Gabriele Cosmo
121 lines
4.7 KiB
C++
121 lines
4.7 KiB
C++
//
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// ********************************************************************
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// * License and Disclaimer *
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// * *
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// * The Geant4 software is copyright of the Copyright Holders of *
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// * the Geant4 Collaboration. It is provided under the terms and *
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// * conditions of the Geant4 Software License, included in the file *
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// * LICENSE and available at http://cern.ch/geant4/license . These *
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// * include a list of copyright holders. *
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// * *
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// * Neither the authors of this software system, nor their employing *
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// * institutes,nor the agencies providing financial support for this *
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// * work make any representation or warranty, express or implied, *
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// * regarding this software system or assume any liability for its *
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// * use. Please see the license in the file LICENSE and URL above *
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// * for the full disclaimer and the limitation of liability. *
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// * *
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// * This code implementation is the result of the scientific and *
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// * technical work of the GEANT4 collaboration. *
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// * By using, copying, modifying or distributing the software (or *
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// * any work based on the software) you agree to acknowledge its *
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// * use in resulting scientific publications, and indicate your *
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// * acceptance of all terms of the Geant4 Software license. *
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// ********************************************************************
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//
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// class G4HelixMixedStepper
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//
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// Class description:
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//
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// G4HelixMixedStepper split the Method used for Integration in two:
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//
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// If Stepping Angle ( h / R_curve) < pi/3 : use Stepper for small step
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//
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// Else use HelixExplicitEuler Stepper
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//
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// Stepper for the small step is G4ClassicalRK4 by default, but
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// it possible to choose other stepper,like G4CashKarpRK45 or G4RKG3_Stepper,
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// by setting StepperNumber : new HelixMixedStepper(EqRhs,N)
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//
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// N=2 G4SimpleRunge; N=3 G4SimpleHeum;
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// N=4 G4ClassicalRK4;
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// N=6 G4HelixImplicitEuler; N=7 G4HelixSimpleRunge;
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// N=8 G4CashKarpRK45; N=9 G4ExactHelixStepper;
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// N=10 G4RKG3_Stepper; N=13 G4NystromRK4
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// N=23 BogackiShampine23 N=145 TsitourasRK45
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// N=45 BogackiShampine45 N=745 DormandPrince745 (ie DoPri5)
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//
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// For completeness also available are:
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// N=11 G4ExplicitEuler N=12 G4ImplicitEuler; -- Likely poor
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// N=5 G4HelixExplicitEuler (testing only)
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// For recommendations see comments in 'SetupStepper' method.
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//
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// Note: Like other helix steppers, only applicable in pure magnetic field
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//
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// History:
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// Derived from ExactHelicalStepper 18/05/07
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//
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// -------------------------------------------------------------------
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#ifndef G4HELIXMIXEDSTEPPER_HH
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#define G4HELIXMIXEDSTEPPER_HH
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#include "G4MagHelicalStepper.hh"
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class G4HelixMixedStepper: public G4MagHelicalStepper
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{
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public:
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G4HelixMixedStepper(G4Mag_EqRhs *EqRhs,G4int StepperNumber= -1, G4double Angle_threshold= -1.0);
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~G4HelixMixedStepper();
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void Stepper( const G4double y[],
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const G4double dydx[],
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G4double h,
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G4double yout[],
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G4double yerr[] );
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// Step 'integration' for step size 'h'
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// If SteppingAngle=h/R_curve<pi/3 uses RK4Stepper
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// Else Helix Fast Method
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void DumbStepper( const G4double y[],
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G4ThreeVector Bfld,
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G4double h,
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G4double yout[]);
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G4double DistChord() const;
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// Estimate maximum distance of curved solution and chord ...
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public: // with description
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inline void SetVerbose (G4int newvalue){fVerbose=newvalue;}
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public: // without description
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void PrintCalls();
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G4MagIntegratorStepper* SetupStepper(G4Mag_EqRhs* EqRhs, G4int StepperName);
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void SetAngleThreshold( G4double val ){ fAngle_threshold= val;}
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G4double GetAngleThreshold(){ return fAngle_threshold; }
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G4int IntegratorOrder() const { return 4; }
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private:
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// Mixed Integration RK4 for 'small' steps
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G4MagIntegratorStepper* fRK4Stepper;
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G4int fStepperNumber; // Int ID of RK stepper
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// Threshold angle (in radians ) - above it Helical stepper is used
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G4double fAngle_threshold;
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private:
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// Used for statistic = how many calls to different steppers
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G4int fVerbose;
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G4int fNumCallsRK4;
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G4int fNumCallsHelix;
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};
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#endif /* G4HELIXMIXEDSTEPPER_HH */
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