public double gaussianShortfall(double target){
  final CumulativeNormalDistribution gIntegral=new CumulativeNormalDistribution(mean(),standardDeviation());
  return gIntegral.op(target);
}

public double gaussianShortfall ( double target ) { final CumulativeNormalDistribution gIntegral = new CumulativeNormalDistribution ( mean ( ) , standardDeviation ( ) ) ; return gIntegral . op ( target ) ; }
gaussian - assumption shortfall ( observations below target )
