StarGenStats.h

#ifndef __StarGenStats_h__
#define __StarGenStats_h__

#include "TNamed.h"

class StarGenStats : public TNamed
{
 public:

  StarGenStats(const Char_t *name="stats", const Char_t *title="" );
  /*
    StarGenStats( const StarGenStats &other );
  */

  ~StarGenStats(){ /* nada */ };

  Int_t    nTried;        //*< Number of event generator trials        
  Int_t    nSelected;     //*< Number of event generator selected events 
  Int_t    nAccepted;     //*< Number of event generator accepted events 

  Double_t sigmaGen;         //*< Estimated event generator cross section
  Double_t sigmaErr;         //*< Estimated event generator cross section error
  Double_t sumWeightGen;     //*< Sum of event generator weights, equal to nAccepted if generator is unbiased.  pythia 8's info.weightSum()

  //
  // Luminosity is a derived quantity... nAccepted = luminosity * sigmaGen
  //
  Double_t luminosity(){ return sumWeightGen / sigmaGen; }    //*< Event generator luminosity
  Double_t luminosityErr(){ return (sigmaErr/sigmaGen)*luminosity(); }

  //
  // Filter statistics
  //
  Int_t    nFilterSeen;   //*< Number of events seen by event filter
  Int_t    nFilterAccept; //*< Number of events accepted by event filter

  Double_t filterAcceptance(){ return Double_t(nFilterAccept)/Double_t(nFilterSeen); }
  Double_t filterRejection() { return 1.0 - filterAcceptance(); }
  

  ClassDef(StarGenStats,1);

};

#endif