:py:mod:`box_embeddings.common.tf_utils`
========================================

.. py:module:: box_embeddings.common.tf_utils


Module Contents
---------------

.. py:function:: tiny_value_of_dtype(dtype: tensorflow.dtypes.DType) -> float

   This implementation is adopted from AllenNLP.

   Returns a moderately tiny value for a given PyTorch data type that is used to avoid numerical
   issues such as division by zero.
   This is different from `info_value_of_dtype(dtype).tiny` because it causes some NaN bugs.
   Only supports floating point dtypes.

   :param dtype: torch dtype of supertype float

   :returns: Tiny value
   :rtype: float

   :raises TypeError: Given non-float or unknown type


.. py:function:: log1mexp(x: tensorflow.Tensor, split_point: float = _log1mexp_switch, exp_zero_eps: float = 1e-07) -> tensorflow.Tensor

   Computes log(1 - exp(x)).

   Splits at x=log(1/2) for x in (-inf, 0] i.e. at -x=log(2) for -x in [0, inf).

   = log1p(-exp(x)) when x <= log(1/2)
   or
   = log(-expm1(x)) when log(1/2) < x <= 0

   For details, see

   https://cran.r-project.org/web/packages/Rmpfr/vignettes/log1mexp-note.pdf

   https://github.com/visinf/n3net/commit/31968bd49c7d638cef5f5656eb62793c46b41d76

   :param x: input tensor
   :param split_point: Should be kept to the default of log(0.5)
   :param exp_zero_eps: Default 1e-7

   :returns: Elementwise log1mexp(x) = log(1-exp(x))
   :rtype: torch.Tensor


.. py:function:: log1pexp(x: tensorflow.Tensor) -> tensorflow.Tensor

   Computes log(1+exp(x))

   see: Page 7, eqn 10 of https://cran.r-project.org/web/packages/Rmpfr/vignettes/log1mexp-note.pdf
   also see: https://github.com/SurajGupta/r-source/blob/master/src/nmath/plogis.c

   :param x: Tensor

   :returns: Elementwise log1pexp(x) = log(1+exp(x))
   :rtype: torch.Tensor


.. py:function:: softplus_inverse(t: tensorflow.Tensor, beta: float = 1.0, threshold: float = 20) -> tensorflow.Tensor

   Computes the inverse softplus

   :param t: input tensor
   :param beta: TODO
   :param threshold: TODO

   :returns: softplus inverse of the input


.. py:data:: lse_eps
   :annotation: = 1e-38

   

.. py:data:: log_lse_eps
   

   

.. py:function:: logsumexp2(t1: tensorflow.Tensor, t2: tensorflow.Tensor) -> tensorflow.Tensor

   Performs element-wise logsumexp of two tensors in a numerically stable manner. This can also
   be thought as a soft/differentiable version of the max operator.

   Specifically, it computes log(exp(t1) + exp(t2)).

   :param t1: First tensor (left operand)
   :param t2: Second tensor (right operand)

   :returns: logsumexp


.. py:function:: inv_sigmoid(t1: tensorflow.Tensor) -> tensorflow.Tensor

   Calculate the inverse of the sigmoid function

   :param t1: a tensor

   :returns: inverse sigmoid of the input


.. py:function:: tf_index_select(input_: tensorflow.Tensor, dim: int, indices: List) -> tensorflow.Tensor

   :param input_: input tensor
   :type input_: tensor
   :param dim: dimension
   :type dim: int
   :param indices: selected indices list
   :type indices: List

   :returns: Tensor