If my memory hasn't too much rust, the derivative you're looking for is:

exp(-$value) * ((1 + exp(-$value)) ** -2)

Flavio.

-- Don't fool yourself.

In reply to Re^2: AI::NNFlex::Backprop error not decreasing by polettix
in thread AI::NNFlex::Backprop error not decreasing by thealienz1

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