| 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 // G4NystromRK4 implmentation 26 // G4NystromRK4 implmentation
27 // 27 //
28 // Created: I.Gavrilenko, 15.05.2009 (as G4Atl 28 // Created: I.Gavrilenko, 15.05.2009 (as G4AtlasRK4)
29 // Adaptations: J.Apostolakis, November 2009 29 // Adaptations: J.Apostolakis, November 2009
30 // ------------------------------------------- 30 // -------------------------------------------------------------------
31 31
32 #include <memory> 32 #include <memory>
33 33
34 #include "G4NystromRK4.hh" 34 #include "G4NystromRK4.hh"
35 35
36 #include "G4Exception.hh" 36 #include "G4Exception.hh"
37 #include "G4SystemOfUnits.hh" 37 #include "G4SystemOfUnits.hh"
38 #include "G4FieldUtils.hh" 38 #include "G4FieldUtils.hh"
39 #include "G4LineSection.hh" 39 #include "G4LineSection.hh"
40 40
41 using namespace field_utils; 41 using namespace field_utils;
42 42
43 namespace 43 namespace
44 { 44 {
45 G4bool notEquals(G4double p1, G4double p2) 45 G4bool notEquals(G4double p1, G4double p2)
46 { 46 {
47 return std::fabs(p1 - p2) > perMillion * 47 return std::fabs(p1 - p2) > perMillion * p2;
48 } 48 }
49 constexpr G4int INTEGRATED_COMPONENTS = 6; 49 constexpr G4int INTEGRATED_COMPONENTS = 6;
50 } // namespace 50 } // namespace
51 51
52 52
53 G4NystromRK4::G4NystromRK4(G4Mag_EqRhs* equati 53 G4NystromRK4::G4NystromRK4(G4Mag_EqRhs* equation, G4double distanceConstField)
54 : G4MagIntegratorStepper(equation, INTEGRATE 54 : G4MagIntegratorStepper(equation, INTEGRATED_COMPONENTS)
55 { 55 {
56 if (distanceConstField > 0) 56 if (distanceConstField > 0)
57 { 57 {
58 SetDistanceForConstantField(distanceCo 58 SetDistanceForConstantField(distanceConstField);
59 } 59 }
60 } 60 }
61 61
62 void G4NystromRK4::Stepper(const G4double y[], 62 void G4NystromRK4::Stepper(const G4double y[],
63 const G4double dydx 63 const G4double dydx[],
64 G4double hstep, 64 G4double hstep,
65 G4double yOut[], 65 G4double yOut[],
66 G4double yError[]) 66 G4double yError[])
67 { 67 {
68 fInitialPoint = { y[0], y[1], y[2] }; 68 fInitialPoint = { y[0], y[1], y[2] };
69 69
70 G4double field[3]; 70 G4double field[3];
71 71
72 constexpr G4double one_sixth= 1./6.; 72 constexpr G4double one_sixth= 1./6.;
73 const G4double S5 = 0.5 * hstep; 73 const G4double S5 = 0.5 * hstep;
74 const G4double S4 = .25 * hstep; 74 const G4double S4 = .25 * hstep;
75 const G4double S6 = hstep * one_sixth; 75 const G4double S6 = hstep * one_sixth;
76 76
77 const G4double momentum2 = getValue2(y, Va 77 const G4double momentum2 = getValue2(y, Value3D::Momentum);
78 if (notEquals(momentum2, fMomentum2)) 78 if (notEquals(momentum2, fMomentum2))
79 { 79 {
80 fMomentum = std::sqrt(momentum2); 80 fMomentum = std::sqrt(momentum2);
81 fMomentum2 = momentum2; 81 fMomentum2 = momentum2;
82 fInverseMomentum = 1. / fMomentum; 82 fInverseMomentum = 1. / fMomentum;
83 fCoefficient = GetFCof() * fInverseMom 83 fCoefficient = GetFCof() * fInverseMomentum;
84 } 84 }
85 85
86 // Point 1 86 // Point 1
87 const G4double K1[3] = { 87 const G4double K1[3] = {
88 fInverseMomentum * dydx[3], 88 fInverseMomentum * dydx[3],
89 fInverseMomentum * dydx[4], 89 fInverseMomentum * dydx[4],
90 fInverseMomentum * dydx[5] 90 fInverseMomentum * dydx[5]
91 }; 91 };
92 92
93 // Point2 93 // Point2
94 G4double p[4] = { 94 G4double p[4] = {
95 y[0] + S5 * (dydx[0] + S4 * K1[0]), 95 y[0] + S5 * (dydx[0] + S4 * K1[0]),
96 y[1] + S5 * (dydx[1] + S4 * K1[1]), 96 y[1] + S5 * (dydx[1] + S4 * K1[1]),
97 y[2] + S5 * (dydx[2] + S4 * K1[2]), 97 y[2] + S5 * (dydx[2] + S4 * K1[2]),
98 y[7] 98 y[7]
99 }; 99 };
100 100
101 GetFieldValue(p, field); 101 GetFieldValue(p, field);
102 102
103 const G4double A2[3] = { 103 const G4double A2[3] = {
104 dydx[0] + S5 * K1[0], 104 dydx[0] + S5 * K1[0],
105 dydx[1] + S5 * K1[1], 105 dydx[1] + S5 * K1[1],
106 dydx[2] + S5 * K1[2] 106 dydx[2] + S5 * K1[2]
107 }; 107 };
108 108
109 const G4double K2[3] = { 109 const G4double K2[3] = {
110 (A2[1] * field[2] - A2[2] * field[1]) 110 (A2[1] * field[2] - A2[2] * field[1]) * fCoefficient,
111 (A2[2] * field[0] - A2[0] * field[2]) 111 (A2[2] * field[0] - A2[0] * field[2]) * fCoefficient,
112 (A2[0] * field[1] - A2[1] * field[0]) 112 (A2[0] * field[1] - A2[1] * field[0]) * fCoefficient
113 }; 113 };
114 114
115 fMidPoint = { p[0], p[1], p[2] }; 115 fMidPoint = { p[0], p[1], p[2] };
116 116
117 // Point 3 with the same magnetic field 117 // Point 3 with the same magnetic field
118 const G4double A3[3] = { 118 const G4double A3[3] = {
119 dydx[0] + S5 * K2[0], 119 dydx[0] + S5 * K2[0],
120 dydx[1] + S5 * K2[1], 120 dydx[1] + S5 * K2[1],
121 dydx[2] + S5 * K2[2] 121 dydx[2] + S5 * K2[2]
122 }; 122 };
123 123
124 const G4double K3[3] = { 124 const G4double K3[3] = {
125 (A3[1] * field[2] - A3[2] * field[1]) 125 (A3[1] * field[2] - A3[2] * field[1]) * fCoefficient,
126 (A3[2] * field[0] - A3[0] * field[2]) 126 (A3[2] * field[0] - A3[0] * field[2]) * fCoefficient,
127 (A3[0] * field[1] - A3[1] * field[0]) 127 (A3[0] * field[1] - A3[1] * field[0]) * fCoefficient
128 }; 128 };
129 129
130 // Point 4 130 // Point 4
131 p[0] = y[0] + hstep * (dydx[0] + S5 * K3[0 131 p[0] = y[0] + hstep * (dydx[0] + S5 * K3[0]);
132 p[1] = y[1] + hstep * (dydx[1] + S5 * K3[1 132 p[1] = y[1] + hstep * (dydx[1] + S5 * K3[1]);
133 p[2] = y[2] + hstep * (dydx[2] + S5 * K3[2 133 p[2] = y[2] + hstep * (dydx[2] + S5 * K3[2]);
134 134
135 GetFieldValue(p, field); 135 GetFieldValue(p, field);
136 136
137 const G4double A4[3] = { 137 const G4double A4[3] = {
138 dydx[0] + hstep * K3[0], 138 dydx[0] + hstep * K3[0],
139 dydx[1] + hstep * K3[1], 139 dydx[1] + hstep * K3[1],
140 dydx[2] + hstep * K3[2] 140 dydx[2] + hstep * K3[2]
141 }; 141 };
142 142
143 const G4double K4[3] = { 143 const G4double K4[3] = {
144 (A4[1] * field[2] - A4[2] * field[1]) 144 (A4[1] * field[2] - A4[2] * field[1]) * fCoefficient,
145 (A4[2] * field[0] - A4[0] * field[2]) 145 (A4[2] * field[0] - A4[0] * field[2]) * fCoefficient,
146 (A4[0] * field[1] - A4[1] * field[0]) 146 (A4[0] * field[1] - A4[1] * field[0]) * fCoefficient
147 }; 147 };
148 148
149 // New position 149 // New position
150 yOut[0] = y[0] + hstep * (dydx[0] + S6 * ( 150 yOut[0] = y[0] + hstep * (dydx[0] + S6 * (K1[0] + K2[0] + K3[0]));
151 yOut[1] = y[1] + hstep * (dydx[1] + S6 * ( 151 yOut[1] = y[1] + hstep * (dydx[1] + S6 * (K1[1] + K2[1] + K3[1]));
152 yOut[2] = y[2] + hstep * (dydx[2] + S6 * ( 152 yOut[2] = y[2] + hstep * (dydx[2] + S6 * (K1[2] + K2[2] + K3[2]));
153 // New direction 153 // New direction
154 yOut[3] = dydx[0] + S6 * (K1[0] + K4[0] + 154 yOut[3] = dydx[0] + S6 * (K1[0] + K4[0] + 2. * (K2[0] + K3[0]));
155 yOut[4] = dydx[1] + S6 * (K1[1] + K4[1] + 155 yOut[4] = dydx[1] + S6 * (K1[1] + K4[1] + 2. * (K2[1] + K3[1]));
156 yOut[5] = dydx[2] + S6 * (K1[2] + K4[2] + 156 yOut[5] = dydx[2] + S6 * (K1[2] + K4[2] + 2. * (K2[2] + K3[2]));
157 // Pass Energy, time unchanged -- time is 157 // Pass Energy, time unchanged -- time is not integrated !!
158 yOut[6] = y[6]; 158 yOut[6] = y[6];
159 yOut[7] = y[7]; 159 yOut[7] = y[7];
160 160
161 fEndPoint = { yOut[0], yOut[1], yOut[2] }; 161 fEndPoint = { yOut[0], yOut[1], yOut[2] };
162 162
163 // Errors 163 // Errors
164 yError[3] = hstep * std::fabs(K1[0] - K2[0 164 yError[3] = hstep * std::fabs(K1[0] - K2[0] - K3[0] + K4[0]);
165 yError[4] = hstep * std::fabs(K1[1] - K2[1 165 yError[4] = hstep * std::fabs(K1[1] - K2[1] - K3[1] + K4[1]);
166 yError[5] = hstep * std::fabs(K1[2] - K2[2 166 yError[5] = hstep * std::fabs(K1[2] - K2[2] - K3[2] + K4[2]);
167 yError[0] = hstep * yError[3]; 167 yError[0] = hstep * yError[3];
168 yError[1] = hstep * yError[4]; 168 yError[1] = hstep * yError[4];
169 yError[2] = hstep * yError[5]; 169 yError[2] = hstep * yError[5];
170 yError[3] *= fMomentum; 170 yError[3] *= fMomentum;
171 yError[4] *= fMomentum; 171 yError[4] *= fMomentum;
172 yError[5] *= fMomentum; 172 yError[5] *= fMomentum;
173 173
174 // Normalize momentum 174 // Normalize momentum
175 const G4double normF = fMomentum / getValu 175 const G4double normF = fMomentum / getValue(yOut, Value3D::Momentum);
176 yOut[3] *= normF; 176 yOut[3] *= normF;
177 yOut[4] *= normF; 177 yOut[4] *= normF;
178 yOut[5] *= normF; 178 yOut[5] *= normF;
179 179
180 // My trial code: 180 // My trial code:
181 // G4double endMom2 = yOut[3]*yOut[3]+yOut 181 // G4double endMom2 = yOut[3]*yOut[3]+yOut[4]*yOut[4]+yOut[5]*yOut[5];
182 // G4double normF = std::sqrt( startMom2 / 182 // G4double normF = std::sqrt( startMom2 / endMom2 );
183 } 183 }
184 184
185 G4double G4NystromRK4::DistChord() const 185 G4double G4NystromRK4::DistChord() const
186 { 186 {
187 return G4LineSection::Distline(fMidPoint, 187 return G4LineSection::Distline(fMidPoint, fInitialPoint, fEndPoint);
188 } 188 }
189 189
190 void G4NystromRK4::SetDistanceForConstantField 190 void G4NystromRK4::SetDistanceForConstantField(G4double length)
191 { 191 {
192 if (GetField() == nullptr) 192 if (GetField() == nullptr)
193 { 193 {
194 G4Exception("G4NystromRK4::SetDistanceForC 194 G4Exception("G4NystromRK4::SetDistanceForConstantField",
195 "Nystrom 001", JustWarning, 195 "Nystrom 001", JustWarning,
196 "Provided field is not G4CachedMagneti 196 "Provided field is not G4CachedMagneticField. Changing field type.");
197 197
198 fCachedField = std::make_unique<G4CachedMa 198 fCachedField = std::make_unique<G4CachedMagneticField>(
199 dynamic_cast<G4MagneticField*>(GetE 199 dynamic_cast<G4MagneticField*>(GetEquationOfMotion()->GetFieldObj()),
200 length); 200 length);
201 201
202 GetEquationOfMotion()->SetFieldObj(fCached 202 GetEquationOfMotion()->SetFieldObj(fCachedField.get());
203 } 203 }
204 GetField()->SetConstDistance(length); 204 GetField()->SetConstDistance(length);
205 } 205 }
206 206
207 G4double G4NystromRK4::GetDistanceForConstantF 207 G4double G4NystromRK4::GetDistanceForConstantField() const
208 { 208 {
209 if (GetField() == nullptr) 209 if (GetField() == nullptr)
210 { 210 {
211 return 0.0; 211 return 0.0;
212 } 212 }
213 return GetField()->GetConstDistance(); 213 return GetField()->GetConstDistance();
214 } 214 }
215 215
216 G4CachedMagneticField* G4NystromRK4::GetField( 216 G4CachedMagneticField* G4NystromRK4::GetField()
217 { 217 {
218 return dynamic_cast<G4CachedMagneticField*>( 218 return dynamic_cast<G4CachedMagneticField*>(GetEquationOfMotion()->GetFieldObj());
219 } 219 }
220 220
221 const G4CachedMagneticField* G4NystromRK4::Get 221 const G4CachedMagneticField* G4NystromRK4::GetField() const
222 { 222 {
223 return const_cast<G4NystromRK4*>(this)->GetF 223 return const_cast<G4NystromRK4*>(this)->GetField();
224 } 224 }
225 225