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

def _ImageDimensions(images, dynamic_shape=False):
  """Returns the dimensions of an image tensor.
  Args:
    images: 4-D Tensor of shape [batch, height, width, channels]
    dynamic_shape: Whether the input image has undertermined shape. If set to
      `True`, shape information will be retrieved at run time. Default to
      `False`.

  Returns:
    list of integers [batch, height, width, channels]
  """
  # A simple abstraction to provide names for each dimension. This abstraction
  # should make it simpler to switch dimensions in the future (e.g. if we ever
  # want to switch height and width.)
  if dynamic_shape:
    return array_ops.unpack(array_ops.shape(images))
  else:
    return images.get_shape().as_list()


# In[6]: 

def _reverse_seq(input_seq, lengths):
    """Reverse a list of Tensors up to specified lengths.
    Args:
        input_seq: Sequence of seq_len tensors of dimension (batch_size, depth)
        lengths:   A tensor of dimension batch_size, containing lengths for each
                   sequence in the batch. If "None" is specified, simply reverses
                   the list.
    Returns:
        time-reversed sequence
    """
    for input_ in input_seq:
        input_.set_shape(input_.get_shape().with_rank(2))

    # Join into (time, batch_size, depth)
    s_joined = array_ops_.pack(input_seq)

    # Reverse along dimension 0
    s_reversed = array_ops_.reverse_sequence(s_joined, lengths, 0, 1)
    # Split again into list
    result = array_ops_.unpack(s_reversed)
    return result 

def testBatch(self):
    # Build an arbitrary RGB image
    np.random.seed(7)
    batch_size = 5
    shape = (batch_size, 2, 7, 3)

    for nptype in [np.float32, np.float64]:
      inp = np.random.rand(*shape).astype(nptype)

      # Convert to HSV and back, as a batch and individually
      with self.test_session(use_gpu=True) as sess:
        batch0 = constant_op.constant(inp)
        batch1 = image_ops.rgb_to_hsv(batch0)
        batch2 = image_ops.hsv_to_rgb(batch1)
        split0 = array_ops.unpack(batch0)
        split1 = list(map(image_ops.rgb_to_hsv, split0))
        split2 = list(map(image_ops.hsv_to_rgb, split1))
        join1 = array_ops.pack(split1)
        join2 = array_ops.pack(split2)
        batch1, batch2, join1, join2 = sess.run([batch1, batch2, join1, join2])

      # Verify that processing batch elements together is the same as separate
      self.assertAllClose(batch1, join1)
      self.assertAllClose(batch2, join2)
      self.assertAllClose(batch2, inp) 

def _ImageDimensions(image):
  """Returns the dimensions of an image tensor.

  Args:
    image: A 3-D Tensor of shape `[height, width, channels]`.

  Returns:
    A list of `[height, width, channels]` corresponding to the dimensions of the
    input image.  Dimensions that are statically known are python integers,
    otherwise they are integer scalar tensors.
  """
  if image.get_shape().is_fully_defined():
    return image.get_shape().as_list()
  else:
    static_shape = image.get_shape().with_rank(3).as_list()
    dynamic_shape = array_ops.unpack(array_ops.shape(image), 3)
    return [s if s is not None else d
            for s, d in zip(static_shape, dynamic_shape)] 

def _reverse_seq(input_seq, lengths):
  """Reverse a list of Tensors up to specified lengths.

  Args:
    input_seq: Sequence of seq_len tensors of dimension (batch_size, depth)
    lengths:   A tensor of dimension batch_size, containing lengths for each
               sequence in the batch. If "None" is specified, simply
               reverses the list.

  Returns:
    time-reversed sequence
  """
  if lengths is None:
    return list(reversed(input_seq))

  for input_ in input_seq:
    input_.set_shape(input_.get_shape().with_rank(2))

  # Join into (time, batch_size, depth)
  s_joined = array_ops_.pack(input_seq)

  # Reverse along dimension 0
  s_reversed = array_ops_.reverse_sequence(s_joined, lengths, 0, 1)
  # Split again into list
  result = array_ops_.unpack(s_reversed)
  return result 

def __call__(self, inputs, state, scope=None):
    """Run this multi-layer cell on inputs, starting from state."""
    with vs.variable_scope(scope or type(self).__name__):  # "MultiRNNCell"
      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:
            # print("STATE",state)
            """
            cur_state = array_ops.slice(
                state, [0, cur_state_pos], [-1, cell.state_size])
            """
            cur_state = array_ops.unpack(state)[i]
            # 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(1, new_states))
    """
    new_states = array_ops.pack(new_states)
    return cur_inp, new_states 

def _cat_probs(self, log_probs):
    """Get a list of num_components batchwise probabilities."""
    which_softmax = nn_ops.log_softmax if log_probs else nn_ops.softmax
    cat_probs = which_softmax(self.cat.logits)
    cat_probs = array_ops.unpack(
        cat_probs, num=self.num_components, axis=-1)
    return cat_probs 

def seq2seq_inputs(x, y, input_length, output_length, sentinel=None, name=None):
  """Processes inputs for Sequence to Sequence models.

  Args:
    x: Input Tensor [batch_size, input_length, embed_dim].
    y: Output Tensor [batch_size, output_length, embed_dim].
    input_length: length of input x.
    output_length: length of output y.
    sentinel: optional first input to decoder and final output expected.
      If sentinel is not provided, zeros are used. Due to fact that y is not
      available in sampling time, shape of sentinel will be inferred from x.
    name: Operation name.

  Returns:
    Encoder input from x, and decoder inputs and outputs from y.
  """
  with ops.name_scope(name, "seq2seq_inputs", [x, y]):
    in_x = array_ops_.unpack(x, axis=1)
    y = array_ops_.unpack(y, axis=1)
    if not sentinel:
      # Set to zeros of shape of y[0], using x for batch size.
      sentinel_shape = array_ops_.pack(
          [array_ops_.shape(x)[0], y[0].get_shape()[1]])
      sentinel = array_ops_.zeros(sentinel_shape)
      sentinel.set_shape(y[0].get_shape())
    in_y = [sentinel] + y
    out_y = y + [sentinel]
    return in_x, in_y, out_y 

def _reverse_seq(input_seq, lengths):
  """Reverse a list of Tensors up to specified lengths.

  Args:
    input_seq: Sequence of seq_len tensors of dimension (batch_size, depth)
    lengths:   A tensor of dimension batch_size, containing lengths for each
               sequence in the batch. If "None" is specified, simply
               reverses the list.

  Returns:
    time-reversed sequence
  """
  if lengths is None:
    return list(reversed(input_seq))

  for input_ in input_seq:
    input_.set_shape(input_.get_shape().with_rank(2))

  # Join into (time, batch_size, depth)
  s_joined = array_ops_.pack(input_seq)

  # Reverse along dimension 0
  s_reversed = array_ops_.reverse_sequence(s_joined, lengths, 0, 1)
  # Split again into list
  result = array_ops_.unpack(s_reversed)
  return result 

def _UnpackGrad(op, *grads):
  """Gradient for unpack op."""
  return array_ops.pack(grads, axis=op.get_attr("axis")) 

def _PackGrad(op, grad):
  """Gradient for pack op."""
  return array_ops.unpack(grad, num=op.get_attr("N"), axis=op.get_attr("axis")) 

def _reverse_seq(input_seq, lengths):
  """Reverse a list of Tensors up to specified lengths.
  Args:
    input_seq: Sequence of seq_len tensors of dimension (batch_size, depth)
    lengths:   A tensor of dimension batch_size, containing lengths for each
               sequence in the batch. If "None" is specified, simply reverses
               the list.
  Returns:
    time-reversed sequence
  """
  if lengths is None:
    return list(reversed(input_seq))

  input_shape = tensor_shape.matrix(None, None)
  for input_ in input_seq:
    input_shape.merge_with(input_.get_shape())
    input_.set_shape(input_shape)

  # Join into (time, batch_size, depth)
  s_joined = array_ops.pack(input_seq)

  # TODO(schuster, ebrevdo): Remove cast when reverse_sequence takes int32
  if lengths is not None:
    lengths = math_ops.to_int64(lengths)

  # Reverse along dimension 0
  s_reversed = array_ops.reverse_sequence(s_joined, lengths, 0, 1)
  # Split again into list
  result = array_ops.unpack(s_reversed)
  for r in result:
    r.set_shape(input_shape)
  return result 

def _reverse_seq(input_seq, lengths):
  """Reverse a list of Tensors up to specified lengths.

  Args:
    input_seq: Sequence of seq_len tensors of dimension (batch_size, depth)
    lengths:   A tensor of dimension batch_size, containing lengths for each
               sequence in the batch. If "None" is specified, simply
               reverses the list.

  Returns:
    time-reversed sequence
  """
  if lengths is None:
    return list(reversed(input_seq))

  for input_ in input_seq:
    input_.set_shape(input_.get_shape().with_rank(2))

  # Join into (time, batch_size, depth)
  s_joined = array_ops_.pack(input_seq)

  # Reverse along dimension 0
  s_reversed = array_ops_.reverse_sequence(s_joined, lengths, 0, 1)
  # Split again into list
  result = array_ops_.unpack(s_reversed)
  return result 

def _reverse_seq(input_seq, lengths):
  """Reverse a list of Tensors up to specified lengths.

  Args:
    input_seq: Sequence of seq_len tensors of dimension (batch_size, depth)
    lengths:   A tensor of dimension batch_size, containing lengths for each
               sequence in the batch. If "None" is specified, simply
               reverses the list.

  Returns:
    time-reversed sequence
  """
  if lengths is None:
    return list(reversed(input_seq))

  for input_ in input_seq:
    input_.set_shape(input_.get_shape().with_rank(2))

  # Join into (time, batch_size, depth)
  s_joined = array_ops_.pack(input_seq)

  # Reverse along dimension 0
  s_reversed = array_ops_.reverse_sequence(s_joined, lengths, 0, 1)
  # Split again into list
  result = array_ops_.unpack(s_reversed)
  return result 

def _reverse_seq(input_seq, lengths):
  """Reverse a list of Tensors up to specified lengths.

  Args:
    input_seq: Sequence of seq_len tensors of dimension (batch_size, n_features)
               or nested tuples of tensors.
    lengths:   A `Tensor` of dimension batch_size, containing lengths for each
               sequence in the batch. If "None" is specified, simply reverses
               the list.

  Returns:
    time-reversed sequence
  """
  if lengths is None:
    return list(reversed(input_seq))

  flat_input_seq = tuple(nest.flatten(input_) for input_ in input_seq)

  flat_results = [[] for _ in range(len(input_seq))]
  for sequence in zip(*flat_input_seq):
    input_shape = tensor_shape.unknown_shape(
        ndims=sequence[0].get_shape().ndims)
    for input_ in sequence:
      input_shape.merge_with(input_.get_shape())
      input_.set_shape(input_shape)

    # Join into (time, batch_size, depth)
    s_joined = array_ops.pack(sequence)

    # TODO(schuster, ebrevdo): Remove cast when reverse_sequence takes int32
    if lengths is not None:
      lengths = math_ops.to_int64(lengths)

    # Reverse along dimension 0
    s_reversed = array_ops.reverse_sequence(s_joined, lengths, 0, 1)
    # Split again into list
    result = array_ops.unpack(s_reversed)
    for r, flat_result in zip(result, flat_results):
      r.set_shape(input_shape)
      flat_result.append(r)

  results = [nest.pack_sequence_as(structure=input_, flat_sequence=flat_result)
             for input_, flat_result in zip(input_seq, flat_results)]
  return results 

def dense_to_sparse_tensor(dense_tensor, ignore_value=None):
  """Converts a dense Tensor to a SparseTensor, dropping ignore_value cells.

  Args:
    dense_tensor: A `Tensor`.
    ignore_value: Entries in `dense_tensor` equal to this value will be
      absent from the return `SparseTensor`. If `None`, default value of
      dense_tensor's dtype will be used (e.g. '' for `str`, 0 for `int`).

  Returns:
    A `SparseTensor` with the same shape as `dense_tensor`.

  Raises:
    ValueError: when `dense_tensor`'s rank is `None`.
  """
  with ops.name_scope("DenseToSparseTensor"):
    dense_t = ops.convert_to_tensor(dense_tensor)
    if dense_t.get_shape().ndims is None:
      # TODO(b/32318825): Implement dense_to_sparse_tensor for undefined rank.
      raise ValueError("dense_tensor.get_shape() should be defined, got None.")
    if ignore_value is None:
      if dense_t.dtype == dtypes.string:
        # Exception due to TF strings are converted to numpy objects by default.
        ignore_value = ""
      else:
        ignore_value = dense_t.dtype.as_numpy_dtype()
    dense_shape = math_ops.cast(array_ops.shape(dense_t), dtypes.int64)
    indices = array_ops.where(
        math_ops.not_equal(dense_t, math_ops.cast(ignore_value, dense_t.dtype)))
    index_dims = len(dense_t.get_shape())
    # Flattens the tensor and indices for use with gather.
    flat_tensor = array_ops.reshape(dense_t, [-1])
    flat_indices = indices[:, index_dims - 1]
    # Computes the correct flattened indices for 2d (or higher) tensors.
    if index_dims > 1:
      higher_dims = indices[:, :index_dims - 1]
      shape_multipliers = array_ops.pack(
          _multiplier_helper(array_ops.unpack(dense_shape)[1:]))
      offsets = math_ops.reduce_sum(
          math_ops.mul(higher_dims, shape_multipliers), reduction_indices=[1])
      flat_indices = math_ops.add(flat_indices, offsets)
    values = array_ops.gather(flat_tensor, flat_indices)
    return sparse_tensor.SparseTensor(indices, values, dense_shape) 

def _reverse_seq(input_seq, lengths):
  """Reverse a list of Tensors up to specified lengths.

  Args:
    input_seq: Sequence of seq_len tensors of dimension (batch_size, n_features)
               or nested tuples of tensors.
    lengths:   A `Tensor` of dimension batch_size, containing lengths for each
               sequence in the batch. If "None" is specified, simply reverses
               the list.

  Returns:
    time-reversed sequence
  """
  if lengths is None:
    return list(reversed(input_seq))

  flat_input_seq = tuple(nest.flatten(input_) for input_ in input_seq)

  flat_results = [[] for _ in range(len(input_seq))]
  for sequence in zip(*flat_input_seq):
    input_shape = tensor_shape.unknown_shape(
        ndims=sequence[0].get_shape().ndims)
    for input_ in sequence:
      input_shape.merge_with(input_.get_shape())
      input_.set_shape(input_shape)

    # Join into (time, batch_size, depth)
    s_joined = array_ops.pack(sequence)

    # TODO(schuster, ebrevdo): Remove cast when reverse_sequence takes int32
    if lengths is not None:
      lengths = math_ops.to_int64(lengths)

    # Reverse along dimension 0
    s_reversed = array_ops.reverse_sequence(s_joined, lengths, 0, 1)
    # Split again into list
    result = array_ops.unpack(s_reversed)
    for r, flat_result in zip(result, flat_results):
      r.set_shape(input_shape)
      flat_result.append(r)

  results = [nest.pack_sequence_as(structure=input_, flat_sequence=flat_result)
             for input_, flat_result in zip(input_seq, flat_results)]
  return results 

def _reverse_seq(input_seq, lengths):
    """Reverse a list of Tensors up to specified lengths.
    Args:
        input_seq: Sequence of seq_len tensors of dimension (batch_size, n_features)
                   or nested tuples of tensors.
        lengths:   A `Tensor` of dimension batch_size, containing lengths for each
                   sequence in the batch. If "None" is specified, simply reverses
                   the list.
    Returns:
        time-reversed sequence
    """
    if lengths is None:
        return list(reversed(input_seq))

    flat_input_seq = tuple(nest.flatten(input_) for input_ in input_seq)

    flat_results = [[] for _ in range(len(input_seq))]
    for sequence in zip(*flat_input_seq):
        input_shape = tensor_shape.unknown_shape(
                ndims=sequence[0].get_shape().ndims)
        for input_ in sequence:
            input_shape.merge_with(input_.get_shape())
            input_.set_shape(input_shape)

        # Join into (time, batch_size, depth)
        s_joined = array_ops.pack(sequence)

        # TODO(schuster, ebrevdo): Remove cast when reverse_sequence takes int32
        if lengths is not None:
            lengths = math_ops.to_int64(lengths)

        # Reverse along dimension 0
        s_reversed = array_ops.reverse_sequence(s_joined, lengths, 0, 1)
        # Split again into list
        result = array_ops.unpack(s_reversed)
        for r, flat_result in zip(result, flat_results):
            r.set_shape(input_shape)
            flat_result.append(r)

    results = [nest.pack_sequence_as(structure=input_, flat_sequence=flat_result)
               for input_, flat_result in zip(input_seq, flat_results)]
    return results