Gabriele Cosmo
166 lines
5.6 KiB
C++
166 lines
5.6 KiB
C++
// This code implementation is the intellectual property of
|
|
// the GEANT4 collaboration.
|
|
//
|
|
// By copying, distributing or modifying the Program (or any work
|
|
// based on the Program) you indicate your acceptance of this statement,
|
|
// and all its terms.
|
|
//
|
|
// $Id: G4MagIntegratorDriver.hh,v 1.7 2000/11/01 15:15:50 gcosmo Exp $
|
|
// GEANT4 tag $Name: geant4-03-00 $
|
|
//
|
|
//
|
|
// class G4MagInt_Driver
|
|
//
|
|
// Class description:
|
|
//
|
|
// Provides a driver that talks to the Integrator Stepper, and insures that
|
|
// the error is within acceptable bounds.
|
|
|
|
// History:
|
|
// - Created. J.Apostolakis.
|
|
|
|
#ifndef G4MagInt_Driver_Def
|
|
#define G4MagInt_Driver_Def
|
|
|
|
#include "globals.hh"
|
|
#include "G4FieldTrack.hh"
|
|
#include "G4MagIntegratorStepper.hh"
|
|
|
|
class G4MagInt_Driver
|
|
{
|
|
public: // with description
|
|
|
|
G4bool AccurateAdvance(G4FieldTrack& y_current,
|
|
G4double hstep,
|
|
G4double eps); // Requested y_err/hstep
|
|
// Above drivers for integrator (Runge-Kutta) with stepsize control.
|
|
// Integrates ODE starting values y_current
|
|
// from current s (s=s0) to s=s0+h with accuracy eps.
|
|
// On output ystart is replaced by value at end of interval.
|
|
// The concept is similar to the odeint routine from NRC p.721-722.
|
|
|
|
G4bool QuickAdvance(G4FieldTrack& y_val, // INOUT
|
|
const G4double dydx[],
|
|
G4double hstep, // IN
|
|
G4double& dchord_step,
|
|
G4double& dyerr ) ;
|
|
// QuickAdvance just tries one Step - it does not ensure accuracy.
|
|
|
|
G4MagInt_Driver( G4double hminimum,
|
|
G4MagIntegratorStepper *pItsStepper,
|
|
G4int numberOfComponents=6);
|
|
~G4MagInt_Driver();
|
|
// Constructor, destructor.
|
|
|
|
inline G4double GetHmin() const;
|
|
inline G4double Hmin() const; // Obsolete
|
|
inline G4double GetSafety() const;
|
|
inline G4double GetPshrnk() const;
|
|
inline G4double GetPgrow() const;
|
|
inline G4double GetErrcon() const;
|
|
inline void GetDerivatives( const G4FieldTrack y_curr, // const, INput
|
|
G4double dydx[] ); // OUTput
|
|
// Accessors.
|
|
|
|
inline void RenewStepperAndAdjust(G4MagIntegratorStepper *pItsStepper);
|
|
// Sets a new stepper pItsStepper for this driver. Then it calls
|
|
// ReSetParameters to reset its parameters accordingly.
|
|
|
|
inline void ReSetParameters(G4double new_safety= 0.9 );
|
|
// i) sets the exponents (pgrow & pshrnk),
|
|
// using the current Stepper's order,
|
|
// ii) sets the safety
|
|
// ii) calculates "errcon" according to the above values.
|
|
|
|
inline void SetSafety(G4double valS);
|
|
inline void SetPshrnk(G4double valPs);
|
|
inline void SetPgrow (G4double valPg);
|
|
inline void SetErrcon(G4double valEc);
|
|
// When setting safety or pgrow, errcon will be set to a
|
|
// compatible value.
|
|
|
|
inline G4double ComputeAndSetErrcon();
|
|
|
|
inline void SetChargeMomentumMass( G4double particleCharge,
|
|
G4double MomentumXc,
|
|
G4double Mass );
|
|
// Change them in Equation. particleCharge is in e+ units.
|
|
|
|
inline const G4MagIntegratorStepper* GetStepper() const;
|
|
|
|
void OneGoodStep( G4double ystart[], // Like old RKF45step()
|
|
const G4double dydx[],
|
|
G4double& x,
|
|
G4double htry,
|
|
G4double eps, // memb variables ?
|
|
G4double& hdid,
|
|
G4double& hnext ) ;
|
|
// This takes one Step that is as large as possible while
|
|
// satisfying the accuracy criterion of:
|
|
// yerr < eps * |y_end-y_start|
|
|
|
|
G4double ComputeNewStepSize( G4double errMaxNorm, // normalised error
|
|
G4double hstepCurrent); // current step size
|
|
// Taking the last step's normalised error, calculate
|
|
// a step size for the next step.
|
|
// Do not limit the next step's size within a factor of the
|
|
// current one.
|
|
|
|
G4double ComputeNewStepSize_WithinLimits(
|
|
G4double errMaxNorm, // normalised error
|
|
G4double hstepCurrent); // current step size
|
|
// Taking the last step's normalised error, calculate
|
|
// a step size for the next step.
|
|
// Limit the next step's size within a range around the current one.
|
|
|
|
inline G4int GetMaxNoSteps() const;
|
|
inline void SetMaxNoSteps( G4int val);
|
|
|
|
public: // without description
|
|
|
|
inline void SetHmin(G4double newval);
|
|
|
|
protected:
|
|
|
|
void WarnSmallStepSize( G4double hnext, G4double hstep,
|
|
G4double h, G4double xDone,
|
|
G4int noSteps);
|
|
void WarnTooManyStep( G4double x1start, G4double x2end, G4double xCurrent);
|
|
void WarnEndPointTooFar (G4double endPointDist,
|
|
G4double hStepSize ,
|
|
G4double epsilonRelative,
|
|
G4int debugFlag);
|
|
// Issue warnings for undesirable situations
|
|
|
|
private:
|
|
|
|
G4MagInt_Driver(const G4MagInt_Driver&);
|
|
G4MagInt_Driver& operator=(const G4MagInt_Driver&);
|
|
// Private copy constructor and assignment operator.
|
|
|
|
private:
|
|
|
|
G4double hminimum_val;
|
|
// Minimum Step allowed in a Step.
|
|
|
|
G4int nvar;
|
|
|
|
G4MagIntegratorStepper *pIntStepper;
|
|
G4int fMaxNoSteps;
|
|
static const G4int fMaxStepBase;
|
|
|
|
G4double safety;
|
|
G4double pshrnk; // exponent for shrinking
|
|
G4double pgrow; // exponent for growth
|
|
G4double errcon;
|
|
// Parameters used to grow and shrink trial stepsize.
|
|
|
|
static const G4double max_stepping_increase;
|
|
static const G4double max_stepping_decrease;
|
|
// Maximum stepsize increase/decrease factors.
|
|
};
|
|
|
|
#include "G4MagIntegratorDriver.icc"
|
|
|
|
#endif /* G4MagInt_Driver_Def */
|