THaEpicsEbeam.cxx

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//*-- Author :    Ole Hansen 07-May-2004
 
//
// THaEpicsEbeam
//
// A physics module that provides beam energy/momentum based on
// EPCIS information
// 
 
#include "THaEpicsEbeam.h"
#include "VarDef.h"
#include "THaEvData.h"
#include "TMath.h"
 
//_____________________________________________________________________________
THaEpicsEbeam::THaEpicsEbeam( const char* name, const char* description,
                              const char* beam, const char* epics_var,
                              Double_t scale_factor ) : 
  THaPhysicsModule( name,description ), fEcorr(0.0), fEpicsIsMomentum(false),
  fScaleFactor(scale_factor), fBeamName(beam), fEpicsVar(epics_var), 
  fBeamModule(nullptr)
{
  // Constructor.
}
 
 
//_____________________________________________________________________________
THaEpicsEbeam::~THaEpicsEbeam()
{
  // Destructor
 
  RemoveVariables();
}
 
//_____________________________________________________________________________
void THaEpicsEbeam::Clear( Option_t* opt )
{
  // Clear all event-by-event variables.
  
  THaPhysicsModule::Clear(opt);
  BeamIfoClear();
  fEcorr = 0.0;
}
 
//_____________________________________________________________________________
THaAnalysisObject::EStatus THaEpicsEbeam::Init( const TDatime& run_time )
{
  // Initialize the module.
 
  fBeamModule = dynamic_cast<THaBeamModule*>
    ( FindModule( fBeamName.Data(), "THaBeamModule"));
  if( !fBeamModule )
    return fStatus;
 
  //this is done by THaBeamInfo::operator= in Process
  //  fBeamIfo.SetBeam( fBeamModule->GetBeamInfo()->GetBeam() );
 
  return THaPhysicsModule::Init(run_time);
}
  
//_____________________________________________________________________________
Int_t THaEpicsEbeam::DefineVariables( EMode mode )
{
  // Initialize global variables
 
  RVarDef vars[] = {
    { "ecorr", "Beam energy correction (output-input) (GeV)", "fEcorr" },
    { nullptr }
  };
  return DefineVarsFromList( vars, mode );
}
 
//_____________________________________________________________________________
Int_t THaEpicsEbeam::Process( const THaEvData& evdata )
{
  // Obtain actual beam energy from EPICS (if available) and 
  // calculate new beam parameters
 
  if( !IsOK() ) return -1;
 
  THaBeamInfo* input = fBeamModule->GetBeamInfo();
  if( !input->IsOK() ) return 2;
 
  // Copy the input beam info
  fBeamIfo = *input;
 
  // Obtain current beam energy (or momentum) from EPICS
  // If requested EPICS variable not loaded, do nothing
  if( evdata.IsLoadedEpics(fEpicsVar) ) {
    Double_t e = evdata.GetEpicsData(fEpicsVar);
    // the scale factor must convert the EPICS value to GeV
    e *= fScaleFactor;
    Double_t m = fBeamIfo.GetM();
    Double_t p;
    if( fEpicsIsMomentum ) {
      p = e;
      e = TMath::Sqrt(p*p+m*m);
    } else {
      p = TMath::Sqrt( TMath::Max(e*e-m*m,0.0) );
    }
    fBeamIfo.SetP(p);
    fEcorr = e - input->GetE();
  }
  
  fDataValid = true;
  return 0;
}
 
//_____________________________________________________________________________
void THaEpicsEbeam::SetBeam( const char* name ) 
{
  // Set the name of the module providing the beam input data
  if( !IsInit())
    fBeamName = name; 
  else
    PrintInitError("SetBeam");
}
 
//_____________________________________________________________________________
void THaEpicsEbeam::SetEpicsVar( const char* name ) 
{
  // Set the name of the EPICS variable to use for corrections
  if( !IsInit())
    fEpicsVar = name; 
  else
    PrintInitError("SetEpicsVar");
}
 
//_____________________________________________________________________________
void THaEpicsEbeam::SetEpicsIsMomentum( Bool_t mode ) 
{
  // If mode=true, interpret EPICS data as momentum rather than energy
  if( !IsInit())
    fEpicsIsMomentum = mode; 
  else
    PrintInitError("SetEpicsIsMomentum");
}
 
//_____________________________________________________________________________
void THaEpicsEbeam::SetScaleFactor( Double_t factor ) 
{
  // If mode=true, interpret EPICS data as momentum rather than energy
  if( !IsInit())
    fScaleFactor = factor;
  else
    PrintInitError("SetEpicsIsMomentum");
}
 
//_____________________________________________________________________________
ClassImp(THaEpicsEbeam)