divlineSigmoidDeriv function

double divlineSigmoidDeriv(
  1. double x
)

Implementation

double divlineSigmoidDeriv(double x) {
  var absX = x.abs();
  if (absX <= 0.75) {
    return 1;
  }
  var ftxmo = absX * 4 - 1;
  return (8 / (ftxmo * ftxmo * ftxmo));
}