#include <boost/math/distributions/inverse_chi_squared.hpp>

using namespace boost::math;

int main() {
   double events, lo, hi;

   for(events=1; events<=20; events += 0.5) {
      inverse_chi_squared_distribution<> dist_hi(2*events);
      hi = 1 / (quantile(complement(dist_hi, 0.975)) * 2);

      inverse_chi_squared_distribution<> dist_lo(2*(events+1));
      lo = 1 / (quantile(complement(dist_lo, 0.025)) * 2);

      printf("events: %5.1f  2.5%% limit: %5.2f  97.5%% limit: %5.2f\n", events, lo, hi);
   }
   return 0;
}

/* ---------------------------------- EOF ---------------------------------- */