protected static double calcP_i(double f,double mu,double sigma){
  final double fmu=f - mu;
  return ONEBYSQRT2PI / sigma * Math.exp(fmu * fmu / (-2 * sigma * sigma));
}

protected static double calcP_i ( double f , double mu , double sigma ) { final double fmu = f - mu ; return ONEBYSQRT2PI / sigma * Math . exp ( fmu * fmu / ( - 2 * sigma * sigma ) ) ; }
compute p_i ( gaussian distribution , outliers )
