megengine.functional.logaddexp¶

Element-wise \(\log(e^x + e^y)\) function.

This function is useful in statistics where the calculated probabilities of events may be so small as to exceed the range of normal floating point numbers. In such cases the logarithm of the calculated probability is stored. This function allows adding probabilities stored in such a fashion.

参数

x (Tensor) – input tensor. Should have a floating-point data type.
y (Tensor) – input tensor. Must be compatible with \(x\) (see 广播机制与规则 ). Should have a floating-point data type.

返回类型

Tensor

返回

a tensor containing the evaluated result for each element in \(x\) and \(y\). The returned tensor must have a floating-point data type determined by 类型提升规则.

实际案例

>>> prob1 = F.log(1e-10)
>>> prob2 = F.log(2e-10)
>>> F.logaddexp(prob1, prob2)
Tensor(-21.927238, device=xpux:0)

megengine.functional.log1p

megengine.functional.sin