| Geant4 Cross Reference |
1 // 1 //
2 // ******************************************* 2 // ********************************************************************
3 // * License and Disclaimer 3 // * License and Disclaimer *
4 // * 4 // * *
5 // * The Geant4 software is copyright of th 5 // * The Geant4 software is copyright of the Copyright Holders of *
6 // * the Geant4 Collaboration. It is provided 6 // * the Geant4 Collaboration. It is provided under the terms and *
7 // * conditions of the Geant4 Software License 7 // * conditions of the Geant4 Software License, included in the file *
8 // * LICENSE and available at http://cern.ch/ 8 // * LICENSE and available at http://cern.ch/geant4/license . These *
9 // * include a list of copyright holders. 9 // * include a list of copyright holders. *
10 // * 10 // * *
11 // * Neither the authors of this software syst 11 // * Neither the authors of this software system, nor their employing *
12 // * institutes,nor the agencies providing fin 12 // * institutes,nor the agencies providing financial support for this *
13 // * work make any representation or warran 13 // * work make any representation or warranty, express or implied, *
14 // * regarding this software system or assum 14 // * regarding this software system or assume any liability for its *
15 // * use. Please see the license in the file 15 // * use. Please see the license in the file LICENSE and URL above *
16 // * for the full disclaimer and the limitatio 16 // * for the full disclaimer and the limitation of liability. *
17 // * 17 // * *
18 // * This code implementation is the result 18 // * This code implementation is the result of the scientific and *
19 // * technical work of the GEANT4 collaboratio 19 // * technical work of the GEANT4 collaboration. *
20 // * By using, copying, modifying or distri 20 // * By using, copying, modifying or distributing the software (or *
21 // * any work based on the software) you ag 21 // * any work based on the software) you agree to acknowledge its *
22 // * use in resulting scientific publicati 22 // * use in resulting scientific publications, and indicate your *
23 // * acceptance of all terms of the Geant4 Sof 23 // * acceptance of all terms of the Geant4 Software license. *
24 // ******************************************* 24 // ********************************************************************
25 // 25 //
26 // G4RKG3_Stepper implementation <<
27 // 26 //
28 // Created: J.Apostolakis, V.Grichine - 30.01. << 27 // $Id: G4RKG3_Stepper.cc,v 1.15 2007/08/21 10:17:41 tnikitin Exp $
>> 28 // GEANT4 tag $Name: geant4-09-01-patch-02 $
>> 29 //
29 // ------------------------------------------- 30 // -------------------------------------------------------------------
30 31
31 #include "G4RKG3_Stepper.hh" 32 #include "G4RKG3_Stepper.hh"
32 #include "G4LineSection.hh" 33 #include "G4LineSection.hh"
33 #include "G4Mag_EqRhs.hh" 34 #include "G4Mag_EqRhs.hh"
34 35
35 G4RKG3_Stepper::G4RKG3_Stepper(G4Mag_EqRhs* Eq << 36 G4RKG3_Stepper::G4RKG3_Stepper(G4Mag_EqRhs *EqRhs)
36 : G4MagIntegratorStepper(EqRhs,6) 37 : G4MagIntegratorStepper(EqRhs,6)
37 { 38 {
>> 39
>> 40 fPtrMagEqOfMot=EqRhs;
>> 41
38 } 42 }
39 43
40 G4RKG3_Stepper::~G4RKG3_Stepper() = default; << 44 G4RKG3_Stepper::~G4RKG3_Stepper()
>> 45 {
>> 46 }
41 47
42 void G4RKG3_Stepper::Stepper( const G4double y << 48 void G4RKG3_Stepper::Stepper( const G4double yInput[7],
43 const G4double d << 49 const G4double dydx[7],
44 G4double S << 50 G4double Step,
45 G4double y << 51 G4double yOut[7],
46 G4double y << 52 G4double yErr[])
47 { 53 {
48 G4double B[3]; 54 G4double B[3];
49 G4int nvar = 6 ; 55 G4int nvar = 6 ;
>> 56 G4int i;
50 G4double by15 = 1. / 15. ; // was 0.06666 57 G4double by15 = 1. / 15. ; // was 0.066666666 ;
51 58
52 G4double yTemp[8], dydxTemp[6], yIn[8]; << 59 G4double yTemp[7], dydxTemp[6], yIn[7] ;
>> 60 // Saving yInput because yInput and yOut can be aliases for same array
>> 61 for(i=0;i<nvar;i++) yIn[i]=yInput[i];
53 62
54 // Saving yInput because yInput and yOut ca <<
55 // <<
56 for(G4int i=0; i<nvar; ++i) <<
57 { <<
58 yIn[i]=yInput[i]; <<
59 } <<
60 yIn[6] = yInput[6]; <<
61 yIn[7] = yInput[7]; <<
62 G4double h = Step * 0.5; 63 G4double h = Step * 0.5;
63 hStep = Step; << 64 hStep=Step;
64 // Do two half steps << 65 // Do two half steps
65 66
66 StepNoErr(yIn, dydx,h, yTemp,B) ; 67 StepNoErr(yIn, dydx,h, yTemp,B) ;
67 68
68 // Store Bfld for DistChord Calculation << 69 //Store Bfld for DistChord Calculation
69 // << 70 for(i=0;i<3;i++)BfldIn[i]=B[i];
70 for(auto i=0; i<3; ++i) << 71
71 { << 72 // RightHandSide(yTemp,dydxTemp) ;
72 BfldIn[i] = B[i]; <<
73 } <<
74 // RightHandSide(yTemp,dydxTemp) ; <<
75 73
76 GetEquationOfMotion()->EvaluateRhsGivenB(yT 74 GetEquationOfMotion()->EvaluateRhsGivenB(yTemp,B,dydxTemp) ;
77 StepNoErr(yTemp,dydxTemp,h,yOut,B); 75 StepNoErr(yTemp,dydxTemp,h,yOut,B);
78 76
79 // Store midpoint, chord calculation 77 // Store midpoint, chord calculation
80 78
81 fyMidPoint = G4ThreeVector(yTemp[0], yTemp << 79 fyMidPoint = G4ThreeVector( yTemp[0], yTemp[1], yTemp[2]);
82 80
83 // Do a full Step 81 // Do a full Step
84 // << 82
85 h *= 2 ; 83 h *= 2 ;
86 StepNoErr(yIn,dydx,h,yTemp,B); << 84 StepNoErr(yIn,dydx,h,yTemp,B); // ,beTemp2) ;
87 for(G4int i=0; i<nvar; ++i) << 85 for(i=0;i<nvar;i++)
88 { 86 {
89 yErr[i] = yOut[i] - yTemp[i] ; 87 yErr[i] = yOut[i] - yTemp[i] ;
90 yOut[i] += yErr[i]*by15 ; // Pr 88 yOut[i] += yErr[i]*by15 ; // Provides 5th order of accuracy
91 } 89 }
92 90
93 // Store values for DistChord method << 91 //Store values for DistChord method
94 // << 92
95 fyInitial = G4ThreeVector( yIn[0], yIn[1] 93 fyInitial = G4ThreeVector( yIn[0], yIn[1], yIn[2]);
96 fpInitial = G4ThreeVector( yIn[3], yIn[4] 94 fpInitial = G4ThreeVector( yIn[3], yIn[4], yIn[5]);
97 fyFinal = G4ThreeVector( yOut[0], yOut[1 95 fyFinal = G4ThreeVector( yOut[0], yOut[1], yOut[2]);
>> 96
>> 97 // NormaliseTangentVector( yOut ); // Deleted
98 } 98 }
99 99
100 // ------------------------------------------- 100 // ---------------------------------------------------------------------------
101 101
102 // Integrator for RK from G3 with evaluation o 102 // Integrator for RK from G3 with evaluation of error in solution and delta
103 // geometry based on naive similarity with the 103 // geometry based on naive similarity with the case of uniform magnetic field.
104 // B1[3] is input and is the first magnetic f 104 // B1[3] is input and is the first magnetic field values
105 // B2[3] is output and is the final magnetic f 105 // B2[3] is output and is the final magnetic field values.
106 // << 106
107 void G4RKG3_Stepper::StepWithEst( const G4doub 107 void G4RKG3_Stepper::StepWithEst( const G4double*,
108 const G4doub 108 const G4double*,
109 G4doub 109 G4double,
110 G4doub 110 G4double*,
111 G4doub 111 G4double&,
112 G4doub 112 G4double&,
113 const G4doub 113 const G4double*,
114 G4doub 114 G4double* )
115 115
116 { 116 {
117 G4Exception("G4RKG3_Stepper::StepWithEst()", << 117 G4Exception("G4RKG3_Stepper::StepWithEst()", "ObsoleteMethod",
118 FatalException, "Method no longe 118 FatalException, "Method no longer used.");
119 } 119 }
120 120
121 // ------------------------------------------- 121 // -----------------------------------------------------------------
122 122
>> 123
123 // Integrator RK Stepper from G3 with only two 124 // Integrator RK Stepper from G3 with only two field evaluation per Step.
124 // It is used in propagation initial Step by s 125 // It is used in propagation initial Step by small substeps after solution
125 // error and delta geometry considerations. B[ 126 // error and delta geometry considerations. B[3] is magnetic field which
126 // is passed from substep to substep. 127 // is passed from substep to substep.
127 // << 128
128 void G4RKG3_Stepper::StepNoErr(const G4double << 129 void G4RKG3_Stepper::StepNoErr(const G4double tIn[7],
129 const G4double << 130 const G4double dydx[7],
130 G4double 131 G4double Step,
131 G4double << 132 G4double tOut[7],
132 G4double << 133 G4double B[3] ) // const
133 134
134 { 135 {
135 136
136 // Copy and edit the routine above, to dele << 137 // Copy and edit the routine above, to delete alpha2, beta2, ...
137 // << 138 G4double K1[7],K2[7],K3[7],K4[7] ;
138 G4double K1[7], K2[7], K3[7], K4[7]; << 139 G4double tTemp[7], yderiv[6] ;
139 G4double tTemp[8]={0.0}, yderiv[6]={0.0}; << 140
140 << 141 // Need Momentum value to give correct values to the coefficients in equation
141 // Need Momentum value to give correct valu << 142 // Integration on unit velocity, but tIn[3,4,5] is momentum
142 // equation. Integration on unit velocity, << 143 G4double mom,inverse_mom;
143 << 144 G4int i ;
144 G4double mom, inverse_mom; << 145 const G4double c1=0.5,c2=0.125,c3=1./6.;
145 const G4double c1=0.5, c2=0.125, c3=1./6.; <<
146 146
>> 147 // GetEquationOfMotion()->EvaluateRhsReturnB(tIn,dydx,B1) ;
147 // Correction for momentum not a velocity 148 // Correction for momentum not a velocity
148 // Need the protection !!! must be not zero << 149 // Need the protection !!! must be not zero
149 // << 150 mom=std::sqrt(tIn[3]*tIn[3]+tIn[4]*tIn[4]+tIn[5]*tIn[5]);
150 mom = std::sqrt(tIn[3]*tIn[3]+tIn[4]*tIn[4] << 151 inverse_mom=1./mom;
151 inverse_mom = 1./mom; << 152 for(i=0;i<3;i++)
152 for(auto i=0; i<3; ++i) <<
153 { 153 {
154 K1[i] = Step * dydx[i+3]*inverse_mom; 154 K1[i] = Step * dydx[i+3]*inverse_mom;
155 tTemp[i] = tIn[i] + Step*(c1*tIn[i+3]*in 155 tTemp[i] = tIn[i] + Step*(c1*tIn[i+3]*inverse_mom + c2*K1[i]) ;
156 tTemp[i+3] = tIn[i+3] + c1*K1[i]*mom ; 156 tTemp[i+3] = tIn[i+3] + c1*K1[i]*mom ;
>> 157
157 } 158 }
158 159
159 GetEquationOfMotion()->EvaluateRhsReturnB(t 160 GetEquationOfMotion()->EvaluateRhsReturnB(tTemp,yderiv,B) ;
>> 161
160 162
161 for(auto i=0; i<3; ++i) << 163 for(i=0;i<3;i++)
162 { 164 {
163 K2[i] = Step * yderiv[i+3]*inverse_mom; 165 K2[i] = Step * yderiv[i+3]*inverse_mom;
164 tTemp[i+3] = tIn[i+3] + c1*K2[i]*mom ; 166 tTemp[i+3] = tIn[i+3] + c1*K2[i]*mom ;
165 } 167 }
166 168
167 // Given B, calculate yderiv ! << 169 // Given B, calculate yderiv !
168 // <<
169 GetEquationOfMotion()->EvaluateRhsGivenB(tT 170 GetEquationOfMotion()->EvaluateRhsGivenB(tTemp,B,yderiv) ;
170 171
171 for(auto i=0; i<3; ++i) << 172 for(i=0;i<3;i++)
172 { 173 {
173 K3[i] = Step * yderiv[i+3]*inverse_mom; 174 K3[i] = Step * yderiv[i+3]*inverse_mom;
174 tTemp[i] = tIn[i] + Step*(tIn[i+3]*inver 175 tTemp[i] = tIn[i] + Step*(tIn[i+3]*inverse_mom + c1*K3[i]) ;
175 tTemp[i+3] = tIn[i+3] + K3[i]*mom ; 176 tTemp[i+3] = tIn[i+3] + K3[i]*mom ;
176 } 177 }
>> 178
177 179
178 // Calculates y-deriv(atives) & returns B t << 180 // Calculates y-deriv(atives) & returns B too!
179 // <<
180 GetEquationOfMotion()->EvaluateRhsReturnB(t 181 GetEquationOfMotion()->EvaluateRhsReturnB(tTemp,yderiv,B) ;
>> 182
181 183
182 for(auto i=0; i<3; ++i) // Output tr << 184 for(i=0;i<3;i++) // Output trajectory vector
183 { 185 {
184 K4[i] = Step * yderiv[i+3]*inverse_mom; 186 K4[i] = Step * yderiv[i+3]*inverse_mom;
185 tOut[i] = tIn[i] + Step*(tIn[i+3]*invers << 187 tOut[i] = tIn[i] + Step*(tIn[i+3]*inverse_mom+ (K1[i] + K2[i] + K3[i])*c3) ;
186 tOut[i+3] = tIn[i+3] + mom*(K1[i] + 2*K2 188 tOut[i+3] = tIn[i+3] + mom*(K1[i] + 2*K2[i] + 2*K3[i] +K4[i])*c3 ;
187 } 189 }
188 tOut[6] = tIn[6]; << 190
189 tOut[7] = tIn[7]; << 191 // NormaliseTangentVector( tOut );
>> 192
>> 193
190 } 194 }
191 195
>> 196
192 // ------------------------------------------- 197 // ---------------------------------------------------------------------------
193 198
194 G4double G4RKG3_Stepper::DistChord() const << 199 G4double G4RKG3_Stepper::DistChord() const
195 { << 200 {
196 // Soon: must check whether h/R > 2 pi !! 201 // Soon: must check whether h/R > 2 pi !!
197 // Method below is good only for < 2 pi << 202 // Method below is good only for < 2 pi
198 <<
199 G4double distChord,distLine; 203 G4double distChord,distLine;
200 204
201 if (fyInitial != fyFinal) << 205 if (fyInitial != fyFinal) {
202 { << 206 distLine= G4LineSection::Distline(fyMidPoint,fyInitial,fyFinal );
203 distLine = G4LineSection::Distline(fyMid << 207
204 distChord = distLine; << 208 distChord = distLine;
205 } << 209 }else{
206 else <<
207 { <<
208 distChord = (fyMidPoint-fyInitial).mag() 210 distChord = (fyMidPoint-fyInitial).mag();
209 } 211 }
210 << 212
>> 213
211 return distChord; 214 return distChord;
212 } << 215
>> 216 }
>> 217
213 218