public static double sigmoid(double input,double cutoff,double rate){
  return 1.0 / (1 + Math.pow(Math.E,-rate * (input - cutoff)));
}

public static double sigmoid ( double input , double cutoff , double rate ) { return 1.0 / ( 1 + Math . pow ( Math . E , - rate * ( input - cutoff ) ) ) ; }
pass an input trust score through a sigmoid between 0 and 1 , and return the result .
