Python control_flow_ops.cond方法代码示例

# 需要导入模块: from tensorflow.python.ops import control_flow_ops [as 别名]
# 或者: from tensorflow.python.ops.control_flow_ops import cond [as 别名]
def static_cond(pred, fn1, fn2):
  """Return either fn1() or fn2() based on the boolean value of `pred`.

  Same signature as `control_flow_ops.cond()` but requires pred to be a bool.

  Args:
    pred: A value 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.

  Returns:
    Tensors returned by the call to either `fn1` or `fn2`.

  Raises:
    TypeError: if `fn1` or `fn2` is not callable.
  """
  if not callable(fn1):
    raise TypeError('fn1 must be callable.')
  if not callable(fn2):
    raise TypeError('fn2 must be callable.')
  if pred:
    return fn1()
  else:
    return fn2() 

# 需要导入模块: from tensorflow.python.ops import control_flow_ops [as 别名]
# 或者: from tensorflow.python.ops.control_flow_ops import cond [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.ops import control_flow_ops [as 别名]
# 或者: from tensorflow.python.ops.control_flow_ops import cond [as 别名]
def _assert(cond, ex_type, msg):
    """A polymorphic assert, works with tensors and boolean expressions.
    If `cond` is not a tensor, behave like an ordinary assert statement, except
    that a empty list is returned. If `cond` is a tensor, return a list
    containing a single TensorFlow assert op.
    Args:
      cond: Something evaluates to a boolean value. May be a tensor.
      ex_type: The exception class to use.
      msg: The error message.
    Returns:
      A list, containing at most one assert op.
    """
    if _is_tensor(cond):
        return [control_flow_ops.Assert(cond, [msg])]
    else:
        if not cond:
            raise ex_type(msg)
        else:
            return [] 

# 需要导入模块: from tensorflow.python.ops import control_flow_ops [as 别名]
# 或者: from tensorflow.python.ops.control_flow_ops import cond [as 别名]
def random_flip_left_right(image, bboxes, seed=None):
    """Random flip left-right of an image and its bounding boxes.
    """
    def flip_bboxes(bboxes):
        """Flip bounding boxes coordinates.
        """
        bboxes = tf.stack([bboxes[:, 0], 1 - bboxes[:, 3],
                           bboxes[:, 2], 1 - bboxes[:, 1]], axis=-1)
        return bboxes

    # Random flip. Tensorflow implementation.
    with tf.name_scope('random_flip_left_right'):
        image = ops.convert_to_tensor(image, name='image')
        _Check3DImage(image, require_static=False)
        uniform_random = random_ops.random_uniform([], 0, 1.0, seed=seed)
        mirror_cond = math_ops.less(uniform_random, .5)
        # Flip image.
        result = control_flow_ops.cond(mirror_cond,
                                       lambda: array_ops.reverse_v2(image, [1]),
                                       lambda: image)
        # Flip bboxes.
        bboxes = control_flow_ops.cond(mirror_cond,
                                       lambda: flip_bboxes(bboxes),
                                       lambda: bboxes)
        return fix_image_flip_shape(image, result), bboxes 

# 需要导入模块: from tensorflow.python.ops import control_flow_ops [as 别名]
# 或者: from tensorflow.python.ops.control_flow_ops import cond [as 别名]
def testDebugCondWatchingWholeGraphWorks(self):
    with session.Session() as sess:
      x = variables.Variable(10.0, name="x")
      y = variables.Variable(20.0, name="y")
      cond = control_flow_ops.cond(
          x > y, lambda: math_ops.add(x, 1), lambda: math_ops.add(y, 1))

      sess.run(variables.global_variables_initializer())

      run_options = config_pb2.RunOptions(output_partition_graphs=True)
      debug_utils.watch_graph(run_options,
                              sess.graph,
                              debug_urls=self._debug_urls())
      run_metadata = config_pb2.RunMetadata()
      self.assertEqual(
          21, sess.run(cond, options=run_options, run_metadata=run_metadata))

      dump = debug_data.DebugDumpDir(
          self._dump_root, partition_graphs=run_metadata.partition_graphs)
      self.assertAllClose(
          [21.0], dump.get_tensors("cond/Merge", 0, "DebugIdentity")) 

# 需要导入模块: from tensorflow.python.ops import control_flow_ops [as 别名]
# 或者: from tensorflow.python.ops.control_flow_ops import cond [as 别名]
def _safe_scalar_div(numerator, denominator, name):
  """Divides two values, returning 0 if the denominator is 0.

  Args:
    numerator: A scalar `float64` `Tensor`.
    denominator: A scalar `float64` `Tensor`.
    name: Name for the returned op.

  Returns:
    0 if `denominator` == 0, else `numerator` / `denominator`
  """
  numerator.get_shape().with_rank_at_most(1)
  denominator.get_shape().with_rank_at_most(1)
  return control_flow_ops.cond(
      math_ops.equal(
          array_ops.constant(0.0, dtype=dtypes.float64), denominator),
      lambda: array_ops.constant(0.0, dtype=dtypes.float64),
      lambda: math_ops.div(numerator, denominator),
      name=name) 

# 需要导入模块: from tensorflow.python.ops import control_flow_ops [as 别名]
# 或者: from tensorflow.python.ops.control_flow_ops import cond [as 别名]
def initialized_value(self):
    """Returns the value of the initialized variable.

    You should use this instead of the variable itself to initialize another
    variable with a value that depends on the value of this variable.

    ```python
    # Initialize 'v' with a random tensor.
    v = tf.Variable(tf.truncated_normal([10, 40]))
    # Use `initialized_value` to guarantee that `v` has been
    # initialized before its value is used to initialize `w`.
    # The random values are picked only once.
    w = tf.Variable(v.initialized_value() * 2.0)
    ```

    Returns:
      A `Tensor` holding the value of this variable after its initializer
      has run.
    """
    with ops.control_dependencies(None):
      return control_flow_ops.cond(is_variable_initialized(self),
                                   self.read_value,
                                   lambda: self.initial_value) 

# 需要导入模块: from tensorflow.python.ops import control_flow_ops [as 别名]
# 或者: from tensorflow.python.ops.control_flow_ops import cond [as 别名]
def _assert(cond, ex_type, msg):
  """A polymorphic assert, works with tensors and boolean expressions.

  If `cond` is not a tensor, behave like an ordinary assert statement, except
  that a empty list is returned. If `cond` is a tensor, return a list
  containing a single TensorFlow assert op.

  Args:
    cond: Something evaluates to a boolean value. May be a tensor.
    ex_type: The exception class to use.
    msg: The error message.

  Returns:
    A list, containing at most one assert op.
  """
  if _is_tensor(cond):
    return [control_flow_ops.Assert(cond, [msg])]
  else:
    if not cond:
      raise ex_type(msg)
    else:
      return [] 

# 需要导入模块: from tensorflow.python.ops import control_flow_ops [as 别名]
# 或者: from tensorflow.python.ops.control_flow_ops import cond [as 别名]
def _log_prob(self, event):
    event = self._maybe_assert_valid_sample(event)
    # TODO(jaana): The current sigmoid_cross_entropy_with_logits has
    # inconsistent  behavior for logits = inf/-inf.
    event = math_ops.cast(event, self.logits.dtype)
    logits = self.logits
    # sigmoid_cross_entropy_with_logits doesn't broadcast shape,
    # so we do this here.

    def _broadcast(logits, event):
      return (array_ops.ones_like(event) * logits,
              array_ops.ones_like(logits) * event)

    # First check static shape.
    if (event.get_shape().is_fully_defined() and
        logits.get_shape().is_fully_defined()):
      if event.get_shape() != logits.get_shape():
        logits, event = _broadcast(logits, event)
    else:
      logits, event = control_flow_ops.cond(
          distribution_util.same_dynamic_shape(logits, event),
          lambda: (logits, event),
          lambda: _broadcast(logits, event))
    return -nn.sigmoid_cross_entropy_with_logits(labels=event, logits=logits) 

# 需要导入模块: from tensorflow.python.ops import control_flow_ops [as 别名]
# 或者: from tensorflow.python.ops.control_flow_ops import cond [as 别名]
def average_impurity(self):
    """Constructs a TF graph for evaluating the average leaf impurity of a tree.

    If in regression mode, this is the leaf variance. If in classification mode,
    this is the gini impurity.

    Returns:
      The last op in the graph.
    """
    children = array_ops.squeeze(array_ops.slice(
        self.variables.tree, [0, 0], [-1, 1]), squeeze_dims=[1])
    is_leaf = math_ops.equal(constants.LEAF_NODE, children)
    leaves = math_ops.to_int32(array_ops.squeeze(array_ops.where(is_leaf),
                                                 squeeze_dims=[1]))
    counts = array_ops.gather(self.variables.node_sums, leaves)
    gini = self._weighted_gini(counts)
    # Guard against step 1, when there often are no leaves yet.
    def impurity():
      return gini
    # Since average impurity can be used for loss, when there's no data just
    # return a big number so that loss always decreases.
    def big():
      return array_ops.ones_like(gini, dtype=dtypes.float32) * 10000000.
    return control_flow_ops.cond(math_ops.greater(
        array_ops.shape(leaves)[0], 0), impurity, big) 

# 需要导入模块: from tensorflow.python.ops import control_flow_ops [as 别名]
# 或者: from tensorflow.python.ops.control_flow_ops import cond [as 别名]
def insert(self, ids, scores):
    """Insert the ids and scores into the TopN."""
    with ops.control_dependencies(self.last_ops):
      scatter_op = state_ops.scatter_update(self.id_to_score, ids, scores)
      larger_scores = math_ops.greater(scores, self.sl_scores[0])

      def shortlist_insert():
        larger_ids = array_ops.boolean_mask(
            math_ops.to_int64(ids), larger_scores)
        larger_score_values = array_ops.boolean_mask(scores, larger_scores)
        shortlist_ids, new_ids, new_scores = tensor_forest_ops.top_n_insert(
            self.sl_ids, self.sl_scores, larger_ids, larger_score_values)
        u1 = state_ops.scatter_update(self.sl_ids, shortlist_ids, new_ids)
        u2 = state_ops.scatter_update(self.sl_scores, shortlist_ids, new_scores)
        return control_flow_ops.group(u1, u2)

      # We only need to insert into the shortlist if there are any
      # scores larger than the threshold.
      cond_op = control_flow_ops.cond(
          math_ops.reduce_any(larger_scores), shortlist_insert,
          control_flow_ops.no_op)
      with ops.control_dependencies([cond_op]):
        self.last_ops = [scatter_op, cond_op] 

# 需要导入模块: from tensorflow.python.ops import control_flow_ops [as 别名]
# 或者: from tensorflow.python.ops.control_flow_ops import cond [as 别名]
def _log_prob(self, event):
    # TODO(jaana): The current sigmoid_cross_entropy_with_logits has
    # inconsistent  behavior for logits = inf/-inf.
    event = ops.convert_to_tensor(event, name="event")
    event = math_ops.cast(event, self.logits.dtype)
    logits = self.logits
    # sigmoid_cross_entropy_with_logits doesn't broadcast shape,
    # so we do this here.

    broadcast = lambda logits, event: (
        array_ops.ones_like(event) * logits,
        array_ops.ones_like(logits) * event)

    # First check static shape.
    if (event.get_shape().is_fully_defined() and
        logits.get_shape().is_fully_defined()):
      if event.get_shape() != logits.get_shape():
        logits, event = broadcast(logits, event)
    else:
      logits, event = control_flow_ops.cond(
          distribution_util.same_dynamic_shape(logits, event),
          lambda: (logits, event),
          lambda: broadcast(logits, event))
    return -nn.sigmoid_cross_entropy_with_logits(labels=event, logits=logits) 

# 需要导入模块: from tensorflow.python.ops import control_flow_ops [as 别名]
# 或者: from tensorflow.python.ops.control_flow_ops import cond [as 别名]
def _wrap_computation_in_while_loop_with_stopping_signals(device, op_fn):
  """Wraps the ops generated by `op_fn` in tf.while_loop."""

  def cond(scalar_stopping_signal):
    return math_ops.logical_not(
        _StopSignals.should_stop(scalar_stopping_signal))

  def computation(unused_scalar_stopping_signal):
    return_value = op_fn()
    execute_ops = return_value['ops']
    signals = return_value['signals']
    with ops.control_dependencies(execute_ops):
      return _StopSignals.as_scalar_stopping_signal(signals)

  # By setting parallel_iterations=1, the parallel execution in while_loop is
  # basically turned off.
  with ops.device(device):
    return control_flow_ops.while_loop(
        cond,
        computation, [_StopSignals.NON_STOPPING_SIGNAL],
        parallel_iterations=1) 

# 需要导入模块: from tensorflow.python.ops import control_flow_ops [as 别名]
# 或者: from tensorflow.python.ops.control_flow_ops import cond [as 别名]
def AddCrossEntropy(batch_size, n):
  """Adds a cross entropy cost function."""
  cross_entropies = []
  def _Pass():
    return tf.constant(0, dtype=tf.float32, shape=[1])

  for beam_id in range(batch_size):
    beam_gold_slot = tf.reshape(
        tf.strided_slice(n['gold_slot'], [beam_id], [beam_id + 1]), [1])
    def _ComputeCrossEntropy():
      """Adds ops to compute cross entropy of the gold path in a beam."""
      # Requires a cast so that UnsortedSegmentSum, in the gradient,
      # is happy with the type of its input 'segment_ids', which
      # must be int32.
      idx = tf.cast(
          tf.reshape(
              tf.where(tf.equal(n['beam_ids'], beam_id)), [-1]), tf.int32)
      beam_scores = tf.reshape(tf.gather(n['all_path_scores'], idx), [1, -1])
      num = tf.shape(idx)
      return tf.nn.softmax_cross_entropy_with_logits(
          labels=tf.expand_dims(
              tf.sparse_to_dense(beam_gold_slot, num, [1.], 0.), 0),
          logits=beam_scores)
    # The conditional here is needed to deal with the last few batches of the
    # corpus which can contain -1 in beam_gold_slot for empty batch slots.
    cross_entropies.append(cf.cond(
        beam_gold_slot[0] >= 0, _ComputeCrossEntropy, _Pass))
  return {'cross_entropy': tf.div(tf.add_n(cross_entropies), batch_size)} 

# 需要导入模块: from tensorflow.python.ops import control_flow_ops [as 别名]
# 或者: from tensorflow.python.ops.control_flow_ops import cond [as 别名]
def initialize(self, name=None):
        with ops.name_scope(name, "TrainingHelperInitialize"):
            finished = math_ops.equal(0, self._sequence_length)
            all_finished = math_ops.reduce_all(finished)
            next_inputs = control_flow_ops.cond(
                all_finished, lambda: self._zero_inputs,
                lambda: nest.map_structure(lambda inp: inp.read(0), self._input_tas))
            return (finished, next_inputs)