public static double logcdf(double x,double k,double theta,double shift){
  if (x <= shift) {
    return 0.;
  }
  final double e=Math.exp((x - shift) * theta);
  return e < Double.POSITIVE_INFINITY ? GammaDistribution.logregularizedGammaP(k,e) : 0.;
}

public static double logcdf ( double x , double k , double theta , double shift ) { if ( x <= shift ) { return 0. ; } final double e = Math . exp ( ( x - shift ) * theta ) ; return e < Double . POSITIVE_INFINITY ? GammaDistribution . logregularizedGammaP ( k , e ) : 0. ; }
the log cdf , static version .
