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
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