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