JTrack3D.cc

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#include <string>
#include <iostream>
#include <iomanip>

#include "TRandom3.h"

#include "JMath/JConstants.hh"

#include "JGeometry3D/JVector3D.hh"
#include "JGeometry3D/JVersor3D.hh"
#include "JGeometry3D/JAxis3D.hh"
#include "JGeometry3D/JTrack3D.hh"
#include "JGeometry3D/JRotation3D.hh"

#include "Jeep/JParser.hh"
#include "Jeep/JMessage.hh"


/**
 * \file
 *
 * Example program to test angle of incidence of a photon from a muon on a PMT.
 * \author mdejong
 */
int main(int argc, char**argv)
{
  using namespace std;
  using namespace JPP;

  JAxis3D  pmt;
  int      numberOfEvents;
  double   precision;
  UInt_t   seed;
  int      debug;

  try {

    JParser<> zap("Example program to test angle of incidence of a photon from a muon on a PMT.");

    zap['n'] = make_field(numberOfEvents)      = 1000;
    zap['P'] = make_field(pmt)                 = JAxis3D(JVector3D(0,0,1), JVersor3D(0,0,1));
    zap['e'] = make_field(precision)           = 1.0e-6;
    zap['S'] = make_field(seed)                = 0;
    zap['d'] = make_field(debug)               = 3;

    zap(argc, argv);
  }
  catch(const exception &error) {
    FATAL(error.what() << endl);
  }

  gRandom->SetSeed(seed);


  const JVersor3D U(getSinThetaC(), 0.0, getCosThetaC());            // photon direction in the reference frame of muon track

  int number_of_errors = 0;
  int number_of_events = 0;

  for (int i = 0; i != numberOfEvents; ++i) {

    STATUS(setw(4) << i << '\r'); DEBUG(endl);    

    const double x  = gRandom->Uniform(-1.0, +1.0);
    const double y  = gRandom->Uniform(-1.0, +1.0);
    const double z  = gRandom->Uniform(-1.0, +1.0);

    const double dx = gRandom->Uniform(-1.0, +1.0);
    const double dy = gRandom->Uniform(-1.0, +1.0);
    const double dz = gRandom->Uniform(-1.0, +1.0);

    JTrack3D ta(JVector3D(x, y, z), JVersor3D(dx, dy, dz), 0.0);
    JAxis3D  tb(pmt);
    
    tb.transform(ta);                                                // transform PMT to reference frame of muon track
    
    if (ta.getDistance(pmt) > precision) {
    
      ++number_of_events;

      // method JTrack3D::getDot(..) calculates angle of incidence of photon on PMT

      if (fabs(tb.getDirection().getDot(U) - ta.getDot(pmt)) > precision) {
        ++number_of_errors;
      }
    }

    DEBUG("distance " << ta.getDistance(pmt)         << endl);
    DEBUG("dot (1)  " << tb.getDirection().getDot(U) << endl);
    DEBUG("dot (2)  " << ta.getDot(pmt)              << endl);
  }
  STATUS(endl);

  NOTICE("Number of errors: " << number_of_errors << " out of " << number_of_events << " events." << endl);

  ASSERT(number_of_events >  0);
  ASSERT(number_of_errors == 0);

  return 0;
}