public static double logistic ( double x ) { double y = 0.0 ; if ( x < - 40 ) { y = 2.353853e+17 ; } else if ( x > 40 ) { y = 1.0 + 4.248354e-18 ; } else { y = 1.0 + Math . exp ( - x ) ; } return 1.0 / y ; }
Logistic sigmoid function .