#include "RooStats/RooStatsUtils.h"
#include <iostream>

using namespace RooFit;
using namespace RooStats; // the utilities are in the RooStats namespace
using std::cout, std::endl;

void rs_numbercountingutils()
{

   // From the root prompt, you can see the full list of functions by using tab-completion
   // ~~~{.bash}
   // root [0] RooStats::NumberCountingUtils::  <tab>
   // BinomialExpZ
   // BinomialWithTauExpZ
   // BinomialObsZ
   // BinomialWithTauObsZ
   // BinomialExpP
   // BinomialWithTauExpP
   // BinomialObsP
   // BinomialWithTauObsP
   // ~~~

   // For each of the utilities you can inspect the arguments by tab completion
   // ~~~{.bash}
   // root [1] NumberCountingUtils::BinomialExpZ( <tab>
   // Double_t BinomialExpZ(Double_t sExp, Double_t bExp, Double_t fractionalBUncertainty)
   // ~~~

   // -------------------------------------------------
   // Here we see common usages where the experimenter
   // has a relative background uncertainty, without
   // explicit reference to the auxiliary or sideband
   // measurement

   // -------------------------------------------------------------
   // Expected p-values and significance with background uncertainty
   double sExpected = 50;
   double bExpected = 100;
   double relativeBkgUncert = 0.1;

   double pExp = NumberCountingUtils::BinomialExpP(sExpected, bExpected, relativeBkgUncert);
   double zExp = NumberCountingUtils::BinomialExpZ(sExpected, bExpected, relativeBkgUncert);
   cout << "expected p-value =" << pExp << "  Z value (Gaussian sigma) = " << zExp << endl;

   // -------------------------------------------------
   // Expected p-values and significance with background uncertainty
   double observed = 150;
   double pObs = NumberCountingUtils::BinomialObsP(observed, bExpected, relativeBkgUncert);
   double zObs = NumberCountingUtils::BinomialObsZ(observed, bExpected, relativeBkgUncert);
   cout << "observed p-value =" << pObs << "  Z value (Gaussian sigma) = " << zObs << endl;

   // ---------------------------------------------------------
   // Here we see usages where the experimenter has knowledge
   // about the properties of the auxiliary or sideband
   // measurement.  In particular, the ratio tau of background
   // in the auxiliary measurement to the main measurement.
   // Large values of tau mean small background uncertainty
   // because the sideband is very constraining.

   // Usage:
   // ~~~{.bash}
   // root [0] RooStats::NumberCountingUtils::BinomialWithTauExpP(
   // Double_t BinomialWithTauExpP(Double_t sExp, Double_t bExp, Double_t tau)
   // ~~~

   // --------------------------------------------------------------
   // Expected p-values and significance with background uncertainty
   double tau = 1;

   double pExpWithTau = NumberCountingUtils::BinomialWithTauExpP(sExpected, bExpected, tau);
   double zExpWithTau = NumberCountingUtils::BinomialWithTauExpZ(sExpected, bExpected, tau);
   cout << "expected p-value =" << pExpWithTau << "  Z value (Gaussian sigma) = " << zExpWithTau << endl;

   // ---------------------------------------------------------------
   // Expected p-values and significance with background uncertainty
   double pObsWithTau = NumberCountingUtils::BinomialWithTauObsP(observed, bExpected, tau);
   double zObsWithTau = NumberCountingUtils::BinomialWithTauObsZ(observed, bExpected, tau);
   cout << "observed p-value =" << pObsWithTau << "  Z value (Gaussian sigma) = " << zObsWithTau << endl;
}