sigmoid

its derivative is
its inverse function is the logit

  f = "<<src-eval-elisp(data=(cached-file "AkxdnCv.svg"))>>"
  sigmoid(z::Real) = one(z) / (one(z) + exp(-z))
  using Plots
  x = range(-10, 10, length=100)
  y = sigmoid.(x)
  plot(x, y)
  savefig(f)
  f

broken link: file:/home/mahmooz/brain/out/AkxdnCv.svg