Possibility to set offset in SZ runs
[u/mrichter/AliRoot.git] / HMPID / AliHMPIDRecon.cxx
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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
e26c20fa 127
128 if(nmean < 0){ //track didn' t pass through the radiator
129 pTrk->SetHMPIDsignal(kNoRad); //set the appropriate flag
130 pTrk->SetHMPIDcluIdx(chId,mipId+1000*sizeClu); //set index of cluster
131 return;
132 }
133
39cd22e6 134 if(fPhotCnt<=nMinPhotAcc) { //no reconstruction with <=3 photon candidates
135 pTrk->SetHMPIDsignal(kNoPhotAccept); //set the appropriate flag
43d3333b 136 pTrk->SetHMPIDcluIdx(chId,mipId+1000*sizeClu); //set index of cluster
39cd22e6 137 return;
138 }
139
f1970e74 140 if(mipId==-1) {
141 pTrk->SetHMPIDcluIdx(chId,9999); //set index of cluster
142 pTrk->SetHMPIDsignal(kMipQdcCut);
143 return;
144 } //no clusters with QDC more the threshold at all
43d3333b 145 pTrk->SetHMPIDcluIdx(chId,mipId+1000*sizeClu); //set chamber, index of cluster + cluster size
f1970e74 146 if(dMin>fParam->DistCut()) {pTrk->SetHMPIDsignal(kMipDistCut); return;} //closest cluster with enough charge is still too far from intersection
147
148 fMipPos.Set(mipX,mipY);
149
39cd22e6 150
151//PATTERN RECOGNITION STARTED:
152
2d1a9b21 153 Int_t iNrec=FlagPhot(HoughResponse()); //flag photons according to individual theta ckov with respect to most probable
154 pTrk->SetHMPIDmip(mipX,mipY,mipQ,iNrec); //store mip info
59280a5a 155
2d1a9b21 156 if(iNrec<1){
157 pTrk->SetHMPIDsignal(kNoPhotAccept); //no photon candidates are accepted
f1970e74 158 return;
76fd1a96 159 }
f1970e74 160 Double_t thetaC = FindRingCkov(pCluLst->GetEntries()); //find the best reconstructed theta Cherenkov
2d1a9b21 161// FindRingGeom(thetaC,2);
f1970e74 162 pTrk->SetHMPIDsignal(thetaC); //store theta Cherenkov
163 pTrk->SetHMPIDchi2(fCkovSigma2); //store errors squared
d3da6dc4 164
ffb1ac19 165 DeleteVars();
43400d2d 166}//CkovAngle()
d3da6dc4 167//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
a591e55f 168Bool_t AliHMPIDRecon::FindPhotCkov(Double_t cluX,Double_t cluY,Double_t &thetaCer,Double_t &phiCer)
d3da6dc4 169{
170// Finds Cerenkov angle for this photon candidate
171// Arguments: cluX,cluY - position of cadidate's cluster
a591e55f 172// Returns: Cerenkov angle
d3da6dc4 173
a591e55f 174 TVector3 dirCkov;
175
ffb1ac19 176 Double_t zRad= -0.5*fParam->RadThick()-0.5*fParam->WinThick(); //z position of middle of RAD
67a1c24c 177 TVector3 rad(fTrkPos.X(),fTrkPos.Y(),zRad); //impact point at middle of RAD
ffb1ac19 178 TVector3 pc(cluX,cluY,0.5*fParam->WinThick()+fParam->GapIdx()); //mip at PC
a591e55f 179 Double_t cluR = TMath::Sqrt((cluX-fTrkPos.X())*(cluX-fTrkPos.X())+
180 (cluY-fTrkPos.Y())*(cluY-fTrkPos.Y()));//ref. distance impact RAD-CLUSTER
67a1c24c 181 Double_t phi=(pc-rad).Phi(); //phi of photon
a591e55f 182
b4ad85e9 183 Double_t ckov1=0;
67a1c24c 184 Double_t ckov2=0.75+fTrkDir.Theta(); //start to find theta cerenkov in DRS
b4ad85e9 185 const Double_t kTol=0.01;
d3da6dc4 186 Int_t iIterCnt = 0;
187 while(1){
a591e55f 188 if(iIterCnt>=50) return kFALSE;
d3da6dc4 189 Double_t ckov=0.5*(ckov1+ckov2);
67a1c24c 190 dirCkov.SetMagThetaPhi(1,ckov,phi);
a591e55f 191 TVector2 posC=TraceForward(dirCkov); //trace photon with actual angles
192 Double_t dist=cluR-(posC-fTrkPos).Mod(); //get distance between trial point and cluster position
193 if(posC.X()==-999) dist = - 999; //total reflection problem
194 iIterCnt++; //counter step
b4ad85e9 195 if (dist> kTol) ckov1=ckov; //cluster @ larger ckov
d3da6dc4 196 else if(dist<-kTol) ckov2=ckov; //cluster @ smaller ckov
a591e55f 197 else{ //precision achived: ckov in DRS found
198 dirCkov.SetMagThetaPhi(1,ckov,phi); //
2d1a9b21 199 Lors2Trs(dirCkov,thetaCer,phiCer); //find ckov (in TRS:the effective Cherenkov angle!)
a591e55f 200 return kTRUE;
201 }
d3da6dc4 202 }
203}//FindPhotTheta()
204//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
a591e55f 205TVector2 AliHMPIDRecon::TraceForward(TVector3 dirCkov)const
d3da6dc4 206{
a591e55f 207 //Trace forward a photon from (x,y) up to PC
208 // Arguments: dirCkov photon vector in LORS
209 // Returns: pos of traced photon at PC
ffb1ac19 210
a591e55f 211 TVector2 pos(-999,-999);
67a1c24c 212 Double_t thetaCer = dirCkov.Theta();
ffb1ac19 213 if(thetaCer > TMath::ASin(1./fParam->GetRefIdx())) return pos; //total refraction on WIN-GAP boundary
214 Double_t zRad= -0.5*fParam->RadThick()-0.5*fParam->WinThick(); //z position of middle of RAD
215 TVector3 posCkov(fTrkPos.X(),fTrkPos.Y(),zRad); //RAD: photon position is track position @ middle of RAD
216 Propagate(dirCkov,posCkov, -0.5*fParam->WinThick()); //go to RAD-WIN boundary
217 Refract (dirCkov, fParam->GetRefIdx(),fParam->WinIdx()); //RAD-WIN refraction
218 Propagate(dirCkov,posCkov, 0.5*fParam->WinThick()); //go to WIN-GAP boundary
219 Refract (dirCkov, fParam->WinIdx(),fParam->GapIdx()); //WIN-GAP refraction
220 Propagate(dirCkov,posCkov,0.5*fParam->WinThick()+fParam->GapThick()); //go to PC
a591e55f 221 pos.Set(posCkov.X(),posCkov.Y());
222 return pos;
223}//TraceForward()
224//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
2d1a9b21 225void AliHMPIDRecon::Lors2Trs(TVector3 dirCkov,Double_t &thetaCer,Double_t &phiCer)const
a591e55f 226{
227 //Theta Cerenkov reconstruction
2d1a9b21 228 // Arguments: dirCkov photon vector in LORS
229 // Returns: thetaCer of photon in TRS
230 // phiCer of photon in TRS
a591e55f 231// TVector3 dirTrk;
232// dirTrk.SetMagThetaPhi(1,fTrkDir.Theta(),fTrkDir.Phi());
233// Double_t thetaCer = TMath::ACos(dirCkov*dirTrk);
2d1a9b21 234 TRotation mtheta; mtheta.RotateY(-fTrkDir.Theta());
235 TRotation mphi; mphi.RotateZ(-fTrkDir.Phi());
a591e55f 236 TRotation mrot=mtheta*mphi;
237 TVector3 dirCkovTRS;
238 dirCkovTRS=mrot*dirCkov;
239 phiCer = dirCkovTRS.Phi(); //actual value of the phi of the photon
240 thetaCer= dirCkovTRS.Theta(); //actual value of thetaCerenkov of the photon
d3da6dc4 241}
242//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
2d1a9b21 243void AliHMPIDRecon::Trs2Lors(TVector3 dirCkov,Double_t &thetaCer,Double_t &phiCer)const
244{
245 //Theta Cerenkov reconstruction
246 // Arguments: dirCkov photon vector in TRS
247 // Returns: thetaCer of photon in LORS
248 // phiCer of photon in LORS
249 TRotation mtheta; mtheta.RotateY(fTrkDir.Theta());
250 TRotation mphi; mphi.RotateZ(fTrkDir.Phi());
251 TRotation mrot=mphi*mtheta;
252 TVector3 dirCkovLORS;
253 dirCkovLORS=mrot*dirCkov;
254 phiCer = dirCkovLORS.Phi(); //actual value of the phi of the photon
255 thetaCer= dirCkovLORS.Theta(); //actual value of thetaCerenkov of the photon
256}
257//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
258void AliHMPIDRecon::FindRingGeom(Double_t ckovAng,Int_t level)
d3da6dc4 259{
4598109f 260// Find area covered in the PC acceptance
2d1a9b21 261// Arguments: ckovAng - cerenkov angle
262// level - precision in finding area and portion of ring accepted (multiple of 50)
d3da6dc4 263// Returns: area of the ring in cm^2 for given theta ckov
264
2d1a9b21 265 Int_t kN=50*level;
266 Int_t nPoints = 0;
afe12692 267 Double_t area=0;
2d1a9b21 268
4598109f 269 Bool_t first=kFALSE;
2d1a9b21 270 TVector2 pos1;
271
afe12692 272 for(Int_t i=0;i<kN;i++){
4598109f 273 if(!first) {
2d1a9b21 274 pos1=TracePhot(ckovAng,Double_t(TMath::TwoPi()*(i+1)/kN)); //find a good trace for the first photon
4598109f 275 if(pos1.X()==-999) continue; //no area: open ring
2d1a9b21 276 if(!fParam->IsInside(pos1.X(),pos1.Y(),0)) {
277 pos1 = IntWithEdge(fMipPos,pos1); // find the very first intersection...
278 } else {
279 if(!AliHMPIDParam::IsInDead(pos1.X(),pos1.Y())) nPoints++; //photon is accepted if not in dead zone
280 }
4598109f 281 first=kTRUE;
282 continue;
283 }
284 TVector2 pos2=TracePhot(ckovAng,Double_t(TMath::TwoPi()*(i+1)/kN)); //trace the next photon
285 if(pos2.X()==-999) continue; //no area: open ring
ffb1ac19 286 if(!fParam->IsInside(pos2.X(),pos2.Y(),0)) {
4598109f 287 pos2 = IntWithEdge(fMipPos,pos2);
2d1a9b21 288 } else {
289 if(!AliHMPIDParam::IsInDead(pos2.X(),pos2.Y())) nPoints++; //photon is accepted if not in dead zone
4598109f 290 }
291 area+=TMath::Abs((pos1-fMipPos).X()*(pos2-fMipPos).Y()-(pos1-fMipPos).Y()*(pos2-fMipPos).X()); //add area of the triangle...
292 pos1 = pos2;
d3da6dc4 293 }
2d1a9b21 294//--- find area and length of the ring;
295 fRingAcc = (Double_t)nPoints/(Double_t)kN;
7fc88c5e 296 area*=0.5;
2d1a9b21 297 fRingArea = area;
298}//FindRingGeom()
d3da6dc4 299//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
4598109f 300TVector2 AliHMPIDRecon::IntWithEdge(TVector2 p1,TVector2 p2)const
301{
302// It finds the intersection of the line for 2 points traced as photons
303// and the edge of a given PC
304// Arguments: 2 points obtained tracing the photons
305// Returns: intersection point with detector (PC) edges
306
4598109f 307 Double_t xmin = (p1.X()<p2.X())? p1.X():p2.X();
308 Double_t xmax = (p1.X()<p2.X())? p2.X():p1.X();
309 Double_t ymin = (p1.Y()<p2.Y())? p1.Y():p2.Y();
310 Double_t ymax = (p1.Y()<p2.Y())? p2.Y():p1.Y();
311
312 Double_t m = TMath::Tan((p2-p1).Phi());
313 TVector2 pint;
314 //intersection with low X
315 pint.Set((Double_t)(p1.X() + (0-p1.Y())/m),0.);
ffb1ac19 316 if(pint.X()>=0 && pint.X()<=fParam->SizeAllX() &&
4598109f 317 pint.X()>=xmin && pint.X()<=xmax &&
318 pint.Y()>=ymin && pint.Y()<=ymax) return pint;
319 //intersection with high X
ffb1ac19 320 pint.Set((Double_t)(p1.X() + (fParam->SizeAllY()-p1.Y())/m),(Double_t)(fParam->SizeAllY()));
321 if(pint.X()>=0 && pint.X()<=fParam->SizeAllX() &&
4598109f 322 pint.X()>=xmin && pint.X()<=xmax &&
323 pint.Y()>=ymin && pint.Y()<=ymax) return pint;
324 //intersection with left Y
325 pint.Set(0.,(Double_t)(p1.Y() + m*(0-p1.X())));
ffb1ac19 326 if(pint.Y()>=0 && pint.Y()<=fParam->SizeAllY() &&
4598109f 327 pint.Y()>=ymin && pint.Y()<=ymax &&
328 pint.X()>=xmin && pint.X()<=xmax) return pint;
329 //intersection with righ Y
ffb1ac19 330 pint.Set((Double_t)(fParam->SizeAllX()),(Double_t)(p1.Y() + m*(fParam->SizeAllX()-p1.X())));
331 if(pint.Y()>=0 && pint.Y()<=fParam->SizeAllY() &&
4598109f 332 pint.Y()>=ymin && pint.Y()<=ymax &&
333 pint.X()>=xmin && pint.X()<=xmax) return pint;
334 return p1;
335}//IntWithEdge()
336//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
d3da6dc4 337Double_t AliHMPIDRecon::FindRingCkov(Int_t)
338{
339// 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
340// collecting errors for all single Ckov candidates thetas. (Assuming they are independent)
341// Arguments: iNclus- total number of clusters in chamber for background estimation
342// Return: best estimation of track Theta ckov
343
344 Double_t wei = 0.;
345 Double_t weightThetaCerenkov = 0.;
346
347 Double_t ckovMin=9999.,ckovMax=0.;
348 Double_t sigma2 = 0; //to collect error squared for this ring
349
350 for(Int_t i=0;i<fPhotCnt;i++){//candidates loop
351 if(fPhotFlag[i] == 2){
a591e55f 352 if(fPhotCkov[i]<ckovMin) ckovMin=fPhotCkov[i]; //find max and min Theta ckov from all candidates within probable window
d3da6dc4 353 if(fPhotCkov[i]>ckovMax) ckovMax=fPhotCkov[i];
a591e55f 354 weightThetaCerenkov += fPhotCkov[i]*fPhotWei[i];
355 wei += fPhotWei[i]; //collect weight as sum of all candidate weghts
d3da6dc4 356
3278403b 357 sigma2 += 1./fParam->Sigma2(fTrkDir.Theta(),fTrkDir.Phi(),fPhotCkov[i],fPhotPhi[i]);
d3da6dc4 358 }
359 }//candidates loop
360
361 if(sigma2>0) fCkovSigma2=1./sigma2;
362 else fCkovSigma2=1e10;
363
b4ad85e9 364 if(wei != 0.) weightThetaCerenkov /= wei; else weightThetaCerenkov = 0.;
d3da6dc4 365 return weightThetaCerenkov;
366}//FindCkovRing()
367//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
368Int_t AliHMPIDRecon::FlagPhot(Double_t ckov)
369{
370// Flag photon candidates if their individual ckov angle is inside the window around ckov angle returned by HoughResponse()
371// Arguments: ckov- value of most probable ckov angle for track as returned by HoughResponse()
372// Returns: number of photon candidates happened to be inside the window
373
a591e55f 374// Photon Flag: Flag = 0 initial set;
375// Flag = 1 good candidate (charge compatible with photon);
376// Flag = 2 photon used for the ring;
d3da6dc4 377
378 Int_t steps = (Int_t)((ckov )/ fDTheta); //how many times we need to have fDTheta to fill the distance between 0 and thetaCkovHough
379
380 Double_t tmin = (Double_t)(steps - 1)*fDTheta;
381 Double_t tmax = (Double_t)(steps)*fDTheta;
382 Double_t tavg = 0.5*(tmin+tmax);
383
384 tmin = tavg - 0.5*fWindowWidth; tmax = tavg + 0.5*fWindowWidth;
385
386 Int_t iInsideCnt = 0; //count photons which Theta ckov inside the window
387 for(Int_t i=0;i<fPhotCnt;i++){//photon candidates loop
afe12692 388 fPhotFlag[i] = 0;
d3da6dc4 389 if(fPhotCkov[i] >= tmin && fPhotCkov[i] <= tmax) {
390 fPhotFlag[i]=2;
391 iInsideCnt++;
392 }
393 }
394 return iInsideCnt;
395}//FlagPhot()
396//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
a591e55f 397TVector2 AliHMPIDRecon::TracePhot(Double_t ckovThe,Double_t ckovPhi)const
d3da6dc4 398{
399// Trace a single Ckov photon from emission point somewhere in radiator up to photocathode taking into account ref indexes of materials it travereses
ffb1ac19 400// Arguments: ckovThe,ckovPhi- photon ckov angles in TRS, [rad]
d3da6dc4 401// Returns: distance between photon point on PC and track projection
2d1a9b21 402
403 Double_t theta,phi;
404 TVector3 dirTRS,dirLORS;
405 dirTRS.SetMagThetaPhi(1,ckovThe,ckovPhi); //photon in TRS
406 Trs2Lors(dirTRS,theta,phi);
407 dirLORS.SetMagThetaPhi(1,theta,phi); //photon in LORS
408 return TraceForward(dirLORS); //now foward tracing
a591e55f 409}//TracePhot()
d3da6dc4 410//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
a591e55f 411void AliHMPIDRecon::Propagate(const TVector3 dir,TVector3 &pos,Double_t z)const
d3da6dc4 412{
413// Finds an intersection point between a line and XY plane shifted along Z.
414// Arguments: dir,pos - vector along the line and any point of the line
415// z - z coordinate of plain
416// Returns: none
417// On exit: pos is the position if this intesection if any
418 static TVector3 nrm(0,0,1);
419 TVector3 pnt(0,0,z);
420
421 TVector3 diff=pnt-pos;
422 Double_t sint=(nrm*diff)/(nrm*dir);
423 pos+=sint*dir;
424}//Propagate()
425//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
426void AliHMPIDRecon::Refract(TVector3 &dir,Double_t n1,Double_t n2)const
427{
428// Refract direction vector according to Snell law
429// Arguments:
430// n1 - ref idx of first substance
431// n2 - ref idx of second substance
432// Returns: none
433// On exit: dir is new direction
67a1c24c 434 Double_t sinref=(n1/n2)*TMath::Sin(dir.Theta());
76fd1a96 435 if(TMath::Abs(sinref)>1.) dir.SetXYZ(-999,-999,-999);
67a1c24c 436 else dir.SetTheta(TMath::ASin(sinref));
d3da6dc4 437}//Refract()
438//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
439Double_t AliHMPIDRecon::HoughResponse()
440{
441//
611e810d 442// fIdxMip = mipId;
443
d3da6dc4 444//
445 Double_t kThetaMax=0.75;
446 Int_t nChannels = (Int_t)(kThetaMax/fDTheta+0.5);
447 TH1D *phots = new TH1D("Rphot" ,"phots" ,nChannels,0,kThetaMax);
448 TH1D *photsw = new TH1D("RphotWeighted" ,"photsw" ,nChannels,0,kThetaMax);
449 TH1D *resultw = new TH1D("resultw","resultw" ,nChannels,0,kThetaMax);
450 Int_t nBin = (Int_t)(kThetaMax/fDTheta);
451 Int_t nCorrBand = (Int_t)(fWindowWidth/(2*fDTheta));
452
453 for (Int_t i=0; i< fPhotCnt; i++){//photon cadidates loop
454 Double_t angle = fPhotCkov[i]; if(angle<0||angle>kThetaMax) continue;
455 phots->Fill(angle);
456 Int_t bin = (Int_t)(0.5+angle/(fDTheta));
457 Double_t weight=1.;
458 if(fIsWEIGHT){
afe12692 459 Double_t lowerlimit = ((Double_t)bin)*fDTheta - 0.5*fDTheta; Double_t upperlimit = ((Double_t)bin)*fDTheta + 0.5*fDTheta;
2d1a9b21 460 FindRingGeom(lowerlimit);
461 Double_t areaLow = GetRingArea();
462 FindRingGeom(upperlimit);
463 Double_t areaHigh = GetRingArea();
464 Double_t diffArea = areaHigh - areaLow;
d3da6dc4 465 if(diffArea>0) weight = 1./diffArea;
466 }
467 photsw->Fill(angle,weight);
468 fPhotWei[i]=weight;
469 }//photon candidates loop
470
471 for (Int_t i=1; i<=nBin;i++){
472 Int_t bin1= i-nCorrBand;
473 Int_t bin2= i+nCorrBand;
474 if(bin1<1) bin1=1;
475 if(bin2>nBin)bin2=nBin;
476 Double_t sumPhots=phots->Integral(bin1,bin2);
477 if(sumPhots<3) continue; // if less then 3 photons don't trust to this ring
478 Double_t sumPhotsw=photsw->Integral(bin1,bin2);
479 resultw->Fill((Double_t)((i+0.5)*fDTheta),sumPhotsw);
480 }
481// evaluate the "BEST" theta ckov as the maximum value of histogramm
482 Double_t *pVec = resultw->GetArray();
483 Int_t locMax = TMath::LocMax(nBin,pVec);
3ebd8038 484 delete phots;delete photsw;delete resultw; // Reset and delete objects
d3da6dc4 485
486 return (Double_t)(locMax*fDTheta+0.5*fDTheta); //final most probable track theta ckov
487}//HoughResponse()
488//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++