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 #include "AliTPCTrackHitsInterfaces.h"
44 ClassImp(AliTPCTrackHits)
45 LClassImp(AliTrackHitsInfo)
46 LClassImp(AliTrackHitsParam)
49 Int_t AliTrackHitsInfo::fgCounter1 =0;
50 Int_t AliTrackHitsInfo::fgCounter2 =0;
51 Int_t AliTrackHitsParam::fgCounter1 =0;
52 Int_t AliTrackHitsParam::fgCounter2 =0;
53 Int_t AliHitInfo::fgCounter1 =0;
54 Int_t AliHitInfo::fgCounter2 =0;
55 Int_t AliTPCTrackHits::fgCounter1 =0;
56 Int_t AliTPCTrackHits::fgCounter2 =0;
57 const Double_t AliTPCTrackHits::fgkPrecision=1e-6; //precision
58 const Double_t AliTPCTrackHits::fgkPrecision2=1e-20; //precision
59 const Double_t AliTPCTrackHits::fgkTimePrecision=20.e-9; //hit time precision
62 class AliTPCCurrentHit {
63 friend class AliTPCTrackHits;
65 AliTPChit fHit; // - hit in "standard" representation
66 UInt_t fInfoIndex;// - current info pointer
67 UInt_t fParamIndex;// - current param pointer
68 UInt_t fStackIndex; // - current hit stack index
69 Double_t fR; //current Radius
70 Bool_t fStatus; //current status
74 class AliTPCTempHitInfo {
75 friend class AliTPCTrackHits;
77 enum { kStackSize = 100};
79 AliTPCTempHitInfo(const AliTPCTempHitInfo &)
80 {::Fatal("copy ctor","Not implemented\n");}
81 AliTPCTempHitInfo & operator = (const AliTPCTempHitInfo &)
82 {::Fatal("= operator","Not implemented\n");return *this;}
84 void NewParam(Double_t r, Double_t z, Double_t fi, Int_t q, Float_t time);
85 void SetHit(Double_t r, Double_t z, Double_t fi, Int_t q, Float_t time);
86 Double_t * GetPosition(Int_t index){return &fPositionStack[index*3];}
87 void UpdateParam(Double_t maxdelta); //recal
88 void Fit2(Double_t fSumY, Double_t fSumYX, Double_t fSumYX2,
89 Double_t fSumX, Double_t fSumX2, Double_t fSumX3,
90 Double_t fSumX4, Int_t n,
91 Double_t &a, Double_t &b, Double_t &c);
92 void Fit(AliTrackHitsParam * param);
93 Double_t fSumDr; //fSumDr
94 Double_t fSumDr2; //fSumDr2
95 Double_t fSumDr3; // fSumDr3
96 Double_t fSumDr4; //fSumDr4
97 Double_t fSumDFi; //fSumDFi
98 Double_t fSumDFiDr; // fSumDFiDr
99 Double_t fSumDFiDr2;//fSumDFiDr2
100 Double_t fSumDZ; //fSumDZ
101 Double_t fSumDZDr; //fSumDZDr
102 Double_t fSumDZDr2; //fSumDZDr2
103 Double_t fOldR; //previos r
104 Double_t fPositionStack[3*kStackSize]; //position stack
105 UInt_t fQStack[kStackSize]; //Q stack
106 Float_t fTimeStack[kStackSize]; //time stack
107 UInt_t fStackIndex; //current stack index
108 UInt_t fInfoIndex; //current track info index
109 UInt_t fParamIndex; //current track parameters index
110 AliTrackHitsInfo * fInfo; //current track info
111 AliTrackHitsParam * fParam; //current track param
115 AliTPCTempHitInfo::AliTPCTempHitInfo()
118 //set to default value
119 fSumDr=fSumDr2=fSumDr3=fSumDr4=
120 fSumDFi=fSumDFiDr=fSumDFiDr2=
121 fSumDZ=fSumDZDr=fSumDZDr2=0;
128 void AliTPCTempHitInfo::NewParam(Double_t r, Double_t z, Double_t fi, Int_t q, Float_t time)
131 //reset stack and sum parameters
132 //store line initial point
133 fSumDr=fSumDr2=fSumDr3=fSumDr4=
134 fSumDFi=fSumDFiDr=fSumDFiDr2=
135 fSumDZ=fSumDZDr=fSumDZDr2=0;
145 SetHit(r,z,fi,q,time);
148 void AliTPCTempHitInfo::SetHit(Double_t r, Double_t z, Double_t fi, Int_t q, Float_t time)
151 //add hit to the stack
152 //recalculate new estimete of line parameters
153 Double_t *f = GetPosition(fStackIndex);
157 fQStack[fStackIndex]=q;
158 fTimeStack[fStackIndex]=time;
159 if (fStackIndex==0) return;
160 Double_t dr = (r-fParam->fR);
161 if (TMath::Abs(dr)<AliTPCTrackHits::fgkPrecision) dr =AliTPCTrackHits::fgkPrecision;
162 Double_t dfi = fi-fParam->fFi;
163 Double_t dz = z -fParam->fZ;
165 Double_t dr3 =dr2*dr;
166 Double_t dr4 =dr3*dr;
178 //update fit parameters
180 Double_t det = fSumDr2*fSumDr4-fSumDr3*fSumDr3;
181 if (TMath::Abs(det)<AliTPCTrackHits::fgkPrecision2) return;
182 if ( ( fStackIndex>1 ) ){
183 fParam->fAn = (fSumDr4*fSumDFiDr-fSumDr3*fSumDFiDr2)/det;
184 fParam->fAd = (fSumDr2*fSumDFiDr2-fSumDr3*fSumDFiDr)/det;
187 fParam->fAn = fSumDFiDr/fSumDr2;
188 if ( ( fStackIndex>1 ) ){
189 fParam->fTheta = (fSumDr4*fSumDZDr-fSumDr3*fSumDZDr2)/det;
190 fParam->fThetaD= (fSumDr2*fSumDZDr2-fSumDr3*fSumDZDr)/det;
193 fParam->fTheta = fSumDZDr/fSumDr2;
197 void AliTPCTempHitInfo::UpdateParam(Double_t maxdelta)
199 //recalc parameters not fixing origin point
203 Fit2(fSumDFi, fSumDFiDr, fSumDFiDr2, fSumDr,fSumDr2,fSumDr3,fSumDr4,
205 if (TMath::Abs(a)<maxdelta){
206 fParam->fFi +=a/fParam->fR;
210 Fit2(fSumDZ, fSumDZDr, fSumDZDr2, fSumDr,fSumDr2,fSumDr3,fSumDr4,
211 fStackIndex, a,b,c) ;
212 if (TMath::Abs(a)<maxdelta){
220 void AliTPCTempHitInfo::Fit2(Double_t fSumY, Double_t fSumYX, Double_t fSumYX2,
221 Double_t fSumX, Double_t fSumX2, Double_t fSumX3,
222 Double_t fSumX4, Int_t n,
223 Double_t &a, Double_t &b, Double_t &c)
225 //fit of second order
227 n* (fSumX2*fSumX4-fSumX3*fSumX3) -
228 fSumX* (fSumX*fSumX4-fSumX3*fSumX2)+
229 fSumX2* (fSumX*fSumX3-fSumX2*fSumX2);
231 if (TMath::Abs(det)> AliTPCTrackHits::fgkPrecision) {
233 (fSumY * (fSumX2*fSumX4-fSumX3*fSumX3)-
234 fSumX *(fSumYX*fSumX4-fSumYX2*fSumX3)+
235 fSumX2*(fSumYX*fSumX3-fSumYX2*fSumX2))/det;
237 (n*(fSumYX*fSumX4-fSumX3*fSumYX2)-
238 fSumY*(fSumX*fSumX4-fSumX3*fSumX2)+
239 fSumX2*(fSumX*fSumYX2-fSumYX*fSumX2))/det;
241 (n*(fSumX2*fSumYX2-fSumYX*fSumX3)-
242 fSumX*(fSumX*fSumYX2-fSumYX*fSumX2)+
243 fSumY*(fSumX*fSumX3-fSumX2*fSumX2))/det;
247 void AliTPCTempHitInfo::Fit(AliTrackHitsParam * param)
249 // fit fixing first and the last point
250 //result stored in new param
251 Double_t dx2 = (GetPosition(fStackIndex))[0]-fParam->fR;
252 Double_t det = fSumDr4+dx2*fSumDr2-2*dx2*fSumDr3;
253 if ( (TMath::Abs(det)> AliTPCTrackHits::fgkPrecision) &&
254 ((TMath::Abs(dx2)> AliTPCTrackHits::fgkPrecision))){
255 Double_t dfi2 = (GetPosition(fStackIndex))[1]-fParam->fFi;
256 param->fAd = (fSumDFiDr2+dfi2*fSumDr-dx2*fSumDFiDr-dfi2*fSumDr3/dx2)/det;
257 param->fAn = (dfi2-param->fAd*dx2*dx2)/dx2;
259 Double_t dz2 = (GetPosition(fStackIndex))[1]-fParam->fZ;
260 param->fTheta = (fSumDZDr2+dz2*fSumDr-dx2*fSumDZDr-dz2*fSumDr3/dx2)/det;
261 param->fTheta = (dz2-param->fAd*dx2*dx2)/dx2;
266 //______________________________________________________________________
267 AliTrackHitsInfo::AliTrackHitsInfo() :
273 // Default constructor
279 //______________________________________________________________________
280 AliTrackHitsParam::AliTrackHitsParam() :
290 // Default constructor
297 AliTPCTrackHits::AliTPCTrackHits()
300 //default constructor
302 const Float_t kHitPrecision=0.002; //default precision for hit position in cm
303 const Float_t kStep =0.003; //30 mum step
304 const UShort_t kMaxDistance =100; //maximum distance 100
306 fPrecision=kHitPrecision; //precision in cm
307 fStep = kStep; //step size
308 fMaxDistance = kMaxDistance; //maximum distance
310 fTrackHitsInfo = new AliObjectArray("AliTrackHitsInfo");
311 fTrackHitsParam = new AliObjectArray("AliTrackHitsParam");
312 fHitsPosAndQ = new TArrayOfArrayVStack("AliHitInfo");
313 fCurrentHit = new AliTPCCurrentHit;
319 AliTPCTrackHits::AliTPCTrackHits(const AliTPCTrackHits& r) : TObject(r)
323 AliTPCTrackHits &AliTPCTrackHits::operator=(const AliTPCTrackHits& /* r */)
329 AliTPCTrackHits::~AliTPCTrackHits()
334 if (fTrackHitsInfo) delete fTrackHitsInfo;
335 if (fTrackHitsParam) delete fTrackHitsParam;
336 if (fHitsPosAndQ) delete fHitsPosAndQ;
337 if (fCurrentHit) delete fCurrentHit;
338 if (fTempInfo) delete fTempInfo;
342 void AliTPCTrackHits::Clear()
346 fTrackHitsInfo->Clear();
347 fTrackHitsParam->Clear();
348 //fTrackHitsInfo->Resize(0);
349 //fTrackHitsParam->Resize(0);
350 fHitsPosAndQ->Clear();
359 void AliTPCTrackHits::AddHitKartez(Int_t volumeID, Int_t trackID, Double_t x,
360 Double_t y, Double_t z,Int_t q, Float_t time)
362 //add hits (cartesian)
363 Double_t r = TMath::Sqrt(x*x+y*y);
364 Double_t fi = TMath::ACos(x/r);
366 AddHit(volumeID,trackID,r,z,fi,q,time);
369 void AliTPCTrackHits::AddHit(Int_t volumeID, Int_t trackID,
370 Double_t r, Double_t z, Double_t fi, Int_t q, Float_t time)
374 if (!fTempInfo) { //initialsation of track
375 fTempInfo = new AliTPCTempHitInfo;
377 if (fTrackHitsInfo->GetCapacity()<10) fTrackHitsInfo->Reserve(10);
378 fTrackHitsInfo->Resize(1);
379 fTempInfo->fInfoIndex =0;
380 if (fTrackHitsParam->GetCapacity()<100) fTrackHitsParam->Reserve(100);
381 fTrackHitsParam->Resize(1);
384 (AliTrackHitsInfo*) (fTrackHitsInfo->At(0));
385 fTempInfo->fInfo->fVolumeID = volumeID;
386 fTempInfo->fInfo->fTrackID = trackID;
387 fTempInfo->fInfo->fHitParamIndex =0;
388 fTempInfo->fInfoIndex = 0;
391 (AliTrackHitsParam*) (fTrackHitsParam->At(0));
392 fTempInfo->fParamIndex = 0;
393 fTempInfo->NewParam(r,z,fi,q,time);
397 Int_t size = fHitsPosAndQ->GetSize();
398 if (size>(Int_t)fTempInfo->fParamIndex) {
399 fTempInfo->fParamIndex++;
400 if (fTempInfo->fParamIndex+1>fTrackHitsParam->GetSize())
401 fTrackHitsParam->Resize(fTempInfo->fParamIndex+1);
403 (AliTrackHitsParam*) (fTrackHitsParam->At(fTempInfo->fParamIndex));
404 fTempInfo->NewParam(r,z,fi,q,time);
409 // if new volume or new trackID
410 if ( (volumeID!=fTempInfo->fInfo->fVolumeID) ||
411 (trackID!=fTempInfo->fInfo->fTrackID)){
414 FlushHitStack(kTRUE);
416 fTempInfo->fInfoIndex++;
417 if (fTempInfo->fInfoIndex+1>fTrackHitsInfo->GetSize())
418 fTrackHitsInfo->Resize(fTempInfo->fInfoIndex+1);
420 (AliTrackHitsInfo*) (fTrackHitsInfo->At(fTempInfo->fInfoIndex));
421 fTempInfo->fInfo->fVolumeID = volumeID;
422 fTempInfo->fInfo->fTrackID = trackID;
423 fTempInfo->fInfo->fHitParamIndex =fTempInfo->fParamIndex+1;
424 // FlushHitStack(kTRUE);
426 fTempInfo->fParamIndex++;
427 if (fTempInfo->fParamIndex+1>fTrackHitsParam->GetSize())
428 fTrackHitsParam->Resize(fTempInfo->fParamIndex+1);
430 (AliTrackHitsParam*) (fTrackHitsParam->At(fTempInfo->fParamIndex));
431 fTempInfo->NewParam(r,z,fi,q,time);
435 //calculate current fit precission to next point
436 AliTrackHitsParam ¶m = *(fTempInfo->fParam);
440 Double_t dr,dz,dfi,ddz,ddfi;
442 dr=dz=dfi=ddz=ddfi=0;
443 drhit = r-fTempInfo->fOldR;
445 //Double_t dfi2 = param.fAn+2*param.fAd*(r-param.fR);
446 Double_t dfi2 = param.fAn;
447 dfi2*=dfi2*fTempInfo->fOldR*fTempInfo->fOldR;
448 //Double_t ddz2 = param.fTheta+2*param.fThetaD*(r-param.fR);
449 Double_t ddz2 = param.fTheta;
451 ratio = TMath::Sqrt(1.+ dfi2+ ddz2);
456 dl = (TMath::Abs(drhit*ratio/fStep)<32000) ? fStep * Short_t(TMath::Nint(drhit*ratio/fStep)):0;
457 ddl = dl - drhit*ratio;
458 fTempInfo->fOldR += dl/ratio;
460 if (fTempInfo->fStackIndex>2){
464 ddz = dr*param.fTheta+dr*dr*param.fThetaD-dz;
465 ddfi= dr*param.fAn+dr*dr*param.fAd-dfi;
466 dd = TMath::Sqrt(ddz*ddz+r*r*ddfi*ddfi+ddl*ddl);
470 if ( ( (dd*1.25>fPrecision) ) ||
471 (fTempInfo->fStackIndex+4>fTempInfo->kStackSize) ||
472 (TMath::Abs(dl/fStep)>fMaxDistance) )
475 fTempInfo->fStackIndex++;
476 fTempInfo->SetHit(r,z,fi,q,time);
479 //if parameter changed
480 if (FlushHitStack(kFALSE)){ //if full buffer flushed
481 fTempInfo->fParamIndex++;
482 if (fTempInfo->fParamIndex+1>fTrackHitsParam->GetSize())
483 fTrackHitsParam->Resize(fTempInfo->fParamIndex+1);
485 (AliTrackHitsParam*) (fTrackHitsParam->At(fTempInfo->fParamIndex));
486 fTempInfo->NewParam(r,z,fi,q,time);
489 fTempInfo->fStackIndex++;
490 fTempInfo->SetHit(r,z,fi,q,time);
494 Bool_t AliTPCTrackHits::FlushHitStack(Bool_t force)
497 //write fHitsPosAndQ information from the stack to te arrays
498 if (!fTempInfo) return kFALSE;
499 Int_t size = fHitsPosAndQ->GetSize();
501 if ( (size>0)&&(size!=(Int_t)fTempInfo->fParamIndex)) return kFALSE;
503 if (fHitsPosAndQ->Push(fTempInfo->fStackIndex+1)!=fTempInfo->fParamIndex){
504 cout<<"internal error - contact MI\n";
509 AliTrackHitsParam & param = *(fTempInfo->fParam);
510 //recalculate track parameter not fixing first point
511 fTempInfo->UpdateParam(fStep/4.);
512 //fTempInfo->Fit(fTempInfo->fParam); //- fixing the first and the last point
514 Double_t oldr = param.fR;
515 //cout<<"C3"<<fTempInfo->fStackIndex<<"\n"<<flush;
518 for (i=0; i <= fTempInfo->fStackIndex; i++){
519 Double_t * position = fTempInfo->GetPosition(i);
520 Double_t dr = position[0]-oldr;
523 //Double_t dfi2 = param.fAn+2*param.fAd*(position[0]-param.fR);
524 Double_t dfi2 = param.fAn;
525 dfi2*=dfi2*oldr*oldr;
526 //Double_t ddz2 = param.fTheta+2*param.fThetaD*(position[0]-param.fR);
527 Double_t ddz2 = param.fTheta;
529 ratio = TMath::Sqrt(1.+ dfi2+ ddz2);
532 Double_t dl = (TMath::Abs(dr*ratio/fStep)<32000) ? fStep*(Short_t)TMath::Nint(dr*ratio/fStep):0;
535 //calculate precission
536 AliTrackHitsParam ¶m = *(fTempInfo->fParam);
538 Double_t dr1= position[0]-param.fR;
539 Double_t dz = position[1]-param.fZ;
541 Double_t dfi = position[2]-param.fFi;
542 //extrapolated deltas
543 Double_t dr2 = oldr-param.fR;
544 Double_t ddr = dr2-dr1;
545 Double_t ddz = dr2*param.fTheta+dr2*dr2*param.fThetaD-dz;
546 Double_t ddfi= dr2*param.fAn+dr2*dr2*param.fAd-dfi;
547 dd = TMath::Sqrt(ddz*ddz+oldr*oldr*ddfi*ddfi+ddr*ddr);
549 if ( (dd>fPrecision) ){
555 Double_t ddz = dr2*param.fTheta+dr2*dr2*param.fThetaD-dz;
556 Double_t ddfi= dr2*param.fAn+dr2*dr2*param.fAd-dfi;
558 dd = TMath::Sqrt(ddz*ddz+oldr*oldr*ddfi*ddfi+ddr*ddr);
564 info = (AliHitInfo*)(fHitsPosAndQ->At(fTempInfo->fParamIndex,i));
565 info->fHitDistance = (TMath::Abs(dl/fStep)<32000) ?Short_t(TMath::Nint(dl/fStep)):0;
566 info->fCharge = Short_t(fTempInfo->fQStack[i]);
567 info->fTime = TMath::Nint(fTempInfo->fTimeStack[i]/AliTPCTrackHits::fgkTimePrecision);
570 cout<<" "<<fTempInfo->fStackIndex<<" \t";
572 cout<<position[0]<<"\t";
573 cout<<position[1]<<"\t";
574 cout<<position[2]<<"\t";
575 cout<<param.fAn<<"\t";
576 cout<<param.fTheta<<"\t";
577 cout<<dr1<<"\t"<<ddr<<"\t"<<ddz<<"\t"<<ddfi<<"\t"<<dd<<"\n"<<flush;
581 if (i<=fTempInfo->fStackIndex){ //if previous iteration not succesfull
582 fHitsPosAndQ->Resize(fTempInfo->fParamIndex,i);
584 fTempInfo->fParamIndex++;
585 if (fTempInfo->fParamIndex+1>fTrackHitsParam->GetSize())
586 fTrackHitsParam->Resize(fTempInfo->fParamIndex+1);
588 (AliTrackHitsParam*) (fTrackHitsParam->At(fTempInfo->fParamIndex));
589 Double_t * p = fTempInfo->GetPosition(i);
590 UInt_t index2 = fTempInfo->fStackIndex;
591 fTempInfo->NewParam(p[0],p[1],p[2],fTempInfo->fQStack[i],fTempInfo->fTimeStack[i]);
592 if (i+1<=index2) FlushHitStack2(i+1,index2);
594 if (force) return FlushHitStack(kTRUE);
601 void AliTPCTrackHits::FlushHitStack2(Int_t index1, Int_t index2)
604 // second iteration flush stack
605 // call only for hits where first iteration were not succesfully interpolated
606 Double_t * positionstack = new Double_t[3*(index2-index1+1)];
607 UInt_t * qstack = new UInt_t[index2-index1+1];
608 Float_t * timestack = new Float_t[index2-index1+1];
609 memcpy(positionstack, &fTempInfo->fPositionStack[3*index1],
610 (3*(index2-index1+1))*sizeof(Double_t));
611 memcpy(qstack, &fTempInfo->fQStack[index1],(index2-index1+1)*sizeof(UInt_t));
612 memcpy(timestack, &fTempInfo->fTimeStack[index1],(index2-index1+1)*sizeof(Float_t));
613 Double_t *p = positionstack;
614 for (Int_t j=0; j<=index2-index1;j++){
615 fTempInfo->fStackIndex++;
616 fTempInfo->SetHit(p[3*j+0],p[3*j+1],p[3*j+2],qstack[j],timestack[j]);
618 delete []positionstack;
631 Bool_t AliTPCTrackHits::First()
634 //set Current hit for the first hit
636 AliTrackHitsInfo *info = (AliTrackHitsInfo *)fTrackHitsInfo->At(0);
637 AliTrackHitsParam *param = (AliTrackHitsParam *)fTrackHitsParam->At(0);
638 AliHitInfo * hinfo = (AliHitInfo *)fHitsPosAndQ->At(0,0);
640 if (!(info) || !(param) || !(hinfo) ) {
641 fCurrentHit->fStatus = kFALSE;
645 fCurrentHit->fInfoIndex = 0;
646 fCurrentHit->fParamIndex = 0;
647 fCurrentHit->fStackIndex = 0;
649 fCurrentHit->fHit.fSector = info->fVolumeID;
650 fCurrentHit->fHit.SetTrack(info->fTrackID);
651 fCurrentHit->fHit.SetX(param->fR*TMath::Cos(param->fFi));
652 fCurrentHit->fHit.SetY(param->fR*TMath::Sin(param->fFi));
653 fCurrentHit->fHit.SetZ(param->fZ);
654 fCurrentHit->fHit.fQ = (Float_t)(hinfo->fCharge*AliTPCTrackHits::fgkTimePrecision);
655 fCurrentHit->fHit.fTime = hinfo->fTime;
657 fCurrentHit->fR = param->fR;
659 return fCurrentHit->fStatus = kTRUE;
664 Bool_t AliTPCTrackHits::Next()
668 if (!(fCurrentHit->fStatus))
671 fCurrentHit->fStackIndex++;
672 AliHitInfo * hinfo = (AliHitInfo *)fHitsPosAndQ->At(fCurrentHit->fParamIndex,
673 fCurrentHit->fStackIndex);
674 AliTrackHitsInfo *info = (AliTrackHitsInfo *)fTrackHitsInfo->At(fCurrentHit->fInfoIndex);
675 AliTrackHitsParam *param = (AliTrackHitsParam *)fTrackHitsParam->At(fCurrentHit->fParamIndex);
678 hinfo = (AliHitInfo *)fHitsPosAndQ->At(fCurrentHit->fParamIndex+1, 0);
680 return fCurrentHit->fStatus = kFALSE;
682 fCurrentHit->fParamIndex++;
683 fCurrentHit->fStackIndex = 0;
684 param = (AliTrackHitsParam *)fTrackHitsParam->At(fCurrentHit->fParamIndex);
686 return fCurrentHit->fStatus = kFALSE;
687 fCurrentHit->fR = param->fR;
689 if ((fCurrentHit->fInfoIndex+1<fTrackHitsInfo->GetSize())
690 &&((info+1)->fHitParamIndex<=fCurrentHit->fParamIndex)){
691 fCurrentHit->fInfoIndex++;
692 info = (AliTrackHitsInfo *)fTrackHitsInfo->At(fCurrentHit->fInfoIndex);
694 return fCurrentHit->fStatus = kFALSE;
695 fCurrentHit->fHit.fSector = info->fVolumeID;
696 fCurrentHit->fHit.SetTrack(info->fTrackID);
702 // Double_t dfi2 = param->fAn+2*param->fAd*(fCurrentHit->fR-param->fR);
703 Double_t dfi2 = param->fAn;
704 dfi2*=dfi2*fCurrentHit->fR*fCurrentHit->fR;
705 // Double_t ddz2 = param->fTheta+2*param->fThetaD*(fCurrentHit->fR-param->fR);
706 Double_t ddz2 = param->fTheta;
708 ratio = TMath::Sqrt(1.+ dfi2+ ddz2);
711 fCurrentHit->fHit.fQ = hinfo->fCharge;
712 fCurrentHit->fHit.fTime = (Float_t)(hinfo->fTime*AliTPCTrackHits::fgkTimePrecision);
713 fCurrentHit->fR += fStep*hinfo->fHitDistance/ratio;
714 Double_t dR = fCurrentHit->fR - param->fR;
716 Double_t fi = param->fFi + (param->fAn*dR+param->fAd*dR*dR);
717 Double_t z = param->fZ + (param->fTheta*dR+param->fThetaD*dR*dR);
719 fCurrentHit->fHit.SetX(fCurrentHit->fR*TMath::Cos(fi));
720 fCurrentHit->fHit.SetY(fCurrentHit->fR*TMath::Sin(fi));
721 fCurrentHit->fHit.SetZ(z);
726 AliTPChit * AliTPCTrackHits::GetHit() const
729 return (fCurrentHit->fStatus)? &fCurrentHit->fHit:0;
730 //return &fCurrentHit->fHit;
736 Bool_t AliTPCTrackHits::Next(Int_t id)
740 if (!(fCurrentHit->fStatus))
743 // fCurrentHit->fStackIndex++;
744 AliHitInfo * hinfo = (AliHitInfo *)fHitsPosAndQ->At(fCurrentHit->fParamIndex,
745 fCurrentHit->fStackIndex);
746 AliTrackHitsInfo *info = (AliTrackHitsInfo *)fTrackHitsInfo->At(fCurrentHit->fInfoIndex);
748 fCurrentHit->fStatus = kFALSE;
751 AliTrackHitsParam *param = (AliTrackHitsParam *)fTrackHitsParam->At(fCurrentHit->fParamIndex);
753 if ( (id>=0) && (info!=0) && (info->fVolumeID!=id)){
754 fCurrentHit->fInfoIndex++;
755 info = (AliTrackHitsInfo *)fTrackHitsInfo->At(fCurrentHit->fInfoIndex);
757 fCurrentHit->fStatus = kFALSE;
760 fCurrentHit->fParamIndex = info->fHitParamIndex;
761 param = (AliTrackHitsParam *)fTrackHitsParam->At(fCurrentHit->fParamIndex);
762 fCurrentHit->fStackIndex =0;
763 fCurrentHit->fR = param->fR;
767 fCurrentHit->fStatus = kFALSE;
771 hinfo = (AliHitInfo *)fHitsPosAndQ->At(fCurrentHit->fParamIndex+1, 0);
773 fCurrentHit->fStatus = kFALSE;
777 fCurrentHit->fParamIndex++;
778 fCurrentHit->fStackIndex = 0;
779 param = (AliTrackHitsParam *)fTrackHitsParam->At(fCurrentHit->fParamIndex);
781 fCurrentHit->fStatus = kFALSE;
784 fCurrentHit->fR = param->fR;
786 if ((fCurrentHit->fInfoIndex+1<fTrackHitsInfo->GetSize())
787 &&((info+1)->fHitParamIndex<=fCurrentHit->fParamIndex)){
788 fCurrentHit->fInfoIndex++;
789 info = (AliTrackHitsInfo *)fTrackHitsInfo->At(fCurrentHit->fInfoIndex);
791 fCurrentHit->fStatus = kFALSE;
794 if ( (id>=0) && (info!=0) && (info->fVolumeID!=id)){
797 fCurrentHit->fHit.fSector = info->fVolumeID;
798 fCurrentHit->fHit.SetTrack(info->fTrackID);
804 // Double_t dfi2 = param->fAn+2*param->fAd*(fCurrentHit->fR-param->fR);
805 Double_t dfi2 = param->fAn;
806 dfi2*=dfi2*fCurrentHit->fR*fCurrentHit->fR;
807 // Double_t ddz2 = param->fTheta+2*param->fThetaD*(fCurrentHit->fR-param->fR);
808 Double_t ddz2 = param->fTheta;
810 ratio = TMath::Sqrt(1.+ dfi2+ ddz2);
813 fCurrentHit->fHit.fQ = hinfo->fCharge;
814 fCurrentHit->fHit.fTime = (Float_t)(hinfo->fTime*AliTPCTrackHits::fgkTimePrecision);
815 fCurrentHit->fR += fStep*hinfo->fHitDistance/ratio;
816 Double_t dR = fCurrentHit->fR - param->fR;
818 Double_t fi = param->fFi + (param->fAn*dR+param->fAd*dR*dR);
819 Double_t z = param->fZ + (param->fTheta*dR+param->fThetaD*dR*dR);
821 fCurrentHit->fHit.SetX(fCurrentHit->fR*TMath::Cos(fi));
822 fCurrentHit->fHit.SetY(fCurrentHit->fR*TMath::Sin(fi));
823 fCurrentHit->fHit.SetZ(z);
824 fCurrentHit->fHit.fSector = info->fVolumeID;
825 fCurrentHit->fHit.SetTrack(info->fTrackID);
827 fCurrentHit->fStatus = kTRUE;
828 fCurrentHit->fStackIndex++;
833 AliTrackHitsParam * AliTPCTrackHits::GetParam()
836 return (fCurrentHit->fStatus)? (AliTrackHitsParam *)fTrackHitsParam->At(fCurrentHit->fParamIndex) :0;
839 AliHitInfo * AliTPCTrackHits::GetHitInfo()
842 return (fCurrentHit->fStatus)?
843 (AliHitInfo *)fHitsPosAndQ->At(fCurrentHit->fParamIndex,fCurrentHit->fStackIndex) :0;