// ExR01Histograms.cc
// 25-Aug-99 Bill Seligman
// This is an example class for booking histograms in GEANT4.

#include "ExR01Histograms.hh"
// Include the CLHEP Histogram classes
#include "CLHEP/Hist/Histogram.h"
#include "CLHEP/Hist/Tuple.h"
#include "CLHEP/Hist/HBookFile.h"

// For the random numbers in the StepFill example.
#include "Randomize.hh"
#include "globals.hh"

// These are needed because they're arguments to the methods in
// the RecorderBase class that we plan to use.  In real life, we
// might use the variables in G4Run or G4Step to 
// histogram or otherwise record values.
#include "G4Run.hh"
#include "G4Step.hh"


// Let's be neat.  Make sure that hfile is deleted even if the
// the EndOfRun is never called. 

ExR01Histograms::ExR01Histograms() {
  hfile = NULL;
}

ExR01Histograms::~ExR01Histograms() {
  if (hfile != NULL) {
    delete hfile;
  }
}


void ExR01Histograms::RecordBeginOfRun(const G4Run* r)
{
  // Open a new HBook file.
  // Side note: In my experience, it's not possible to open more than
  // one CLHEP HBookFile in a program at once, even if you give them unique
  // names and FORTRAN I/O numbers.

  if (hfile != NULL) delete hfile; // make sure the object doesn't exist.

  int lun = 66; // Fortran I/O unit number
  hfile = new HBookFile("example.hbook",lun);

  // Number of histogram bins  
  int nBins1d = 100;
  int nBins2d = 40;

  // Limits for values
  double  low = 0,  high = 1;
  double xlow = 0, xhigh = 1, ylow = 0, yhigh = 1;

  // Histogram IDs.
  int id1D = 100;
  int id2D = 201;

  // A couple of notes:
  // 1) CLHEP tells whether you're creating a 1D or 2D histogram by looking
  //    at the number and type of arguments to the histogram routine.
  // 2) If we had not chosen to supply a histogram ID, the HBookFile class
  //    will choose it for us.  This is not a good idea; you should supply the ID.
  // 3) If a histogram with the given title does not already exist, the "histogram"
  //    routine will create it and return a point to the new histogram.  If a
  //    histogram with the given title already exists, "histogram" will return a pointer
  //    that histogram; it will not overwrite the existing one.

  myHisto1D = hfile->histogram("HepJamesRandom1", nBins1d, low, high, id1D);

  myHisto2D = hfile->histogram("HepJamesVsDRand48", nBins2d, xlow, xhigh, nBins2d, ylow, yhigh, id2D);

  // The same general ideas apply to ntuples:

  int ntID = 1000;
  myTuple = hfile->ntuple("RandomNumbers",ntID);

}


void ExR01Histograms::RecordEndOfRun(const G4Run* r)
{
  // Write the contents of the HBookFile.
  hfile->write();

  // We created it with "new", so we have to destroy it with "delete":
  delete hfile;
  hfile = NULL; // Make sure that we'll recognize that it's been deleted.
}


void ExR01Histograms::RecordStep(const G4Step*) {

  // Generate random numbers using two different CLHEP "engines".
  // Accumulate the results of the James Engine in the 1-d histogram;
  // accumulate the results of the James versus "Rand48" in the
  // 2-d histogram.

  HepRandom::setTheEngine(&theJamesEngine);

  double james = RandGauss::shoot(0.3,0.1);
  myHisto1D->accumulate(james,0.01);

  HepRandom::setTheEngine(&theDRand48Engine);

  double d48 = RandGauss::shoot(0.7,0.1);
  myHisto2D->accumulate(james,d48,0.01);   


  // Add the random numbers to the ntuple.  The first time
  // the column method is called, it creates the column.  Each
  // subsequent call adds to the column.  Once all the columns
  // are filled, you must call dumpData to add the information
  // to the ntuple.

  myTuple->column("James",james);
  myTuple->column("Rand48",d48);
  myTuple->dumpData();

}