private double gammaRatio(int n,int k){
  double top=(n - k + 1) / 2.0;
  double bottom=(n - k) / 2.0;
  double lngamma=ProbUtils.lngamma(top) - ProbUtils.lngamma(bottom);
  return Math.exp(lngamma);
}

private double gammaRatio ( int n , int k ) { double top = ( n - k + 1 ) / 2.0 ; double bottom = ( n - k ) / 2.0 ; double lngamma = ProbUtils . lngamma ( top ) - ProbUtils . lngamma ( bottom ) ; return Math . exp ( lngamma ) ; }
calculates the ratio of gamma values in the distribution equation .
