MIP cluster size added (compacted word) and infos re-arranganged in HMPID
[u/mrichter/AliRoot.git] / HMPID / AliHMPIDRecon.cxx
CommitLineData
d3da6dc4 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
16//////////////////////////////////////////////////////////////////////////
17// //
18// AliHMPIDRecon //
19// //
20// HMPID class to perfom pattern recognition based on Hough transfrom //
21// for single chamber //
22//////////////////////////////////////////////////////////////////////////
23
a591e55f 24#include "AliHMPIDRecon.h" //class header
d3da6dc4 25#include "AliHMPIDCluster.h" //CkovAngle()
a591e55f 26#include <TRotation.h> //TracePhot()
27#include <TH1D.h> //HoughResponse()
28#include <TClonesArray.h> //CkovAngle()
29#include <AliESDtrack.h> //CkovAngle()
d3da6dc4 30
d3da6dc4 31//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
c61a7285 32AliHMPIDRecon::AliHMPIDRecon():
33 TTask("RichRec","RichPat"),
34 fPhotCnt(-1),
cdf0e3d9 35 fPhotFlag(0x0),
36 fPhotCkov(0x0),
37 fPhotPhi(0x0),
38 fPhotWei(0x0),
c61a7285 39 fCkovSigma2(0),
40 fIsWEIGHT(kFALSE),
41 fDTheta(0.001),
42 fWindowWidth(0.045),
43 fRingArea(0),
44 fRingAcc(0),
45 fTrkDir(0,0,1), // Just for test
46 fTrkPos(30,40), // Just for test
cdf0e3d9 47 fMipPos(0,0),
48 fPc(0,0),
c61a7285 49 fParam(AliHMPIDParam::Instance())
d3da6dc4 50{
ffb1ac19 51//..
52//init of data members
53//..
54
ffb1ac19 55 fParam->SetRefIdx(fParam->MeanIdxRad()); // initialization of ref index to a default one
56}
57//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
58void AliHMPIDRecon::InitVars(Int_t n)
59{
60//..
61//Init some variables
62//..
63 if(n<0) return;
64 fPhotFlag = new Int_t[n];
65 fPhotCkov = new Double_t[n];
66 fPhotPhi = new Double_t[n];
67 fPhotWei = new Double_t[n];
68//
69}
70//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
606697a8 71void AliHMPIDRecon::DeleteVars()const
ffb1ac19 72{
73//..
74//Delete variables
75//..
76 delete fPhotFlag;
77 delete fPhotCkov;
78 delete fPhotPhi;
79 delete fPhotWei;
d3da6dc4 80}
81//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
afe12692 82void AliHMPIDRecon::CkovAngle(AliESDtrack *pTrk,TClonesArray *pCluLst,Double_t nmean,Double_t qthre)
d3da6dc4 83{
84// Pattern recognition method based on Hough transform
59280a5a 85// Arguments: pTrk - track for which Ckov angle is to be found
86// pCluLst - list of clusters for this chamber
87// Returns: - track ckov angle, [rad],
a591e55f 88
39cd22e6 89
90 const Int_t nMinPhotAcc = 3; // Minimum number of photons required to perform the pattern recognition
91
92
ffb1ac19 93 Int_t nClusTot = pCluLst->GetEntries();
94 if(nClusTot>fParam->MultCut()) fIsWEIGHT = kTRUE; // offset to take into account bkg in reconstruction
95 else fIsWEIGHT = kFALSE;
d3da6dc4 96
ffb1ac19 97 InitVars(nClusTot);
98
611e810d 99 Float_t xRa,yRa,th,ph;
a591e55f 100 pTrk->GetHMPIDtrk(xRa,yRa,th,ph); //initialize this track: th and ph angles at middle of RAD
a591e55f 101 SetTrack(xRa,yRa,th,ph);
611e810d 102
ffb1ac19 103 fParam->SetRefIdx(nmean);
d3da6dc4 104
43d3333b 105 Float_t dMin=999,mipX=-1,mipY=-1;Int_t chId=-1,mipId=-1,mipQ=-1;
106 Int_t sizeClu = -1;
107 fPhotCnt=0;
d3da6dc4 108 for (Int_t iClu=0; iClu<pCluLst->GetEntriesFast();iClu++){//clusters loop
109 AliHMPIDCluster *pClu=(AliHMPIDCluster*)pCluLst->UncheckedAt(iClu); //get pointer to current cluster
59280a5a 110 chId=pClu->Ch();
afe12692 111 if(pClu->Q()>qthre){ //charge compartible with MIP clusters
a591e55f 112 Float_t dX=fPc.X()-pClu->X(),dY=fPc.Y()-pClu->Y(),d =TMath::Sqrt(dX*dX+dY*dY); //distance between current cluster and intersection point
43d3333b 113 if( d < dMin) {mipId=iClu; dMin=d;mipX=pClu->X();
114 mipY=pClu->Y();mipQ=(Int_t)pClu->Q();sizeClu=pClu->Size();} //current cluster is closer, overwrite data for min cluster
a591e55f 115 }else{ //charge compatible with photon cluster
116 Double_t thetaCer,phiCer;
117 if(FindPhotCkov(pClu->X(),pClu->Y(),thetaCer,phiCer)){ //find ckov angle for this photon candidate
118 fPhotCkov[fPhotCnt]=thetaCer; //actual theta Cerenkov (in TRS)
b4ad85e9 119 fPhotPhi [fPhotCnt]=phiCer; //actual phi Cerenkov (in TRS): -pi to come back to "unusual" ref system (X,Y,-Z)
28500fe1 120 //PH Printf("photon n. %i reconstructed theta = %f",fPhotCnt,fPhotCkov[fPhotCnt]);
a591e55f 121 fPhotCnt++; //increment counter of photon candidates
122 }
59280a5a 123 }
d3da6dc4 124 }//clusters loop
43d3333b 125
126 pTrk->SetHMPIDmip(mipX,mipY,mipQ,fPhotCnt); //store mip info in any case
127
39cd22e6 128 if(fPhotCnt<=nMinPhotAcc) { //no reconstruction with <=3 photon candidates
129 pTrk->SetHMPIDsignal(kNoPhotAccept); //set the appropriate flag
43d3333b 130 pTrk->SetHMPIDcluIdx(chId,mipId+1000*sizeClu); //set index of cluster
39cd22e6 131 return;
132 }
133
f1970e74 134 if(mipId==-1) {
135 pTrk->SetHMPIDcluIdx(chId,9999); //set index of cluster
136 pTrk->SetHMPIDsignal(kMipQdcCut);
137 return;
138 } //no clusters with QDC more the threshold at all
43d3333b 139 pTrk->SetHMPIDcluIdx(chId,mipId+1000*sizeClu); //set chamber, index of cluster + cluster size
f1970e74 140 if(dMin>fParam->DistCut()) {pTrk->SetHMPIDsignal(kMipDistCut); return;} //closest cluster with enough charge is still too far from intersection
141
142 fMipPos.Set(mipX,mipY);
143
39cd22e6 144
145//PATTERN RECOGNITION STARTED:
146
2d1a9b21 147 Int_t iNrec=FlagPhot(HoughResponse()); //flag photons according to individual theta ckov with respect to most probable
148 pTrk->SetHMPIDmip(mipX,mipY,mipQ,iNrec); //store mip info
59280a5a 149
2d1a9b21 150 if(iNrec<1){
151 pTrk->SetHMPIDsignal(kNoPhotAccept); //no photon candidates are accepted
f1970e74 152 return;
76fd1a96 153 }
f1970e74 154 Double_t thetaC = FindRingCkov(pCluLst->GetEntries()); //find the best reconstructed theta Cherenkov
2d1a9b21 155// FindRingGeom(thetaC,2);
f1970e74 156 pTrk->SetHMPIDsignal(thetaC); //store theta Cherenkov
157 pTrk->SetHMPIDchi2(fCkovSigma2); //store errors squared
d3da6dc4 158
ffb1ac19 159 DeleteVars();
43400d2d 160}//CkovAngle()
d3da6dc4 161//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
a591e55f 162Bool_t AliHMPIDRecon::FindPhotCkov(Double_t cluX,Double_t cluY,Double_t &thetaCer,Double_t &phiCer)
d3da6dc4 163{
164// Finds Cerenkov angle for this photon candidate
165// Arguments: cluX,cluY - position of cadidate's cluster
a591e55f 166// Returns: Cerenkov angle
d3da6dc4 167
a591e55f 168 TVector3 dirCkov;
169
ffb1ac19 170 Double_t zRad= -0.5*fParam->RadThick()-0.5*fParam->WinThick(); //z position of middle of RAD
67a1c24c 171 TVector3 rad(fTrkPos.X(),fTrkPos.Y(),zRad); //impact point at middle of RAD
ffb1ac19 172 TVector3 pc(cluX,cluY,0.5*fParam->WinThick()+fParam->GapIdx()); //mip at PC
a591e55f 173 Double_t cluR = TMath::Sqrt((cluX-fTrkPos.X())*(cluX-fTrkPos.X())+
174 (cluY-fTrkPos.Y())*(cluY-fTrkPos.Y()));//ref. distance impact RAD-CLUSTER
67a1c24c 175 Double_t phi=(pc-rad).Phi(); //phi of photon
a591e55f 176
b4ad85e9 177 Double_t ckov1=0;
67a1c24c 178 Double_t ckov2=0.75+fTrkDir.Theta(); //start to find theta cerenkov in DRS
b4ad85e9 179 const Double_t kTol=0.01;
d3da6dc4 180 Int_t iIterCnt = 0;
181 while(1){
a591e55f 182 if(iIterCnt>=50) return kFALSE;
d3da6dc4 183 Double_t ckov=0.5*(ckov1+ckov2);
67a1c24c 184 dirCkov.SetMagThetaPhi(1,ckov,phi);
a591e55f 185 TVector2 posC=TraceForward(dirCkov); //trace photon with actual angles
186 Double_t dist=cluR-(posC-fTrkPos).Mod(); //get distance between trial point and cluster position
187 if(posC.X()==-999) dist = - 999; //total reflection problem
188 iIterCnt++; //counter step
b4ad85e9 189 if (dist> kTol) ckov1=ckov; //cluster @ larger ckov
d3da6dc4 190 else if(dist<-kTol) ckov2=ckov; //cluster @ smaller ckov
a591e55f 191 else{ //precision achived: ckov in DRS found
192 dirCkov.SetMagThetaPhi(1,ckov,phi); //
2d1a9b21 193 Lors2Trs(dirCkov,thetaCer,phiCer); //find ckov (in TRS:the effective Cherenkov angle!)
a591e55f 194 return kTRUE;
195 }
d3da6dc4 196 }
197}//FindPhotTheta()
198//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
a591e55f 199TVector2 AliHMPIDRecon::TraceForward(TVector3 dirCkov)const
d3da6dc4 200{
a591e55f 201 //Trace forward a photon from (x,y) up to PC
202 // Arguments: dirCkov photon vector in LORS
203 // Returns: pos of traced photon at PC
ffb1ac19 204
a591e55f 205 TVector2 pos(-999,-999);
67a1c24c 206 Double_t thetaCer = dirCkov.Theta();
ffb1ac19 207 if(thetaCer > TMath::ASin(1./fParam->GetRefIdx())) return pos; //total refraction on WIN-GAP boundary
208 Double_t zRad= -0.5*fParam->RadThick()-0.5*fParam->WinThick(); //z position of middle of RAD
209 TVector3 posCkov(fTrkPos.X(),fTrkPos.Y(),zRad); //RAD: photon position is track position @ middle of RAD
210 Propagate(dirCkov,posCkov, -0.5*fParam->WinThick()); //go to RAD-WIN boundary
211 Refract (dirCkov, fParam->GetRefIdx(),fParam->WinIdx()); //RAD-WIN refraction
212 Propagate(dirCkov,posCkov, 0.5*fParam->WinThick()); //go to WIN-GAP boundary
213 Refract (dirCkov, fParam->WinIdx(),fParam->GapIdx()); //WIN-GAP refraction
214 Propagate(dirCkov,posCkov,0.5*fParam->WinThick()+fParam->GapThick()); //go to PC
a591e55f 215 pos.Set(posCkov.X(),posCkov.Y());
216 return pos;
217}//TraceForward()
218//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
2d1a9b21 219void AliHMPIDRecon::Lors2Trs(TVector3 dirCkov,Double_t &thetaCer,Double_t &phiCer)const
a591e55f 220{
221 //Theta Cerenkov reconstruction
2d1a9b21 222 // Arguments: dirCkov photon vector in LORS
223 // Returns: thetaCer of photon in TRS
224 // phiCer of photon in TRS
a591e55f 225// TVector3 dirTrk;
226// dirTrk.SetMagThetaPhi(1,fTrkDir.Theta(),fTrkDir.Phi());
227// Double_t thetaCer = TMath::ACos(dirCkov*dirTrk);
2d1a9b21 228 TRotation mtheta; mtheta.RotateY(-fTrkDir.Theta());
229 TRotation mphi; mphi.RotateZ(-fTrkDir.Phi());
a591e55f 230 TRotation mrot=mtheta*mphi;
231 TVector3 dirCkovTRS;
232 dirCkovTRS=mrot*dirCkov;
233 phiCer = dirCkovTRS.Phi(); //actual value of the phi of the photon
234 thetaCer= dirCkovTRS.Theta(); //actual value of thetaCerenkov of the photon
d3da6dc4 235}
236//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
2d1a9b21 237void AliHMPIDRecon::Trs2Lors(TVector3 dirCkov,Double_t &thetaCer,Double_t &phiCer)const
238{
239 //Theta Cerenkov reconstruction
240 // Arguments: dirCkov photon vector in TRS
241 // Returns: thetaCer of photon in LORS
242 // phiCer of photon in LORS
243 TRotation mtheta; mtheta.RotateY(fTrkDir.Theta());
244 TRotation mphi; mphi.RotateZ(fTrkDir.Phi());
245 TRotation mrot=mphi*mtheta;
246 TVector3 dirCkovLORS;
247 dirCkovLORS=mrot*dirCkov;
248 phiCer = dirCkovLORS.Phi(); //actual value of the phi of the photon
249 thetaCer= dirCkovLORS.Theta(); //actual value of thetaCerenkov of the photon
250}
251//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
252void AliHMPIDRecon::FindRingGeom(Double_t ckovAng,Int_t level)
d3da6dc4 253{
4598109f 254// Find area covered in the PC acceptance
2d1a9b21 255// Arguments: ckovAng - cerenkov angle
256// level - precision in finding area and portion of ring accepted (multiple of 50)
d3da6dc4 257// Returns: area of the ring in cm^2 for given theta ckov
258
2d1a9b21 259 Int_t kN=50*level;
260 Int_t nPoints = 0;
afe12692 261 Double_t area=0;
2d1a9b21 262
4598109f 263 Bool_t first=kFALSE;
2d1a9b21 264 TVector2 pos1;
265
afe12692 266 for(Int_t i=0;i<kN;i++){
4598109f 267 if(!first) {
2d1a9b21 268 pos1=TracePhot(ckovAng,Double_t(TMath::TwoPi()*(i+1)/kN)); //find a good trace for the first photon
4598109f 269 if(pos1.X()==-999) continue; //no area: open ring
2d1a9b21 270 if(!fParam->IsInside(pos1.X(),pos1.Y(),0)) {
271 pos1 = IntWithEdge(fMipPos,pos1); // find the very first intersection...
272 } else {
273 if(!AliHMPIDParam::IsInDead(pos1.X(),pos1.Y())) nPoints++; //photon is accepted if not in dead zone
274 }
4598109f 275 first=kTRUE;
276 continue;
277 }
278 TVector2 pos2=TracePhot(ckovAng,Double_t(TMath::TwoPi()*(i+1)/kN)); //trace the next photon
279 if(pos2.X()==-999) continue; //no area: open ring
ffb1ac19 280 if(!fParam->IsInside(pos2.X(),pos2.Y(),0)) {
4598109f 281 pos2 = IntWithEdge(fMipPos,pos2);
2d1a9b21 282 } else {
283 if(!AliHMPIDParam::IsInDead(pos2.X(),pos2.Y())) nPoints++; //photon is accepted if not in dead zone
4598109f 284 }
285 area+=TMath::Abs((pos1-fMipPos).X()*(pos2-fMipPos).Y()-(pos1-fMipPos).Y()*(pos2-fMipPos).X()); //add area of the triangle...
286 pos1 = pos2;
d3da6dc4 287 }
2d1a9b21 288//--- find area and length of the ring;
289 fRingAcc = (Double_t)nPoints/(Double_t)kN;
7fc88c5e 290 area*=0.5;
2d1a9b21 291 fRingArea = area;
292}//FindRingGeom()
d3da6dc4 293//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
4598109f 294TVector2 AliHMPIDRecon::IntWithEdge(TVector2 p1,TVector2 p2)const
295{
296// It finds the intersection of the line for 2 points traced as photons
297// and the edge of a given PC
298// Arguments: 2 points obtained tracing the photons
299// Returns: intersection point with detector (PC) edges
300
4598109f 301 Double_t xmin = (p1.X()<p2.X())? p1.X():p2.X();
302 Double_t xmax = (p1.X()<p2.X())? p2.X():p1.X();
303 Double_t ymin = (p1.Y()<p2.Y())? p1.Y():p2.Y();
304 Double_t ymax = (p1.Y()<p2.Y())? p2.Y():p1.Y();
305
306 Double_t m = TMath::Tan((p2-p1).Phi());
307 TVector2 pint;
308 //intersection with low X
309 pint.Set((Double_t)(p1.X() + (0-p1.Y())/m),0.);
ffb1ac19 310 if(pint.X()>=0 && pint.X()<=fParam->SizeAllX() &&
4598109f 311 pint.X()>=xmin && pint.X()<=xmax &&
312 pint.Y()>=ymin && pint.Y()<=ymax) return pint;
313 //intersection with high X
ffb1ac19 314 pint.Set((Double_t)(p1.X() + (fParam->SizeAllY()-p1.Y())/m),(Double_t)(fParam->SizeAllY()));
315 if(pint.X()>=0 && pint.X()<=fParam->SizeAllX() &&
4598109f 316 pint.X()>=xmin && pint.X()<=xmax &&
317 pint.Y()>=ymin && pint.Y()<=ymax) return pint;
318 //intersection with left Y
319 pint.Set(0.,(Double_t)(p1.Y() + m*(0-p1.X())));
ffb1ac19 320 if(pint.Y()>=0 && pint.Y()<=fParam->SizeAllY() &&
4598109f 321 pint.Y()>=ymin && pint.Y()<=ymax &&
322 pint.X()>=xmin && pint.X()<=xmax) return pint;
323 //intersection with righ Y
ffb1ac19 324 pint.Set((Double_t)(fParam->SizeAllX()),(Double_t)(p1.Y() + m*(fParam->SizeAllX()-p1.X())));
325 if(pint.Y()>=0 && pint.Y()<=fParam->SizeAllY() &&
4598109f 326 pint.Y()>=ymin && pint.Y()<=ymax &&
327 pint.X()>=xmin && pint.X()<=xmax) return pint;
328 return p1;
329}//IntWithEdge()
330//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
d3da6dc4 331Double_t AliHMPIDRecon::FindRingCkov(Int_t)
332{
333// Loops on all Ckov candidates and estimates the best Theta Ckov for a ring formed by those candidates. Also estimates an error for that Theat Ckov
334// collecting errors for all single Ckov candidates thetas. (Assuming they are independent)
335// Arguments: iNclus- total number of clusters in chamber for background estimation
336// Return: best estimation of track Theta ckov
337
338 Double_t wei = 0.;
339 Double_t weightThetaCerenkov = 0.;
340
341 Double_t ckovMin=9999.,ckovMax=0.;
342 Double_t sigma2 = 0; //to collect error squared for this ring
343
344 for(Int_t i=0;i<fPhotCnt;i++){//candidates loop
345 if(fPhotFlag[i] == 2){
a591e55f 346 if(fPhotCkov[i]<ckovMin) ckovMin=fPhotCkov[i]; //find max and min Theta ckov from all candidates within probable window
d3da6dc4 347 if(fPhotCkov[i]>ckovMax) ckovMax=fPhotCkov[i];
a591e55f 348 weightThetaCerenkov += fPhotCkov[i]*fPhotWei[i];
349 wei += fPhotWei[i]; //collect weight as sum of all candidate weghts
d3da6dc4 350
3278403b 351 sigma2 += 1./fParam->Sigma2(fTrkDir.Theta(),fTrkDir.Phi(),fPhotCkov[i],fPhotPhi[i]);
d3da6dc4 352 }
353 }//candidates loop
354
355 if(sigma2>0) fCkovSigma2=1./sigma2;
356 else fCkovSigma2=1e10;
357
b4ad85e9 358 if(wei != 0.) weightThetaCerenkov /= wei; else weightThetaCerenkov = 0.;
d3da6dc4 359 return weightThetaCerenkov;
360}//FindCkovRing()
361//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
362Int_t AliHMPIDRecon::FlagPhot(Double_t ckov)
363{
364// Flag photon candidates if their individual ckov angle is inside the window around ckov angle returned by HoughResponse()
365// Arguments: ckov- value of most probable ckov angle for track as returned by HoughResponse()
366// Returns: number of photon candidates happened to be inside the window
367
a591e55f 368// Photon Flag: Flag = 0 initial set;
369// Flag = 1 good candidate (charge compatible with photon);
370// Flag = 2 photon used for the ring;
d3da6dc4 371
372 Int_t steps = (Int_t)((ckov )/ fDTheta); //how many times we need to have fDTheta to fill the distance between 0 and thetaCkovHough
373
374 Double_t tmin = (Double_t)(steps - 1)*fDTheta;
375 Double_t tmax = (Double_t)(steps)*fDTheta;
376 Double_t tavg = 0.5*(tmin+tmax);
377
378 tmin = tavg - 0.5*fWindowWidth; tmax = tavg + 0.5*fWindowWidth;
379
380 Int_t iInsideCnt = 0; //count photons which Theta ckov inside the window
381 for(Int_t i=0;i<fPhotCnt;i++){//photon candidates loop
afe12692 382 fPhotFlag[i] = 0;
d3da6dc4 383 if(fPhotCkov[i] >= tmin && fPhotCkov[i] <= tmax) {
384 fPhotFlag[i]=2;
385 iInsideCnt++;
386 }
387 }
388 return iInsideCnt;
389}//FlagPhot()
390//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
a591e55f 391TVector2 AliHMPIDRecon::TracePhot(Double_t ckovThe,Double_t ckovPhi)const
d3da6dc4 392{
393// Trace a single Ckov photon from emission point somewhere in radiator up to photocathode taking into account ref indexes of materials it travereses
ffb1ac19 394// Arguments: ckovThe,ckovPhi- photon ckov angles in TRS, [rad]
d3da6dc4 395// Returns: distance between photon point on PC and track projection
2d1a9b21 396
397 Double_t theta,phi;
398 TVector3 dirTRS,dirLORS;
399 dirTRS.SetMagThetaPhi(1,ckovThe,ckovPhi); //photon in TRS
400 Trs2Lors(dirTRS,theta,phi);
401 dirLORS.SetMagThetaPhi(1,theta,phi); //photon in LORS
402 return TraceForward(dirLORS); //now foward tracing
a591e55f 403}//TracePhot()
d3da6dc4 404//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
a591e55f 405void AliHMPIDRecon::Propagate(const TVector3 dir,TVector3 &pos,Double_t z)const
d3da6dc4 406{
407// Finds an intersection point between a line and XY plane shifted along Z.
408// Arguments: dir,pos - vector along the line and any point of the line
409// z - z coordinate of plain
410// Returns: none
411// On exit: pos is the position if this intesection if any
412 static TVector3 nrm(0,0,1);
413 TVector3 pnt(0,0,z);
414
415 TVector3 diff=pnt-pos;
416 Double_t sint=(nrm*diff)/(nrm*dir);
417 pos+=sint*dir;
418}//Propagate()
419//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
420void AliHMPIDRecon::Refract(TVector3 &dir,Double_t n1,Double_t n2)const
421{
422// Refract direction vector according to Snell law
423// Arguments:
424// n1 - ref idx of first substance
425// n2 - ref idx of second substance
426// Returns: none
427// On exit: dir is new direction
67a1c24c 428 Double_t sinref=(n1/n2)*TMath::Sin(dir.Theta());
76fd1a96 429 if(TMath::Abs(sinref)>1.) dir.SetXYZ(-999,-999,-999);
67a1c24c 430 else dir.SetTheta(TMath::ASin(sinref));
d3da6dc4 431}//Refract()
432//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
433Double_t AliHMPIDRecon::HoughResponse()
434{
435//
611e810d 436// fIdxMip = mipId;
437
d3da6dc4 438//
439 Double_t kThetaMax=0.75;
440 Int_t nChannels = (Int_t)(kThetaMax/fDTheta+0.5);
441 TH1D *phots = new TH1D("Rphot" ,"phots" ,nChannels,0,kThetaMax);
442 TH1D *photsw = new TH1D("RphotWeighted" ,"photsw" ,nChannels,0,kThetaMax);
443 TH1D *resultw = new TH1D("resultw","resultw" ,nChannels,0,kThetaMax);
444 Int_t nBin = (Int_t)(kThetaMax/fDTheta);
445 Int_t nCorrBand = (Int_t)(fWindowWidth/(2*fDTheta));
446
447 for (Int_t i=0; i< fPhotCnt; i++){//photon cadidates loop
448 Double_t angle = fPhotCkov[i]; if(angle<0||angle>kThetaMax) continue;
449 phots->Fill(angle);
450 Int_t bin = (Int_t)(0.5+angle/(fDTheta));
451 Double_t weight=1.;
452 if(fIsWEIGHT){
afe12692 453 Double_t lowerlimit = ((Double_t)bin)*fDTheta - 0.5*fDTheta; Double_t upperlimit = ((Double_t)bin)*fDTheta + 0.5*fDTheta;
2d1a9b21 454 FindRingGeom(lowerlimit);
455 Double_t areaLow = GetRingArea();
456 FindRingGeom(upperlimit);
457 Double_t areaHigh = GetRingArea();
458 Double_t diffArea = areaHigh - areaLow;
d3da6dc4 459 if(diffArea>0) weight = 1./diffArea;
460 }
461 photsw->Fill(angle,weight);
462 fPhotWei[i]=weight;
463 }//photon candidates loop
464
465 for (Int_t i=1; i<=nBin;i++){
466 Int_t bin1= i-nCorrBand;
467 Int_t bin2= i+nCorrBand;
468 if(bin1<1) bin1=1;
469 if(bin2>nBin)bin2=nBin;
470 Double_t sumPhots=phots->Integral(bin1,bin2);
471 if(sumPhots<3) continue; // if less then 3 photons don't trust to this ring
472 Double_t sumPhotsw=photsw->Integral(bin1,bin2);
473 resultw->Fill((Double_t)((i+0.5)*fDTheta),sumPhotsw);
474 }
475// evaluate the "BEST" theta ckov as the maximum value of histogramm
476 Double_t *pVec = resultw->GetArray();
477 Int_t locMax = TMath::LocMax(nBin,pVec);
3ebd8038 478 delete phots;delete photsw;delete resultw; // Reset and delete objects
d3da6dc4 479
480 return (Double_t)(locMax*fDTheta+0.5*fDTheta); //final most probable track theta ckov
481}//HoughResponse()
482//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++