| 1 | // |
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| 2 | // ******************************************************************** |
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| 3 | // * License and Disclaimer * |
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| 4 | // * * |
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| 5 | // * The Geant4 software is copyright of the Copyright Holders of * |
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| 6 | // * the Geant4 Collaboration. It is provided under the terms and * |
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| 7 | // * conditions of the Geant4 Software License, included in the file * |
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| 8 | // * LICENSE and available at http://cern.ch/geant4/license . These * |
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| 9 | // * include a list of copyright holders. * |
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| 10 | // * * |
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| 11 | // * Neither the authors of this software system, nor their employing * |
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| 12 | // * institutes,nor the agencies providing financial support for this * |
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| 13 | // * work make any representation or warranty, express or implied, * |
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| 14 | // * regarding this software system or assume any liability for its * |
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| 15 | // * use. Please see the license in the file LICENSE and URL above * |
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| 16 | // * for the full disclaimer and the limitation of liability. * |
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| 17 | // * * |
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| 18 | // * This code implementation is the result of the scientific and * |
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| 19 | // * technical work of the GEANT4 collaboration. * |
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| 20 | // * By using, copying, modifying or distributing the software (or * |
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| 21 | // * any work based on the software) you agree to acknowledge its * |
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| 22 | // * use in resulting scientific publications, and indicate your * |
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| 23 | // * acceptance of all terms of the Geant4 Software license. * |
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| 24 | // ******************************************************************** |
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| 25 | // |
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| 26 | // |
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| 27 | // $Id: G4MagIntegratorDriver.hh,v 1.21 2010/07/14 10:00:36 gcosmo Exp $ |
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| 28 | // GEANT4 tag $Name: field-V09-03-03 $ |
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| 29 | // |
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| 30 | // |
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| 31 | // class G4MagInt_Driver |
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| 32 | // |
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| 33 | // Class description: |
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| 34 | // |
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| 35 | // Provides a driver that talks to the Integrator Stepper, and insures that |
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| 36 | // the error is within acceptable bounds. |
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| 37 | |
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| 38 | // History: |
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| 39 | // - Created. J.Apostolakis. |
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| 40 | // -------------------------------------------------------------------- |
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| 41 | |
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| 42 | #ifndef G4MagInt_Driver_Def |
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| 43 | #define G4MagInt_Driver_Def |
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| 44 | |
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| 45 | #include "G4Types.hh" |
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| 46 | #include "G4FieldTrack.hh" |
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| 47 | #include "G4MagIntegratorStepper.hh" |
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| 48 | |
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| 49 | class G4MagInt_Driver |
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| 50 | { |
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| 51 | public: // with description |
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| 52 | |
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| 53 | G4bool AccurateAdvance(G4FieldTrack& y_current, |
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| 54 | G4double hstep, |
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| 55 | G4double eps, // Requested y_err/hstep |
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| 56 | G4double hinitial=0.0); // Suggested 1st interval |
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| 57 | // Above drivers for integrator (Runge-Kutta) with stepsize control. |
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| 58 | // Integrates ODE starting values y_current |
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| 59 | // from current s (s=s0) to s=s0+h with accuracy eps. |
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| 60 | // On output ystart is replaced by value at end of interval. |
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| 61 | // The concept is similar to the odeint routine from NRC p.721-722. |
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| 62 | |
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| 63 | G4bool QuickAdvance( G4FieldTrack& y_val, // INOUT |
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| 64 | const G4double dydx[], |
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| 65 | G4double hstep, // IN |
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| 66 | G4double& dchord_step, |
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| 67 | G4double& dyerr ) ; |
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| 68 | // QuickAdvance just tries one Step - it does not ensure accuracy. |
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| 69 | |
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| 70 | G4bool QuickAdvance( G4FieldTrack& y_posvel, // INOUT |
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| 71 | const G4double dydx[], |
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| 72 | G4double hstep, // IN |
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| 73 | G4double& dchord_step, |
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| 74 | G4double& dyerr_pos_sq, |
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| 75 | G4double& dyerr_mom_rel_sq ) ; |
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| 76 | // New QuickAdvance that also just tries one Step |
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| 77 | // (so also does not ensure accuracy) |
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| 78 | // but does return the errors in position and |
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| 79 | // momentum (normalised: Delta_Integration(p^2)/(p^2) ) |
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| 80 | |
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| 81 | G4MagInt_Driver( G4double hminimum, |
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| 82 | G4MagIntegratorStepper *pItsStepper, |
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| 83 | G4int numberOfComponents=6, |
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| 84 | G4int statisticsVerbosity=1); |
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| 85 | ~G4MagInt_Driver(); |
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| 86 | // Constructor, destructor. |
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| 87 | |
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| 88 | inline G4double GetHmin() const; |
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| 89 | inline G4double Hmin() const; // Obsolete |
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| 90 | inline G4double GetSafety() const; |
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| 91 | inline G4double GetPshrnk() const; |
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| 92 | inline G4double GetPgrow() const; |
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| 93 | inline G4double GetErrcon() const; |
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| 94 | inline void GetDerivatives( const G4FieldTrack &y_curr, // const, INput |
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| 95 | G4double dydx[] ); // OUTput |
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| 96 | // Accessors. |
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| 97 | |
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| 98 | inline void RenewStepperAndAdjust(G4MagIntegratorStepper *pItsStepper); |
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| 99 | // Sets a new stepper pItsStepper for this driver. Then it calls |
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| 100 | // ReSetParameters to reset its parameters accordingly. |
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| 101 | |
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| 102 | inline void ReSetParameters(G4double new_safety= 0.9 ); |
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| 103 | // i) sets the exponents (pgrow & pshrnk), |
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| 104 | // using the current Stepper's order, |
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| 105 | // ii) sets the safety |
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| 106 | // ii) calculates "errcon" according to the above values. |
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| 107 | |
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| 108 | inline void SetSafety(G4double valS); |
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| 109 | inline void SetPshrnk(G4double valPs); |
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| 110 | inline void SetPgrow (G4double valPg); |
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| 111 | inline void SetErrcon(G4double valEc); |
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| 112 | // When setting safety or pgrow, errcon will be set to a |
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| 113 | // compatible value. |
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| 114 | |
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| 115 | inline G4double ComputeAndSetErrcon(); |
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| 116 | |
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| 117 | inline void SetChargeMomentumMass( G4double particleCharge, |
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| 118 | G4double MomentumXc, |
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| 119 | G4double Mass ); |
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| 120 | // Change them in Equation. particleCharge is in e+ units. |
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| 121 | |
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| 122 | inline const G4MagIntegratorStepper* GetStepper() const; |
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| 123 | |
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| 124 | void OneGoodStep( G4double ystart[], // Like old RKF45step() |
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| 125 | const G4double dydx[], |
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| 126 | G4double& x, |
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| 127 | G4double htry, |
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| 128 | G4double eps, // memb variables ? |
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| 129 | G4double& hdid, |
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| 130 | G4double& hnext ) ; |
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| 131 | // This takes one Step that is as large as possible while |
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| 132 | // satisfying the accuracy criterion of: |
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| 133 | // yerr < eps * |y_end-y_start| |
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| 134 | |
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| 135 | G4double ComputeNewStepSize( G4double errMaxNorm, // normalised error |
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| 136 | G4double hstepCurrent); // current step size |
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| 137 | // Taking the last step's normalised error, calculate |
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| 138 | // a step size for the next step. |
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| 139 | // Do not limit the next step's size within a factor of the |
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| 140 | // current one. |
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| 141 | |
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| 142 | G4double ComputeNewStepSize_WithinLimits( |
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| 143 | G4double errMaxNorm, // normalised error |
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| 144 | G4double hstepCurrent); // current step size |
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| 145 | // Taking the last step's normalised error, calculate |
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| 146 | // a step size for the next step. |
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| 147 | // Limit the next step's size within a range around the current one. |
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| 148 | |
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| 149 | inline G4int GetMaxNoSteps() const; |
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| 150 | inline void SetMaxNoSteps( G4int val); |
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| 151 | // Modify and Get the Maximum number of Steps that can be |
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| 152 | // taken for the integration of a single segment - |
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| 153 | // (ie a single call to AccurateAdvance). |
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| 154 | |
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| 155 | public: // without description |
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| 156 | |
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| 157 | inline void SetHmin(G4double newval); |
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| 158 | inline void SetVerboseLevel(G4int newLevel); |
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| 159 | inline G4double GetVerboseLevel() const; |
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| 160 | |
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| 161 | inline G4double GetSmallestFraction() const; |
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| 162 | void SetSmallestFraction( G4double val ); |
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| 163 | |
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| 164 | protected: // without description |
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| 165 | void WarnSmallStepSize( G4double hnext, G4double hstep, |
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| 166 | G4double h, G4double xDone, |
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| 167 | G4int noSteps); |
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| 168 | void WarnTooManyStep( G4double x1start, G4double x2end, G4double xCurrent); |
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| 169 | void WarnEndPointTooFar (G4double endPointDist, |
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| 170 | G4double hStepSize , |
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| 171 | G4double epsilonRelative, |
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| 172 | G4int debugFlag); |
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| 173 | // Issue warnings for undesirable situations |
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| 174 | |
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| 175 | void PrintStatus( const G4double* StartArr, |
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| 176 | G4double xstart, |
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| 177 | const G4double* CurrentArr, |
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| 178 | G4double xcurrent, |
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| 179 | G4double requestStep, |
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| 180 | G4int subStepNo ); |
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| 181 | void PrintStatus( const G4FieldTrack& StartFT, |
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| 182 | const G4FieldTrack& CurrentFT, |
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| 183 | G4double requestStep, |
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| 184 | G4int subStepNo ); |
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| 185 | void PrintStat_Aux( const G4FieldTrack& aFieldTrack, |
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| 186 | G4double requestStep, |
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| 187 | G4double actualStep, |
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| 188 | G4int subStepNo, |
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| 189 | G4double subStepSize, |
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| 190 | G4double dotVelocities ); |
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| 191 | // Verbose output for debugging |
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| 192 | |
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| 193 | void PrintStatisticsReport() ; |
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| 194 | // Report on the number of steps, maximum errors etc. |
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| 195 | |
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| 196 | #ifdef QUICK_ADV_TWO |
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| 197 | G4bool QuickAdvance( G4double yarrin[], // In |
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| 198 | const G4double dydx[], |
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| 199 | G4double hstep, |
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| 200 | G4double yarrout[], // Out |
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| 201 | G4double& dchord_step, // Out |
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| 202 | G4double& dyerr ); // in length |
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| 203 | #endif |
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| 204 | |
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| 205 | private: |
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| 206 | |
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| 207 | G4MagInt_Driver(const G4MagInt_Driver&); |
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| 208 | G4MagInt_Driver& operator=(const G4MagInt_Driver&); |
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| 209 | // Private copy constructor and assignment operator. |
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| 210 | |
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| 211 | private: |
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| 212 | |
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| 213 | G4double fMinimumStep; |
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| 214 | // Minimum Step allowed in a Step (in absolute units) |
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| 215 | G4double fSmallestFraction; // Expected range 1e-12 to 5e-15; |
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| 216 | // Smallest fraction of (existing) curve length - in relative units |
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| 217 | // below this fraction the current step will be the last |
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| 218 | |
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| 219 | |
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| 220 | const G4int fNoIntegrationVariables; // Number of Variables in integration |
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| 221 | const G4int fMinNoVars; // Minimum number for FieldTrack |
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| 222 | const G4int fNoVars; // Full number of variable |
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| 223 | |
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| 224 | G4MagIntegratorStepper *pIntStepper; |
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| 225 | G4int fMaxNoSteps; |
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| 226 | static const G4int fMaxStepBase; |
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| 227 | |
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| 228 | G4double safety; |
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| 229 | G4double pshrnk; // exponent for shrinking |
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| 230 | G4double pgrow; // exponent for growth |
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| 231 | G4double errcon; |
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| 232 | // Parameters used to grow and shrink trial stepsize. |
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| 233 | |
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| 234 | static const G4double max_stepping_increase; |
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| 235 | static const G4double max_stepping_decrease; |
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| 236 | // Maximum stepsize increase/decrease factors. |
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| 237 | |
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| 238 | G4int fVerboseLevel; |
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| 239 | // Verbosity level for printing (debug, ..) |
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| 240 | |
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| 241 | G4int fNoTotalSteps, fNoBadSteps, fNoSmallSteps, fNoInitialSmallSteps; |
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| 242 | G4double fDyerr_max, fDyerr_mx2; |
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| 243 | G4double fDyerrPos_smTot, fDyerrPos_lgTot, fDyerrVel_lgTot; |
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| 244 | G4double fSumH_sm, fSumH_lg; |
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| 245 | // Step Statistics |
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| 246 | |
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| 247 | G4int fStatisticsVerboseLevel; |
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| 248 | }; |
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| 249 | |
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| 250 | #include "G4MagIntegratorDriver.icc" |
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| 251 | |
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| 252 | #endif /* G4MagInt_Driver_Def */ |
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