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/// \file field/field01/src/F01FieldSetup.cc
/// \brief Implementation of the F01FieldSetup class
//
//
// $Id: F01FieldSetup.cc 90341 2015-05-26 08:38:36Z gcosmo $
//
//   User Field setup class implementation.
//
//
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#include "F01FieldSetup.hh"
#include "F01FieldMessenger.hh"

#include "G4MagneticField.hh"
#include "G4UniformMagField.hh"
#include "G4FieldManager.hh"
#include "G4TransportationManager.hh"
#include "G4Mag_UsualEqRhs.hh"
#include "G4MagIntegratorStepper.hh"
#include "G4ChordFinder.hh"

#include "G4ExplicitEuler.hh"
#include "G4ImplicitEuler.hh"
#include "G4SimpleRunge.hh"
#include "G4SimpleHeum.hh"
#include "G4ClassicalRK4.hh"
#include "G4HelixExplicitEuler.hh"
#include "G4HelixImplicitEuler.hh"
#include "G4HelixSimpleRunge.hh"
#include "G4CashKarpRKF45.hh"
#include "G4RKG3_Stepper.hh"
#include "G4ConstRK4.hh"
#include "G4NystromRK4.hh"
#include "G4HelixMixedStepper.hh"
#include "G4ExactHelixStepper.hh"

#include "G4PhysicalConstants.hh"
#include "G4SystemOfUnits.hh"

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//  Constructors:

F01FieldSetup::F01FieldSetup(G4ThreeVector fieldVector)
 : fFieldManager(0),
   fChordFinder(0),
   fEquation(0),
   fMagneticField(new G4UniformMagField(fieldVector)),
   fStepper(0),
   fStepperType(0),
   fMinStep(0.),
   fFieldMessenger(0)
{
  G4cout << " F01FieldSetup: magnetic field set to Uniform( "
         << fieldVector << " ) " << G4endl;
  InitialiseAll();
}

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F01FieldSetup::F01FieldSetup()
 : fFieldManager(0),
   fChordFinder(0),
   fEquation(0),
   fMagneticField(new G4UniformMagField(G4ThreeVector())),
   fStepper(0),
   fStepperType(0),
   fMinStep(0.),
   fFieldMessenger(0)
{
  G4cout << " F01FieldSetup: magnetic field set to Uniform( 0.0, 0, 0 ) "
         << G4endl;
  InitialiseAll();
}

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void F01FieldSetup::InitialiseAll()
{
  fFieldMessenger = new F01FieldMessenger(this);
 
  fEquation = new G4Mag_UsualEqRhs(fMagneticField);
 
  fMinStep     = 1.0*mm; // minimal step of 1 mm is default

  fStepperType = 4;      // ClassicalRK4 is default stepper

  fFieldManager = G4TransportationManager::GetTransportationManager()
                    ->GetFieldManager();
  CreateStepperAndChordFinder();
}

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F01FieldSetup::~F01FieldSetup()
{
  delete fMagneticField;
  delete fChordFinder;
  delete fStepper;
  delete fFieldMessenger;
}

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void F01FieldSetup::CreateStepperAndChordFinder()
{
  // Update field

  G4cout<< " F01FieldSetup::CreateStepperAndChordFinder() called "
        << " to reset Stepper."  << G4endl;

  SetStepper();
  G4cout<<"The minimal step is equal to "<<fMinStep/mm<<" mm"<<G4endl;

  fFieldManager->SetDetectorField(fMagneticField );

  if (fChordFinder) delete fChordFinder;

  fChordFinder = new G4ChordFinder( fMagneticField, fMinStep,fStepper );

  fFieldManager->SetChordFinder( fChordFinder );
}

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void F01FieldSetup::SetStepper()
{
// Set stepper according to the stepper type

  if (fStepper) delete fStepper;

  switch ( fStepperType )
  {
    case 0:
      fStepper = new G4ExplicitEuler( fEquation );
      G4cout<<"G4ExplicitEuler is chosen."<<G4endl;
      break;
    case 1:
      fStepper = new G4ImplicitEuler( fEquation );
      G4cout<<"G4ImplicitEuler is chosen"<<G4endl;
      break;
    case 2:
      fStepper = new G4SimpleRunge( fEquation );
      G4cout<<"G4SimpleRunge is chosen"<<G4endl;
      break;
    case 3:
      fStepper = new G4SimpleHeum( fEquation );
      G4cout<<"G4SimpleHeum is chosen"<<G4endl;
      break;
    case 4:
      fStepper = new G4ClassicalRK4( fEquation );
      G4cout<<"G4ClassicalRK4 (default) is chosen"<<G4endl;
      break;
    case 5:
      fStepper = new G4HelixExplicitEuler( fEquation );
      G4cout<<"G4HelixExplicitEuler is chosen"<<G4endl;
      break;
    case 6:
      fStepper = new G4HelixImplicitEuler( fEquation );
      G4cout<<"G4HelixImplicitEuler is chosen"<<G4endl;
      break;
    case 7:
      fStepper = new G4HelixSimpleRunge( fEquation );
      G4cout<<"G4HelixSimpleRunge is chosen"<<G4endl;
      break;
    case 8:
      fStepper = new G4CashKarpRKF45( fEquation );
      G4cout<<"G4CashKarpRKF45 is chosen"<<G4endl;
      break;
    case 9:
      fStepper = new G4RKG3_Stepper( fEquation );
      G4cout<<"G4RKG3_Stepper is chosen"<<G4endl;
      break;
    case 10: 
       fStepper = new G4ExactHelixStepper( fEquation );   
       G4cout<<"G4ExactHelixStepper is chosen"<<G4endl;
       break;
    case 11: 
       fStepper = new G4HelixMixedStepper( fEquation );  
       G4cout<<"G4HelixMixedStepper is chosen"<<G4endl;
       break;
    case 12: 
       fStepper = new G4ConstRK4( fEquation ); 
       G4cout<<"G4ConstRK4 Stepper is chosen"<<G4endl;
       break;
    case 13:
      fStepper = new G4NystromRK4( fEquation );
      G4cout<<" G4NystromRK4 Stepper is chosen"<<G4endl;
      break;
    default: // fStepper = 4;
      fStepper = new G4ClassicalRK4( fEquation );
      G4cout<<"G4ClassicalRK4 Stepper (default) is chosen"<<G4endl;
      break;
  }
}

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void F01FieldSetup::SetFieldValue(G4double fieldStrength)
{
  // Set the value of the Global Field to fieldValue along Z

#ifdef G4VERBOSE
  G4cout << "Setting Field strength to "
         << fieldStrength / gauss  << " Gauss."; // << G4endl;
#endif

  G4ThreeVector fieldSetVec(0.0, 0.0, fieldStrength);
  this->SetFieldValue( fieldSetVec );

#ifdef G4VERBOSE
  G4double fieldValue[6],  position[4];
  position[0] = position[1] = position[2] = position[3] = 0.0;
  if ( fieldStrength != 0.0 ) {
    fMagneticField->GetFieldValue( position, fieldValue);
    G4ThreeVector fieldVec(fieldValue[0], fieldValue[1], fieldValue[2]);
    // G4cout << " fMagneticField is now " << fMagneticField
    G4cout << " Magnetic field vector is "
           << fieldVec / gauss << " G " << G4endl;
  } else {
    if ( fMagneticField == 0 )
      G4cout << " Magnetic field pointer is null." << G4endl;
    else
      G4Exception("F01FieldSetup::SetFieldValue(double)",
                  "IncorrectForZeroField",
                  FatalException,
                  "fMagneticField ptr should be set to 0 for no field.");
  }
#endif
}

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void F01FieldSetup::SetFieldValue(G4ThreeVector fieldVector)
{
  // Set the value of the Global Field

  if (fMagneticField) delete fMagneticField;
 
  if (fieldVector != G4ThreeVector(0.,0.,0.))
  {
    fMagneticField = new G4UniformMagField(fieldVector);
  }
  else
  {
    // If the new field's value is Zero, signal it as below
    // so that it is not used for propagation.
    fMagneticField = 0;
  }

  // Set this as the field of the global Field Manager
  GetGlobalFieldManager()->SetDetectorField(fMagneticField);

  // Now notify equation of new field
  fEquation->SetFieldObj( fMagneticField );

}

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G4FieldManager* F01FieldSetup::GetGlobalFieldManager()
{
  //  Utility method

  return G4TransportationManager::GetTransportationManager()
           ->GetFieldManager();
}

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