1 /**************************************************************************
2 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
4 * Author: The ALICE Off-line Project. *
5 * Contributors are mentioned in the code where appropriate. *
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 **************************************************************************/
18 ///////////////////////////////////////////////////////////////////////////////
20 // Time Projection Chamber track hits object //
22 // Origin: Marian Ivanov , GSI Darmstadt
24 // Class for storing simulated AliTPCHits for given track //
25 // -average compression comparing to classical ClonesArray is //
26 // around 5-7 (depending on the required hit precision) //
30 <img src="gif/AliTPCTrackHits.gif">
35 ///////////////////////////////////////////////////////////////////////////////
40 #include "AliTPCTrackHits.h"
42 ClassImp(AliTPCTrackHits)
43 LClassImp(AliTrackHitsInfo)
44 LClassImp(AliTrackHitsParam)
47 Int_t AliTrackHitsInfo::fgCounter1 =0;
48 Int_t AliTrackHitsInfo::fgCounter2 =0;
49 Int_t AliTrackHitsParam::fgCounter1 =0;
50 Int_t AliTrackHitsParam::fgCounter2 =0;
51 Int_t AliHitInfo::fgCounter1 =0;
52 Int_t AliHitInfo::fgCounter2 =0;
53 Int_t AliTPCTrackHits::fgCounter1 =0;
54 Int_t AliTPCTrackHits::fgCounter2 =0;
55 const Double_t AliTPCTrackHits::fgkPrecision=1e-6; //precision
56 const Double_t AliTPCTrackHits::fgkPrecision2=1e-20; //precision
59 class AliTPCCurrentHit {
60 friend class AliTPCTrackHits;
62 AliTPChit fHit; // - hit in "standard" representation
63 UInt_t fInfoIndex;// - current info pointer
64 UInt_t fParamIndex;// - current param pointer
65 UInt_t fStackIndex; // - current hit stack index
66 Double_t fR; //current Radius
67 Bool_t fStatus; //current status
71 class AliTPCTempHitInfo {
72 friend class AliTPCTrackHits;
74 enum { kStackSize = 100};
76 AliTPCTempHitInfo(const AliTPCTempHitInfo &)
77 {::Fatal("copy ctor","Not implemented\n");}
78 AliTPCTempHitInfo & operator = (const AliTPCTempHitInfo &)
79 {::Fatal("= operator","Not implemented\n");return *this;}
81 void NewParam(Double_t r, Double_t z, Double_t fi, Int_t q);
82 void SetHit(Double_t r, Double_t z, Double_t fi, Int_t q);
83 Double_t * GetPosition(Int_t index){return &fPositionStack[index*3];}
84 void UpdateParam(Double_t maxdelta); //recal
85 void Fit2(Double_t fSumY, Double_t fSumYX, Double_t fSumYX2,
86 Double_t fSumX, Double_t fSumX2, Double_t fSumX3,
87 Double_t fSumX4, Int_t n,
88 Double_t &a, Double_t &b, Double_t &c);
89 void Fit(AliTrackHitsParam * param);
90 Double_t fSumDr; //fSumDr
91 Double_t fSumDr2; //fSumDr2
92 Double_t fSumDr3; // fSumDr3
93 Double_t fSumDr4; //fSumDr4
94 Double_t fSumDFi; //fSumDFi
95 Double_t fSumDFiDr; // fSumDFiDr
96 Double_t fSumDFiDr2;//fSumDFiDr2
97 Double_t fSumDZ; //fSumDZ
98 Double_t fSumDZDr; //fSumDZDr
99 Double_t fSumDZDr2; //fSumDZDr2
100 Double_t fOldR; //previos r
101 Double_t fPositionStack[3*kStackSize]; //position stack
102 UInt_t fQStack[kStackSize]; //Q stack
103 UInt_t fStackIndex; //current stack index
104 UInt_t fInfoIndex; //current track info index
105 UInt_t fParamIndex; //current track parameters index
106 AliTrackHitsInfo * fInfo; //current track info
107 AliTrackHitsParam * fParam; //current track param
111 AliTPCTempHitInfo::AliTPCTempHitInfo()
114 //set to default value
115 fSumDr=fSumDr2=fSumDr3=fSumDr4=
116 fSumDFi=fSumDFiDr=fSumDFiDr2=
117 fSumDZ=fSumDZDr=fSumDZDr2=0;
124 void AliTPCTempHitInfo::NewParam(Double_t r, Double_t z, Double_t fi, Int_t q)
127 //reset stack and sum parameters
128 //store line initial point
129 fSumDr=fSumDr2=fSumDr3=fSumDr4=
130 fSumDFi=fSumDFiDr=fSumDFiDr2=
131 fSumDZ=fSumDZDr=fSumDZDr2=0;
144 void AliTPCTempHitInfo::SetHit(Double_t r, Double_t z, Double_t fi, Int_t q)
147 //add hit to the stack
148 //recalculate new estimete of line parameters
149 Double_t *f = GetPosition(fStackIndex);
153 fQStack[fStackIndex]=q;
154 if (fStackIndex==0) return;
155 Double_t dr = (r-fParam->fR);
156 if (TMath::Abs(dr)<AliTPCTrackHits::fgkPrecision) dr =AliTPCTrackHits::fgkPrecision;
157 Double_t dfi = fi-fParam->fFi;
158 Double_t dz = z -fParam->fZ;
160 Double_t dr3 =dr2*dr;
161 Double_t dr4 =dr3*dr;
173 //update fit parameters
175 Double_t det = fSumDr2*fSumDr4-fSumDr3*fSumDr3;
176 if (TMath::Abs(det)<AliTPCTrackHits::fgkPrecision2) return;
177 if ( ( fStackIndex>1 ) ){
178 fParam->fAn = (fSumDr4*fSumDFiDr-fSumDr3*fSumDFiDr2)/det;
179 fParam->fAd = (fSumDr2*fSumDFiDr2-fSumDr3*fSumDFiDr)/det;
182 fParam->fAn = fSumDFiDr/fSumDr2;
183 if ( ( fStackIndex>1 ) ){
184 fParam->fTheta = (fSumDr4*fSumDZDr-fSumDr3*fSumDZDr2)/det;
185 fParam->fThetaD= (fSumDr2*fSumDZDr2-fSumDr3*fSumDZDr)/det;
188 fParam->fTheta = fSumDZDr/fSumDr2;
192 void AliTPCTempHitInfo::UpdateParam(Double_t maxdelta)
194 //recalc parameters not fixing origin point
198 Fit2(fSumDFi, fSumDFiDr, fSumDFiDr2, fSumDr,fSumDr2,fSumDr3,fSumDr4,
200 if (TMath::Abs(a)<maxdelta){
201 fParam->fFi +=a/fParam->fR;
205 Fit2(fSumDZ, fSumDZDr, fSumDZDr2, fSumDr,fSumDr2,fSumDr3,fSumDr4,
206 fStackIndex, a,b,c) ;
207 if (TMath::Abs(a)<maxdelta){
215 void AliTPCTempHitInfo::Fit2(Double_t fSumY, Double_t fSumYX, Double_t fSumYX2,
216 Double_t fSumX, Double_t fSumX2, Double_t fSumX3,
217 Double_t fSumX4, Int_t n,
218 Double_t &a, Double_t &b, Double_t &c)
220 //fit of second order
222 n* (fSumX2*fSumX4-fSumX3*fSumX3) -
223 fSumX* (fSumX*fSumX4-fSumX3*fSumX2)+
224 fSumX2* (fSumX*fSumX3-fSumX2*fSumX2);
226 if (TMath::Abs(det)> AliTPCTrackHits::fgkPrecision) {
228 (fSumY * (fSumX2*fSumX4-fSumX3*fSumX3)-
229 fSumX *(fSumYX*fSumX4-fSumYX2*fSumX3)+
230 fSumX2*(fSumYX*fSumX3-fSumYX2*fSumX2))/det;
232 (n*(fSumYX*fSumX4-fSumX3*fSumYX2)-
233 fSumY*(fSumX*fSumX4-fSumX3*fSumX2)+
234 fSumX2*(fSumX*fSumYX2-fSumYX*fSumX2))/det;
236 (n*(fSumX2*fSumYX2-fSumYX*fSumX3)-
237 fSumX*(fSumX*fSumYX2-fSumYX*fSumX2)+
238 fSumY*(fSumX*fSumX3-fSumX2*fSumX2))/det;
242 void AliTPCTempHitInfo::Fit(AliTrackHitsParam * param)
244 // fit fixing first and the last point
245 //result stored in new param
246 Double_t dx2 = (GetPosition(fStackIndex))[0]-fParam->fR;
247 Double_t det = fSumDr4+dx2*fSumDr2-2*dx2*fSumDr3;
248 if ( (TMath::Abs(det)> AliTPCTrackHits::fgkPrecision) &&
249 ((TMath::Abs(dx2)> AliTPCTrackHits::fgkPrecision))){
250 Double_t dfi2 = (GetPosition(fStackIndex))[1]-fParam->fFi;
251 param->fAd = (fSumDFiDr2+dfi2*fSumDr-dx2*fSumDFiDr-dfi2*fSumDr3/dx2)/det;
252 param->fAn = (dfi2-param->fAd*dx2*dx2)/dx2;
254 Double_t dz2 = (GetPosition(fStackIndex))[1]-fParam->fZ;
255 param->fTheta = (fSumDZDr2+dz2*fSumDr-dx2*fSumDZDr-dz2*fSumDr3/dx2)/det;
256 param->fTheta = (dz2-param->fAd*dx2*dx2)/dx2;
264 AliTPCTrackHits::AliTPCTrackHits()
267 //default constructor
269 const Float_t kHitPrecision=0.002; //default precision for hit position in cm
270 const Float_t kStep =0.003; //30 mum step
271 const UShort_t kMaxDistance =100; //maximum distance 100
273 fPrecision=kHitPrecision; //precision in cm
274 fStep = kStep; //step size
275 fMaxDistance = kMaxDistance; //maximum distance
277 fTrackHitsInfo = new AliObjectArray("AliTrackHitsInfo");
278 fTrackHitsParam = new AliObjectArray("AliTrackHitsParam");
279 fHitsPosAndQ = new TArrayOfArrayVStack("AliHitInfo");
280 fCurrentHit = new AliTPCCurrentHit;
286 AliTPCTrackHits::AliTPCTrackHits(const AliTPCTrackHits& r) : TObject(r)
290 AliTPCTrackHits &AliTPCTrackHits::operator=(const AliTPCTrackHits& /* r */)
296 AliTPCTrackHits::~AliTPCTrackHits()
301 if (fTrackHitsInfo) delete fTrackHitsInfo;
302 if (fTrackHitsParam) delete fTrackHitsParam;
303 if (fHitsPosAndQ) delete fHitsPosAndQ;
304 if (fCurrentHit) delete fCurrentHit;
305 if (fTempInfo) delete fTempInfo;
309 void AliTPCTrackHits::Clear()
313 fTrackHitsInfo->Clear();
314 fTrackHitsParam->Clear();
315 //fTrackHitsInfo->Resize(0);
316 //fTrackHitsParam->Resize(0);
317 fHitsPosAndQ->Clear();
326 void AliTPCTrackHits::AddHitKartez(Int_t volumeID, Int_t trackID, Double_t x,
327 Double_t y, Double_t z,Int_t q)
329 //add hits (cartesian)
330 Double_t r = TMath::Sqrt(x*x+y*y);
331 Double_t fi = TMath::ACos(x/r);
333 AddHit(volumeID,trackID,r,z,fi,q);
336 void AliTPCTrackHits::AddHit(Int_t volumeID, Int_t trackID,
337 Double_t r, Double_t z, Double_t fi, Int_t q)
341 if (!fTempInfo) { //initialsation of track
342 fTempInfo = new AliTPCTempHitInfo;
344 if (fTrackHitsInfo->GetCapacity()<10) fTrackHitsInfo->Reserve(10);
345 fTrackHitsInfo->Resize(1);
346 fTempInfo->fInfoIndex =0;
347 if (fTrackHitsParam->GetCapacity()<100) fTrackHitsParam->Reserve(100);
348 fTrackHitsParam->Resize(1);
351 (AliTrackHitsInfo*) (fTrackHitsInfo->At(0));
352 fTempInfo->fInfo->fVolumeID = volumeID;
353 fTempInfo->fInfo->fTrackID = trackID;
354 fTempInfo->fInfo->fHitParamIndex =0;
355 fTempInfo->fInfoIndex = 0;
358 (AliTrackHitsParam*) (fTrackHitsParam->At(0));
359 fTempInfo->fParamIndex = 0;
360 fTempInfo->NewParam(r,z,fi,q);
364 Int_t size = fHitsPosAndQ->GetSize();
365 if (size>(Int_t)fTempInfo->fParamIndex) {
366 fTempInfo->fParamIndex++;
367 if (fTempInfo->fParamIndex+1>fTrackHitsParam->GetSize())
368 fTrackHitsParam->Resize(fTempInfo->fParamIndex+1);
370 (AliTrackHitsParam*) (fTrackHitsParam->At(fTempInfo->fParamIndex));
371 fTempInfo->NewParam(r,z,fi,q);
376 // if new volume or new trackID
377 if ( (volumeID!=fTempInfo->fInfo->fVolumeID) ||
378 (trackID!=fTempInfo->fInfo->fTrackID)){
381 FlushHitStack(kTRUE);
383 fTempInfo->fInfoIndex++;
384 if (fTempInfo->fInfoIndex+1>fTrackHitsInfo->GetSize())
385 fTrackHitsInfo->Resize(fTempInfo->fInfoIndex+1);
387 (AliTrackHitsInfo*) (fTrackHitsInfo->At(fTempInfo->fInfoIndex));
388 fTempInfo->fInfo->fVolumeID = volumeID;
389 fTempInfo->fInfo->fTrackID = trackID;
390 fTempInfo->fInfo->fHitParamIndex =fTempInfo->fParamIndex+1;
391 // FlushHitStack(kTRUE);
393 fTempInfo->fParamIndex++;
394 if (fTempInfo->fParamIndex+1>fTrackHitsParam->GetSize())
395 fTrackHitsParam->Resize(fTempInfo->fParamIndex+1);
397 (AliTrackHitsParam*) (fTrackHitsParam->At(fTempInfo->fParamIndex));
398 fTempInfo->NewParam(r,z,fi,q);
402 //calculate current fit precission to next point
403 AliTrackHitsParam ¶m = *(fTempInfo->fParam);
407 Double_t dr,dz,dfi,ddz,ddfi;
409 dr=dz=dfi=ddz=ddfi=0;
410 drhit = r-fTempInfo->fOldR;
412 //Double_t dfi2 = param.fAn+2*param.fAd*(r-param.fR);
413 Double_t dfi2 = param.fAn;
414 dfi2*=dfi2*fTempInfo->fOldR*fTempInfo->fOldR;
415 //Double_t ddz2 = param.fTheta+2*param.fThetaD*(r-param.fR);
416 Double_t ddz2 = param.fTheta;
418 ratio = TMath::Sqrt(1.+ dfi2+ ddz2);
423 dl = (TMath::Abs(drhit*ratio/fStep)<32000) ? fStep * Short_t(TMath::Nint(drhit*ratio/fStep)):0;
424 ddl = dl - drhit*ratio;
425 fTempInfo->fOldR += dl/ratio;
427 if (fTempInfo->fStackIndex>2){
431 ddz = dr*param.fTheta+dr*dr*param.fThetaD-dz;
432 ddfi= dr*param.fAn+dr*dr*param.fAd-dfi;
433 dd = TMath::Sqrt(ddz*ddz+r*r*ddfi*ddfi+ddl*ddl);
437 if ( ( (dd*1.25>fPrecision) ) ||
438 (fTempInfo->fStackIndex+4>fTempInfo->kStackSize) ||
439 (TMath::Abs(dl/fStep)>fMaxDistance) )
442 fTempInfo->fStackIndex++;
443 fTempInfo->SetHit(r,z,fi,q);
446 //if parameter changed
447 if (FlushHitStack(kFALSE)){ //if full buffer flushed
448 fTempInfo->fParamIndex++;
449 if (fTempInfo->fParamIndex+1>fTrackHitsParam->GetSize())
450 fTrackHitsParam->Resize(fTempInfo->fParamIndex+1);
452 (AliTrackHitsParam*) (fTrackHitsParam->At(fTempInfo->fParamIndex));
453 fTempInfo->NewParam(r,z,fi,q);
456 fTempInfo->fStackIndex++;
457 fTempInfo->SetHit(r,z,fi,q);
461 Bool_t AliTPCTrackHits::FlushHitStack(Bool_t force)
464 //write fHitsPosAndQ information from the stack to te arrays
465 if (!fTempInfo) return kFALSE;
466 Int_t size = fHitsPosAndQ->GetSize();
468 if ( (size>0)&&(size!=(Int_t)fTempInfo->fParamIndex)) return kFALSE;
470 if (fHitsPosAndQ->Push(fTempInfo->fStackIndex+1)!=fTempInfo->fParamIndex){
471 cout<<"internal error - contact MI\n";
476 AliTrackHitsParam & param = *(fTempInfo->fParam);
477 //recalculate track parameter not fixing first point
478 fTempInfo->UpdateParam(fStep/4.);
479 //fTempInfo->Fit(fTempInfo->fParam); //- fixing the first and the last point
481 Double_t oldr = param.fR;
482 //cout<<"C3"<<fTempInfo->fStackIndex<<"\n"<<flush;
485 for (i=0; i <= fTempInfo->fStackIndex; i++){
486 Double_t * position = fTempInfo->GetPosition(i);
487 Double_t dr = position[0]-oldr;
490 //Double_t dfi2 = param.fAn+2*param.fAd*(position[0]-param.fR);
491 Double_t dfi2 = param.fAn;
492 dfi2*=dfi2*oldr*oldr;
493 //Double_t ddz2 = param.fTheta+2*param.fThetaD*(position[0]-param.fR);
494 Double_t ddz2 = param.fTheta;
496 ratio = TMath::Sqrt(1.+ dfi2+ ddz2);
499 Double_t dl = (TMath::Abs(dr*ratio/fStep)<32000) ? fStep*(Short_t)TMath::Nint(dr*ratio/fStep):0;
502 //calculate precission
503 AliTrackHitsParam ¶m = *(fTempInfo->fParam);
505 Double_t dr1= position[0]-param.fR;
506 Double_t dz = position[1]-param.fZ;
508 Double_t dfi = position[2]-param.fFi;
509 //extrapolated deltas
510 Double_t dr2 = oldr-param.fR;
511 Double_t ddr = dr2-dr1;
512 Double_t ddz = dr2*param.fTheta+dr2*dr2*param.fThetaD-dz;
513 Double_t ddfi= dr2*param.fAn+dr2*dr2*param.fAd-dfi;
514 dd = TMath::Sqrt(ddz*ddz+oldr*oldr*ddfi*ddfi+ddr*ddr);
516 if ( (dd>fPrecision) ){
522 Double_t ddz = dr2*param.fTheta+dr2*dr2*param.fThetaD-dz;
523 Double_t ddfi= dr2*param.fAn+dr2*dr2*param.fAd-dfi;
525 dd = TMath::Sqrt(ddz*ddz+oldr*oldr*ddfi*ddfi+ddr*ddr);
531 info = (AliHitInfo*)(fHitsPosAndQ->At(fTempInfo->fParamIndex,i));
532 info->fHitDistance = (TMath::Abs(dl/fStep)<32000) ?Short_t(TMath::Nint(dl/fStep)):0;
533 info->fCharge = Short_t(fTempInfo->fQStack[i]);
536 cout<<" "<<fTempInfo->fStackIndex<<" \t";
538 cout<<position[0]<<"\t";
539 cout<<position[1]<<"\t";
540 cout<<position[2]<<"\t";
541 cout<<param.fAn<<"\t";
542 cout<<param.fTheta<<"\t";
543 cout<<dr1<<"\t"<<ddr<<"\t"<<ddz<<"\t"<<ddfi<<"\t"<<dd<<"\n"<<flush;
547 if (i<=fTempInfo->fStackIndex){ //if previous iteration not succesfull
548 fHitsPosAndQ->Resize(fTempInfo->fParamIndex,i);
550 fTempInfo->fParamIndex++;
551 if (fTempInfo->fParamIndex+1>fTrackHitsParam->GetSize())
552 fTrackHitsParam->Resize(fTempInfo->fParamIndex+1);
554 (AliTrackHitsParam*) (fTrackHitsParam->At(fTempInfo->fParamIndex));
555 Double_t * p = fTempInfo->GetPosition(i);
556 UInt_t index2 = fTempInfo->fStackIndex;
557 fTempInfo->NewParam(p[0],p[1],p[2],fTempInfo->fQStack[i]);
558 if (i+1<=index2) FlushHitStack2(i+1,index2);
560 if (force) return FlushHitStack(kTRUE);
567 void AliTPCTrackHits::FlushHitStack2(Int_t index1, Int_t index2)
570 // second iteration flush stack
571 // call only for hits where first iteration were not succesfully interpolated
572 Double_t * positionstack = new Double_t[3*(index2-index1+1)];
573 UInt_t * qstack = new UInt_t[index2-index1+1];
574 memcpy(positionstack, &fTempInfo->fPositionStack[3*index1],
575 (3*(index2-index1+1))*sizeof(Double_t));
576 memcpy(qstack, &fTempInfo->fQStack[index1],(index2-index1+1)*sizeof(UInt_t));
577 Double_t *p = positionstack;
578 for (Int_t j=0; j<=index2-index1;j++){
579 fTempInfo->fStackIndex++;
580 fTempInfo->SetHit(p[3*j+0],p[3*j+1],p[3*j+2],qstack[j]);
582 delete []positionstack;
594 Bool_t AliTPCTrackHits::First()
597 //set Current hit for the first hit
599 AliTrackHitsInfo *info = (AliTrackHitsInfo *)fTrackHitsInfo->At(0);
600 AliTrackHitsParam *param = (AliTrackHitsParam *)fTrackHitsParam->At(0);
601 AliHitInfo * hinfo = (AliHitInfo *)fHitsPosAndQ->At(0,0);
603 if (!(info) || !(param) || !(hinfo) ) {
604 fCurrentHit->fStatus = kFALSE;
608 fCurrentHit->fInfoIndex = 0;
609 fCurrentHit->fParamIndex = 0;
610 fCurrentHit->fStackIndex = 0;
612 fCurrentHit->fHit.fSector = info->fVolumeID;
613 fCurrentHit->fHit.SetTrack(info->fTrackID);
614 fCurrentHit->fHit.SetX(param->fR*TMath::Cos(param->fFi));
615 fCurrentHit->fHit.SetY(param->fR*TMath::Sin(param->fFi));
616 fCurrentHit->fHit.SetZ(param->fZ);
617 fCurrentHit->fHit.fQ = hinfo->fCharge;
619 fCurrentHit->fR = param->fR;
621 return fCurrentHit->fStatus = kTRUE;
626 Bool_t AliTPCTrackHits::Next()
630 if (!(fCurrentHit->fStatus))
633 fCurrentHit->fStackIndex++;
634 AliHitInfo * hinfo = (AliHitInfo *)fHitsPosAndQ->At(fCurrentHit->fParamIndex,
635 fCurrentHit->fStackIndex);
636 AliTrackHitsInfo *info = (AliTrackHitsInfo *)fTrackHitsInfo->At(fCurrentHit->fInfoIndex);
637 AliTrackHitsParam *param = (AliTrackHitsParam *)fTrackHitsParam->At(fCurrentHit->fParamIndex);
640 hinfo = (AliHitInfo *)fHitsPosAndQ->At(fCurrentHit->fParamIndex+1, 0);
642 return fCurrentHit->fStatus = kFALSE;
644 fCurrentHit->fParamIndex++;
645 fCurrentHit->fStackIndex = 0;
646 param = (AliTrackHitsParam *)fTrackHitsParam->At(fCurrentHit->fParamIndex);
648 return fCurrentHit->fStatus = kFALSE;
649 fCurrentHit->fR = param->fR;
651 if ((fCurrentHit->fInfoIndex+1<fTrackHitsInfo->GetSize())
652 &&((info+1)->fHitParamIndex<=fCurrentHit->fParamIndex)){
653 fCurrentHit->fInfoIndex++;
654 info = (AliTrackHitsInfo *)fTrackHitsInfo->At(fCurrentHit->fInfoIndex);
656 return fCurrentHit->fStatus = kFALSE;
657 fCurrentHit->fHit.fSector = info->fVolumeID;
658 fCurrentHit->fHit.SetTrack(info->fTrackID);
664 // Double_t dfi2 = param->fAn+2*param->fAd*(fCurrentHit->fR-param->fR);
665 Double_t dfi2 = param->fAn;
666 dfi2*=dfi2*fCurrentHit->fR*fCurrentHit->fR;
667 // Double_t ddz2 = param->fTheta+2*param->fThetaD*(fCurrentHit->fR-param->fR);
668 Double_t ddz2 = param->fTheta;
670 ratio = TMath::Sqrt(1.+ dfi2+ ddz2);
673 fCurrentHit->fHit.fQ = hinfo->fCharge;
674 fCurrentHit->fR += fStep*hinfo->fHitDistance/ratio;
675 Double_t dR = fCurrentHit->fR - param->fR;
677 Double_t fi = param->fFi + (param->fAn*dR+param->fAd*dR*dR);
678 Double_t z = param->fZ + (param->fTheta*dR+param->fThetaD*dR*dR);
680 fCurrentHit->fHit.SetX(fCurrentHit->fR*TMath::Cos(fi));
681 fCurrentHit->fHit.SetY(fCurrentHit->fR*TMath::Sin(fi));
682 fCurrentHit->fHit.SetZ(z);
687 AliTPChit * AliTPCTrackHits::GetHit() const
690 return (fCurrentHit->fStatus)? &fCurrentHit->fHit:0;
691 //return &fCurrentHit->fHit;
697 Bool_t AliTPCTrackHits::Next(Int_t id)
701 if (!(fCurrentHit->fStatus))
704 // fCurrentHit->fStackIndex++;
705 AliHitInfo * hinfo = (AliHitInfo *)fHitsPosAndQ->At(fCurrentHit->fParamIndex,
706 fCurrentHit->fStackIndex);
707 AliTrackHitsInfo *info = (AliTrackHitsInfo *)fTrackHitsInfo->At(fCurrentHit->fInfoIndex);
709 fCurrentHit->fStatus = kFALSE;
712 AliTrackHitsParam *param = (AliTrackHitsParam *)fTrackHitsParam->At(fCurrentHit->fParamIndex);
714 if ( (id>=0) && (info!=0) && (info->fVolumeID!=id)){
715 fCurrentHit->fInfoIndex++;
716 info = (AliTrackHitsInfo *)fTrackHitsInfo->At(fCurrentHit->fInfoIndex);
718 fCurrentHit->fStatus = kFALSE;
721 fCurrentHit->fParamIndex = info->fHitParamIndex;
722 param = (AliTrackHitsParam *)fTrackHitsParam->At(fCurrentHit->fParamIndex);
723 fCurrentHit->fStackIndex =0;
724 fCurrentHit->fR = param->fR;
728 fCurrentHit->fStatus = kFALSE;
732 hinfo = (AliHitInfo *)fHitsPosAndQ->At(fCurrentHit->fParamIndex+1, 0);
734 fCurrentHit->fStatus = kFALSE;
738 fCurrentHit->fParamIndex++;
739 fCurrentHit->fStackIndex = 0;
740 param = (AliTrackHitsParam *)fTrackHitsParam->At(fCurrentHit->fParamIndex);
742 fCurrentHit->fStatus = kFALSE;
745 fCurrentHit->fR = param->fR;
747 if ((fCurrentHit->fInfoIndex+1<fTrackHitsInfo->GetSize())
748 &&((info+1)->fHitParamIndex<=fCurrentHit->fParamIndex)){
749 fCurrentHit->fInfoIndex++;
750 info = (AliTrackHitsInfo *)fTrackHitsInfo->At(fCurrentHit->fInfoIndex);
752 fCurrentHit->fStatus = kFALSE;
755 if ( (id>=0) && (info!=0) && (info->fVolumeID!=id)){
758 fCurrentHit->fHit.fSector = info->fVolumeID;
759 fCurrentHit->fHit.SetTrack(info->fTrackID);
765 // Double_t dfi2 = param->fAn+2*param->fAd*(fCurrentHit->fR-param->fR);
766 Double_t dfi2 = param->fAn;
767 dfi2*=dfi2*fCurrentHit->fR*fCurrentHit->fR;
768 // Double_t ddz2 = param->fTheta+2*param->fThetaD*(fCurrentHit->fR-param->fR);
769 Double_t ddz2 = param->fTheta;
771 ratio = TMath::Sqrt(1.+ dfi2+ ddz2);
774 fCurrentHit->fHit.fQ = hinfo->fCharge;
775 fCurrentHit->fR += fStep*hinfo->fHitDistance/ratio;
776 Double_t dR = fCurrentHit->fR - param->fR;
778 Double_t fi = param->fFi + (param->fAn*dR+param->fAd*dR*dR);
779 Double_t z = param->fZ + (param->fTheta*dR+param->fThetaD*dR*dR);
781 fCurrentHit->fHit.SetX(fCurrentHit->fR*TMath::Cos(fi));
782 fCurrentHit->fHit.SetY(fCurrentHit->fR*TMath::Sin(fi));
783 fCurrentHit->fHit.SetZ(z);
784 fCurrentHit->fHit.fSector = info->fVolumeID;
785 fCurrentHit->fHit.SetTrack(info->fTrackID);
787 fCurrentHit->fStatus = kTRUE;
788 fCurrentHit->fStackIndex++;
793 AliTrackHitsParam * AliTPCTrackHits::GetParam()
796 return (fCurrentHit->fStatus)? (AliTrackHitsParam *)fTrackHitsParam->At(fCurrentHit->fParamIndex) :0;
799 AliHitInfo * AliTPCTrackHits::GetHitInfo()
802 return (fCurrentHit->fStatus)?
803 (AliHitInfo *)fHitsPosAndQ->At(fCurrentHit->fParamIndex,fCurrentHit->fStackIndex) :0;