Neural Network Toolbox

dlogsig

Log sigmoid transfer derivative function

Syntax

dA_dN = dlogsig(N,A)

Description

dlogsig is the derivative function for logsig.

dlogsig(N,A) takes two arguments,

• N -- S x Q net input

  A -- S x Q output

and returns the S x Q derivative dA/dN.

Examples

Here we define the net input N for a layer of 3 tansig neurons.

• N = [0.1; 0.8; -0.7];
  

We calculate the layer's output A with logsig and then the derivative of A with respect to N.

• A = logsig(N)
  dA_dN = dlogsig(N,A)
  

Algorithm

The derivative of logsig is calculated as follows:

• d = a * (1 - a)
  

See Also

logsig, tansig, dtansig

dist

dmae

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