Python v1.to_float方法代码示例

# 需要导入模块: from tensorflow.compat import v1 [as 别名]
# 或者: from tensorflow.compat.v1 import to_float [as 别名]
def _distributional_to_value(value_d, size, subscale, threshold):
  """Get a scalar value out of a value distribution in distributional RL."""
  half = size // 2
  value_range = (tf.to_float(tf.range(-half, half)) + 0.5) * subscale
  probs = tf.nn.softmax(value_d)

  if threshold == 0.0:
    return tf.reduce_sum(probs * value_range, axis=-1)

  # accumulated_probs[..., i] is the sum of probabilities in buckets upto i
  # so it is the probability that value <= i'th bucket value
  accumulated_probs = tf.cumsum(probs, axis=-1)
  # New probs are 0 on all lower buckets, until the threshold
  probs = tf.where(accumulated_probs < threshold, tf.zeros_like(probs), probs)
  probs /= tf.reduce_sum(probs, axis=-1, keepdims=True)  # Re-normalize.
  return tf.reduce_sum(probs * value_range, axis=-1) 

# 需要导入模块: from tensorflow.compat import v1 [as 别名]
# 或者: from tensorflow.compat.v1 import to_float [as 别名]
def set_precision(predictions, labels,
                  weights_fn=common_layers.weights_nonzero):
  """Precision of set predictions.

  Args:
    predictions : A Tensor of scores of shape [batch, nlabels].
    labels: A Tensor of int32s giving true set elements,
      of shape [batch, seq_length].
    weights_fn: A function to weight the elements.

  Returns:
    hits: A Tensor of shape [batch, nlabels].
    weights: A Tensor of shape [batch, nlabels].
  """
  with tf.variable_scope("set_precision", values=[predictions, labels]):
    labels = tf.squeeze(labels, [2, 3])
    weights = weights_fn(labels)
    labels = tf.one_hot(labels, predictions.shape[-1])
    labels = tf.reduce_max(labels, axis=1)
    labels = tf.cast(labels, tf.bool)
    return tf.to_float(tf.equal(labels, predictions)), weights 

# 需要导入模块: from tensorflow.compat import v1 [as 别名]
# 或者: from tensorflow.compat.v1 import to_float [as 别名]
def set_recall(predictions, labels, weights_fn=common_layers.weights_nonzero):
  """Recall of set predictions.

  Args:
    predictions : A Tensor of scores of shape [batch, nlabels].
    labels: A Tensor of int32s giving true set elements,
      of shape [batch, seq_length].
    weights_fn: A function to weight the elements.

  Returns:
    hits: A Tensor of shape [batch, nlabels].
    weights: A Tensor of shape [batch, nlabels].
  """
  with tf.variable_scope("set_recall", values=[predictions, labels]):
    labels = tf.squeeze(labels, [2, 3])
    weights = weights_fn(labels)
    labels = tf.one_hot(labels, predictions.shape[-1])
    labels = tf.reduce_max(labels, axis=1)
    labels = tf.cast(labels, tf.bool)
    return tf.to_float(tf.equal(labels, predictions)), weights 

# 需要导入模块: from tensorflow.compat import v1 [as 别名]
# 或者: from tensorflow.compat.v1 import to_float [as 别名]
def cv_squared(x):
  """The squared coefficient of variation of a sample.

  Useful as a loss to encourage a positive distribution to be more uniform.
  Epsilons added for numerical stability.
  Returns 0 for an empty Tensor.

  Args:
    x: a `Tensor`.

  Returns:
    a `Scalar`.
  """
  epsilon = 1e-10
  float_size = tf.to_float(tf.size(x)) + epsilon
  mean = tf.reduce_sum(x) / float_size
  variance = tf.reduce_sum(tf.squared_difference(x, mean)) / float_size
  return variance / (tf.square(mean) + epsilon) 

# 需要导入模块: from tensorflow.compat import v1 [as 别名]
# 或者: from tensorflow.compat.v1 import to_float [as 别名]
def diet_expert(x, hidden_size, params):
  """A two-layer feed-forward network with relu activation on hidden layer.

  Uses diet variables.
  Recomputes hidden layer on backprop to save activation memory.

  Args:
    x: a Tensor with shape [batch, io_size]
    hidden_size: an integer
    params: a diet variable HParams object.

  Returns:
    a Tensor with shape [batch, io_size]
  """

  @fn_with_diet_vars(params)
  def diet_expert_internal(x):
    dim = x.get_shape().as_list()[-1]
    h = tf.layers.dense(x, hidden_size, activation=tf.nn.relu, use_bias=False)
    y = tf.layers.dense(h, dim, use_bias=False)
    y *= tf.rsqrt(tf.to_float(dim * hidden_size))
    return y

  return diet_expert_internal(x) 

# 需要导入模块: from tensorflow.compat import v1 [as 别名]
# 或者: from tensorflow.compat.v1 import to_float [as 别名]
def summarize_features(features, num_shards=1):
  """Generate summaries for features."""
  if not common_layers.should_generate_summaries():
    return

  with tf.name_scope("input_stats"):
    for (k, v) in sorted(six.iteritems(features)):
      if (isinstance(v, tf.Tensor) and (v.get_shape().ndims > 1) and
          (v.dtype != tf.string)):
        tf.summary.scalar("%s_batch" % k, tf.shape(v)[0] // num_shards)
        tf.summary.scalar("%s_length" % k, tf.shape(v)[1])
        nonpadding = tf.to_float(tf.not_equal(v, 0))
        nonpadding_tokens = tf.reduce_sum(nonpadding)
        tf.summary.scalar("%s_nonpadding_tokens" % k, nonpadding_tokens)
        tf.summary.scalar("%s_nonpadding_fraction" % k,
                          tf.reduce_mean(nonpadding)) 

# 需要导入模块: from tensorflow.compat import v1 [as 别名]
# 或者: from tensorflow.compat.v1 import to_float [as 别名]
def _learning_rate_warmup(warmup_steps, warmup_schedule="exp", hparams=None):
  """Learning rate warmup multiplier."""
  if not warmup_steps:
    return tf.constant(1.)

  tf.logging.info("Applying %s learning rate warmup for %d steps",
                  warmup_schedule, warmup_steps)

  warmup_steps = tf.to_float(warmup_steps)
  global_step = _global_step(hparams)

  if warmup_schedule == "exp":
    return tf.exp(tf.log(0.01) / warmup_steps)**(warmup_steps - global_step)
  else:
    assert warmup_schedule == "linear"
    start = tf.constant(0.35)
    return ((tf.constant(1.) - start) / warmup_steps) * global_step + start 

# 需要导入模块: from tensorflow.compat import v1 [as 别名]
# 或者: from tensorflow.compat.v1 import to_float [as 别名]
def noise_from_step_num():
  """Quantization noise equal to (phi * (step_num + 1)) mod 1.0.

  Not using random_uniform here due to a problem on TPU in that random seeds
  are not respected, which may cause the parameters on different replicas
  to go out-of-sync.

  Returns:
    a float32 scalar
  """
  step = tf.to_int32(tf.train.get_or_create_global_step()) + 1
  phi = ((5 ** 0.5) - 1) / 2
  # Naive computation tf.mod(phi * step, 1.0) in float32 would be disastrous
  # due to loss of precision when the step number gets large.
  # Computation in doubles does not work on TPU, so we use this complicated
  # alternative computation which does not suffer from these roundoff errors.
  ret = 0.0
  for i in range(30):
    ret += (((phi * (2 ** i)) % 1.0)  # double-precision computation in python
            * tf.to_float(tf.mod(step // (2 ** i), 2)))
  return tf.mod(ret, 1.0) 

# 需要导入模块: from tensorflow.compat import v1 [as 别名]
# 或者: from tensorflow.compat.v1 import to_float [as 别名]
def _randomized_roundoff_to_bfloat16(x, noise, cand1, cand2):
  """Round-off x to cand1 or to cand2 in an unbiased way.

  Cand1 and cand2 are the same shape as x.
  For every element of x, the corresponding elements of cand1 and cand2 should
  be the two closest bfloat16 values to x.  Order does not matter.
  cand1 and cand2 must differ from each other.

  Args:
    x: A float32 Tensor.
    noise: A Tensor broadcastable to the shape of x containing
    random uniform values in [0.0, 1.0].
    cand1: A bfloat16 Tensor the same shape as x.
    cand2: A bfloat16 Tensor the same shape as x.

  Returns:
    A bfloat16 Tensor.
  """
  cand1_f = tf.to_float(cand1)
  cand2_f = tf.to_float(cand2)
  step_size = cand2_f - cand1_f
  fpart = (x - cand1_f) / step_size
  ret = tf.where(tf.greater(fpart, noise), cand2, cand1)
  return ret 

# 需要导入模块: from tensorflow.compat import v1 [as 别名]
# 或者: from tensorflow.compat.v1 import to_float [as 别名]
def _to_bfloat16_unbiased(x, noise):
  """Convert a float32 to a bfloat16 using randomized roundoff.

  Args:
    x: A float32 Tensor.
    noise: a float32 Tensor with values in [0, 1), broadcastable to tf.shape(x)
  Returns:
    A float32 Tensor.
  """
  x_sign = tf.sign(x)
  # Make sure x is positive.  If it is zero, the two candidates are identical.
  x = x * x_sign + 1e-30
  cand1 = tf.to_bfloat16(x)
  cand1_f = tf.to_float(cand1)
  # This relies on the fact that for a positive bfloat16 b,
  # b * 1.005 gives you the next higher bfloat16 and b*0.995 gives you the
  # next lower one. Both 1.005 and 0.995 are ballpark estimation.
  cand2 = tf.to_bfloat16(
      tf.where(tf.greater(x, cand1_f), cand1_f * 1.005, cand1_f * 0.995))
  ret = _randomized_roundoff_to_bfloat16(x, noise, cand1, cand2)
  return ret * tf.to_bfloat16(x_sign) 

# 需要导入模块: from tensorflow.compat import v1 [as 别名]
# 或者: from tensorflow.compat.v1 import to_float [as 别名]
def fill_memory_slot(memory, value, index):
  """Fills the memory slot at a particular index with the given value.

  Args:
    memory: a 4-d tensor [memory_size, batch, length, channel] containing
      the state of all steps
    value: a 3-d tensor [batch, length, channel] as the sate
    index: integer in [0, memory_size)

  Returns:
    filled memory

  """
  mask = tf.to_float(
      tf.one_hot(index,
                 tf.shape(memory)[0])[:, None, None, None])
  fill_memory = (1 - mask) * memory + mask * value[None, ...]
  return fill_memory 

# 需要导入模块: from tensorflow.compat import v1 [as 别名]
# 或者: from tensorflow.compat.v1 import to_float [as 别名]
def sample(self, features=None, shape=None):
    del features
    hp = self.hparams
    div_x = 2**hp.num_hidden_layers
    div_y = 1 if self.is1d else 2**hp.num_hidden_layers
    size = [
        hp.batch_size, hp.sample_height // div_x, hp.sample_width // div_y,
        hp.bottleneck_bits
    ]
    size = size if shape is None else shape
    rand = tf.random_uniform(size)
    res = 2.0 * tf.to_float(tf.less(0.5, rand)) - 1.0
    # If you want to set some first bits to a fixed value, do this:
    # fixed = tf.zeros_like(rand) - 1.0
    # nbits = 3
    # res = tf.concat([fixed[:, :, :, :nbits], res[:, :, :, nbits:]], axis=-1)
    return res 

# 需要导入模块: from tensorflow.compat import v1 [as 别名]
# 或者: from tensorflow.compat.v1 import to_float [as 别名]
def bottleneck(self, x):  # pylint: disable=arguments-differ
    hparams = self.hparams
    if hparams.unordered:
      return super(AutoencoderOrderedDiscrete, self).bottleneck(x)
    noise = hparams.bottleneck_noise
    hparams.bottleneck_noise = 0.0  # We'll add noise below.
    x, loss = discretization.parametrized_bottleneck(x, hparams)
    hparams.bottleneck_noise = noise
    if hparams.mode == tf.estimator.ModeKeys.TRAIN:
      # We want a number p such that p^bottleneck_bits = 1 - noise.
      # So log(p) * bottleneck_bits = log(noise)
      log_p = tf.log1p(-float(noise) / 2) / float(hparams.bottleneck_bits)
      # Probabilities of flipping are p, p^2, p^3, ..., p^bottleneck_bits.
      noise_mask = 1.0 - tf.exp(tf.cumsum(tf.zeros_like(x) + log_p, axis=-1))
      # Having the no-noise mask, we can make noise just uniformly at random.
      ordered_noise = tf.random_uniform(tf.shape(x))
      # We want our noise to be 1s at the start and random {-1, 1} bits later.
      ordered_noise = tf.to_float(tf.less(noise_mask, ordered_noise))
      # Now we flip the bits of x on the noisy positions (ordered and normal).
      x *= 2.0 * ordered_noise - 1
    return x, loss 

# 需要导入模块: from tensorflow.compat import v1 [as 别名]
# 或者: from tensorflow.compat.v1 import to_float [as 别名]
def compute_last_embedding(input_embeddings, input_lengths, hparams):
  """Computes average of last K embedding.

  Args:
    input_embeddings: <tf.float32>[bs, max_seq_len, emb_dim]
    input_lengths: <tf.int64>[bs, 1]
    hparams: model hparams

  Returns:
    last_k_embedding: <tf.float32>[bs, emb_dim]
  """
  max_seq_len = tf.shape(input_embeddings)[1]
  # <tf.float32>[bs, 1, max_seq_len]
  mask = tf.sequence_mask(input_lengths, max_seq_len, dtype=tf.float32)
  del_mask = tf.sequence_mask(
      input_lengths - hparams.last_k, max_seq_len, dtype=tf.float32)
  final_mask = mask - del_mask
  # <tf.float32>[bs, 1, emb_dim]
  sum_embedding = tf.matmul(final_mask, input_embeddings)
  # <tf.float32>[bs, 1, emb_dim]
  last_k_embedding = sum_embedding / tf.to_float(
      tf.expand_dims(
          tf.ones([tf.shape(input_embeddings)[0], 1]) * hparams.last_k, 2))
  # <tf.float32>[bs, dim]
  return tf.squeeze(last_k_embedding, 1) 

# 需要导入模块: from tensorflow.compat import v1 [as 别名]
# 或者: from tensorflow.compat.v1 import to_float [as 别名]
def xception_exit(inputs):
  """Xception exit flow."""
  with tf.variable_scope("xception_exit"):
    x = inputs
    x_shape = x.get_shape().as_list()
    if x_shape[1] is None or x_shape[2] is None:
      length_float = tf.to_float(tf.shape(x)[1])
      length_float *= tf.to_float(tf.shape(x)[2])
      spatial_dim_float = tf.sqrt(length_float)
      spatial_dim = tf.to_int32(spatial_dim_float)
      x_depth = x_shape[3]
      x = tf.reshape(x, [-1, spatial_dim, spatial_dim, x_depth])
    elif x_shape[1] != x_shape[2]:
      spatial_dim = int(math.sqrt(float(x_shape[1] * x_shape[2])))
      if spatial_dim * spatial_dim != x_shape[1] * x_shape[2]:
        raise ValueError("Assumed inputs were square-able but they were "
                         "not. Shape: %s" % x_shape)
      x = tf.reshape(x, [-1, spatial_dim, spatial_dim, x_depth])

    x = common_layers.conv_block_downsample(x, (3, 3), (2, 2), "SAME")
    return tf.nn.relu(x)