
    m_out = array_ops.concat(m_out_lst, 1)
    return m_out, state_out 
Example #29
Source File: rnn_cell.py    From lambda-packs with MIT License 5 votes vote down vote up
def call(self, inputs, state):
    """Long short-term memory cell with attention (LSTMA)."""
    if self._state_is_tuple:
      state, attns, attn_states = state
    else:
      states = state
      state = array_ops.slice(states, [0, 0], [-1, self._cell.state_size])
      attns = array_ops.slice(
          states, [0, self._cell.state_size], [-1, self._attn_size])
      attn_states = array_ops.slice(
          states, [0, self._cell.state_size + self._attn_size],
          [-1, self._attn_size * self._attn_length])
    attn_states = array_ops.reshape(attn_states,
                                    [-1, self._attn_length, self._attn_size])
    input_size = self._input_size
    if input_size is None:
      input_size = inputs.get_shape().as_list()[1]
    inputs = _linear([inputs, attns], input_size, True)
    lstm_output, new_state = self._cell(inputs, state)
    if self._state_is_tuple:
      new_state_cat = array_ops.concat(nest.flatten(new_state), 1)
    else:
      new_state_cat = new_state
    new_attns, new_attn_states = self._attention(new_state_cat, attn_states)
    with vs.variable_scope("attn_output_projection"):
      output = _linear([lstm_output, new_attns], self._attn_size, True)
    new_attn_states = array_ops.concat(
        [new_attn_states, array_ops.expand_dims(output, 1)], 1)
    new_attn_states = array_ops.reshape(
        new_attn_states, [-1, self._attn_length * self._attn_size])
    new_state = (new_state, new_attns, new_attn_states)
    if not self._state_is_tuple:
      new_state = array_ops.concat(list(new_state), 1)
    return output, new_state 
Example #30
Source File: embedding_ops.py    From lambda-packs with MIT License 5 votes vote down vote up
def embedding_lookup_unique(params, ids, name=None):
  """Version of embedding_lookup that avoids duplicate lookups.

  This can save communication in the case of repeated ids.
  Same interface as embedding_lookup. Except it supports multi-dimensional `ids`
  which allows to not reshape input/output to fit gather.

  Args:
    params: A list of tensors with the same shape and type, or a
      `PartitionedVariable`. Shape `[index, d1, d2, ...]`.
    ids: A one-dimensional `Tensor` with type `int32` or `int64` containing
      the ids to be looked up in `params`. Shape `[ids1, ids2, ...]`.
    name: A name for this operation (optional).

  Returns:
    A `Tensor` with the same type as the tensors in `params` and dimension of
    `[ids1, ids2, d1, d2, ...]`.

  Raises:
    ValueError: If `params` is empty.
  """
  with ops.name_scope(name, "EmbeddingLookupUnique", [params, ids]):
    ids = ops.convert_to_tensor(ids)
    shape = array_ops.shape(ids)
    ids_flat = array_ops.reshape(
        ids, math_ops.reduce_prod(shape, keep_dims=True))
    unique_ids, idx = array_ops.unique(ids_flat)
    unique_embeddings = embedding_ops.embedding_lookup(params, unique_ids)
    embeds_flat = array_ops.gather(unique_embeddings, idx)
    embed_shape = array_ops.concat(
        [shape, array_ops.shape(unique_embeddings)[1:]], 0)
    embeds = array_ops.reshape(embeds_flat, embed_shape)
    embeds.set_shape(ids.get_shape().concatenate(
        unique_embeddings.get_shape()[1:]))
    return embeds