Python tensor_util.constant_value方法代码示例

# 需要导入模块: from tensorflow.python.framework import tensor_util [as 别名]
# 或者: from tensorflow.python.framework.tensor_util import constant_value [as 别名]
def smart_cond(pred, fn1, fn2, name=None):
  """Return either fn1() or fn2() based on the boolean predicate/value `pred`.

  If `pred` is bool or has a constant value it would use `static_cond`,
  otherwise it would use `tf.cond`.

  Args:
    pred: A scalar determining whether to return the result of `fn1` or `fn2`.
    fn1: The callable to be performed if pred is true.
    fn2: The callable to be performed if pred is false.
    name: Optional name prefix when using tf.cond
  Returns:
    Tensors returned by the call to either `fn1` or `fn2`.
  """
  pred_value = constant_value(pred)
  if pred_value is not None:
    # Use static_cond if pred has a constant value.
    return static_cond(pred_value, fn1, fn2)
  else:
    # Use dynamic cond otherwise.
    return control_flow_ops.cond(pred, fn1, fn2, name) 

# 需要导入模块: from tensorflow.python.framework import tensor_util [as 别名]
# 或者: from tensorflow.python.framework.tensor_util import constant_value [as 别名]
def _merge_batch_beams(self, t, s=None):
        """Merges the tensor from a batch of beams into a batch by beams.
        More exactly, t is a tensor of dimension [batch_size, beam_width, s]. We
        reshape this into [batch_size*beam_width, s]
        Args:
          t: Tensor of dimension [batch_size, beam_width, s]
          s: (Possibly known) depth shape.
        Returns:
          A reshaped version of t with dimension [batch_size * beam_width, s].
        """
        if isinstance(s, ops.Tensor):
            s = tensor_shape.as_shape(tensor_util.constant_value(s))
        else:
            s = tensor_shape.TensorShape(s)
        t_shape = tf.shape(t)
        static_batch_size = tensor_util.constant_value(self._batch_size)
        batch_size_beam_width = (
            None if static_batch_size is None
            else static_batch_size * self._beam_width)
        reshaped_t = tf.reshape(
            t, tf.concat(
                ([self._batch_size * self._beam_width], t_shape[2:]), 0))
        reshaped_t.set_shape(
            (tensor_shape.TensorShape([batch_size_beam_width]).concatenate(s)))
        return reshaped_t 

# 需要导入模块: from tensorflow.python.framework import tensor_util [as 别名]
# 或者: from tensorflow.python.framework.tensor_util import constant_value [as 别名]
def _event_dims_tensor(self, sample):
    """Return a 1D `int32` tensor: `range(rank(sample))[-event_ndims:]`."""
    if self.event_ndims is None:
      raise ValueError("Jacobian cannot be computed with unknown event_ndims")
    static_event_ndims = tensor_util.constant_value(self.event_ndims)
    static_rank = sample.get_shape().ndims
    if static_event_ndims is not None and static_rank is not None:
      return ops.convert_to_tensor(
          static_rank + np.arange(-static_event_ndims, 0).astype(np.int32))

    if static_event_ndims is not None:
      event_range = np.arange(-static_event_ndims, 0).astype(np.int32)
    else:
      event_range = math_ops.range(-self.event_ndims, 0, dtype=dtypes.int32)

    if static_rank is not None:
      return event_range + static_rank
    else:
      return event_range + array_ops.rank(sample) 

# 需要导入模块: from tensorflow.python.framework import tensor_util [as 别名]
# 或者: from tensorflow.python.framework.tensor_util import constant_value [as 别名]
def constant_value(pred):
  """Return the bool value for `pred`, or None if `pred` had a dynamic value.

  Arguments:
    pred: A scalar, either a Python bool or a TensorFlow boolean variable
      or tensor.

  Returns:
    True or False if `pred` has a constant boolean value, None otherwise.

  Raises:
    TypeError is pred is not a Variable, Tensor or bool.
  """
  if isinstance(pred, bool):
    pred_value = pred
  elif isinstance(pred, variables.Variable):
    pred_value = None
  elif isinstance(pred, ops.Tensor):
    pred_value = tensor_util.constant_value(pred)
  else:
    raise TypeError('`pred` must be a Tensor, a Variable, or a Python bool.')
  return pred_value 

# 需要导入模块: from tensorflow.python.framework import tensor_util [as 别名]
# 或者: from tensorflow.python.framework.tensor_util import constant_value [as 别名]
def _length_penalty(sequence_lengths, penalty_factor):
  """Calculates the length penalty. See https://arxiv.org/abs/1609.08144.

  Args:
    sequence_lengths: The sequence length of all hypotheses, a tensor
      of shape [beam_size, vocab_size].
    penalty_factor: A scalar that weights the length penalty.

  Returns:
    The length penalty factor, a tensor fo shape [beam_size].
  """
  penalty_factor = ops.convert_to_tensor(penalty_factor, name="penalty_factor")
  penalty_factor.set_shape(())  # penalty should be a scalar.
  static_penalty = tensor_util.constant_value(penalty_factor)
  if static_penalty is not None and static_penalty == 0:
    return 1.0
  return math_ops.div((5. + math_ops.to_float(sequence_lengths))
                      **penalty_factor, (5. + 1.)**penalty_factor) 

# 需要导入模块: from tensorflow.python.framework import tensor_util [as 别名]
# 或者: from tensorflow.python.framework.tensor_util import constant_value [as 别名]
def prefer_static_broadcast_shape(
    shape1, shape2, name="prefer_static_broadcast_shape"):
  """Convenience function which statically broadcasts shape when possible.

  Args:
    shape1:  `1-D` integer `Tensor`.  Already converted to tensor!
    shape2:  `1-D` integer `Tensor`.  Already converted to tensor!
    name:  A string name to prepend to created ops.

  Returns:
    The broadcast shape, either as `TensorShape` (if broadcast can be done
      statically), or as a `Tensor`.
  """
  with ops.name_scope(name, values=[shape1, shape2]):
    if (tensor_util.constant_value(shape1) is not None and
        tensor_util.constant_value(shape2) is not None):
      return array_ops.broadcast_static_shape(
          tensor_shape.TensorShape(tensor_util.constant_value(shape1)),
          tensor_shape.TensorShape(tensor_util.constant_value(shape2)))
    return array_ops.broadcast_dynamic_shape(shape1, shape2) 

# 需要导入模块: from tensorflow.python.framework import tensor_util [as 别名]
# 或者: from tensorflow.python.framework.tensor_util import constant_value [as 别名]
def _assert_non_negative_int32_scalar(self, x):
    """Helper which ensures that input is a non-negative, int32, scalar."""
    x = ops.convert_to_tensor(x, name="x")
    if x.dtype.base_dtype != dtypes.int32.base_dtype:
      raise TypeError("%s.dtype=%s is not %s" % (x.name, x.dtype, dtypes.int32))
    x_value_static = tensor_util.constant_value(x)
    if x.get_shape().ndims is not None and x_value_static is not None:
      if x.get_shape().ndims != 0:
        raise ValueError("%s.ndims=%d is not 0 (scalar)" %
                         (x.name, x.get_shape().ndims))
      if x_value_static < 0:
        raise ValueError("%s.value=%d cannot be negative" %
                         (x.name, x_value_static))
      return x
    if self.validate_args:
      x = control_flow_ops.with_dependencies([
          check_ops.assert_rank(x, 0),
          check_ops.assert_non_negative(x)], x)
    return x 

# 需要导入模块: from tensorflow.python.framework import tensor_util [as 别名]
# 或者: from tensorflow.python.framework.tensor_util import constant_value [as 别名]
def __init__(self,
               event_ndims=0,
               validate_args=False,
               name="softmax_centered"):
    self._graph_parents = []
    self._name = name
    with self._name_scope("init", values=[event_ndims]):
      event_ndims = ops.convert_to_tensor(event_ndims, name="event_ndims")
      event_ndims = tensor_util.constant_value(event_ndims)
      if event_ndims is None or event_ndims not in [0, 1]:
        raise ValueError("`event_ndims` must be a TF constant which is 0 or 1")
    self._static_event_ndims = event_ndims
    super(SoftmaxCentered, self).__init__(
        event_ndims=event_ndims,
        validate_args=validate_args,
        name=name) 

# 需要导入模块: from tensorflow.python.framework import tensor_util [as 别名]
# 或者: from tensorflow.python.framework.tensor_util import constant_value [as 别名]
def __init__(self,
               event_ndims=0,
               validate_args=False,
               name="softmax_centered"):
    self._graph_parents = []
    self._name = name
    with self._name_scope("init", values=[event_ndims]):
      event_ndims = ops.convert_to_tensor(event_ndims, name="event_ndims")
      event_ndims = tensor_util.constant_value(event_ndims)
      if event_ndims is None or event_ndims not in [0, 1]:
        raise ValueError("`event_ndims` must be a TF constant which is 0 or 1")
    self._static_event_ndims = event_ndims
    super(SoftmaxCentered, self).__init__(
        batch_ndims=0,  # We'll regard all non-event dims as sample dims.
        event_ndims=event_ndims,
        validate_args=validate_args,
        name=name) 

# 需要导入模块: from tensorflow.python.framework import tensor_util [as 别名]
# 或者: from tensorflow.python.framework.tensor_util import constant_value [as 别名]
def _FillShape(op):
  """Shape function for the Fill op.

  This op takes a vector of dimensions and a scalar, and produces a
  tensor with the given dimensions.

  Args:
    op: A Fill Operation.

  Returns:
    A single-element list containing the shape of the output.

  Raises:
    ValueError: If the shapes or arguments are known to be invalid.
  """
  op.inputs[0].get_shape().assert_has_rank(1)
  op.inputs[1].get_shape().assert_has_rank(0)
  fill_dims = tensor_util.constant_value(op.inputs[0])
  if fill_dims is not None and any(d < 0 for d in fill_dims):
    raise ValueError("Fill dimensions must be >= 0")
  return [tensor_util.constant_value_as_shape(op.inputs[0])] 

# 需要导入模块: from tensorflow.python.framework import tensor_util [as 别名]
# 或者: from tensorflow.python.framework.tensor_util import constant_value [as 别名]
def constant_value(value_or_tensor_or_var, dtype=None):
  """Returns value if value_or_tensor_or_var has a constant value.

  Args:
    value_or_tensor_or_var: A value, a `Tensor` or a `Variable`.
    dtype: Optional `tf.dtype`, if set it would check it has the right
      dtype.

  Returns:
    The constant value or None if it not constant.

  Raises:
    ValueError: if value_or_tensor_or_var is None or the tensor_variable has the
    wrong dtype.
  """
  if value_or_tensor_or_var is None:
    raise ValueError('value_or_tensor_or_var cannot be None')
  value = value_or_tensor_or_var
  if isinstance(value_or_tensor_or_var, (ops.Tensor, variables.Variable)):
    if dtype and value_or_tensor_or_var.dtype != dtype:
      raise ValueError('It has the wrong type %s instead of %s' % (
          value_or_tensor_or_var.dtype, dtype))
    if isinstance(value_or_tensor_or_var, variables.Variable):
      value = None
    else:
      value = tensor_util.constant_value(value_or_tensor_or_var)
  return value 

# 需要导入模块: from tensorflow.python.framework import tensor_util [as 别名]
# 或者: from tensorflow.python.framework.tensor_util import constant_value [as 别名]
def _split_batch_beams(self, t, s=None):
        """Splits the tensor from a batch by beams into a batch of beams.
        More exactly, t is a tensor of dimension [batch_size*beam_width, s]. We
        reshape this into [batch_size, beam_width, s]
        Args:
          t: Tensor of dimension [batch_size*beam_width, s].
          s: (Possibly known) depth shape.
        Returns:
          A reshaped version of t with dimension [batch_size, beam_width, s].
        Raises:
          ValueError: If, after reshaping, the new tensor is not shaped
            `[batch_size, beam_width, s]` (assuming batch_size and beam_width
            are known statically).
        """
        if isinstance(s, ops.Tensor):
            s = tensor_shape.TensorShape(tensor_util.constant_value(s))
        else:
            s = tensor_shape.TensorShape(s)
        t_shape = tf.shape(t)
        reshaped_t = tf.reshape(
            t, tf.concat(
                ([self._batch_size, self._beam_width], t_shape[1:]), 0))
        static_batch_size = tensor_util.constant_value(self._batch_size)
        expected_reshaped_shape = tensor_shape.TensorShape(
            [static_batch_size, self._beam_width]).concatenate(s)
        if not reshaped_t.shape.is_compatible_with(expected_reshaped_shape):
            raise ValueError("Unexpected behavior when reshaping between beam width "
                             "and batch size.  The reshaped tensor has shape: %s.  "
                             "We expected it to have shape "
                             "(batch_size, beam_width, depth) == %s.  Perhaps you "
                             "forgot to create a zero_state with "
                             "batch_size=encoder_batch_size * beam_width?"
                             % (reshaped_t.shape, expected_reshaped_shape))
        reshaped_t.set_shape(expected_reshaped_shape)
        return reshaped_t 

# 需要导入模块: from tensorflow.python.framework import tensor_util [as 别名]
# 或者: from tensorflow.python.framework.tensor_util import constant_value [as 别名]
def _tensor_gather_helper(gather_indices, gather_from, batch_size,
                          range_size, gather_shape):
    """Helper for gathering the right indices from the tensor.
    This works by reshaping gather_from to gather_shape (e.g. [-1]) and then
    gathering from that according to the gather_indices, which are offset by
    the right amounts in order to preserve the batch order.
    Args:
      gather_indices: The tensor indices that we use to gather.
      gather_from: The tensor that we are gathering from.
      batch_size: The input batch size.
      range_size: The number of values in each range. Likely equal to beam_width.
      gather_shape: What we should reshape gather_from to in order to preserve the
        correct values. An example is when gather_from is the attention from an
        AttentionWrapperState with shape [batch_size, beam_width, attention_size].
        There, we want to preserve the attention_size elements, so gather_shape is
        [batch_size * beam_width, -1]. Then, upon reshape, we still have the
        attention_size as desired.
    Returns:
      output: Gathered tensor of shape tf.shape(gather_from)[:1+len(gather_shape)]
    """
    range_ = tf.expand_dims(tf.range(batch_size) * range_size, 1)
    gather_indices = tf.reshape(gather_indices + range_, [-1])
    output = tf.gather(
        tf.reshape(gather_from, gather_shape), gather_indices)
    final_shape = tf.shape(gather_from)[:1 + len(gather_shape)]
    static_batch_size = tensor_util.constant_value(batch_size)
    final_static_shape = (tensor_shape.TensorShape([static_batch_size])
                          .concatenate(
                              gather_from.shape[1:1 + len(gather_shape)]))
    output = tf.reshape(output, final_shape)
    output.set_shape(final_static_shape)
    return output 

# 需要导入模块: from tensorflow.python.framework import tensor_util [as 别名]
# 或者: from tensorflow.python.framework.tensor_util import constant_value [as 别名]
def dequeue_many(self, n, name=None):
    """Dequeues and concatenates `n` elements from this queue.

    This operation concatenates queue-element component tensors along
    the 0th dimension to make a single component tensor.  All of the
    components in the dequeued tuple will have size `n` in the 0th dimension.

    If the queue is closed and there are less than `n` elements left, then an
    `OutOfRange` exception is raised.

    At runtime, this operation may raise an error if the queue is
    @{tf.QueueBase.close} before or during its execution. If the
    queue is closed, the queue contains fewer than `n` elements, and
    there are no pending enqueue operations that can fulfill this
    request, `tf.errors.OutOfRangeError` will be raised. If the
    session is @{tf.Session.close},
    `tf.errors.CancelledError` will be raised.

    Args:
      n: A scalar `Tensor` containing the number of elements to dequeue.
      name: A name for the operation (optional).

    Returns:
      The tuple of concatenated tensors that was dequeued.
    """
    if name is None:
      name = "%s_DequeueMany" % self._name

    ret = gen_data_flow_ops._queue_dequeue_many_v2(
        self._queue_ref, n=n, component_types=self._dtypes, name=name)

    # NOTE(mrry): Not using a shape function because we need access to
    # the Queue object.
    op = ret[0].op
    batch_dim = tensor_shape.Dimension(tensor_util.constant_value(op.inputs[1]))
    for output, shape in zip(op.values(), self._shapes):
      output.set_shape(tensor_shape.TensorShape([batch_dim]).concatenate(shape))

    return self._dequeue_return_value(ret) 

# 需要导入模块: from tensorflow.python.framework import tensor_util [as 别名]
# 或者: from tensorflow.python.framework.tensor_util import constant_value [as 别名]
def _IndexedSlicesToTensor(value, dtype=None, name=None, as_ref=False):
  """Converts an IndexedSlices object `value` to a Tensor.

  NOTE(mrry): This function is potentially expensive.

  Args:
    value: An ops.IndexedSlices object.
    dtype: The dtype of the Tensor to be returned.
    name: Optional name to use for the returned Tensor.
    as_ref: True if a ref is requested.

  Returns:
    A dense Tensor representing the values in the given IndexedSlices.

  Raises:
    ValueError: If the IndexedSlices does not have the same dtype.
  """
  _ = as_ref
  if dtype and not dtype.is_compatible_with(value.dtype):
    raise ValueError(
        "Tensor conversion requested dtype %s for IndexedSlices with dtype %s" %
        (dtype.name, value.dtype.name))
  if value.dense_shape is None:
    raise ValueError(
        "Tensor conversion requested for IndexedSlices without dense_shape: %s"
        % str(value))
  # TODO(mrry): Consider adding static shape information to
  # IndexedSlices, to avoid using numpy here.
  dense_shape_value = tensor_util.constant_value(value.dense_shape)
  if dense_shape_value is not None:
    num_elements = np.prod(dense_shape_value)
    if num_elements >= _LARGE_SPARSE_NUM_ELEMENTS:
      warnings.warn(
          "Converting sparse IndexedSlices to a dense Tensor with %d elements. "
          "This may consume a large amount of memory." % num_elements)
  else:
    warnings.warn(
        "Converting sparse IndexedSlices to a dense Tensor of unknown shape. "
        "This may consume a large amount of memory.")
  return math_ops.unsorted_segment_sum(
      value.values, value.indices, value.dense_shape[0], name=name)