BDSIM
BDSIM is a Geant4 extension toolkit for simulation of particle transport in accelerator beamlines.
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BDSPrimaryGeneratorFileSampler.cc
1/*
2Beam Delivery Simulation (BDSIM) Copyright (C) Royal Holloway,
3University of London 2001 - 2023.
4
5This file is part of BDSIM.
6
7BDSIM is free software: you can redistribute it and/or modify
8it under the terms of the GNU General Public License as published
9by the Free Software Foundation version 3 of the License.
10
11BDSIM is distributed in the hope that it will be useful, but
12WITHOUT ANY WARRANTY; without even the implied warranty of
13MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14GNU General Public License for more details.
15
16You should have received a copy of the GNU General Public License
17along with BDSIM. If not, see <http://www.gnu.org/licenses/>.
18*/
19#include "BDSBunchEventGenerator.hh"
20#include "BDSDebug.hh"
21#include "BDSException.hh"
22#include "BDSOutputLoaderSampler.hh"
23#include "BDSPrimaryGeneratorFileSampler.hh"
24#include "BDSParticleCoords.hh"
25#include "BDSParticleCoordsFull.hh"
26#include "BDSParticleCoordsFullGlobal.hh"
27#include "BDSPhysicalConstants.hh"
28#include "BDSPrimaryVertexInformation.hh"
29#include "BDSPrimaryVertexInformationV.hh"
30#include "BDSUtilities.hh"
31#include "BDSWarning.hh"
32
33#include "G4Event.hh"
34#include "G4EventManager.hh"
35#include "G4LorentzVector.hh"
36#include "G4PrimaryParticle.hh"
37#include "G4PrimaryVertex.hh"
38
39#include "CLHEP/Units/SystemOfUnits.h"
40
41#include "globals.hh"
42
43#include <utility>
44
46 const G4String& fileNameIn,
48 G4bool loopFileIn,
49 G4bool removeUnstableWithoutDecayIn,
50 G4bool warnAboutSkippedParticlesIn):
51 BDSPrimaryGeneratorFile(loopFileIn, bunchIn),
52 reader(nullptr),
53 fileName(fileNameIn),
54 removeUnstableWithoutDecay(removeUnstableWithoutDecayIn),
55 warnAboutSkippedParticles(warnAboutSkippedParticlesIn)
56{
57 std::pair<G4String, G4String> ba = BDS::SplitOnColon(distrType); // before:after
58 samplerName = ba.second;
59 G4cout << __METHOD_NAME__ << "reading sampler named: \"" << samplerName << "\"" << G4endl;
60 referenceBeamMomentumOffset = bunch->ReferenceBeamMomentumOffset();
61 reader = new BDSOutputLoaderSampler(fileName, samplerName);
62 nEventsInFile = reader->NEventsInFile();
63 bunch->SetNEventsInFile(nEventsInFile);
64 bunch->SetNOriginalEvents(reader->NOriginalEvents());
65 G4cout << __METHOD_NAME__ << nEventsInFile << " events found in file" << G4endl;
66 if (!bunch)
67 {throw BDSException(__METHOD_NAME__, "must be constructed with a valid BDSBunchEventGenerator instance");}
69}
70
71BDSPrimaryGeneratorFileSampler::~BDSPrimaryGeneratorFileSampler()
72{
73 delete reader;
74}
75
77{
78 if (!reader)
79 {throw BDSException(__METHOD_NAME__, "no file reader available");}
80
81 currentVertices.clear();
82
83 // currentFileEventIndex is zero counting by nEventsInFile will be 1 greater
84 if (currentFileEventIndex >= nEventsInFile)
85 {
86 endOfFileReached = true;
87 G4cout << __METHOD_NAME__ << "End of file reached. ";
88
89 if (loopFile)
90 {
91 if (OKToLoopFile())
92 {
93 G4cout << "Returning to beginning of file for next event." << G4endl;
94 currentFileEventIndex = 0;
95 endOfFileReached = false;
96 }
97 else
98 {
99 BDS::Warning(__METHOD_NAME__, "file looping requested, but 0 events passed filters - ending.");
100 return;
101 }
102 }
103 else
104 {
105 G4cout << G4endl; // to flush output
106 return;
107 }
108 }
109
110 ReadSingleEvent(currentFileEventIndex, anEvent);
111}
112
114{
115 G4cout << "BDSROOTSamplerLoader::RecreateAdvanceToEvent> Advancing file to event: " << eventOffset << G4endl;
117 SkipEvents(eventOffset);
118}
119
121{
122 vertices.clear();
123 const auto sampler = reader->SamplerDataFloat(index);
124
125 int n = sampler->n;
126 for (int i = 0; i < n; i++)
127 {
128 G4int pdgID = (G4int)sampler->partID[i];
129 G4double xp = (G4double)sampler->xp[i];
130 G4double yp = (G4double)sampler->yp[i];
131 G4double zp = (G4double)sampler->zp[i];
132 G4double p = (G4double)sampler->p[i];
133 G4ThreeVector momentum = G4ThreeVector(xp,yp,zp) * p * CLHEP::GeV;
134 G4double x = (G4double)sampler->x[i] * CLHEP::m;
135 G4double y = (G4double)sampler->y[i] * CLHEP::m;
136 G4ThreeVector localPosition(x,y,0);
137 auto g4prim = new G4PrimaryParticle(pdgID, momentum.x(), momentum.y(), momentum.z());
138 vertices.emplace_back(DisplacedVertex{localPosition, g4prim});
139 }
140}
141
142void BDSPrimaryGeneratorFileSampler::ReadPrimaryParticlesDouble(G4long index)
143{
144 vertices.clear();
145 const auto sampler = reader->SamplerDataDouble(index);
146
147 int n = sampler->n;
148 for (int i = 0; i < n; i++)
149 {
150 G4int pdgID = (G4int)sampler->partID[i];
151 G4double xp = (G4double)sampler->xp[i];
152 G4double yp = (G4double)sampler->yp[i];
153 G4double zp = (G4double)sampler->zp[i];
154 G4double p = (G4double)sampler->p[i];
155 G4ThreeVector momentum = G4ThreeVector(xp,yp,zp) * p;
156 G4double x = (G4double)sampler->x[i] * CLHEP::m;
157 G4double y = (G4double)sampler->y[i] * CLHEP::m;
158 G4ThreeVector localPosition(x,y,0);
159 auto g4prim = new G4PrimaryParticle(pdgID, momentum.x(), momentum.y(), momentum.z());
160 vertices.emplace_back(DisplacedVertex{localPosition, g4prim});
161 }
162}
163
164void BDSPrimaryGeneratorFileSampler::ReadSingleEvent(G4long index, G4Event* anEvent)
165{
166 if (reader->DoublePrecision())
167 {ReadPrimaryParticlesDouble(index);}
168 else
170
171 double overallWeight = 1.0;
172 G4int nParticlesSkipped = 0;
173 for (const auto& xyzVertex : vertices)
174 {
175 const auto vertex = xyzVertex.vertex;
176 // if the particle definition isn't found from the pdgcode in the construction
177 // of G4PrimaryParticle, it means the mass, charge, etc. will be wrong - don't
178 // stack this particle into the vertex.
179 // technically shouldn't happen as bdsim produced this output... but safety first
180 const G4ParticleDefinition* pd = vertex->GetParticleDefinition();
181 G4bool deleteIt = !pd;
182 if (pd && removeUnstableWithoutDecay)
183 {deleteIt = !(pd->GetPDGStable()) && !pd->GetDecayTable();}
184
185 if (deleteIt)
186 {
187 nParticlesSkipped++;
188 continue;
189 }
190
191 G4ThreeVector unitMomentum = vertex->GetMomentumDirection();
192 unitMomentum.transform(referenceBeamMomentumOffset);
193 G4double rp = unitMomentum.perp();
194
195 BDSParticleCoordsFull centralCoords = bunch->GetNextParticleLocal();
196 centralCoords.AddOffset(xyzVertex.xyz); // add on the local offset from the sampler
197
198 BDSParticleCoordsFull local(centralCoords.x,
199 centralCoords.y,
200 centralCoords.z,
201 unitMomentum.x(),
202 unitMomentum.y(),
203 unitMomentum.z(),
204 centralCoords.T,
205 centralCoords.s,
206 vertex->GetTotalEnergy(),
207 overallWeight);
208
209 if (!bunch->AcceptParticle(local, rp, vertex->GetKineticEnergy(), vertex->GetPDGcode()))
210 {
211 nParticlesSkipped++;
212 continue;
213 }
214
215 BDSParticleCoordsFullGlobal fullCoordsGlobal = bunch->ApplyTransform(local);
216
217 auto g4vtx = new G4PrimaryVertex(fullCoordsGlobal.global.x,
218 fullCoordsGlobal.global.y,
219 fullCoordsGlobal.global.z,
220 fullCoordsGlobal.global.T);
221
222 // ensure it's in the world - not done in primary generator action for event generators
223 if (!VertexInsideWorld(fullCoordsGlobal.global.Position()))
224 {
225 delete g4vtx;
226 nParticlesSkipped++;
227 continue;
228 }
229
230 G4double brho = 0;
231 G4double charge = vertex->GetCharge();
232 G4double momentum = vertex->GetTotalMomentum();
233 if (BDS::IsFinite(charge)) // else leave as 0
234 {
235 brho = momentum / CLHEP::GeV / BDS::cOverGeV / charge;
236 brho *= CLHEP::tesla*CLHEP::m; // rigidity (in Geant4 units)
237 }
238 auto vertexInfo = new BDSPrimaryVertexInformation(fullCoordsGlobal,
239 vertex->GetTotalMomentum(),
240 vertex->GetCharge(),
241 brho,
242 vertex->GetMass(),
243 vertex->GetPDGcode());
244
245 // update momentum in case of a beam line transform
246 auto prim = new G4PrimaryParticle(*vertex);
247 prim->SetMomentumDirection(G4ThreeVector(fullCoordsGlobal.global.xp,
248 fullCoordsGlobal.global.yp,
249 fullCoordsGlobal.global.zp));
250 g4vtx->SetPrimary(prim);
251 g4vtx->SetUserInformation(vertexInfo);
252 currentVertices.push_back(g4vtx);
253 }
254
255 if (nParticlesSkipped > 0 && warnAboutSkippedParticles)
256 {G4cout << __METHOD_NAME__ << nParticlesSkipped << " particles skipped" << G4endl;}
257
258 if (currentVertices.empty())
259 {// no particles found that pass criteria... we can't simulate this event... abort and move on
260 nEventsSkipped++;
261 if (warnAboutSkippedParticles)
262 {G4cout << __METHOD_NAME__ << "no particles found in event number: " << currentFileEventIndex << " in the file" << G4endl;}
263 }
264 else
265 {
266 vertexGeneratedSuccessfully = true;
267 nEventsReadThatPassedFilters++;
268 }
269
270 // clear initially loaded ones
271 for (auto& v : vertices)
272 {delete v.vertex;}
273 vertices.clear();
274
275 currentFileEventIndex++;
276
277 for (auto* v : currentVertices)
278 {anEvent->AddPrimaryVertex(v);}
279 currentVertices.clear();
280}
281
283{
284 if (nEventsToSkip > 0)
285 {G4cout << __METHOD_NAME__ << "skipping " << nEventsToSkip << " into file." << G4endl;}
286 else
287 {return ;}
288 G4long distrFileLoopNTimes = bunch->DistrFileLoopNTimes();
289 G4long nAvailable = nEventsInFile * distrFileLoopNTimes;
290 if ((G4long)nEventsToSkip > nAvailable)
291 {
292 G4String msg = "number of events to skip (" + std::to_string(nEventsToSkip) + ") is greater than the number of events (";
293 msg += std::to_string(nEventsInFile);
294 if (distrFileLoopNTimes > 1)
295 {msg += " x " + std::to_string(distrFileLoopNTimes) + " loops of file";}
296 msg += ") in this file.";
297 throw BDSException("BDSBunchUserFile::RecreateAdvanceToEvent>", msg);
298 }
299 G4long nToSkipSinglePass = nAvailable % nEventsToSkip;
300 currentFileEventIndex = nToSkipSinglePass;
301}
A wrapper of BDSBunch to include a filter for the events loaded by an event generator.
G4RotationMatrix ReferenceBeamMomentumOffset() const
Get a rotation matrix according to Xp0 and Yp0.
G4int eventGeneratorNEventsSkip
Cache of limit.
G4bool AcceptParticle(const BDSParticleCoordsFull &coords, G4double rpOriginal, G4double kineticEnergy, G4int pdgID)
G4int DistrFileLoopNTimes() const
Accessor.
BDSParticleCoordsFullGlobal ApplyTransform(const BDSParticleCoordsFull &localIn) const
Definition: BDSBunch.cc:292
virtual BDSParticleCoordsFull GetNextParticleLocal()
Definition: BDSBunch.cc:272
General exception with possible name of object and message.
Definition: BDSException.hh:35
Loader of ROOT Event output for receating events.
A set of particle coordinates in both local and global.
A set of particle coordinates including energy and weight.
G4double s
TODO - remove this. Unused. S (global) is calculated from S0 + z.
void AddOffset(const G4ThreeVector &offset)
Apply an offset to the spatial coordinates only - assignment.
virtual void RecreateAdvanceToEvent(G4int eventOffset)
Advance to the correct event number in the file for recreation.
void ReadSingleEvent(G4long index, G4Event *anEvent)
Read sampler hits and put into primary vertices if they pass filters.
std::vector< DisplacedVertex > vertices
Used for transiently loading information.
BDSPrimaryGeneratorFileSampler()=delete
Do not require default constructor.
void ReadPrimaryParticlesFloat(G4long index)
Conversion from HepMC::GenEvent to G4Event.
virtual void GeneratePrimaryVertex(G4Event *anEvent)
Read the next non-empty sampler entry from the file.
Common interface for any primary generators that are file based.
void ThrowExceptionIfRecreateOffsetTooHigh(G4long eventOffset) const
G4bool VertexInsideWorld(const G4ThreeVector &pos) const
Utility function for derived classes to check a position is inside the world.
Full set of coordinates for association with primary vertex.
std::pair< G4String, G4String > SplitOnColon(const G4String &formatAndPath)
static const G4double cOverGeV
speed of light / 1 GeV, used for scaling in brho calculation
G4bool IsFinite(G4double value, G4double tolerance=std::numeric_limits< double >::epsilon())