Updated macro
[u/mrichter/AliRoot.git] / ITS / AliITSVertexerZ.cxx
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0c6af5c9 1/**************************************************************************
2 * Copyright(c) 1998-2003, 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 **************************************************************************/
d531b7a1 15#include "AliITSVertexerZ.h"
0c6af5c9 16#include<TBranch.h>
7299b7a8 17#include<TClonesArray.h>
0c6af5c9 18#include<TH1.h>
d531b7a1 19#include <TString.h>
0c6af5c9 20#include<TTree.h>
6cae184e 21#include "AliRunLoader.h"
d531b7a1 22#include "AliITSLoader.h"
32e63e47 23#include "AliITSgeomTGeo.h"
7d62fb64 24#include "AliITSDetTypeRec.h"
d531b7a1 25#include "AliITSRecPoint.h"
7299b7a8 26#include "AliITSZPoint.h"
0c6af5c9 27
28/////////////////////////////////////////////////////////////////
29// this class implements a fast method to determine
30// the Z coordinate of the primary vertex
31// for p-p collisions it seems to give comparable or better results
32// with respect to what obtained with AliITSVertexerPPZ
33// It can be used successfully with Pb-Pb collisions
34////////////////////////////////////////////////////////////////
35
36ClassImp(AliITSVertexerZ)
37
38
39
40//______________________________________________________________________
8221b41b 41AliITSVertexerZ::AliITSVertexerZ():AliITSVertexer(),
42fFirstL1(0),
43fLastL1(0),
44fFirstL2(0),
45fLastL2(0),
46fDiffPhiMax(0),
8221b41b 47fZFound(0),
48fZsig(0.),
49fZCombc(0),
8221b41b 50fLowLim(0.),
51fHighLim(0.),
52fStepCoarse(0),
8221b41b 53fTolerance(0.),
7299b7a8 54fMaxIter(0),
55fWindowWidth(0) {
0c6af5c9 56 // Default constructor
7299b7a8 57 SetDiffPhiMax();
58 SetFirstLayerModules();
59 SetSecondLayerModules();
60 SetLowLimit();
61 SetHighLimit();
62 SetBinWidthCoarse();
63 SetTolerance();
64 SetPPsetting();
6fd990e3 65 ConfigIterations();
7299b7a8 66 SetWindowWidth();
0c6af5c9 67}
68
69//______________________________________________________________________
8221b41b 70AliITSVertexerZ::AliITSVertexerZ(TString fn, Float_t x0, Float_t y0):AliITSVertexer(fn),
71fFirstL1(0),
72fLastL1(0),
73fFirstL2(0),
74fLastL2(0),
75fDiffPhiMax(0),
8221b41b 76fZFound(0),
77fZsig(0.),
78fZCombc(0),
8221b41b 79fLowLim(0.),
80fHighLim(0.),
81fStepCoarse(0),
8221b41b 82fTolerance(0.),
7299b7a8 83fMaxIter(0),
84fWindowWidth(0) {
0c6af5c9 85 // Standard Constructor
86 SetDiffPhiMax();
0c6af5c9 87 SetFirstLayerModules();
88 SetSecondLayerModules();
0c6af5c9 89 SetLowLimit();
90 SetHighLimit();
91 SetBinWidthCoarse();
0c6af5c9 92 SetTolerance();
ecc64c3f 93 SetPPsetting();
6fd990e3 94 ConfigIterations();
7299b7a8 95 SetWindowWidth();
60b9526b 96 SetVtxStart((Double_t)x0,(Double_t)y0,0.);
0c6af5c9 97
98}
99
100//______________________________________________________________________
8221b41b 101AliITSVertexerZ::AliITSVertexerZ(const AliITSVertexerZ &vtxr) : AliITSVertexer(vtxr),
102fFirstL1(vtxr.fFirstL1),
103fLastL1(vtxr.fLastL1),
104fFirstL2(vtxr.fFirstL2),
105fLastL2(vtxr.fLastL2),
106fDiffPhiMax(vtxr.fDiffPhiMax),
8221b41b 107fZFound(vtxr.fZFound),
108fZsig(vtxr.fZsig),
109fZCombc(vtxr.fZCombc),
8221b41b 110fLowLim(vtxr.fLowLim),
111fHighLim(vtxr.fHighLim),
112fStepCoarse(vtxr.fStepCoarse),
8221b41b 113fTolerance(vtxr.fTolerance),
7299b7a8 114fMaxIter(vtxr.fMaxIter),
115fWindowWidth(vtxr.fWindowWidth){
0c6af5c9 116 // Copy constructor
8221b41b 117
0c6af5c9 118}
119
120//______________________________________________________________________
8221b41b 121AliITSVertexerZ& AliITSVertexerZ::operator=(const AliITSVertexerZ& vtxr ){
0c6af5c9 122 // Assignment operator
8221b41b 123
124 this->~AliITSVertexerZ();
125 new(this) AliITSVertexerZ(vtxr);
0c6af5c9 126 return *this;
127}
128
0c6af5c9 129//______________________________________________________________________
130AliITSVertexerZ::~AliITSVertexerZ() {
ecc64c3f 131 // Destructor
132 delete fZCombc;
0c6af5c9 133}
134
6fd990e3 135//______________________________________________________________________
136void AliITSVertexerZ::ConfigIterations(Int_t noiter,Float_t *ptr){
137 // configure the iterative procedure to gain efficiency for
138 // pp events with very low multiplicity
139 Float_t defaults[5]={0.05,0.1,0.2,0.3,0.5};
140 fMaxIter=noiter;
141 if(noiter>5){
142 Error("ConfigIterations","Maximum number of iterations is 5\n");
143 fMaxIter=5;
144 }
145 for(Int_t j=0;j<5;j++)fPhiDiffIter[j]=defaults[j];
146 if(ptr)for(Int_t j=0;j<fMaxIter;j++)fPhiDiffIter[j]=ptr[j];
147}
148
debb3dde 149//______________________________________________________________________
150Int_t AliITSVertexerZ::GetPeakRegion(TH1F*h, Int_t &binmin, Int_t &binmax) const {
151 // Finds a region around a peak in the Z histogram
152 // Case of 2 peaks is treated
153 Int_t imax=h->GetNbinsX();
154 Float_t maxval=0;
155 Int_t bi1=h->GetMaximumBin();
156 Int_t bi2=0;
157 for(Int_t i=imax;i>=1;i--){
158 if(h->GetBinContent(i)>maxval){
159 maxval=h->GetBinContent(i);
160 bi2=i;
161 }
162 }
163 Int_t npeaks=0;
164
165 if(bi1==bi2){
166 binmin=bi1-3;
167 binmax=bi1+3;
168 npeaks=1;
169 }else{
170 TH1F *copy = new TH1F(*h);
171 copy->SetBinContent(bi1,0.);
172 copy->SetBinContent(bi2,0.);
173 Int_t l1=TMath::Max(bi1-3,1);
174 Int_t l2=TMath::Min(bi1+3,h->GetNbinsX());
175 Float_t cont1=copy->Integral(l1,l2);
176 Int_t ll1=TMath::Max(bi2-3,1);
177 Int_t ll2=TMath::Min(bi2+3,h->GetNbinsX());
178 Float_t cont2=copy->Integral(ll1,ll2);
179 if(cont1>cont2){
180 binmin=l1;
181 binmax=l2;
182 npeaks=1;
183 }
184 if(cont2>cont1){
185 binmin=ll1;
186 binmax=ll2;
187 npeaks=1;
188 }
189 if(cont1==cont2){
190 binmin=l1;
191 binmax=ll2;
192 if(bi2-bi1==1) npeaks=1;
193 else npeaks=2;
194 }
195 delete copy;
196 }
197 return npeaks;
198}
0c6af5c9 199//______________________________________________________________________
d681bb2d 200AliESDVertex* AliITSVertexerZ::FindVertexForCurrentEvent(Int_t evnumber){
201 // Defines the AliESDVertex for the current event
6fd990e3 202 VertexZFinder(evnumber);
203 Int_t ntrackl=0;
204 for(Int_t iteraz=0;iteraz<fMaxIter;iteraz++){
205 if(fCurrentVertex) ntrackl=fCurrentVertex->GetNContributors();
206 if(!fCurrentVertex || ntrackl==0 || ntrackl==-1){
207 Float_t diffPhiMaxOrig=fDiffPhiMax;
208 fDiffPhiMax=GetPhiMaxIter(iteraz);
209 VertexZFinder(evnumber);
210 fDiffPhiMax=diffPhiMaxOrig;
211 }
212 }
32e449be 213 FindMultiplicity(evnumber);
6fd990e3 214 return fCurrentVertex;
215}
216
217//______________________________________________________________________
218void AliITSVertexerZ::VertexZFinder(Int_t evnumber){
219 // Defines the AliESDVertex for the current event
0c6af5c9 220 fCurrentVertex = 0;
221 AliRunLoader *rl =AliRunLoader::GetRunLoader();
7d62fb64 222 AliITSLoader* itsLoader = (AliITSLoader*)rl->GetLoader("ITSLoader");
32e63e47 223 // AliITSgeom* geom = itsLoader->GetITSgeom();
2257f27e 224 itsLoader->LoadRecPoints();
0c6af5c9 225 rl->GetEvent(evnumber);
226
7d62fb64 227 AliITSDetTypeRec detTypeRec;
0c6af5c9 228
229 TTree *tR = itsLoader->TreeR();
7d62fb64 230 detTypeRec.SetTreeAddressR(tR);
0c6af5c9 231 TClonesArray *itsRec = 0;
27167524 232 // lc1 and gc1 are local and global coordinates for layer 1
233 Float_t lc1[3]; for(Int_t ii=0; ii<3; ii++) lc1[ii]=0.;
234 Float_t gc1[3]; for(Int_t ii=0; ii<3; ii++) gc1[ii]=0.;
ecc64c3f 235 // lc2 and gc2 are local and global coordinates for layer 2
0c6af5c9 236 Float_t lc2[3]; for(Int_t ii=0; ii<3; ii++) lc2[ii]=0.;
237 Float_t gc2[3]; for(Int_t ii=0; ii<3; ii++) gc2[ii]=0.;
238
7d62fb64 239 itsRec = detTypeRec.RecPoints();
2257f27e 240 TBranch *branch;
00a7cc50 241 branch = tR->GetBranch("ITSRecPoints");
0c6af5c9 242
0c6af5c9 243 Int_t nrpL1 = 0;
244 Int_t nrpL2 = 0;
27167524 245
ecc64c3f 246 // By default fFirstL1=0 and fLastL1=79
0c6af5c9 247 for(Int_t module= fFirstL1; module<=fLastL1;module++){
0c6af5c9 248 branch->GetEvent(module);
249 nrpL1+= itsRec->GetEntries();
7d62fb64 250 detTypeRec.ResetRecPoints();
0c6af5c9 251 }
ecc64c3f 252 //By default fFirstL2=80 and fLastL2=239
0c6af5c9 253 for(Int_t module= fFirstL2; module<=fLastL2;module++){
254 branch->GetEvent(module);
255 nrpL2+= itsRec->GetEntries();
7d62fb64 256 detTypeRec.ResetRecPoints();
0c6af5c9 257 }
0c6af5c9 258 if(nrpL1 == 0 || nrpL2 == 0){
0c6af5c9 259 ResetHistograms();
6fd990e3 260 itsLoader->UnloadRecPoints();
261 fCurrentVertex = new AliESDVertex(0.,5.3,-2);
262 return;
0c6af5c9 263 }
ecc64c3f 264 // Force a coarse bin size of 200 microns if the number of clusters on layer 2
265 // is low
266 if(nrpL2<fPPsetting[0])SetBinWidthCoarse(fPPsetting[1]);
ecc64c3f 267 // By default nbincoarse=(10+10)/0.01=2000
268 Int_t nbincoarse = static_cast<Int_t>((fHighLim-fLowLim)/fStepCoarse);
ecc64c3f 269 if(fZCombc)delete fZCombc;
270 fZCombc = new TH1F("fZCombc","Z",nbincoarse,fLowLim,fLowLim+nbincoarse*fStepCoarse);
7299b7a8 271
27167524 272 /* Test the ffect of mutiple scatternig on error. Negligible
7299b7a8 273 // Multiple scattering
274 Float_t beta=1.,pmed=0.875; //pmed=875 MeV (for tracks with dphi<0.01 rad)
275 Float_t beta2=beta*beta;
276 Float_t p2=pmed*pmed;
277 Float_t rBP=3; //Beam Pipe radius = 3cm
278 Float_t dBP=0.08/35.3; // 800 um of Be
279 Float_t dL1=0.01; //approx. 1% of radiation length
280 Float_t theta2BP=14.1*14.1/(beta2*p2*1e6)*TMath::Abs(dBP);
281 Float_t theta2L1=14.1*14.1/(beta2*p2*1e6)*TMath::Abs(dL1);
282*/
27167524 283 Int_t maxdim=TMath::Min(nrpL1*nrpL2,50000); // temporary; to limit the size in PbPb
f5f6da22 284 static TClonesArray points("AliITSZPoint",maxdim);
7299b7a8 285 Int_t nopoints =0;
27167524 286 for(Int_t modul1= fFirstL1; modul1<=fLastL1;modul1++){ // Loop on modules of layer 1
287 UShort_t ladder=int(modul1/4)+1; // ladders are numbered starting from 1
288 branch->GetEvent(modul1);
289 Int_t nrecp1 = itsRec->GetEntries();
f5f6da22 290 static TClonesArray prpl1("AliITSRecPoint",nrecp1);
291 prpl1.SetOwner();
27167524 292 for(Int_t j=0;j<nrecp1;j++){
293 AliITSRecPoint *recp = (AliITSRecPoint*)itsRec->At(j);
f5f6da22 294 new(prpl1[j])AliITSRecPoint(*recp);
27167524 295 }
296 detTypeRec.ResetRecPoints();
297 for(Int_t j1=0;j1<nrecp1;j1++){
f5f6da22 298 AliITSRecPoint *recp = (AliITSRecPoint*)prpl1.At(j1);
32e63e47 299 /*
27167524 300 lc1[0]=recp->GetDetLocalX();
301 lc1[2]=recp->GetDetLocalZ();
302 geom->LtoG(modul1,lc1,gc1);
303 // Global coordinates of this recpoints
32e63e47 304 */
305 recp->GetGlobalXYZ(gc1);
27167524 306 gc1[0]-=fNominalPos[0]; // Possible beam offset in the bending plane
307 gc1[1]-=fNominalPos[1]; // " "
308 Float_t r1=TMath::Sqrt(gc1[0]*gc1[0]+gc1[1]*gc1[1]);
309 Float_t phi1 = TMath::ATan2(gc1[1],gc1[0]);
310 if(phi1<0)phi1+=2*TMath::Pi();
311 Float_t zc1=gc1[2];
312 Float_t erz1=recp->GetSigmaZ2();
313 for(Int_t ladl2=0 ; ladl2<fLadOnLay2*2+1;ladl2++){
314 for(Int_t k=0;k<4;k++){
315 Int_t ladmod=fLadders[ladder-1]+ladl2;
32e63e47 316 if(ladmod>AliITSgeomTGeo::GetNLadders(2)) ladmod=ladmod-AliITSgeomTGeo::GetNLadders(2);
317 Int_t modul2=AliITSgeomTGeo::GetModuleIndex(2,ladmod,k+1);
27167524 318 branch->GetEvent(modul2);
319 Int_t nrecp2 = itsRec->GetEntries();
320 for(Int_t j2=0;j2<nrecp2;j2++){
321 recp = (AliITSRecPoint*)itsRec->At(j2);
32e63e47 322 /*
27167524 323 lc2[0]=recp->GetDetLocalX();
324 lc2[2]=recp->GetDetLocalZ();
325 geom->LtoG(modul2,lc2,gc2);
32e63e47 326 */
327 recp->GetGlobalXYZ(gc2);
27167524 328 gc2[0]-=fNominalPos[0];
329 gc2[1]-=fNominalPos[1];
330 Float_t r2=TMath::Sqrt(gc2[0]*gc2[0]+gc2[1]*gc2[1]);
331 Float_t phi2 = TMath::ATan2(gc2[1],gc2[0]);
332 if(phi2<0)phi2+=2*TMath::Pi();
333 Float_t zc2=gc2[2];
334 Float_t erz2=recp->GetSigmaZ2();
335
336 Float_t diff = TMath::Abs(phi2-phi1);
337 if(diff>TMath::Pi())diff=2.*TMath::Pi()-diff;
338 if(diff<fDiffPhiMax){
339 // Float_t tgth=(zc2[j]-zc1[i])/(r2-r1); // slope (used for multiple scattering)
340 Float_t zr0=(r2*zc1-r1*zc2)/(r2-r1); //Z @ null radius
341 Float_t ezr0q=(r2*r2*erz1+r1*r1*erz2)/(r2-r1)/(r2-r1); //error on Z @ null radius
342 /*
343 // Multiple scattering
7299b7a8 344 ezr0q+=r1*r1*(1+tgth*tgth)*theta2L1/2; // multiple scattering in layer 1
345 ezr0q+=rBP*rBP*(1+tgth*tgth)*theta2BP/2; // multiple scattering in beam pipe
346 */
f5f6da22 347 if(nopoints<maxdim) new(points[nopoints++])AliITSZPoint(zr0,ezr0q);
27167524 348 fZCombc->Fill(zr0);
349 }
350 }
351 detTypeRec.ResetRecPoints();
352 }
0c6af5c9 353 }
354 }
f5f6da22 355 prpl1.Clear();
0c6af5c9 356 }
7299b7a8 357
f5f6da22 358 points.Sort();
7299b7a8 359
6fd990e3 360 Double_t contents = fZCombc->GetEntries()- fZCombc->GetBinContent(0)-fZCombc->GetBinContent(nbincoarse+1);
361 if(contents<1.){
362 // Warning("FindVertexForCurrentEvent","Insufficient number of rec. points\n");
0c6af5c9 363 ResetHistograms();
6fd990e3 364 itsLoader->UnloadRecPoints();
365 fCurrentVertex = new AliESDVertex(0.,5.3,-1);
f5f6da22 366 points.Clear();
6fd990e3 367 return;
0c6af5c9 368 }
ecc64c3f 369
370 TH1F *hc = fZCombc;
ecc64c3f 371
ecc64c3f 372
7299b7a8 373 if(hc->GetBinContent(hc->GetMaximumBin())<3)hc->Rebin(3);
debb3dde 374 Int_t binmin,binmax;
375 Int_t nPeaks=GetPeakRegion(hc,binmin,binmax);
376 if(nPeaks==2)AliWarning("2 peaks found");
7299b7a8 377 Float_t zm =0.;
378 Float_t ezm =0.;
379 Float_t lim1 = hc->GetBinLowEdge(binmin);
380 Float_t lim2 = hc->GetBinLowEdge(binmax)+hc->GetBinWidth(binmax);
381
382 if(nPeaks ==1 && (lim2-lim1)<fWindowWidth){
383 Float_t c=(lim1+lim2)/2.;
384 lim1=c-fWindowWidth/2.;
385 lim2=c+fWindowWidth/2.;
ecc64c3f 386 }
7299b7a8 387 Int_t niter = 0, ncontr=0;
388 do {
389 // symmetrization
390 if(zm !=0.){
391 Float_t semilarg=TMath::Min((lim2-zm),(zm-lim1));
392 lim1=zm - semilarg;
393 lim2=zm + semilarg;
0c6af5c9 394 }
7299b7a8 395
396 zm=0.;
397 ezm=0.;
398 ncontr=0;
f5f6da22 399 for(Int_t i =0; i<points.GetEntries(); i++){
400 AliITSZPoint* p=(AliITSZPoint*)points.UncheckedAt(i);
7299b7a8 401 if(p->GetZ()>lim1 && p->GetZ()<lim2){
402 Float_t deno = p->GetErrZ();
403 zm+=p->GetZ()/deno;
404 ezm+=1./deno;
405 ncontr++;
ecc64c3f 406 }
407 }
7299b7a8 408 zm/=ezm;
409 ezm=TMath::Sqrt(1./ezm);
410 niter++;
411 } while(niter<10 && TMath::Abs((zm-lim1)-(lim2-zm))>fTolerance);
412 fCurrentVertex = new AliESDVertex(zm,ezm,ncontr);
0c6af5c9 413 fCurrentVertex->SetTitle("vertexer: B");
f5f6da22 414 points.Clear();
0c6af5c9 415 ResetHistograms();
6fd990e3 416 itsLoader->UnloadRecPoints();
417 return;
0c6af5c9 418}
419
420//_____________________________________________________________________
421void AliITSVertexerZ::ResetHistograms(){
422 // delete TH1 data members
423 if(fZCombc)delete fZCombc;
0c6af5c9 424 fZCombc = 0;
0c6af5c9 425}
426
427//______________________________________________________________________
428void AliITSVertexerZ::FindVertices(){
429 // computes the vertices of the events in the range FirstEvent - LastEvent
430 AliRunLoader *rl = AliRunLoader::GetRunLoader();
431 AliITSLoader* itsLoader = (AliITSLoader*) rl->GetLoader("ITSLoader");
432 itsLoader->ReloadRecPoints();
433 for(Int_t i=fFirstEvent;i<=fLastEvent;i++){
6fd990e3 434 // cout<<"Processing event "<<i<<endl;
0c6af5c9 435 rl->GetEvent(i);
436 FindVertexForCurrentEvent(i);
437 if(fCurrentVertex){
438 WriteCurrentVertex();
439 }
0c6af5c9 440 }
441}
442
443//________________________________________________________
444void AliITSVertexerZ::PrintStatus() const {
445 // Print current status
446 cout <<"=======================================================\n";
447 cout <<" First layer first and last modules: "<<fFirstL1<<", ";
448 cout <<fLastL1<<endl;
449 cout <<" Second layer first and last modules: "<<fFirstL2<<", ";
450 cout <<fLastL2<<endl;
451 cout <<" Max Phi difference: "<<fDiffPhiMax<<endl;
452 cout <<"Limits for Z histograms: "<<fLowLim<<"; "<<fHighLim<<endl;
7299b7a8 453 cout <<"Bin sizes for coarse z histos "<<fStepCoarse<<endl;
0c6af5c9 454 cout <<" Current Z "<<fZFound<<"; Z sig "<<fZsig<<endl;
0c6af5c9 455 cout <<"First event to be processed "<<fFirstEvent;
456 cout <<"\n Last event to be processed "<<fLastEvent<<endl;
ecc64c3f 457 if(fZCombc){
458 cout<<"fZCombc exists - entries="<<fZCombc->GetEntries()<<endl;
459 }
460 else{
461 cout<<"fZCombc does not exist\n";
462 }
0c6af5c9 463
464 cout <<"=======================================================\n";
465}
466