elu function

double elu(
  1. double x, [
  2. double hyperparameter = 1
])

Exponential Linear Unit - Provides a smooth descent below 0, towards the negative of hyperparameter, or returns x if above or equal to 0.

Implementation

double elu(double x, [double hyperparameter = 1]) =>
    x >= 0 ? x : hyperparameter * (exp(x) - 1);