Added vertexer AliITSVertexerZD - It retrieves only the Z coordinate with SDD instead...
[u/mrichter/AliRoot.git] / ITS / AliITSVertexerZD.cxx
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f4f84117 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 **************************************************************************/
15#include "AliITSVertexerZD.h"
16#include<TBranch.h>
17#include<TClonesArray.h>
18#include<TH1.h>
19#include <TString.h>
20#include<TTree.h>
21#include "AliESDVertex.h"
22#include "AliITSgeomTGeo.h"
23#include "AliITSRecPoint.h"
24#include "AliITSRecPointContainer.h"
25#include "AliITSZPoint.h"
26
27/////////////////////////////////////////////////////////////////
28// this class implements a fast method to determine
29// the Z coordinate of the primary vertex
30// it is based on the 2 layers of SDD detectors
31// wider Z acceptance w.r.t. AliITSVertexerZ
32// lower resolution
33// origin masera@to.infn.it
34////////////////////////////////////////////////////////////////
35
36using std::endl;
37using std::cout;
38ClassImp(AliITSVertexerZD)
39
40
41
42//______________________________________________________________________
43AliITSVertexerZD::AliITSVertexerZD():AliITSVertexer(),
44fFirstL1(0),
45fLastL1(0),
46fFirstL2(0),
47fLastL2(0),
48fDiffPhiMax(0),
49fZFound(0),
50fZsig(0.),
51fZCombc(0),
52fLowLim(0.),
53fHighLim(0.),
54fStepCoarse(0),
55fTolerance(0.),
56fMaxIter(0),
57fWindowWidth(0),
58fSearchForPileup(kTRUE)
59{
60 // Default constructor
61 SetDiffPhiMax();
62 SetFirstLayerModules();
63 SetSecondLayerModules();
64 SetLowLimit();
65 SetHighLimit();
66 SetBinWidthCoarse();
67 SetTolerance();
68 SetPPsetting();
69 ConfigIterations();
70 SetWindowWidth();
71}
72
73//______________________________________________________________________
74AliITSVertexerZD::AliITSVertexerZD(Float_t x0, Float_t y0):AliITSVertexer(),
75fFirstL1(0),
76fLastL1(0),
77fFirstL2(0),
78fLastL2(0),
79fDiffPhiMax(0),
80fZFound(0),
81fZsig(0.),
82fZCombc(0),
83fLowLim(0.),
84fHighLim(0.),
85fStepCoarse(0),
86fTolerance(0.),
87fMaxIter(0),
88fWindowWidth(0),
89fSearchForPileup(kTRUE)
90{
91 // Standard Constructor
92 SetDiffPhiMax();
93 SetFirstLayerModules();
94 SetSecondLayerModules();
95 SetLowLimit();
96 SetHighLimit();
97 SetBinWidthCoarse();
98 SetTolerance();
99 SetPPsetting();
100 ConfigIterations();
101 SetWindowWidth();
102 SetVtxStart((Double_t)x0,(Double_t)y0,0.);
103
104}
105
106//______________________________________________________________________
107AliITSVertexerZD::~AliITSVertexerZD() {
108 // Destructor
109 delete fZCombc;
110}
111
112//______________________________________________________________________
113void AliITSVertexerZD::ConfigIterations(Int_t noiter,Float_t *ptr){
114 // configure the iterative procedure to gain efficiency for
115 // pp events with very low multiplicity
116 Float_t defaults[5]={0.02,0.05,0.1,0.2,0.3};
117 fMaxIter=noiter;
118 if(noiter>5){
119 Error("ConfigIterations","Maximum number of iterations is 5\n");
120 fMaxIter=5;
121 }
122 for(Int_t j=0;j<5;j++)fPhiDiffIter[j]=defaults[j];
123 if(ptr)for(Int_t j=0;j<fMaxIter;j++)fPhiDiffIter[j]=ptr[j];
124}
125
126//______________________________________________________________________
127Int_t AliITSVertexerZD::GetPeakRegion(TH1F*h, Int_t &binmin, Int_t &binmax){
128 // Finds a region around a peak in the Z histogram
129 // Case of 2 peaks is treated
130 Int_t imax=h->GetNbinsX();
131 Float_t maxval=0;
132 Int_t bi1=h->GetMaximumBin();
133 Int_t bi2=0;
134 for(Int_t i=imax;i>=1;i--){
135 if(h->GetBinContent(i)>maxval){
136 maxval=h->GetBinContent(i);
137 bi2=i;
138 }
139 }
140 Int_t npeaks=0;
141
142 if(bi1==bi2){
143 binmin=bi1-3;
144 binmax=bi1+3;
145 npeaks=1;
146 }else{
147 TH1F *copy = new TH1F(*h);
148 copy->SetBinContent(bi1,0.);
149 copy->SetBinContent(bi2,0.);
150 Int_t l1=TMath::Max(bi1-3,1);
151 Int_t l2=TMath::Min(bi1+3,h->GetNbinsX());
152 Float_t cont1=copy->Integral(l1,l2);
153 Int_t ll1=TMath::Max(bi2-3,1);
154 Int_t ll2=TMath::Min(bi2+3,h->GetNbinsX());
155 Float_t cont2=copy->Integral(ll1,ll2);
156 if(cont1>cont2){
157 binmin=l1;
158 binmax=l2;
159 npeaks=1;
160 }
161 if(cont2>cont1){
162 binmin=ll1;
163 binmax=ll2;
164 npeaks=1;
165 }
166 if(cont1==cont2){
167 binmin=l1;
168 binmax=ll2;
169 if(bi2-bi1==1) npeaks=1;
170 else npeaks=2;
171 }
172 delete copy;
173 }
174 return npeaks;
175}
176//______________________________________________________________________
177AliESDVertex* AliITSVertexerZD::FindVertexForCurrentEvent(TTree *itsClusterTree){
178 // Defines the AliESDVertex for the current event
179 VertexZFinder(itsClusterTree);
180 Int_t ntrackl=0;
181 for(Int_t iteraz=0;iteraz<fMaxIter;iteraz++){
182 if(fCurrentVertex) ntrackl=fCurrentVertex->GetNContributors();
183 if(!fCurrentVertex || ntrackl==0 || ntrackl==-1){
184 Float_t diffPhiMaxOrig=fDiffPhiMax;
185 fDiffPhiMax=GetPhiMaxIter(iteraz);
186 VertexZFinder(itsClusterTree);
187 fDiffPhiMax=diffPhiMaxOrig;
188 }
189 }
190 if(fComputeMultiplicity) FindMultiplicity(itsClusterTree);
191 return fCurrentVertex;
192}
193
194//______________________________________________________________________
195void AliITSVertexerZD::VertexZFinder(TTree *itsClusterTree){
196 // Defines the AliESDVertex for the current event
197 //debug printf("=========== VertexZFinder has been called \n");
198 fCurrentVertex = 0;
199 Double_t startPos[3]={GetNominalPos()[0],GetNominalPos()[1],GetNominalPos()[2]};
200 Double_t startCov[6]={GetNominalCov()[0],GetNominalCov()[1],GetNominalCov()[2],
201 GetNominalCov()[3],GetNominalCov()[4],GetNominalCov()[5]};
202 ResetVertex();
203 TClonesArray *itsRec = 0;
204 // lc1 and gc1 are local and global coordinates for layer 1
205 Float_t gc1[3]={0.,0.,0.}; // ; for(Int_t ii=0; ii<3; ii++) gc1[ii]=0.;
206 // lc2 and gc2 are local and global coordinates for layer 2
207 Float_t gc2[3]={0.,0.,0.}; //; for(Int_t ii=0; ii<3; ii++) gc2[ii]=0.;
208 AliITSRecPointContainer* rpcont=AliITSRecPointContainer::Instance();
209 rpcont->FetchClusters(0,itsClusterTree);
210 if(!rpcont->IsSDDActive()){
211 AliWarning("Null pointer for RecPoints branch, vertex not calculated");
212 ResetHistograms();
213 fCurrentVertex = new AliESDVertex(startPos,startCov,99999.,-2);
214 return;
215 }
216
217 Int_t nrpL1 = 0;
218 Int_t nrpL2 = 0;
219 nrpL1=rpcont->GetNClustersInLayerFast(3);
220 nrpL2=rpcont->GetNClustersInLayerFast(4);
221
222 if(nrpL1 == 0 || nrpL2 == 0){
223 AliDebug(1,Form("No RecPoints in at least one SDD layer (%d %d)",nrpL1,nrpL2));
224 ResetHistograms();
225 fCurrentVertex = new AliESDVertex(startPos,startCov,99999.,-2);
226 return;
227 }
228 // Force a coarse bin size of 200 microns if the number of clusters on layer 2
229 // is low
230 if(nrpL2<fPPsetting[0])SetBinWidthCoarse(fPPsetting[1]);
231 // By default nbincoarse=(10+10)/0.01=2000
232 Int_t nbincoarse = static_cast<Int_t>((fHighLim-fLowLim)/fStepCoarse);
233 if(fZCombc)delete fZCombc;
234 fZCombc = new TH1F("fZCombc","Z",nbincoarse,fLowLim,fLowLim+nbincoarse*fStepCoarse);
235
236
237 Int_t nEntriesMod[260];
238 TClonesArray* recpArr[260];
239 for(Int_t modul=0; modul<260; ++modul) {
240 recpArr[modul]=rpcont->UncheckedGetClusters(modul+240);
241 nEntriesMod[modul]=recpArr[modul]->GetEntriesFast();
242 }
243
244 Int_t maxdim=TMath::Min(nrpL1*nrpL2,50000); // temporary; to limit the size in PbPb
245 static TClonesArray points("AliITSZPoint",maxdim);
246 Int_t nopoints =0;
247 for(Int_t modul1= fFirstL1; modul1<=fLastL1;modul1++){ // Loop on modules of layer 1
248 // UShort_t ladder=int(modul1/6)+1; // ladders are numbered starting from 1
249 TClonesArray *prpl1=recpArr[modul1-240]; //rpcont->UncheckedGetClusters(modul1);
250 Int_t nrecp1 = nEntriesMod[modul1-240]; //prpl1->GetEntries();
251 for(Int_t j1=0;j1<nrecp1;j1++){
252 AliITSRecPoint *recp1 = (AliITSRecPoint*)prpl1->At(j1);
253 recp1->GetGlobalXYZ(gc1);
254 gc1[0]-=GetNominalPos()[0]; // Possible beam offset in the bending plane
255 gc1[1]-=GetNominalPos()[1]; // " "
256 Float_t phi1 = TMath::ATan2(gc1[1],gc1[0]);
257 if(phi1<0)phi1+=TMath::TwoPi();
258 for(Int_t modul2=fFirstL2;modul2<=fLastL2;modul2++){
259 itsRec=recpArr[modul2-240]; // rpcont->UncheckedGetClusters(modul2);
260 Int_t nrecp2 = nEntriesMod[modul2-240]; // itsRec->GetEntries();
261 for(Int_t j2=0;j2<nrecp2;j2++){
262 AliITSRecPoint *recp2 = (AliITSRecPoint*)itsRec->At(j2);
263 recp2->GetGlobalXYZ(gc2);
264 gc2[0]-=GetNominalPos()[0];
265 gc2[1]-=GetNominalPos()[1];
266 Float_t phi2 = TMath::ATan2(gc2[1],gc2[0]);
267 if(phi2<0)phi2+=TMath::TwoPi();
268
269 Float_t diff = TMath::Abs(phi2-phi1);
270 if(diff>TMath::Pi())diff=TMath::TwoPi()-diff;
271 if(diff<fDiffPhiMax){
272 //================= DEBUG
273 /* Bool_t goodMatch = kFALSE;
274 for(Int_t kl1=0;kl1<3;kl1++){
275 Int_t label1=recp1->GetLabel(kl1);
276 if(label1>0){
277 for(Int_t kl2=0;kl2<3;kl2++){
278 if(label1 == recp2->GetLabel(kl2))goodMatch = kTRUE;
279 }
280 }
281 }
282 */
283 //================= END DEBUG
284 Float_t r1=TMath::Sqrt(gc1[0]*gc1[0]+gc1[1]*gc1[1]);
285 Float_t zc1=gc1[2];
286 Float_t erz1=recp1->GetSigmaZ2();
287 Float_t r2=TMath::Sqrt(gc2[0]*gc2[0]+gc2[1]*gc2[1]);
288 //debug printf("r1 =%f ; r2=%f \n",r1,r2);
289 Float_t zc2=gc2[2];
290 Float_t erz2=recp2->GetSigmaZ2();
291 // Float_t tgth=(zc2[j]-zc1[i])/(r2-r1); // slope (used for multiple scattering)
292 Float_t zr0=(r2*zc1-r1*zc2)/(r2-r1); //Z @ null radius
293 Float_t ezr0q=(r2*r2*erz1+r1*r1*erz2)/((r2-r1)*(r2-r1)); //error on Z @ null radius
294 /*
295 if(goodMatch)printf("Good tracklet: z0=%f, ezr0q=%f\n",zr0,ezr0q);
296 else printf("Fake tracklet: z0=%f, ezr0q=%f\n",zr0,ezr0q);
297 if(goodMatch){
298 printf("Labels: ");
299 for(Int_t kkk=0;kkk<3;kkk++)printf("%d ",recp1->GetLabel(kkk));
300 for(Int_t kkk=0;kkk<3;kkk++)printf("%d ",recp1->GetLabel(kkk));
301 }
302 printf("\n");
303 if(nopoints<maxdim) new(points[nopoints++])AliITSZPoint(zr0,ezr0q,goodMatch);
304 */
305 if(nopoints<maxdim) new(points[nopoints++])AliITSZPoint(zr0,ezr0q);
306 fZCombc->Fill(zr0);
307 }
308 }
309 }
310 }
311 }
312 points.Sort();
313
314 Double_t contents = fZCombc->GetEntries()- fZCombc->GetBinContent(0)-fZCombc->GetBinContent(nbincoarse+1);
315 if(contents<1.){
316 // Warning("FindVertexForCurrentEvent","Insufficient number of rec. points\n");
317 ResetHistograms();
318 fCurrentVertex = new AliESDVertex(startPos,startCov,99999.,-1);
319 points.Clear();
320 return;
321 }
322
323 TH1F *hc = fZCombc;
324
325
326 if(hc->GetBinContent(hc->GetMaximumBin())<3)hc->Rebin(4);
327 Int_t binmin,binmax;
328 Int_t nPeaks=GetPeakRegion(hc,binmin,binmax);
329 if(nPeaks==2)AliDebug(2,"2 peaks found");
330 Float_t zm =0.;
331 Float_t ezm =0.;
332 Float_t lim1 = hc->GetBinLowEdge(binmin);
333 Float_t lim2 = hc->GetBinLowEdge(binmax)+hc->GetBinWidth(binmax);
334 Float_t widthSR=lim2-lim1;
335
336 if(nPeaks ==1 && (lim2-lim1)<fWindowWidth){
337 Float_t c=(lim1+lim2)/2.;
338 lim1=c-fWindowWidth/2.;
339 lim2=c+fWindowWidth/2.;
340 }
341 Int_t niter = 0, ncontr=0;
342 do {
343 // symmetrization
344 if(zm !=0.){
345 Float_t semilarg=TMath::Min((lim2-zm),(zm-lim1));
346 lim1=zm - semilarg;
347 lim2=zm + semilarg;
348 }
349
350 zm=0.;
351 ezm=0.;
352 ncontr=0;
353 for(Int_t i =0; i<points.GetEntriesFast(); i++){
354 AliITSZPoint* p=(AliITSZPoint*)points.UncheckedAt(i);
355 if(p->GetZ()>lim1 && p->GetZ()<lim2){
356 Float_t deno = p->GetErrZ();
357 zm+=p->GetZ()/deno;
358 ezm+=1./deno;
359 ncontr++;
360 }
361 }
362 if(ezm>0) {
363 zm/=ezm;
364 ezm=TMath::Sqrt(1./ezm);
365 }
366 niter++;
367 } while(niter<10 && TMath::Abs((zm-lim1)-(lim2-zm))>fTolerance);
368 if(nPeaks==2) ezm=widthSR;
369 Double_t position[3]={GetNominalPos()[0],GetNominalPos()[1],zm};
370 Double_t covmatrix[6]={GetNominalCov()[0],0.,GetNominalCov()[2],0.,0.,ezm};
371 fCurrentVertex = new AliESDVertex(position,covmatrix,99999.,ncontr);
372 fCurrentVertex->SetTitle("vertexer: Z");
373 fCurrentVertex->SetDispersion(fDiffPhiMax);
374 fNoVertices=1;
375 points.Clear();
376 if(fSearchForPileup && ncontr>fMinTrackletsForPilup){
377 Float_t secPeakPos;
378 Int_t ncontr2=FindSecondPeak(fZCombc,binmin,binmax,secPeakPos);
379 if(ncontr2>=fMinTrackletsForPilup){
380 fIsPileup=kTRUE;
381 fNoVertices=2;
382 fZpuv=secPeakPos;
383 fNTrpuv=ncontr2;
384 AliESDVertex secondVert(secPeakPos,0.1,ncontr2);
385 fVertArray = new AliESDVertex[2];
386 fVertArray[0]=(*fCurrentVertex);
387 fVertArray[1]=secondVert;
388 }
389 }
390 if(fNoVertices==1){
391 fVertArray = new AliESDVertex[1];
392 fVertArray[0]=(*fCurrentVertex);
393 }
394
395 ResetHistograms();
396 return;
397}
398
399//_____________________________________________________________________
400Int_t AliITSVertexerZD::FindSecondPeak(TH1F* h, Int_t binmin,Int_t binmax, Float_t& secPeakPos){
401 // Resets bin contents between binmin and binmax and then search
402 // for a second peak position
403 for(Int_t i=binmin-1;i<=binmax+1;i++){
404 h->SetBinContent(i,0.);
405 }
406 Int_t secPeakBin=h->GetMaximumBin();
407 secPeakPos=h->GetBinCenter(secPeakBin);
408 Int_t secPeakCont=(Int_t)h->GetBinContent(secPeakBin);
409 secPeakCont+=(Int_t)h->GetBinContent(secPeakBin-1);
410 secPeakCont+=(Int_t)h->GetBinContent(secPeakBin+1);
411 secPeakCont+=(Int_t)h->GetBinContent(secPeakBin-2);
412 secPeakCont+=(Int_t)h->GetBinContent(secPeakBin+2);
413 return secPeakCont;
414}
415
416//_____________________________________________________________________
417void AliITSVertexerZD::ResetHistograms(){
418 // delete TH1 data members
419 if(fZCombc)delete fZCombc;
420 fZCombc = 0;
421}
422
423//________________________________________________________
424void AliITSVertexerZD::PrintStatus() const {
425 // Print current status
426 cout <<"=======================================================\n";
427 cout <<" First layer first and last modules: "<<fFirstL1<<", ";
428 cout <<fLastL1<<endl;
429 cout <<" Second layer first and last modules: "<<fFirstL2<<", ";
430 cout <<fLastL2<<endl;
431 cout <<" Max Phi difference: "<<fDiffPhiMax<<endl;
432 cout <<"Limits for Z histograms: "<<fLowLim<<"; "<<fHighLim<<endl;
433 cout <<"Bin sizes for coarse z histos "<<fStepCoarse<<endl;
434 cout <<" Current Z "<<fZFound<<"; Z sig "<<fZsig<<endl;
435 if(fZCombc){
436 cout<<"fZCombc exists - entries="<<fZCombc->GetEntries()<<endl;
437 }
438 else{
439 cout<<"fZCombc does not exist\n";
440 }
441
442 cout <<"=======================================================\n";
443}
444