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