6 gSystem->Load("libSTAT.so");
9 .L $ALICE_ROOT/TPC/fastSimul/AliTPCclusterFast.cxx+
11 AliTPCclusterFast::fPRF = new TF1("fprf","gausn",-5,5);
12 AliTPCclusterFast::fTRF = new TF1("ftrf","gausn",-5,5);
13 AliTPCclusterFast::fPRF->SetParameters(1,0,0.5);
14 AliTPCclusterFast::fTRF->SetParameters(1,0,0.5);
17 AliTPCtrackFast::Simul("trackerSimul.root",100);
18 // AliTPCclusterFast::Simul("cluterSimul.root",20000);
28 #include "TClonesArray.h"
29 #include "TTreeStream.h"
31 class AliTPCclusterFast: public TObject {
36 virtual ~AliTPCclusterFast();
37 void SetParam(Float_t mnprim, Float_t diff, Float_t diffL, Float_t y, Float_t z, Float_t ky, Float_t kz);
38 static void GenerElectrons(AliTPCclusterFast *cl0, AliTPCclusterFast *clm, AliTPCclusterFast *clp);
40 Double_t GetQtot(Float_t gain,Float_t thr, Float_t noise, Bool_t rounding=kTRUE, Bool_t addPedestal=kTRUE);
41 Double_t GetQmax(Float_t gain,Float_t thr, Float_t noise, Bool_t rounding=kTRUE, Bool_t addPedestal=kTRUE);
42 Double_t GetQmaxCorr(Float_t rmsy0, Float_t rmsz0);
43 Double_t GetQtotCorr(Float_t rmsy0, Float_t rmsz0, Float_t gain, Float_t thr);
46 //static void Simul(const char* simul, Int_t npoints);
47 static Double_t GaussConvolution(Double_t x0, Double_t x1, Double_t k0, Double_t k1, Double_t s0, Double_t s1);
48 static Double_t GaussExpConvolution(Double_t x0, Double_t s0,Double_t t1);
49 static Double_t GaussGamma4(Double_t x, Double_t s0, Double_t p1);
50 static Double_t Gamma4(Double_t x, Double_t p0, Double_t p1);
52 Float_t fMNprim; // mean number of primary electrons
53 // //electrons part input
54 Int_t fNprim; // mean number of primary electrons
55 Int_t fNtot; // total number of electrons
56 Float_t fQtot; // total charge - Gas gain flucuation taken into account
58 Float_t fDiff; // diffusion sigma
59 Float_t fDiffLong; // diffusion sigma longitudinal direction
60 Float_t fY; // y position
61 Float_t fZ; // z postion
62 Float_t fAngleY; // y angle - tan(y)
63 Float_t fAngleZ; // z angle - tan z
66 // // electron part simul
67 TVectorD fSec; //! number of secondary electrons
68 TVectorD fPosY; //! position y for each electron
69 TVectorD fPosZ; //! position z for each electron
70 TVectorD fGain; //! gg for each electron
72 TVectorD fStatY; //!stat Y
73 TVectorD fStatZ; //!stat Y
77 TMatrixD fDigits; // response matrix
78 static TF1* fPRF; // Pad response
79 static TF1* fTRF; // Time response function
80 ClassDef(AliTPCclusterFast,1) // container for
84 class AliTPCtrackFast: public TObject {
87 void Add(AliTPCtrackFast &track2);
89 static void Simul(const char* simul, Int_t ntracks);
90 Double_t CookdEdxNtot(Double_t f0,Float_t f1);
91 Double_t CookdEdxQtot(Double_t f0,Float_t f1);
92 Double_t CookdEdxNtotThr(Double_t f0,Float_t f1, Double_t thr, Int_t mode);
93 Double_t CookdEdxQtotThr(Double_t f0,Float_t f1, Double_t thr, Int_t mode);
95 Double_t CookdEdxDtot(Double_t f0,Float_t f1, Float_t gain,Float_t thr, Float_t noise, Bool_t corr, Int_t mode);
96 Double_t CookdEdxDmax(Double_t f0,Float_t f1,Float_t gain,Float_t thr, Float_t noise, Bool_t corr, Int_t mode);
98 Double_t CookdEdx(Int_t npoints, Double_t *amp, Double_t f0,Float_t f1, Int_t mode);
100 Float_t fMNprim; // mean number of primary electrons
101 Float_t fAngleY; // y angle - tan(y)
102 Float_t fAngleZ; // z angle - tan z
103 Float_t fDiff; // diffusion
104 Float_t fDiffLong; // diffusion sigma longitudinal direction
105 Int_t fN; // number of clusters
106 TClonesArray *fCl; // array of clusters
108 Bool_t fInit; // initialization flag
111 ClassDef(AliTPCtrackFast,2) // container for
116 ClassImp(AliTPCclusterFast)
117 ClassImp(AliTPCtrackFast)
123 TF1 *AliTPCclusterFast::fPRF=0;
124 TF1 *AliTPCclusterFast::fTRF=0;
127 AliTPCtrackFast::AliTPCtrackFast():
141 void AliTPCtrackFast::Add(AliTPCtrackFast &track2){
142 if (!track2.fInit) return;
148 void AliTPCtrackFast::MakeTrack(){
152 if (!fCl) fCl = new TClonesArray("AliTPCclusterFast",160);
153 for (Int_t i=0;i<fN;i++){
154 AliTPCclusterFast * cluster = (AliTPCclusterFast*) fCl->UncheckedAt(i);
155 if (!cluster) cluster = new ((*fCl)[i]) AliTPCclusterFast;
159 for (Int_t i=0;i<fN;i++){
160 Double_t tY = i*fAngleY;
161 Double_t tZ = i*fAngleZ;
162 AliTPCclusterFast * cluster = (AliTPCclusterFast*) fCl->UncheckedAt(i);
163 AliTPCclusterFast * clusterm = (AliTPCclusterFast*) fCl->UncheckedAt(TMath::Max(i-1,0));
164 AliTPCclusterFast * clusterp = (AliTPCclusterFast*) fCl->UncheckedAt(TMath::Min(i+1,159));
165 if (!cluster) cluster = new ((*fCl)[i]) AliTPCclusterFast;
167 Double_t posY = tY-TMath::Nint(tY);
168 Double_t posZ = tZ-TMath::Nint(tZ);
169 cluster->SetParam(fMNprim,fDiff, fDiffLong, posY,posZ,fAngleY,fAngleZ);
171 cluster->GenerElectrons(cluster, clusterm, clusterp);
176 Double_t AliTPCtrackFast::CookdEdxNtot(Double_t f0,Float_t f1){
178 // Double_t CookdEdxNtot(Double_t f0,Float_t f1); // dEdx_{hit} reconstructed meen number of electrons
181 for (Int_t i=0;i<fN;i++){
182 AliTPCclusterFast * cluster = ( AliTPCclusterFast *)((*fCl)[i]);
183 amp[i]=cluster->fNtot;
185 return CookdEdx(fN,amp,f0,f1,0);
188 Double_t AliTPCtrackFast::CookdEdxQtot(Double_t f0,Float_t f1){
190 // dEdx_{Q} reconstructed mean number of electronsxGain
193 for (Int_t i=0;i<fN;i++){
194 AliTPCclusterFast * cluster = ( AliTPCclusterFast *)((*fCl)[i]);
195 amp[i]=cluster->fQtot;
197 return CookdEdx(fN,amp,f0,f1,0);
201 Double_t AliTPCtrackFast::CookdEdxNtotThr(Double_t f0,Float_t f1, Double_t thr, Int_t mode){
203 // dEdx_{hit} reconstructed mean number of electrons
204 // thr = threshold in terms of the number of electrons
205 // mode = algorithm to deal with trhesold values replacing
210 Double_t minAbove=-1;
211 for (Int_t i=0;i<fN;i++){
212 AliTPCclusterFast * cluster = ( AliTPCclusterFast *)((*fCl)[i]);
213 Double_t clQ= cluster->fNtot;
218 if (minAbove<0) minAbove=clQ;
219 if (minAbove>clQ) minAbove=clQ;
222 if (mode==-1) return Double_t(nBellow)/Double_t(fN);
224 for (Int_t i=0;i<fN;i++){
225 AliTPCclusterFast * cluster = ( AliTPCclusterFast *)((*fCl)[i]);
226 Double_t clQ= cluster->fNtot;
228 if (mode==0) amp[i]=clQ; // mode0 - not threshold - keep default
231 if (mode==1 && clQ>thr) amp[i]=clQ; // mode1 - skip if bellow
232 if (mode==1 && clQ<thr) amp[i]=0; // mode1 - skip if bellow
235 if (mode==2 && clQ>thr) amp[i]=clQ; // mode2 - use 0 if below
236 if (mode==2 && clQ<thr) amp[i]=0; // mode2 - use 0 if below
239 if (mode==3) amp[i]=(clQ>thr)?clQ:thr; // mode3 - use thr if below
240 if (mode==4) amp[i]=(clQ>thr)?clQ:minAbove; // mode4 - use minimal above threshold if bellow thr
242 return CookdEdx(fN,amp,f0,f1, mode);
247 Double_t AliTPCtrackFast::CookdEdxQtotThr(Double_t f0,Float_t f1, Double_t thr, Int_t mode){
250 // dEdx_{Q} reconstructed mean number of electrons xgain
251 // thr = threshold in terms of the number of electrons
252 // mode = algorithm to deal with trhesold values replacing
259 Double_t minAbove=-1;
260 for (Int_t i=0;i<fN;i++){
261 AliTPCclusterFast * cluster = ( AliTPCclusterFast *)((*fCl)[i]);
262 Double_t clQ= cluster->fQtot;
267 if (minAbove<0) minAbove=clQ;
268 if (minAbove>clQ) minAbove=clQ;
271 if (mode==-1) return Double_t(nBellow)/Double_t(fN);
273 for (Int_t i=0;i<fN;i++){
274 AliTPCclusterFast * cluster = ( AliTPCclusterFast *)((*fCl)[i]);
275 Double_t clQ= cluster->fQtot;
277 if (mode==0) amp[i]=clQ; // mode0 - not threshold - keep default
280 if (mode==1 && clQ>thr) amp[i]=clQ; // mode1 - skip if bellow
281 if (mode==1 && clQ<thr) amp[i]=0; // mode1 - skip if bellow
284 if (mode==2 && clQ>thr) amp[i]=clQ; // mode2 - use 0 if below
285 if (mode==2 && clQ<thr) amp[i]=0; // mode2 - use 0 if below
288 if (mode==3) amp[i]=(clQ>thr)?clQ:thr; // mode3 - use thr if below
289 if (mode==4) amp[i]=(clQ>thr)?clQ:minAbove; // mode4 - use minimal above threshold if bellow thr
291 return CookdEdx(fN,amp,f0,f1, mode);
298 Double_t AliTPCtrackFast::CookdEdxDtot(Double_t f0,Float_t f1, Float_t gain,Float_t thr, Float_t noise, Bool_t doCorr, Int_t mode){
300 // total charge in the cluster (sum of the pad x time matrix ), hits were digitized before, but additional
301 // actions can be specified by switches // dEdx_{Qtot}
306 for (Int_t i=0;i<fN;i++){
307 AliTPCclusterFast * cluster = ( AliTPCclusterFast *)((*fCl)[i]);
309 if (mode==0) camp = cluster->GetQtot(gain,0,noise);
311 camp = cluster->GetQtot(gain,thr,noise);
313 if (doCorr) corr = cluster->GetQtotCorr(0.5,0.5,gain,thr);
317 if (minAmp <0) minAmp=camp;
318 if (minAmp >camp) minAmp=camp;
321 if (mode==3) for (Int_t i=0;i<fN;i++) if (amp[i]<=0) amp[i]=thr;
322 if (mode==4) for (Int_t i=0;i<fN;i++) if (amp[i]<=0) amp[i]=minAmp;
323 return CookdEdx(fN,amp,f0,f1, mode);
328 Double_t AliTPCtrackFast::CookdEdxDmax(Double_t f0,Float_t f1, Float_t gain,Float_t thr, Float_t noise, Bool_t doCorr, Int_t mode){
330 // maximal charge in the cluster (maximal amplitude in the digit matrix), hits were digitized before,
331 // but additional actions can be specified by switches
336 for (Int_t i=0;i<fN;i++){
337 AliTPCclusterFast * cluster = ( AliTPCclusterFast *)((*fCl)[i]);
339 if (mode==0) camp = cluster->GetQmax(gain,0,noise);
341 camp = cluster->GetQmax(gain,thr,noise);
343 if (doCorr) corr = cluster->GetQmaxCorr(0.5,0.5);
347 if (minAmp <0) minAmp=camp;
348 if (minAmp >camp) minAmp=camp;
351 if (mode==3) for (Int_t i=0;i<fN;i++) if (amp[i]<=0) amp[i]=thr;
352 if (mode==4) for (Int_t i=0;i<fN;i++) if (amp[i]<=0) amp[i]=minAmp;
353 return CookdEdx(fN,amp,f0,f1, mode);
357 Double_t AliTPCtrackFast::CookdEdx(Int_t npoints, Double_t *amp,Double_t f0,Float_t f1, Int_t mode){
359 // Calculate truncated mean
360 // npoints - number of points in array
361 // amp - array with points
362 // f0-f1 - truncation range
363 // mode - specify handling of the 0 clusters, actual handling - filling of amplitude defiend in algorithm above
364 // mode = 0 - accept everything
365 // mode = 1 - do not count 0 amplitudes
366 // mode = 2 - use 0 amplitude as it is
367 // mode = 3 - use amplitude as it is (in above function amp. replace by the thr)
368 // mode = 4 - use amplitude as it is (in above function amp. replace by the minimal amplitude)
372 // 0. sorted the array of amplitudes
375 TMath::Sort(npoints,amp,index,kFALSE);
377 // 1.) Calculate truncated mean from the selected range of the array (ranking statistic )
378 // dependening on the mode 0 amplitude can be skipped
379 Float_t sum0=0, sum1=0,sum2=0;
382 for (Int_t i=0;i<npoints;i++) if (amp[index[i]]>0) above++;
384 for (Int_t i=0;i<npoints;i++){
386 if (mode==1 && amp[index[i]]==0) {
389 if (accepted<npoints*f0) continue;
390 if (accepted>npoints*f1) continue;
392 sum1+= amp[index[i]];
393 sum2+= amp[index[i]];
396 if (mode==-1) return 1-Double_t(above)/Double_t(npoints);
397 if (sum0<=0) return 0;
401 void AliTPCtrackFast::Simul(const char* fname, Int_t ntracks){
405 AliTPCtrackFast fast;
406 TTreeSRedirector cstream(fname,"recreate");
407 for (Int_t itr=0; itr<ntracks; itr++){
409 fast.fMNprim=(10.+100*gRandom->Rndm());
410 if (gRandom->Rndm()>0.5) fast.fMNprim=1./(0.00001+gRandom->Rndm()*0.1);
412 fast.fDiff =0.01 +0.35*gRandom->Rndm();
413 fast.fDiffLong = fast.fDiff*0.6/1.;
415 fast.fAngleY = 4.0*(gRandom->Rndm()-0.5);
416 fast.fAngleZ = 4.0*(gRandom->Rndm()-0.5);
419 if (itr%100==0) printf("%d\n",itr);
420 cstream<<"simulTrack"<<
429 AliTPCclusterFast::AliTPCclusterFast(){
432 fDigits.ResizeTo(5,7);
435 void AliTPCclusterFast::Init(){
437 // reset all counters
439 const Int_t knMax=1000;
440 fMNprim=0; // mean number of primary electrons
441 // //electrons part input
442 fNprim=0; // mean number of primary electrons
443 fNtot=0; // total number of electrons
444 fQtot=0; // total charge - Gas gain flucuation taken into account
446 fPosY.ResizeTo(knMax);
447 fPosZ.ResizeTo(knMax);
448 fGain.ResizeTo(knMax);
449 fSec.ResizeTo(knMax);
452 for (Int_t i=0; i<knMax; i++){
461 AliTPCclusterFast::~AliTPCclusterFast(){
465 void AliTPCclusterFast::SetParam(Float_t mnprim, Float_t diff, Float_t diffL,Float_t y, Float_t z, Float_t ky, Float_t kz){
468 fMNprim = mnprim; fDiff = diff; fDiffLong=diffL;
470 fAngleY=ky; fAngleZ=kz;
472 Double_t AliTPCclusterFast::GetNsec(){
474 // Generate number of secondary electrons
475 // copy of procedure implemented in geant
477 const Double_t FPOT=20.77E-9, EEND=10E-6, EEXPO=2.2, EEND1=1E-6;
478 const Double_t XEXPO=-EEXPO+1, YEXPO=1/XEXPO;
479 const Double_t W=20.77E-9;
480 Float_t RAN = gRandom->Rndm();
481 //Double_t edep = TMath::Power((TMath::Power(FPOT,XEXPO)*(1-RAN)+TMath::Power(EEND,XEXPO)*RAN),YEXPO);
482 //edep = TMath::Min(edep, EEND);
483 //return TMath::Nint(edep/W);
484 return TMath::Nint(TMath::Power((TMath::Power(FPOT,XEXPO)*(1-RAN)+TMath::Power(EEND,XEXPO)*RAN),YEXPO)/W);
487 void AliTPCclusterFast::GenerElectrons(AliTPCclusterFast *cl0, AliTPCclusterFast *clm, AliTPCclusterFast *clp){
492 const Int_t knMax=1000;
493 cl0->fNprim = gRandom->Poisson(cl0->fMNprim); //number of primary electrons
494 cl0->fNtot=0; //total number of electrons
495 cl0->fQtot=0; //total number of electrons after gain multiplification
502 for (Int_t i=0;i<knMax;i++){
505 for (Int_t iprim=0; iprim<cl0->fNprim;iprim++){
506 Float_t dN = cl0->GetNsec();
508 Double_t yc = cl0->fY+(gRandom->Rndm()-0.5)*cl0->fAngleY;
509 Double_t zc = cl0->fZ+(gRandom->Rndm()-0.5)*cl0->fAngleZ;
510 Double_t rc = (gRandom->Rndm()-0.5);
512 for (Int_t isec=0;isec<=dN;isec++){
515 Double_t y = gRandom->Gaus(0,cl0->fDiff)+yc;
516 Double_t z = gRandom->Gaus(0,cl0->fDiff)+zc;
517 Double_t r = gRandom->Gaus(0,cl0->fDiffLong)+rc;
519 AliTPCclusterFast *cl=cl0;
520 if (r<-0.5 &&cl) cl=clm;
521 if (r>0.5 &&cl) cl=clp;
523 Double_t gg = -TMath::Log(gRandom->Rndm());
524 cl->fPosY[cl->fNtot]=y;
525 cl->fPosZ[cl->fNtot]=z;
526 cl->fGain[cl->fNtot]=gg;
532 // cl->sumY2Q+=gg*y*y;
534 // cl->sumZ2Q+=gg*z*z;
535 if (cl->fNtot>=knMax) continue;
537 if (cl0->fNtot>=knMax) break;
542 // fStatY[1]=sumYQ/sumQ;
543 // fStatY[2]=sumY2Q/sumQ-fStatY[1]*fStatY[1];
545 // fStatZ[1]=sumZQ/sumQ;
546 // fStatZ[2]=sumZ2Q/sumQ-fStatZ[1]*fStatZ[1];
550 void AliTPCclusterFast::Digitize(){
555 for (Int_t i=0; i<5;i++)
556 for (Int_t j=0; j<7;j++){
561 for (Int_t iel = 0; iel<fNtot; iel++){
562 for (Int_t di=-2; di<=2;di++)
563 for (Int_t dj=-3; dj<=3;dj++){
564 Float_t fac = fPRF->Eval(di-fPosY[iel])*fTRF->Eval(dj-fPosZ[iel]);
566 fDigits(2+di,3+dj)+=fac;
576 // void AliTPCclusterFast::Simul(const char* fname, Int_t npoints){
580 // AliTPCclusterFast fast;
581 // TTreeSRedirector cstream(fname);
582 // for (Int_t icl=0; icl<npoints; icl++){
583 // Float_t nprim=(10+20*gRandom->Rndm());
584 // Float_t diff =0.01 +0.35*gRandom->Rndm();
585 // Float_t posY = gRandom->Rndm()-0.5;
586 // Float_t posZ = gRandom->Rndm()-0.5;
588 // Float_t ky = 4.0*(gRandom->Rndm()-0.5);
589 // Float_t kz = 4.0*(gRandom->Rndm()-0.5);
590 // fast.SetParam(nprim,diff,posY,posZ,ky,kz);
591 // fast.GenerElectrons();
593 // if (icl%10000==0) printf("%d\n",icl);
594 // cstream<<"simul"<<
601 Double_t AliTPCclusterFast::GetQtot(Float_t gain, Float_t thr, Float_t noise, Bool_t brounding, Bool_t baddPedestal){
606 for (Int_t ip=0;ip<5;ip++){
607 Float_t pedestal=gRandom->Rndm()-0.5; //pedestal offset different for each pad
608 for (Int_t it=0;it<7;it++){
609 Float_t amp = gain*fDigits(ip,it)+gRandom->Gaus()*noise;
610 if (baddPedestal) amp+=pedestal;
611 if (brounding) amp=TMath::Nint(amp);
612 if (amp>thr) sum+=amp;
618 Double_t AliTPCclusterFast::GetQmax(Float_t gain, Float_t thr, Float_t noise, Bool_t brounding, Bool_t baddPedestal){
623 for (Int_t ip=0;ip<5;ip++){
624 Float_t pedestal=gRandom->Rndm()-0.5; //pedestal offset different for each pad
625 for (Int_t it=0;it<7;it++){
626 Float_t amp = gain*fDigits(ip,it)+gRandom->Gaus()*noise;
627 if (baddPedestal) amp+=pedestal;
628 if (brounding) amp=TMath::Nint(amp);
629 if (amp>max && amp>thr) max=amp;
637 Double_t AliTPCclusterFast::GetQmaxCorr(Float_t rmsy0, Float_t rmsz0){
639 // Gaus distribution convolueted with rectangular
640 // Gaus width sy and sz is determined by RF width and diffusion
641 // Integral of Q is equal 1
642 // Q max is calculated at position fY,fX
646 Double_t sy = TMath::Sqrt(rmsy0*rmsy0+fDiff*fDiff);
647 Double_t sz = TMath::Sqrt(rmsz0*rmsz0+fDiff*fDiff);
648 return GaussConvolution(fY,fZ, fAngleY,fAngleZ,sy,sz);
652 Double_t AliTPCclusterFast::GetQtotCorr(Float_t rmsy0, Float_t rmsz0, Float_t gain, Float_t thr){
654 // Calculates the fraction of the charge over threshol to total charge
655 // The response function
657 Double_t sy = TMath::Sqrt(rmsy0*rmsy0+fDiff*fDiff);
658 Double_t sz = TMath::Sqrt(rmsz0*rmsz0+fDiff*fDiff);
659 Double_t sumAll=0,sumThr=0;
660 Double_t qtot = GetQtot(gain,thr,0); // sum of signal over threshold
664 for (Int_t iter=0;iter<2;iter++){
665 for (Int_t iy=-2;iy<=2;iy++)
666 for (Int_t iz=-2;iz<=2;iz++){
667 Double_t val = GaussConvolution(fY-iy,fZ-iz, fAngleY,fAngleZ,sy,sz);
668 Double_t qlocal =TMath::Nint(qnorm*val);
669 if (qlocal>thr) sumThr+=qlocal;
672 if (sumAll>0&&sumThr>0) corr=(sumThr)/sumAll;
674 if (corr>0) qnorm=qtot/corr;
684 Double_t AliTPCclusterFast::GaussConvolution(Double_t x0, Double_t x1, Double_t k0, Double_t k1, Double_t s0, Double_t s1){
686 // 2 D gaus convoluted with angular effect
687 // See in mathematica:
688 //Simplify[Integrate[Exp[-(x0-k0*xd)*(x0-k0*xd)/(2*s0*s0)-(x1-k1*xd)*(x1-k1*xd)/(2*s1*s1)]/(s0*s1),{xd,-1/2,1/2}]]
690 //TF1 f1("f1","AliTPCclusterFast::GaussConvolution(x,0,1,0,0.1,0.1)",-2,2)
691 //TF2 f2("f2","AliTPCclusterFast::GaussConvolution(x,y,1,1,0.1,0.1)",-2,2,-2,2)
693 const Float_t kEpsilon = 0.0001;
694 if ((TMath::Abs(k0)+TMath::Abs(k1))<kEpsilon*(s0+s1)){
695 // small angular effect
696 Double_t val = (TMath::Gaus(x0,0,s0)*TMath::Gaus(x1,0,s1))/(s0*s1*2.*TMath::Pi());
700 Double_t sigma2 = k1*k1*s0*s0+k0*k0*s1*s1;
701 Double_t exp0 = TMath::Exp(-(k1*x0-k0*x1)*(k1*x0-k0*x1)/(2*sigma2));
703 Double_t sigmaErf = 2*s0*s1*TMath::Sqrt(2*sigma2);
704 Double_t erf0 = TMath::Erf( (k0*s1*s1*(k0-2*x0)+k1*s0*s0*(k1-2*x1))/sigmaErf);
705 Double_t erf1 = TMath::Erf( (k0*s1*s1*(k0+2*x0)+k1*s0*s0*(k1+2*x1))/sigmaErf);
706 Double_t norm = 1./TMath::Sqrt(sigma2);
707 norm/=2.*TMath::Sqrt(2.*TMath::Pi());
708 Double_t val = norm*exp0*(erf0+erf1);
714 Double_t AliTPCclusterFast::GaussExpConvolution(Double_t x0, Double_t s0,Double_t t1){
716 // 2 D gaus convoluted with exponential
717 // Integral nomalized to 1
718 // See in mathematica:
719 //Simplify[Integrate[Exp[-(x0-x1)*(x0-x1)/(2*s0*s0)]*Exp[-x1*t1],{x1,0,Infinity}]]
720 // TF1 fgexp("fgexp","AliTPCclusterFast::GaussExpConvolution(x,0.5,1)",-2,2)
721 Double_t exp1 = (s0*s0*t1-2*x0)*t1/2.;
722 exp1 = TMath::Exp(exp1);
723 Double_t erf = 1+TMath::Erf((-s0*s0*t1+x0)/(s0*TMath::Sqrt(2.)));
724 Double_t val = exp1*erf;
731 Double_t AliTPCclusterFast::Gamma4(Double_t x, Double_t p0, Double_t p1){
733 // Gamma 4 Time response function of ALTRO
736 Double_t g1 = TMath::Exp(-4.*x/p1);
737 Double_t g2 = TMath::Power(x/p1,4);
743 Double_t AliTPCclusterFast::GaussGamma4(Double_t x, Double_t s0, Double_t p1){
745 // Gamma 4 Time response function of ALTRO convoluted with Gauss
746 // Simplify[Integrate[Exp[-(x0-x1)*(x0-x1)/(2*s0*s0)]*Exp[-4*x1/p1]*(x/p1)^4/s0,{x1,0,Infinity}]]
747 //TF1 fgg4("fgg4","AliTPCclusterFast::GaussGamma4(x,0.5,0.5)",-2,2)
749 Double_t exp1 = (8*s0*s0-4.*p1*x)/(p1*p1);
750 exp1 = TMath::Exp(exp1);
751 Double_t erf1 = 1+TMath::Erf((-4*s0/p1+x/s0)/TMath::Sqrt(2));
752 // Double_t xp14 = TMath::Power(TMath::Abs((x/p1)),4);
758 // Analytical sollution only in 1D - too long expression
759 // Simplify[Integrate[Exp[-(x0-(x1-k*x2))*(x0-(x1-k*x2))/(2*s0*s0)]*Exp[-(x1*t1-k*x2)],{x2,-1,1}]]
762 // No analytical solution
764 //Simplify[Integrate[Exp[-(x0-k0*xd)*(x0-k0*xd)/(2*s0*s0)-(x1-xt-k1*xd)*(x1-xt-k1*xd)/(2*s1*s1)]*Exp[-kt*xt]/(s0*s1),{xd,-1/2,1/2},{xt,0,Infinity}]]