Python math_ops.exp方法代码示例

# 需要导入模块: from tensorflow.python.ops import math_ops [as 别名]
# 或者: from tensorflow.python.ops.math_ops import exp [as 别名]
def _BetaincGrad(op, grad):
  """Returns gradient of betainc(a, b, x) with respect to x."""
  # TODO(ebrevdo): Perhaps add the derivative w.r.t. a, b
  a, b, x = op.inputs

  # two cases: x is a scalar and a/b are same-shaped tensors, or vice
  # versa; so its sufficient to check against shape(a).
  sa = array_ops.shape(a)
  sx = array_ops.shape(x)
  # pylint: disable=protected-access
  _, rx = gen_array_ops._broadcast_gradient_args(sa, sx)
  # pylint: enable=protected-access

  # Perform operations in log space before summing, because terms
  # can grow large.
  log_beta = (gen_math_ops.lgamma(a) + gen_math_ops.lgamma(b)
              - gen_math_ops.lgamma(a + b))
  partial_x = math_ops.exp(
      (b - 1) * math_ops.log(1 - x) + (a - 1) * math_ops.log(x) - log_beta)

  # TODO(b/36815900): Mark None return values as NotImplemented
  return (None,  # da
          None,  # db
          array_ops.reshape(math_ops.reduce_sum(partial_x * grad, rx), sx)) 

# 需要导入模块: from tensorflow.python.ops import math_ops [as 别名]
# 或者: from tensorflow.python.ops.math_ops import exp [as 别名]
def _log_prob_with_logsf_and_logcdf(self, y):
    """Compute log_prob(y) using log survival_function and cdf together."""
    # There are two options that would be equal if we had infinite precision:
    # Log[ sf(y - 1) - sf(y) ]
    #   = Log[ exp{logsf(y - 1)} - exp{logsf(y)} ]
    # Log[ cdf(y) - cdf(y - 1) ]
    #   = Log[ exp{logcdf(y)} - exp{logcdf(y - 1)} ]
    logsf_y = self.log_survival_function(y)
    logsf_y_minus_1 = self.log_survival_function(y - 1)
    logcdf_y = self.log_cdf(y)
    logcdf_y_minus_1 = self.log_cdf(y - 1)

    # Important:  Here we use select in a way such that no input is inf, this
    # prevents the troublesome case where the output of select can be finite,
    # but the output of grad(select) will be NaN.

    # In either case, we are doing Log[ exp{big} - exp{small} ]
    # We want to use the sf items precisely when we are on the right side of the
    # median, which occurs when logsf_y < logcdf_y.
    big = array_ops.where(logsf_y < logcdf_y, logsf_y_minus_1, logcdf_y)
    small = array_ops.where(logsf_y < logcdf_y, logsf_y, logcdf_y_minus_1)

    return _logsum_expbig_minus_expsmall(big, small) 

# 需要导入模块: from tensorflow.python.ops import math_ops [as 别名]
# 或者: from tensorflow.python.ops.math_ops import exp [as 别名]
def _sample_n(self, n, seed=None):
    # Here we use the fact that if:
    # lam ~ Gamma(concentration=total_count, rate=(1-probs)/probs)
    # then X ~ Poisson(lam) is Negative Binomially distributed.
    rate = random_ops.random_gamma(
        shape=[n],
        alpha=self.total_count,
        beta=math_ops.exp(-self.logits),
        dtype=self.dtype,
        seed=seed)

    return random_ops.random_poisson(
        rate,
        shape=[],
        dtype=self.dtype,
        seed=distribution_util.gen_new_seed(seed, "negative_binom")) 

# 需要导入模块: from tensorflow.python.ops import math_ops [as 别名]
# 或者: from tensorflow.python.ops.math_ops import exp [as 别名]
def prob(self, value, name="prob", **condition_kwargs):
    """Probability density/mass function (depending on `is_continuous`).

    Args:
      value: `float` or `double` `Tensor`.
      name: The name to give this op.
      **condition_kwargs: Named arguments forwarded to subclass implementation.

    Returns:
      prob: a `Tensor` of shape `sample_shape(x) + self.batch_shape` with
        values of type `self.dtype`.
    """
    with self._name_scope(name, values=[value]):
      value = ops.convert_to_tensor(value, name="value")
      try:
        return self._prob(value, **condition_kwargs)
      except NotImplementedError as original_exception:
        try:
          return math_ops.exp(self._log_prob(value, **condition_kwargs))
        except NotImplementedError:
          raise original_exception 

# 需要导入模块: from tensorflow.python.ops import math_ops [as 别名]
# 或者: from tensorflow.python.ops.math_ops import exp [as 别名]
def _adaptive_max_norm(norm, std_factor, decay, global_step, epsilon, name):
  """Find max_norm given norm and previous average."""
  with vs.variable_scope(name, "AdaptiveMaxNorm", [norm]):
    log_norm = math_ops.log(norm + epsilon)

    def moving_average(name, value, decay):
      moving_average_variable = vs.get_variable(
          name,
          shape=value.get_shape(),
          dtype=value.dtype,
          initializer=init_ops.zeros_initializer(),
          trainable=False)
      return moving_averages.assign_moving_average(
          moving_average_variable, value, decay, zero_debias=False)

    # quicker adaptation at the beginning
    if global_step is not None:
      n = math_ops.cast(global_step, dtypes.float32)
      decay = math_ops.minimum(decay, n / (n + 1.))

    # update averages
    mean = moving_average("mean", log_norm, decay)
    sq_mean = moving_average("sq_mean", math_ops.square(log_norm), decay)

    variance = sq_mean - math_ops.square(mean)
    std = math_ops.sqrt(math_ops.maximum(epsilon, variance))
    max_norms = math_ops.exp(mean + std_factor * std)
    return max_norms, mean 

# 需要导入模块: from tensorflow.python.ops import math_ops [as 别名]
# 或者: from tensorflow.python.ops.math_ops import exp [as 别名]
def _prob(self, x):
    return math_ops.exp(self._log_prob(x)) 

# 需要导入模块: from tensorflow.python.ops import math_ops [as 别名]
# 或者: from tensorflow.python.ops.math_ops import exp [as 别名]
def _prob(self, counts):
    return math_ops.exp(self._log_prob(counts)) 

# 需要导入模块: from tensorflow.python.ops import math_ops [as 别名]
# 或者: from tensorflow.python.ops.math_ops import exp [as 别名]
def _prob(self, y):
    x = self.bijector.inverse(y)
    ildj = self.bijector.inverse_log_det_jacobian(y)
    x = self._maybe_rotate_dims(x, rotate_right=True)
    prob = self.distribution.prob(x)
    if self._is_maybe_event_override:
      prob = math_ops.reduce_prod(prob, self._reduce_event_indices)
    prob *= math_ops.exp(ildj)
    if self._is_maybe_event_override:
      prob.set_shape(array_ops.broadcast_static_shape(
          y.get_shape().with_rank_at_least(1)[:-1], self.batch_shape))
    return prob 

# 需要导入模块: from tensorflow.python.ops import math_ops [as 别名]
# 或者: from tensorflow.python.ops.math_ops import exp [as 别名]
def _call_cdf(self, value, name, **kwargs):
    with self._name_scope(name, values=[value]):
      value = ops.convert_to_tensor(value, name="value")
      try:
        return self._cdf(value, **kwargs)
      except NotImplementedError as original_exception:
        try:
          return math_ops.exp(self._log_cdf(value, **kwargs))
        except NotImplementedError:
          raise original_exception 

# 需要导入模块: from tensorflow.python.ops import math_ops [as 别名]
# 或者: from tensorflow.python.ops.math_ops import exp [as 别名]
def ndtr(x, name="ndtr"):
  """Normal distribution function.

  Returns the area under the Gaussian probability density function, integrated
  from minus infinity to x:

  ```
                    1       / x
     ndtr(x)  = ----------  |    exp(-0.5 t**2) dt
                sqrt(2 pi)  /-inf

              = 0.5 (1 + erf(x / sqrt(2)))
              = 0.5 erfc(x / sqrt(2))
  ```

  Args:
    x: `Tensor` of type `float32`, `float64`.
    name: Python string. A name for the operation (default="ndtr").

  Returns:
    ndtr: `Tensor` with `dtype=x.dtype`.

  Raises:
    TypeError: if `x` is not floating-type.
  """

  with ops.name_scope(name, values=[x]):
    x = ops.convert_to_tensor(x, name="x")
    if x.dtype.as_numpy_dtype not in [np.float32, np.float64]:
      raise TypeError(
          "x.dtype=%s is not handled, see docstring for supported types."
          % x.dtype)
    return _ndtr(x) 

# 需要导入模块: from tensorflow.python.ops import math_ops [as 别名]
# 或者: from tensorflow.python.ops.math_ops import exp [as 别名]
def _prob(self, event):
    return math_ops.exp(self._log_prob(event)) 

# 需要导入模块: from tensorflow.python.ops import math_ops [as 别名]
# 或者: from tensorflow.python.ops.math_ops import exp [as 别名]
def _cdf(self, x):
    z = self._z(x)
    return (0.5 + 0.5 * math_ops.sign(z) *
            (1. - math_ops.exp(-math_ops.abs(z)))) 

# 需要导入模块: from tensorflow.python.ops import math_ops [as 别名]
# 或者: from tensorflow.python.ops.math_ops import exp [as 别名]
def _prob(self, k):
    return math_ops.exp(self._log_prob(k)) 

# 需要导入模块: from tensorflow.python.ops import math_ops [as 别名]
# 或者: from tensorflow.python.ops.math_ops import exp [as 别名]
def _Expm1Grad(op, grad):
  """Returns grad * exp(x)."""
  x = op.inputs[0]
  with ops.control_dependencies([grad.op]):
    x = math_ops.conj(x)
    y = math_ops.exp(x)
    return grad * y 

# 需要导入模块: from tensorflow.python.ops import math_ops [as 别名]
# 或者: from tensorflow.python.ops.math_ops import exp [as 别名]
def _ErfGrad(op, grad):
  """Returns grad * 2/sqrt(pi) * exp(-x**2)."""
  x = op.inputs[0]
  two_over_root_pi = constant_op.constant(2 / np.sqrt(np.pi), dtype=grad.dtype)
  with ops.control_dependencies([grad.op]):
    x = math_ops.conj(x)
    return grad * two_over_root_pi * math_ops.exp(-math_ops.square(x))