Changes related to the initialization of random numbers generators. Now one can use...
[u/mrichter/AliRoot.git] / THerwig / AliGenHerwig.cxx
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618e1dc0 1/**************************************************************************
2 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
3 * *
4 * Author: The ALICE Off-line Project. *
5 * Contributors are mentioned in the code where appropriate. *
6 * *
7 * Permission to use, copy, modify and distribute this software and its *
8 * documentation strictly for non-commercial purposes is hereby granted *
9 * without fee, provided that the above copyright notice appears in all *
10 * copies and that both the copyright notice and this permission notice *
11 * appear in the supporting documentation. The authors make no claims *
12 * about the suitability of this software for any purpose. It is *
13 * provided "as is" without express or implied warranty. *
14 **************************************************************************/
15
7cdba479 16/* $Id$ */
618e1dc0 17
18
19// Generator using Herwig as an external generator
20// The main Herwig options are accessable for the user through this interface.
21// Uses the THerwig implementation of TGenerator.
22
23#include "AliGenHerwig.h"
24#include "AliRun.h"
25
26#include <TParticle.h>
27#include "THerwig6.h"
28
29#include "Riostream.h"
30
31 ClassImp(AliGenHerwig)
32
7cdba479 33static TRandom * sRandom;
34
618e1dc0 35AliGenHerwig::AliGenHerwig()
36{
37// Constructor
38}
39
40AliGenHerwig::AliGenHerwig(Int_t npart)
41 :AliGenMC(npart)
42{
43 SetBeamMomenta();
44 SetTarget();
45 SetProjectile();
46 SetStrucFunc(kGRVLO98);
47 fKeep=0;
48 fTrigger=0;
49 fDecaysOff=1;
50 fSelectAll=0;
51 fFlavor=0;
52 fPtHardMin=10.;
53 fPtRMS=0.0;
54 fEnSoft=1.0;
55 fMaxPr=1;
56 fMaxErrors=1000;
57// Set random number
58 if (!sRandom) sRandom=fRandom;
59}
60
61AliGenHerwig::AliGenHerwig(const AliGenHerwig & Herwig)
62{
63// copy constructor
64}
65
66
67AliGenHerwig::~AliGenHerwig()
68{
69// Destructor
70}
71
72void AliGenHerwig::Init()
73{
74// Initialisation
75 fTarget.Resize(8);
76 fProjectile.Resize(8);
77 SetMC(new THerwig6());
78 fHerwig=(THerwig6*) fgMCEvGen;
79 // initialize common blocks
80 fHerwig->Initialize(fProjectile, fTarget, fMomentum1, fMomentum2, fProcess);
81 // reset parameters according to user needs
82 InitPDF();
83 fHerwig->SetPTMIN(fPtHardMin);
84 fHerwig->SetPTRMS(fPtRMS);
85 fHerwig->SetMAXPR(fMaxPr);
86 fHerwig->SetMAXER(fMaxErrors);
87 fHerwig->SetENSOF(fEnSoft);
88 // compute parameter dependent constants
89 fHerwig->PrepareRun();
90}
91
92void AliGenHerwig::InitPDF()
93{
94 switch(fStrucFunc)
95 {
96 case kGRVLO:
97 fModPDF=5;
98 fAutPDF="GRV";
99 break;
100 case kGRVHO:
101 fModPDF=6;
102 fAutPDF="GRV";
103 break;
104 case kGRVLO98:
105 fModPDF=12;
106 fAutPDF="GRV";
107 break;
108 case kMRSDminus:
109 fModPDF=31;
110 fAutPDF="MRS";
111 break;
112 case kMRSD0:
113 fModPDF=30;
114 fAutPDF="MRS";
115 break;
116 case kMRSG:
117 fModPDF=41;
118 fAutPDF="MRS";
119 break;
120 case kMRSTcgLO:
121 fModPDF=72;
122 fAutPDF="MRS";
123 break;
124 case kCTEQ4M:
125 fModPDF=34;
126 fAutPDF="CTEQ";
127 break;
128 case kCTEQ5L:
129 fModPDF=46;
130 fAutPDF="CTEQ";
131 break;
132 default:
133 cerr << "This structure function is not inplemented " << fStrucFunc << endl;
134 break;
135 }
136 fAutPDF.Resize(20);
137 fHerwig->SetMODPDF(1,fModPDF);
138 fHerwig->SetMODPDF(2,fModPDF);
139 fHerwig->SetAUTPDF(1,fAutPDF);
140 fHerwig->SetAUTPDF(2,fAutPDF);
141}
142
143void AliGenHerwig::Generate()
144{
145 // Generate one event
146
147 Float_t polar[3] = {0,0,0};
148 Float_t origin[3]= {0,0,0};
149 Float_t origin0[3]= {0,0,0};
150 Float_t p[4], random[6];
151
152 static TClonesArray *particles;
153 // converts from mm/c to s
154 const Float_t kconv=0.001/2.999792458e8;
155 //
156 Int_t nt=0;
157 Int_t jev=0;
158 Int_t j, kf, ks, imo;
159 kf=0;
160
161 if(!particles) particles=new TClonesArray("TParticle",10000);
162
163 fTrials=0;
164 for (j=0;j<3;j++) origin0[j]=fOrigin[j];
165 if(fVertexSmear==kPerEvent) {
166 Rndm(random,6);
167 for (j=0;j<3;j++) {
168 origin0[j]+=fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())*
169 TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
170 }
171 }
172
173 while(1)
174 {
175 fHerwig->GenerateEvent();
176 fTrials++;
177 fHerwig->ImportParticles(particles,"All");
178 Int_t np = particles->GetEntriesFast()-1;
179 if (np == 0 ) continue;
180
181 Int_t nc=0;
182
183 Int_t * newPos = new Int_t[np];
184 for (Int_t i = 0; i<np; i++) *(newPos+i)=-1;
185
186 for (Int_t i = 0; i<np; i++) {
187 TParticle * iparticle = (TParticle *) particles->At(i);
188 imo = iparticle->GetFirstMother();
189 kf = iparticle->GetPdgCode();
190 ks = iparticle->GetStatusCode();
191 if (ks != 3 &&
192 KinematicSelection(iparticle,0))
193 {
194 nc++;
195 p[0]=iparticle->Px();
196 p[1]=iparticle->Py();
197 p[2]=iparticle->Pz();
198 p[3]=iparticle->Energy();
199 origin[0]=origin0[0]+iparticle->Vx()/10;
200 origin[1]=origin0[1]+iparticle->Vy()/10;
201 origin[2]=origin0[2]+iparticle->Vz()/10;
202 Float_t tof = kconv*iparticle->T();
203 Int_t iparent = (imo > -1) ? newPos[imo] : -1;
204 Int_t trackIt = (ks == 1) && fTrackIt;
205 gAlice->SetTrack(trackIt, iparent, kf,
206 p[0], p[1], p[2], p[3],
207 origin[0], origin[1], origin[2],
208 tof,
209 polar[0], polar[1], polar[2],
210 kPPrimary, nt, 1., ks);
211 KeepTrack(nt);
212 newPos[i]=nt;
213 } // end of if: selection of particle
214 } // end of for: particle loop
215 if (newPos) delete[] newPos;
216 printf("\n I've put %i particles on the stack \n",nc);
217 // MakeHeader();
218 printf("nc: %d %d\n", nc, fNpart);
219
220 if (nc > 0) {
221 jev+=nc;
222 if (jev >= fNpart || fNpart == -1) {
223 fKineBias=Float_t(fNpart)/Float_t(fTrials);
224 printf("\n Trials: %i %i %i\n",fTrials, fNpart, jev);
225 break;
226 }
227 }
228 }
229 SetHighWaterMark(nt);
230// adjust weight due to kinematic selection
231 AdjustWeights();
232// get cross-section
233 fXsection=fHerwig->GetAVWGT();
234}
235
236void AliGenHerwig::AdjustWeights()
237{
238// Adjust the weights after generation of all events
239 TParticle *part;
240 Int_t ntrack=gAlice->GetNtrack();
241 for (Int_t i=0; i<ntrack; i++) {
242 part= gAlice->Particle(i);
243 part->SetWeight(part->GetWeight()*fKineBias);
244 }
245}
246
247
248void AliGenHerwig::KeepFullEvent()
249{
250 fKeep=1;
251}
252
253Bool_t AliGenHerwig::DaughtersSelection(TParticle* iparticle, TClonesArray* particles)
254{
255//
256// Looks recursively if one of the daughters has been selected
257//
258// printf("\n Consider daughters %d:",iparticle->GetPdgCode());
259 Int_t imin=-1;
260 Int_t imax=-1;
261 Int_t i;
262 Bool_t hasDaughters= (iparticle->GetFirstDaughter() >=0);
263 Bool_t selected=kFALSE;
264 if (hasDaughters) {
265 imin=iparticle->GetFirstDaughter();
266 imax=iparticle->GetLastDaughter();
267 for (i=imin; i<= imax; i++){
268 TParticle * jparticle = (TParticle *) particles->At(i);
269 Int_t ip=jparticle->GetPdgCode();
270 if (KinematicSelection(jparticle,0)&&SelectFlavor(ip)) {
271 selected=kTRUE; break;
272 }
273 if (DaughtersSelection(jparticle, particles)) {selected=kTRUE; break; }
274 }
275 } else {
276 return kFALSE;
277 }
278
279 return selected;
280}
281
282
283Bool_t AliGenHerwig::SelectFlavor(Int_t pid)
284{
285// Select flavor of particle
286// 0: all
287// 4: charm and beauty
288// 5: beauty
289 if (fFlavor == 0) return kTRUE;
290
291 Int_t ifl=TMath::Abs(pid/100);
292 if (ifl > 10) ifl/=10;
293 return (fFlavor == ifl);
294}
295
296Bool_t AliGenHerwig::Stable(TParticle* particle)
297{
298// Return true for a stable particle
299//
300 Int_t kf = TMath::Abs(particle->GetPdgCode());
301
302 if ( (particle->GetFirstDaughter() < 0 ) || (kf == 1000*fFlavor+122))
303
304 {
305 return kTRUE;
306 } else {
307 return kFALSE;
308 }
309}
310
311void AliGenHerwig::FinishRun()
312{
313 fHerwig->Hwefin();
314}
315
316
317AliGenHerwig& AliGenHerwig::operator=(const AliGenHerwig& rhs)
318{
319// Assignment operator
320 return *this;
321}
322
323
324extern "C" {
325 Double_t hwr_() {return sRandom->Rndm();}
326}