| 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 // class G4HelixMixedStepper 26 // class G4HelixMixedStepper
27 // 27 //
28 // Class description: 28 // Class description:
29 // 29 //
30 // G4HelixMixedStepper split the Method used f 30 // G4HelixMixedStepper split the Method used for Integration in two:
31 // 31 //
32 // If Stepping Angle ( h / R_curve) < pi/3 32 // If Stepping Angle ( h / R_curve) < pi/3
33 // use Stepper for small step(Classical 33 // use Stepper for small step(ClassicalRK4 by default)
34 // Else use HelixExplicitEuler Stepper 34 // Else use HelixExplicitEuler Stepper
35 // 35 //
36 // Created: T.Nikitina, CERN - 18.05.2007, der << 36 // History:
>> 37 // Derived from ExactHelicalStepper 18/05/07
>> 38 //
37 // ------------------------------------------- 39 // -------------------------------------------------------------------------
38 40
39 #include "G4HelixMixedStepper.hh" 41 #include "G4HelixMixedStepper.hh"
40 #include "G4PhysicalConstants.hh" <<
41 #include "G4ClassicalRK4.hh" 42 #include "G4ClassicalRK4.hh"
42 #include "G4CashKarpRKF45.hh" 43 #include "G4CashKarpRKF45.hh"
43 #include "G4SimpleRunge.hh" 44 #include "G4SimpleRunge.hh"
44 #include "G4HelixImplicitEuler.hh" 45 #include "G4HelixImplicitEuler.hh"
45 #include "G4HelixExplicitEuler.hh" 46 #include "G4HelixExplicitEuler.hh"
46 #include "G4HelixSimpleRunge.hh" 47 #include "G4HelixSimpleRunge.hh"
47 #include "G4ExactHelixStepper.hh" 48 #include "G4ExactHelixStepper.hh"
48 #include "G4ExplicitEuler.hh" 49 #include "G4ExplicitEuler.hh"
49 #include "G4ImplicitEuler.hh" 50 #include "G4ImplicitEuler.hh"
50 #include "G4SimpleHeum.hh" 51 #include "G4SimpleHeum.hh"
51 #include "G4RKG3_Stepper.hh" 52 #include "G4RKG3_Stepper.hh"
52 #include "G4NystromRK4.hh" <<
53 <<
54 // Additional potential steppers <<
55 #include "G4DormandPrince745.hh" <<
56 #include "G4BogackiShampine23.hh" <<
57 #include "G4BogackiShampine45.hh" <<
58 #include "G4TsitourasRK45.hh" <<
59 53
60 #include "G4ThreeVector.hh" 54 #include "G4ThreeVector.hh"
61 #include "G4LineSection.hh" 55 #include "G4LineSection.hh"
62 << 56 G4HelixMixedStepper::G4HelixMixedStepper(G4Mag_EqRhs *EqRhs,G4int fStepperNumber)
63 // ------------------------------------------- <<
64 G4HelixMixedStepper:: <<
65 G4HelixMixedStepper(G4Mag_EqRhs* EqRhs, <<
66 G4int stepperNumber <<
67 G4double angleThreshol <<
68 : G4MagHelicalStepper(EqRhs) 57 : G4MagHelicalStepper(EqRhs)
>> 58
69 { 59 {
70 if( angleThreshold < 0.0 ) << 60 SetVerbose(1); fNumCallsRK4=0; fNumCallsHelix=0;
71 { << 61 if(!fStepperNumber) fStepperNumber=4;
72 fAngle_threshold = (1.0/3.0)*pi; <<
73 } <<
74 else <<
75 { <<
76 fAngle_threshold = angleThreshold; <<
77 } <<
78 <<
79 if(stepperNumber<0) <<
80 { <<
81 // stepperNumber = 4; // Default is RK4 <<
82 stepperNumber = 745; // Default is Dorm <<
83 // stepperNumber = 8; // Default is Cash <<
84 } <<
85 <<
86 fStepperNumber = stepperNumber; // Store th <<
87 fRK4Stepper = SetupStepper(EqRhs, fStepper 62 fRK4Stepper = SetupStepper(EqRhs, fStepperNumber);
88 } 63 }
89 64
90 // ------------------------------------------- <<
91 G4HelixMixedStepper::~G4HelixMixedStepper() <<
92 { <<
93 delete fRK4Stepper; <<
94 if (fVerbose>0) { PrintCalls(); } <<
95 } <<
96 65
97 // ------------------------------------------- << 66 G4HelixMixedStepper::~G4HelixMixedStepper() {
98 void G4HelixMixedStepper::Stepper( const G4do << 67
99 const G4do << 68 delete(fRK4Stepper);
100 G4do << 69 if (fVerbose>0){ PrintCalls();};
101 G4do << 70 }
102 G4do << 71 void G4HelixMixedStepper::Stepper( const G4double yInput[7],
>> 72 const G4double dydx[7],
>> 73 G4double Step,
>> 74 G4double yOut[7],
>> 75 G4double yErr[])
>> 76
103 { 77 {
104 // Estimation of the Stepping Angle << 78
105 // << 79 //Estimation of the Stepping Angle
>> 80
106 G4ThreeVector Bfld; 81 G4ThreeVector Bfld;
107 MagFieldEvaluate(yInput, Bfld); << 82 MagFieldEvaluate(yInput, Bfld);
108 << 83
109 G4double Bmag = Bfld.mag(); 84 G4double Bmag = Bfld.mag();
110 const G4double* pIn = yInput+3; << 85 const G4double *pIn = yInput+3;
111 G4ThreeVector initVelocity = G4ThreeVector( << 86 G4ThreeVector initVelocity= G4ThreeVector( pIn[0], pIn[1], pIn[2]);
112 G4double velocityVal = initVelocity.mag(); << 87 G4double velocityVal = initVelocity.mag();
113 << 88 G4double R_1;
114 const G4double R_1 = std::abs(GetInverseCurv << 89 G4double Ang_curve;
115 // curv = inverse Radius << 90
116 G4double Ang_curve = R_1 * Step; << 91 R_1=std::abs(GetInverseCurve(velocityVal,Bmag));
117 // SetAngCurve(Ang_curve); << 92 Ang_curve=R_1*Step;
118 // SetCurve(std::abs(1/R_1)); << 93 SetAngCurve(Ang_curve);
119 << 94 SetCurve(std::abs(1/R_1));
120 if(Ang_curve < fAngle_threshold) << 95
121 { << 96
122 ++fNumCallsRK4; << 97 if(Ang_curve<0.33*pi){
123 fRK4Stepper->Stepper(yInput,dydx,Step,yOut << 98 fNumCallsRK4++;
124 } << 99 fRK4Stepper->Stepper(yInput,dydx,Step,yOut,yErr);
125 else <<
126 { <<
127 constexpr G4int nvar = 6 ; <<
128 constexpr G4int nvarMax = 8 ; <<
129 G4double yTemp[nvarMax], yIn[nvarMax] <<
130 G4ThreeVector Bfld_midpoint; <<
131 100
132 SetAngCurve(Ang_curve); <<
133 SetCurve(std::abs(1.0/R_1)); <<
134 ++fNumCallsHelix; <<
135 <<
136 // Saving yInput because yInput and yOut c <<
137 // <<
138 for(G4int i=0; i<nvar; ++i) <<
139 { <<
140 yIn[i]=yInput[i]; <<
141 } <<
142 <<
143 G4double halfS = Step * 0.5; <<
144 101
145 // 1. Do first half step and full step << 102 }
146 // << 103 else{
147 AdvanceHelix(yIn, Bfld, halfS, yTemp, yTem << 104 fNumCallsHelix++;
148 << 105 const G4int nvar = 6 ;
149 MagFieldEvaluate(yTemp, Bfld_midpoint) ; << 106 G4int i;
150 << 107 G4double yTemp[7], yIn[7] ;
151 // 2. Do second half step - with revised f << 108 G4double yTemp2[7];
152 // NOTE: Could avoid this call if 'Bfld_m << 109 G4ThreeVector Bfld_midpoint;
153 // or diff 'almost' zero << 110 // Saving yInput because yInput and yOut can be aliases for same array
154 // << 111 for(i=0;i<nvar;i++) yIn[i]=yInput[i];
155 AdvanceHelix(yTemp, Bfld_midpoint, halfS, << 112
156 // Not requesting y at s=2*h (halfS) << 113 G4double h = Step * 0.5;
157 << 114 // Do two half steps and full step
158 // 3. Estimate the integration error << 115 AdvanceHelix(yIn, Bfld, h, yTemp,yTemp2);
159 // should be (nearly) zero if Bfield= c << 116 MagFieldEvaluate(yTemp, Bfld_midpoint) ;
160 // << 117 AdvanceHelix(yTemp, Bfld_midpoint, h, yOut);
161 for(G4int i=0; i<nvar; ++i) << 118 // Error estimation
162 { << 119 for(i=0;i<nvar;i++) {
163 yErr[i] = yOut[i] - yTemp2[i]; << 120 yErr[i] = yOut[i] - yTemp2[i] ;
>> 121
>> 122 }
164 } 123 }
165 } << 124
>> 125
>> 126
>> 127
166 } 128 }
167 129
168 // ------------------------------------------- << 130 void
169 void G4HelixMixedStepper::DumbStepper( const G << 131 G4HelixMixedStepper::DumbStepper( const G4double yIn[],
170 G << 132 G4ThreeVector Bfld,
171 G << 133 G4double h,
172 G << 134 G4double yOut[])
173 { 135 {
174 AdvanceHelix(yIn, Bfld, h, yOut); << 136
175 } << 137
>> 138 AdvanceHelix(yIn, Bfld, h, yOut);
176 139
177 // ------------------------------------------- << 140
178 G4double G4HelixMixedStepper::DistChord() cons << 141
>> 142 }
>> 143
>> 144 G4double G4HelixMixedStepper::DistChord() const
179 { 145 {
180 // Implementation : must check whether h/R > 146 // Implementation : must check whether h/R > 2 pi !!
181 // If( h/R < pi) use G4LineSection::DistL 147 // If( h/R < pi) use G4LineSection::DistLine
182 // Else DistChord=R_helix 148 // Else DistChord=R_helix
183 // 149 //
184 G4double distChord; 150 G4double distChord;
185 G4double Ang_curve=GetAngCurve(); 151 G4double Ang_curve=GetAngCurve();
186 << 152
187 if(Ang_curve<=pi) << 153
188 { << 154 if(Ang_curve<=pi){
189 distChord=GetRadHelix()*(1-std::cos(0.5*An << 155 distChord=GetRadHelix()*(1-std::cos(0.5*Ang_curve));
190 } << 156 }
191 else << 157 else
192 { << 158 if(Ang_curve<twopi){
193 if(Ang_curve<twopi) << 159 distChord=GetRadHelix()*(1+std::cos(0.5*(twopi-Ang_curve)));
194 { << 160 }
195 distChord=GetRadHelix()*(1+std::cos(0.5* << 161 else{
196 } << 162 distChord=2.*GetRadHelix();
197 else << 163 }
198 { << 164
199 distChord=2.*GetRadHelix(); << 165
200 } << 166
201 } <<
202 <<
203 return distChord; 167 return distChord;
>> 168
204 } 169 }
205 <<
206 // ------------------------------------------- 170 // ---------------------------------------------------------------------------
207 void G4HelixMixedStepper::PrintCalls() 171 void G4HelixMixedStepper::PrintCalls()
208 { 172 {
209 G4cout << "In HelixMixedStepper::Number of c << 173 G4cout<<"In HelixMixedStepper::Number of calls to smallStepStepper = "<<fNumCallsRK4
210 << fNumCallsRK4 << 174 <<" and Number of calls to Helix = "<<fNumCallsHelix<<G4endl;
211 << " and Number of calls to Helix = <<
212 } 175 }
213 176
214 // ------------------------------------------- << 177
215 G4MagIntegratorStepper* << 178
216 G4HelixMixedStepper::SetupStepper(G4Mag_EqRhs* << 179 G4MagIntegratorStepper* G4HelixMixedStepper:: SetupStepper(G4Mag_EqRhs* pE, G4int StepperNumber)
217 { 180 {
218 G4MagIntegratorStepper* pStepper; 181 G4MagIntegratorStepper* pStepper;
219 if (fVerbose>0) { G4cout << " G4HelixMixedSt << 182 if (fVerbose>0)G4cout<<"In G4HelixMixedStepper Stepper for small steps is ";
220 } <<
221 switch ( StepperNumber ) 183 switch ( StepperNumber )
222 { << 184 {
223 // Robust, classic method << 185 case 0: pStepper = new G4ExplicitEuler( pE ); if (fVerbose>0)G4cout<<"G4ExplicitEuler"<<G4endl; break;
224 case 4: << 186 case 1: pStepper = new G4ImplicitEuler( pE ); if (fVerbose>0)G4cout<<"G4ImplicitEuler"<<G4endl; break;
225 pStepper = new G4ClassicalRK4( pE ); << 187 case 2: pStepper = new G4SimpleRunge( pE ); if (fVerbose>0)G4cout<<"G4SimpleRunge"<<G4endl; break;
226 if (fVerbose>0) { G4cout << "G4Classic << 188 case 3: pStepper = new G4SimpleHeum( pE ); if (fVerbose>0)G4cout<<"G4SimpleHeum"<<G4endl;break;
227 break; << 189 case 4: pStepper = new G4ClassicalRK4( pE ); if (fVerbose>0)G4cout<<"G4ClassicalRK4"<<G4endl; break;
228 << 190 case 5: pStepper = new G4HelixExplicitEuler( pE ); if (fVerbose>0)G4cout<<"G4HelixExplicitEuler"<<G4endl; break;
229 // Steppers with embedded estimation of << 191 case 6: pStepper = new G4HelixImplicitEuler( pE ); if (fVerbose>0)G4cout<<"G4HelixImplicitEuler"<<G4endl; break;
230 case 8: << 192 case 7: pStepper = new G4HelixSimpleRunge( pE ); if (fVerbose>0)G4cout<<"G4HelixSimpleRunge"<<G4endl; break;
231 pStepper = new G4CashKarpRKF45( pE ); << 193 case 8: pStepper = new G4CashKarpRKF45( pE ); if (fVerbose>0)G4cout<<"G4CashKarpRKF45"<<G4endl; break;
232 if (fVerbose>0) { G4cout << "G4CashKar << 194 case 9: pStepper = new G4ExactHelixStepper( pE ); if (fVerbose>0)G4cout<<"G4ExactHelixStepper"<<G4endl; break;
233 break; << 195 case 10: pStepper = new G4RKG3_Stepper( pE ); if (fVerbose>0)G4cout<<"G4RKG3_Stepper"<<G4endl; break;
234 case 13: << 196
235 pStepper = new G4NystromRK4( pE ); << 197 default: pStepper = new G4ClassicalRK4( pE );G4cout<<"Default G4ClassicalRK4"<<G4endl; break;
236 if (fVerbose>0) { G4cout << "G4Nystrom << 198
237 break; << 199 }
238 <<
239 // Lowest order RK Stepper - experimenta <<
240 case 1: <<
241 pStepper = new G4ImplicitEuler( pE ); <<
242 if (fVerbose>0) { G4cout << "G4Implici <<
243 break; <<
244 <<
245 // Lower order RK Steppers - ok overall, <<
246 case 2: <<
247 pStepper = new G4SimpleRunge( pE ); <<
248 if (fVerbose>0) { G4cout << "G4SimpleR <<
249 break; <<
250 case 3: <<
251 pStepper = new G4SimpleHeum( pE ); <<
252 if (fVerbose>0) { G4cout << "G4SimpleH <<
253 break; <<
254 case 23: <<
255 pStepper = new G4BogackiShampine23( pE <<
256 if (fVerbose>0) { G4cout << "G4Bogacki <<
257 break; <<
258 <<
259 // Higher order RK Steppers <<
260 // for smoother fields and high accuracy <<
261 case 45: <<
262 pStepper = new G4BogackiShampine45( pE <<
263 if (fVerbose>0) { G4cout << "G4Bogacki <<
264 break; <<
265 case 145: <<
266 pStepper = new G4TsitourasRK45( pE ); <<
267 if (fVerbose>0) { G4cout << "G4Tsitour <<
268 break; <<
269 case 745: <<
270 pStepper = new G4DormandPrince745( pE <<
271 if (fVerbose>0) { G4cout << "G4Dormand <<
272 break; <<
273 <<
274 // Helical Steppers <<
275 case 6: <<
276 pStepper = new G4HelixImplicitEuler( p <<
277 if (fVerbose>0) { G4cout << "G4HelixIm <<
278 break; <<
279 case 7: <<
280 pStepper = new G4HelixSimpleRunge( pE <<
281 if (fVerbose>0) { G4cout << "G4HelixSi <<
282 break; <<
283 case 5: <<
284 pStepper = new G4HelixExplicitEuler( p <<
285 if (fVerbose>0) { G4cout << "G4HelixEx <<
286 break; // Since Helix Explicit is use <<
287 // this is useful only to measu <<
288 // Exact Helix - likely good only for ca <<
289 // i) uniform field (potentia <<
290 // ii) segmented uniform field <<
291 case 9: <<
292 pStepper = new G4ExactHelixStepper( pE <<
293 if (fVerbose>0) { G4cout << "G4ExactHe <<
294 break; <<
295 case 10: <<
296 pStepper = new G4RKG3_Stepper( pE ); <<
297 if (fVerbose>0) { G4cout << "G4RKG3_St <<
298 break; <<
299 <<
300 // Low Order Steppers - not good except <<
301 case 11: <<
302 pStepper = new G4ExplicitEuler( pE ); <<
303 if (fVerbose>0) { G4cout << "G4Explici <<
304 break; <<
305 case 12: <<
306 pStepper = new G4ImplicitEuler( pE ); <<
307 if (fVerbose>0) { G4cout << "G4Implici <<
308 break; <<
309 <<
310 case 0: <<
311 case -1: <<
312 default: <<
313 pStepper = new G4DormandPrince745( pE <<
314 if (fVerbose>0) { G4cout << "G4Dormand <<
315 break; <<
316 } <<
317 <<
318 if(fVerbose>0) <<
319 { <<
320 G4cout << " chosen as stepper for small st <<
321 << G4endl; <<
322 } <<
323 <<
324 return pStepper; 200 return pStepper;
325 } 201 }
326 202