Gabriele Cosmo
73 lines
2.0 KiB
C++
73 lines
2.0 KiB
C++
// This code implementation is the intellectual property of
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// the GEANT4 collaboration.
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//
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// By copying, distributing or modifying the Program (or any work
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// based on the Program) you indicate your acceptance of this statement,
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// and all its terms.
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//
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// $Id: G4CashKarpRKF45.hh,v 1.4 2000/11/01 15:15:48 gcosmo Exp $
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// GEANT4 tag $Name: geant4-03-00 $
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//
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//
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// class G4CashKarpRKF45
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//
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// Class description:
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//
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// The Cash-Karp Runge-Kutta-Fehlberg 4/5 method is an embedded fourth
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// order method (giving fifth-order accuracy) for the solution of an ODE.
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// Two different fourth order estimates are calculated; their difference
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// gives an error estimate. [ref. Numerical Recipes in C, 2nd Edition]
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// It is used to integrate the equations of the motion of a particle
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// in a magnetic field.
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// History:
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// - Created. J.Apostolakis, V.Grichine - 30.1.97
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#ifndef G4CashKARP_RKF45
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#define G4CashKARP_RKF45
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#include "G4MagIntegratorStepper.hh"
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class G4CashKarpRKF45 : public G4MagIntegratorStepper
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{
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public: // with description
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G4CashKarpRKF45(G4Mag_EqRhs *EqRhs, G4int numberOfVariables = 6) ;
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~G4CashKarpRKF45() ;
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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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void StepWithEst( const G4double yIn[],
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const G4double dydx[],
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G4double Step,
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G4double yOut[],
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G4double& alpha2,
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G4double& beta2,
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const G4double B1[],
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G4double B2[] ) ;
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public: // without description
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G4double DistChord() const = 0 ; // This is not IMPLEMENTED yet.
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// It must be done before it can work.
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G4int IntegratorOrder() const { return 4; }
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private:
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G4CashKarpRKF45(const G4CashKarpRKF45&);
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G4CashKarpRKF45& operator=(const G4CashKarpRKF45&);
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// Private copy constructor and assignment operator.
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private:
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G4int fNumberOfVariables ;
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G4double *ak2, *ak3, *ak4, *ak5, *ak6, *ak7, *yTemp, *yIn; // scratch space
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};
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#endif /* G4CashKARP_RKF45 */
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