op_softmax: Softmax
In Microsoft/CNTK-R: R Interface to the Microsoft Cognitive Toolkit (CNTK)

Computes the gradient of f(z)=log∑iexp(zi)f(z)=log⁡∑iexp⁡(zi) at z = x. Concretely,

1	op_softmax(x, axis = NULL, name = "")

`x`	matrix or CNTK Function that outputs a tensor
`axis`	axis across which to perform operation
`name`	(str) the name of the Function instance in the network

softmax(x)=[exp(x1)∑iexp(xi)exp(x1)∑iexp(xi)…exp(x1)∑iexp(xi)]softmax(x)=[exp⁡(x1)∑iexp⁡(xi)exp⁡(x1)∑iexp⁡(xi)…exp⁡(x1)∑iexp⁡(xi)]

with the understanding that the implementation can use equivalent formulas for efficiency and numerical stability.

The output is a vector of non-negative numbers that sum to 1 and can therefore be interpreted as probabilities for mutually exclusive outcomes as in the case of multiclass classification.

If axis is given, the softmax will be computed along that axis.

Microsoft/CNTK-R documentation built on May 28, 2019, 1:52 p.m.