9 #include "AliITStrack.h"
10 #include "AliGenerator.h"
15 AliITStrack::AliITStrack() {
16 //Origin A. Badala' and G.S. Pappalardo: e-mail Angela.Badala@ct.infn.it, Giuseppe.S.Pappalardo@ct.infn.it
17 // default constructor
20 fmCovariance = new TMatrix(5,5);
21 flistCluster = new TObjArray;
26 fErrorVertex.ResizeTo(3);
28 ClusterInTrack = new TMatrix(6,9);
30 for(i=0; i<6; i++) (*ClusterInTrack)(i,6)=(*ClusterInTrack)(i,7)=
31 (*ClusterInTrack)(i,8)=-1.;
33 //alphaprov=-50.; //provvisorio
41 AliITStrack::AliITStrack(const AliITStrack &cobj) {
42 //Origin A. Badala' and G.S. Pappalardo: e-mail Angela.Badala@ct.infn.it, Giuseppe.S.Pappalardo@ct.infn.it
45 fmCovariance = new TMatrix(5,5);
46 ClusterInTrack = new TMatrix(6,9);
48 for(i=0; i<6; i++) (*ClusterInTrack)(i,6)=(*ClusterInTrack)(i,7)=
49 (*ClusterInTrack)(i,8)=-1.;
50 flistCluster = new TObjArray;
52 fErrorVertex.ResizeTo(3);
53 fVertex = cobj.fVertex;
54 fErrorVertex = cobj.fErrorVertex;
57 fTPCtrack = cobj.fTPCtrack;
58 fNumClustInTrack = cobj.fNumClustInTrack;
60 fvTrack = cobj.fvTrack;
72 //alphaprov=cobj.alphaprov; //provvisorio
74 *fmCovariance = *cobj.fmCovariance;
76 *ClusterInTrack = *cobj.ClusterInTrack;
78 for(i=0; i<cobj.flistCluster->GetSize(); i++)
79 flistCluster->AddLast(cobj.flistCluster->At(i));
83 AliITStrack::AliITStrack(AliTPCtrack &obj)
85 //Origin A. Badala' and G.S. Pappalardo: e-mail Angela.Badala@ct.infn.it, Giuseppe.S.Pappalardo@ct.infn.it
90 fErrorVertex.ResizeTo(3);
95 AliGenerator *gener = gAlice->Generator();
97 gener->GetOrigin(Vxg,Vyg,Vzg);
100 fVertex(0)=(Double_t)Vxg;
101 fVertex(1)=(Double_t)Vyg;
102 fVertex(2)=(Double_t)Vzg;
105 fmCovariance = new TMatrix(5,5);
106 ClusterInTrack = new TMatrix(6,9);
109 for(i=0; i<6; i++) (*ClusterInTrack)(i,6)=(*ClusterInTrack)(i,7)=
110 (*ClusterInTrack)(i,8)=-1.;
111 flistCluster = new TObjArray;
112 fNumClustInTrack = 0;
117 AliITStrack::~AliITStrack() {
121 if(fmCovariance) delete fmCovariance;
122 if(flistCluster) delete flistCluster;
123 if(ClusterInTrack) delete ClusterInTrack;
129 void AliITStrack::LmTPC() {
131 // Transform the TPC state vector from TPC-local to master and build a new state vector ITS-type
132 // The covariance matrix is also modified accordingly
133 //Origin A. Badala' and G.S. Pappalardo: e-mail Angela.Badala@ct.infn.it, Giuseppe.S.Pappalardo@ct.infn.it
137 Double_t Alpha = fTPCtrack->GetAlpha();
139 //printf("LmTPC: Alpha %f\n",Alpha);
141 tpctrack(0) = fTPCtrack->GetY();
142 tpctrack(1) = fTPCtrack->GetZ();
143 tpctrack(2) = fTPCtrack->GetC();
144 tpctrack(3) = fTPCtrack->GetEta();
145 tpctrack(4) = fTPCtrack->GetTgl();
146 //cout<< " tpctracks = "<<tpctrack(0)<<" "<<tpctrack(1)<<" "<<tpctrack(2)<<" "<<tpctrack(3)<<" "<<tpctrack(4)<<
150 Double_t sina = TMath::Sin(Alpha);
151 Double_t cosa = TMath::Cos(Alpha);
152 Double_t xl= fTPCtrack->GetX();
153 xm = xl * cosa - tpctrack(0)*sina;
154 ym = xl * sina + tpctrack(0)*cosa;
156 //cout<<" xl e alpha = "<<xl<<" "<<Alpha<<"\n"; getchar();
160 ///////////////////////////////////// determine yo //////////////////////////////////////////////////
161 Double_t Vxl=fVertex(0)*cosa+fVertex(1)*sina;
162 Double_t Vyl= -fVertex(0)*sina+fVertex(1)*cosa;
163 Double_t Xo,Yo, signy;
164 Double_t R = 1./tpctrack(2);
165 Xo = tpctrack(3) / tpctrack(2);
167 Double_t Yo1, Yo2, diffsq1, diffsq2;
168 Yo1 = tpctrack(0) + TMath::Sqrt(R*R - (xl-Xo)*(xl-Xo));
169 Yo2 = tpctrack(0) - TMath::Sqrt(R*R - (xl-Xo)*(xl-Xo));
170 diffsq1=TMath::Abs((Yo1-Vyl)*(Yo1-Vyl)+(Xo-Vxl)*(Xo-Vxl)-R*R);
171 diffsq2=TMath::Abs((Yo2-Vyl)*(Yo2- Vyl)+(Xo-Vxl)*(Xo-Vxl)-R*R);
172 if(diffsq1<diffsq2) {Yo=Yo1; signy=1.;} else {Yo=Yo2; signy=-1.;};
173 ////////////////////////////////////////////////////////////////////////////////////////////////////
175 x0m = Xo * cosa - Yo * sina;
176 y0m = Xo * sina + Yo * cosa;
178 rtrack=TMath::Sqrt(xm*xm+ym*ym);
179 Double_t pigre=TMath::Pi();
181 if(ym == 0. || xm == 0.) {
182 if(ym == 0. && xm == 0.) {cout << " Error in AliITStrack::LmTPC x=0 and y=0 \n"; getchar();}
183 if(ym ==0. && xm>0.) phi=0.;
184 if(ym==0. && xm<0.) phi=pigre;
185 if(xm==0 && ym>0.) phi=pigre/2.;
186 if(xm==0 && ym<0.) phi=1.5*pigre;
189 if (xm>0. && ym>0.) phi=TMath::ATan(ym/xm);
190 if (xm<0. && ym>0.) phi=pigre+TMath::ATan(ym/xm);
191 if (xm<0. && ym<0.) phi=pigre+TMath::ATan(ym/xm);
192 if (xm>0. && ym<0.) phi=(2*pigre)+TMath::ATan(ym/xm);
194 if(phi<0. || phi>(2*pigre)) {cout<<"attention error on phi in AliITStrack:LmTPC \n"; getchar();}
198 fvTrack(3)=tpctrack(4);
199 fvTrack(4)=tpctrack(2);
202 alphaprov=pigre-PhiDef(x0m,y0m)-PhiDef(fVertex(0),fVertex(1));
203 if(alphaprov<0.) alphaprov=alphaprov+2.*pigre;
204 //cout<<" PhiDef(x0m,y0m) ="<<PhiDef(x0m,y0m)<<"\n";
205 //cout<<" PhiDef(fVertex(0),fVertex(1)) = "<<PhiDef(fVertex(0),fVertex(1))<<"\n";
206 //cout<<"alphaprov = "<<alphaprov<<"\n"; getchar();
207 //cout<<" fvTrack(0) prima = "<<fvTrack(0)<<"\n";
208 fvTrack(0)-=alphaprov;
209 if(fvTrack(0)<0.) fvTrack(0)+= 2.*pigre;
210 //cout<<" fvTrack(0) dopo = "<<fvTrack(0)<<" alphaprov = "<<alphaprov<<"\n";
211 cout<<" fvertex = "<<fVertex(0)<<" "<<fVertex(1)<<" "<<fVertex(2)<<"\n";
214 ///////////////////////////////////////////////////////////////////////////////////////////////////
217 Double_t dd=TMath::Sqrt((x0m-fVertex(0))*(x0m-fVertex(0))+(y0m-fVertex(1))*(y0m-fVertex(1)));
219 if (R>0) signdd=1.; else signdd=-1.;
220 fvTrack(2)=signdd*dd-R;
221 //cout<<" fvertex = "<<fVertex(0)<<" "<<fVertex(1)<<" "<<fVertex(2)<<"\n";
222 //cout<<" fvTrack(2) ="<<fvTrack(2)<<"\n"; getchar();
226 fTPCtrack->GetCovariance(cov);
233 localM(1,0)=localM(0,1)=cov[1];
234 localM(2,0)=localM(0,2)=cov[3];
235 localM(2,1)=localM(1,2)=cov[4];
236 localM(3,0)=localM(0,3)=cov[6];
237 localM(3,1)=localM(1,3)=cov[7];
238 localM(3,2)=localM(2,3)=cov[8];
239 localM(4,0)=localM(0,4)=cov[10];
240 localM(4,1)=localM(1,4)=cov[11];
241 localM(4,2)=localM(2,4)=cov[12];
242 localM(4,3)=localM(3,4)=cov[13];
249 localM(1,0)=localM(0,1)=cov[1];
250 localM(3,0)=localM(0,3)=cov[3];
251 localM(3,1)=localM(1,3)=cov[4];
252 localM(2,0)=localM(0,2)=cov[6];
253 localM(2,1)=localM(1,2)=cov[7];
254 localM(2,3)=localM(3,2)=cov[8];
255 localM(4,0)=localM(0,4)=cov[10];
256 localM(4,1)=localM(1,4)=cov[11];
257 localM(4,3)=localM(3,4)=cov[12];
258 localM(4,2)=localM(2,4)=cov[13];
262 Double_t dfidy, dDdy, dDdC, dDdeta;
264 dfidy=(xm*cosa+ym*sina)/(rtrack*rtrack);
265 dDdy=signdd*((y0m-fVertex(1))*cosa-(x0m-fVertex(0))*sina)/dd;
266 Double_t dyodr=signy*(R+(xl-Xo)*tpctrack(3))/TMath::Sqrt(R*R-(xl-Xo)*(xl-Xo));
267 Double_t dyomdr=sina*tpctrack(3)+cosa*dyodr;
268 Double_t dxomdr=cosa*tpctrack(3)-sina*dyodr;
269 Double_t ddddR=((x0m-fVertex(0))*dxomdr+(y0m-fVertex(1))*dyomdr)/dd;
270 dDdC=-R*R*(signdd*ddddR-1.);
271 Double_t dyoldxol=signy*(xl-Xo)/TMath::Sqrt(R*R-(xl-Xo)*(xl-Xo));
272 Double_t dxomdeta=R*(cosa-sina*dyoldxol);
273 Double_t dyomdeta=R*(sina+cosa*dyoldxol);
274 dDdeta=signdd*((x0m-fVertex(0))*dxomdeta+(y0m-fVertex(1))*dyomdeta)/dd;
276 F(0,1)=F(0,2)=F(0,3)=F(0,4)=0.;
278 F(1,0)=F(1,2)=F(1,3)=F(1,4)=0.;
283 F(3,0)=F(3,1)=F(3,2)=F(3,3)=0.;
285 F(4,0)=F(4,1)=F(4,3)=F(4,4)=0.;
287 // cout<<" Matrice F \n";
288 // F.Print(); getchar();
289 TMatrix Ft(TMatrix::kTransposed,F);
290 TMatrix temp(localM);
293 B*=temp; // B=F*localM*Ft
294 // cout<<" Matrice C\n";
295 // B.Print(); getchar();
300 AliITStrack &AliITStrack::operator=(AliITStrack obj) {
301 //Origin A. Badala' and G.S. Pappalardo: e-mail Angela.Badala@ct.infn.it, Giuseppe.S.Pappalardo@ct.infn.it
305 delete ClusterInTrack;
306 fmCovariance = new TMatrix(5,5);
307 ClusterInTrack = new TMatrix(6,9);
308 flistCluster = new TObjArray;
310 fTPCtrack = obj.fTPCtrack;
312 fNumClustInTrack = obj.fNumClustInTrack;
315 fErrorVertex=obj.fErrorVertex;
316 fvTrack = obj.fvTrack;
326 //alphaprov=obj.alphaprov; //proviisorio
328 *fmCovariance = *obj.fmCovariance;
329 *ClusterInTrack = *obj.ClusterInTrack;
331 for(i=0; i<obj.flistCluster->GetSize(); i++) flistCluster->AddLast(obj.flistCluster->At(i));
337 void AliITStrack::PutCluster(Int_t layerc, TVector vecclust) {
338 //Origin A. Badala' and G.S. Pappalardo: e-mail Angela.Badala@ct.infn.it, Giuseppe.S.Pappalardo@ct.infn.it
340 (*ClusterInTrack)(layerc,0) = vecclust(0);
341 (*ClusterInTrack)(layerc,1) = vecclust(1);
342 (*ClusterInTrack)(layerc,2) = vecclust(2);
343 (*ClusterInTrack)(layerc,3) = vecclust(3);
344 (*ClusterInTrack)(layerc,4) = vecclust(4);
345 (*ClusterInTrack)(layerc,5) = vecclust(5);
346 (*ClusterInTrack)(layerc,6) = vecclust(6);
347 (*ClusterInTrack)(layerc,7) = vecclust(7);
348 (*ClusterInTrack)(layerc,8) = vecclust(8);
353 void AliITStrack::GetClusters() {
355 TMatrix A(*ClusterInTrack);
359 B(i,0)=A(i,6); B(i,1)=A(i,7); B(i,2)=A(i,8);
367 TVector AliITStrack::GetLabTrack(Int_t lay) {
369 VecLabel(0)=( (Float_t) (*ClusterInTrack)(lay,6) );
370 VecLabel(1)=( (Float_t) (*ClusterInTrack)(lay,7) );
371 VecLabel(2)=( (Float_t) (*ClusterInTrack)(lay,8) );
375 void AliITStrack::Search(TVector VecTotLabref, Long_t &labref, Int_t &freq){
376 //Origin A. Badala' and G.S. Pappalardo: e-mail Angela.Badala@ct.infn.it, Giuseppe.S.Pappalardo@ct.infn.it
382 for(i=0; i<18; i++) vecfreq[i]=0;
384 for(i=0; i<18; i++) {
385 for(j=0; j<18; j++) {
386 if(VecTotLabref(i) == 0.) VecTotLabref(i)=-3.;
387 if( (VecTotLabref(i)>=0.) && (VecTotLabref(i)==VecTotLabref(j)) ) vecfreq[i]++;
391 Long_t labdefault= (Long_t)1000000.;
393 for(i=0; i<18; i++) {
394 if(vecfreq[i]>freq) {freq=vecfreq[i]; imax=i;}
396 if(imax<0) labref=labdefault; else labref=(Long_t) VecTotLabref(imax);
400 void AliITStrack::Propagation(Double_t rk) {
401 //Origin A. Badala' and G.S. Pappalardo: e-mail Angela.Badala@ct.infn.it, Giuseppe.S.Pappalardo@ct.infn.it
402 //Propagation of track
403 Double_t duepi=2.*TMath::Pi();
404 Double_t rkm1=rtrack;
405 //cout<<" rk e rkm1 dentro Propagation "<<rk<<" "<<rkm1<<"\n";
408 Double_t Ak=argA(rk), Akm1=argA(rkm1);
409 Double_t ak=arga(rk), akm1=arga(rkm1);
410 fvTrack(0)+=TMath::ASin(Ak)-TMath::ASin(Akm1);
412 if(fvTrack(0)>duepi) fvTrack(0)-=duepi;
413 if(fvTrack(0)<0.) fvTrack(0)+=duepi;
415 Double_t tgl=fvTrack(3);
416 Double_t C=fvTrack(4);
417 Double_t D=fvTrack(2);
419 fvTrack(1)+=tgl/Cy*(TMath::ASin(ak)-TMath::ASin(akm1));
421 //cout<<"fvTrack(0) fvTrack(1) e rtrack dentro Propagation = "<<fvTrack(0)<<" "<<fvTrack(1)<<" "<<rtrack<<"\n";
424 Double_t Bk=argB(rk), Bkm1=argB(rkm1);
425 Double_t Ck=argC(rk), Ckm1=argC(rkm1);
427 F(0,2)=Ck/TMath::Sqrt(1.-Ak*Ak) - Ckm1/TMath::Sqrt(1.-Akm1*Akm1);
428 F(0,4)=Bk/TMath::Sqrt(1.-Ak*Ak) - Bkm1/TMath::Sqrt(1.-Akm1*Akm1);
429 F(1,2)=tgl*D*(1./rk - 1./rkm1);
431 F(0,0)=F(1,1)=F(2,2)=F(3,3)=F(4,4)=1.;
432 TMatrix Ft(TMatrix::kTransposed,F);
433 TMatrix temp(*fmCovariance);
434 //cout<<" C Matrix prima propagation =\n";
435 //temp.Print(); getchar();
439 //cout<<" C Matrix dopo propagation =\n"; // B=F*C*Ft
440 //B.Print(); getchar();
444 void AliITStrack::AddEL(Double_t signdE, Bool_t flagtot, Double_t mass) {
445 //Origin A. Badala' and G.S. Pappalardo: e-mail Angela.Badala@ct.infn.it, Giuseppe.S.Pappalardo@ct.infn.it
449 s(0)=0.0026+0.00283; s(1)=0.018; s(2)=0.0094; s(3)=0.0095; s(4)=0.0091; s(5)=0.0087;
450 //0.00277 is added in the first layer to take into account the energy loss in the beam pipe
452 Double_t cl=1.+fvTrack(3)*fvTrack(3); // cl=1/(cosl)**2 = 1 + (tgl)**2
453 Double_t sqcl=TMath::Sqrt(cl);
456 Double_t p2=pt*pt*cl;
457 Double_t E=TMath::Sqrt(p2+mass*mass);
458 Double_t beta2=p2/(p2+mass*mass);
462 Double_t stot=s(0)+s(1)+s(2)+s(3)+s(4)+s(5);
463 dE=0.153/beta2*(log(5940*beta2/(1-beta2)) - beta2)*stot*21.82*sqcl;
465 dE=0.153/beta2*(log(5940*beta2/(1-beta2)) - beta2)*s(fLayer-1)*21.82*sqcl;
470 Double_t p=TMath::Sqrt(E*E-mass*mass);
472 if((fvTrack)(4) < 0.) sign=-1.;
474 Double_t CC=(0.3*0.2)/(pt*100.);
479 void AliITStrack::Correct(Double_t rk) {
480 //Origin A. Badala' and G.S. Pappalardo: e-mail Angela.Badala@ct.infn.it, Giuseppe.S.Pappalardo@ct.infn.it
481 // correct track to take into account real geometry detector
483 Double_t duepi=2.*TMath::Pi();
484 Double_t rkm1=rtrack;
485 Double_t Ak=argA(rk), Akm1=argA(rkm1);
486 Double_t ak=arga(rk), akm1=arga(rkm1);
488 fvTrack(0)+=TMath::ASin(Ak)-TMath::ASin(Akm1);
489 if(fvTrack(0)>duepi) fvTrack(0)-=duepi;
490 if(fvTrack(0)<0.) fvTrack(0)+=duepi;
492 Double_t tgl=fvTrack(3);
493 Double_t C=fvTrack(4);
495 fvTrack(1)+=tgl/Cy*(TMath::ASin(ak)-TMath::ASin(akm1));
500 void AliITStrack::AddMS() {
502 ////////// Modification of the covariance matrix to take into account multiple scattering ///////////
503 //Origin A. Badala' and G.S. Pappalardo: e-mail Angela.Badala@ct.infn.it, Giuseppe.S.Pappalardo@ct.infn.it
507 s(0)=0.0026+0.00283; s(1)=0.018; s(2)=0.0094; s(3)=0.0095; s(4)=0.0091; s(5)=0.0087;
508 //0.00277 is added in the first layer to take into account the energy loss in the beam pipe
509 Double_t mass=0.1396;
510 Int_t layer=(Int_t)GetLayer();
512 Double_t tgl=fvTrack(3);
513 Double_t cosl=TMath::Cos(TMath::ATan(tgl));
514 Double_t D=fvTrack(2);
515 Double_t C=fvTrack(4);
517 Double_t Q20=1./(cosl*cosl);
520 Double_t Q40=Cy*(rtrack*rtrack-D*D)/(1.+ 2.*Cy*D);
521 Double_t dd=D+Cy*D*D-Cy*rtrack*rtrack;
522 Double_t Q41=-1./cosl*TMath::Sqrt(rtrack*rtrack - dd*dd)/(1.+ 2.*Cy*D);
525 Double_t xk=rtrack*TMath::Cos(fvTrack(0));
526 Double_t yk=rtrack*TMath::Sin(fvTrack(0));
527 Double_t rvertex=TMath::Sqrt((xk-fVertex(0))*(xk-fVertex(0)) + (yk-fVertex(1))*(yk-fVertex(1)));
528 Double_t Q40=Cy*(rvertex*rvertex-D*D)/(1.+ 2.*Cy*D);
529 Double_t dd=D+Cy*D*D-Cy*rvertex*rvertex;
530 Double_t Q41=-1./cosl*TMath::Sqrt(rvertex*rvertex - dd*dd)/(1.+ 2.*Cy*D);
534 J(0,0)=0.; J(0,1)=0.;
535 J(1,0)=0.; J(1,1)=0.;
538 J(3,0)=Q20; J(3,1)=0.;
539 J(4,0)=Q30; J(4,1)=0.;
541 Double_t p2=(GetPt()*GetPt())/(cosl*cosl);
542 Double_t beta2=p2/(p2+mass*mass);
543 Double_t theta2=14.1*14.1/(beta2*p2*1.e6)*(s(layer-1)/cosl);
545 TMatrix Jt(TMatrix::kTransposed,J);
546 TMatrix Q(J,TMatrix::kMult,Jt);
553 void AliITStrack::PrimaryTrack() {
554 //Origin A. Badala' and G.S. Pappalardo: e-mail Angela.Badala@ct.infn.it, Giuseppe.S.Pappalardo@ct.infn.it
555 // calculation of part of covariance matrix for vertex constraint
559 Rlayer[0]=4.; Rlayer[1]=7.; Rlayer[2]=14.9; Rlayer[3]=23.8;
560 Rlayer[4]=39.1; Rlayer[5]=43.6;
562 Double_t Cy=fvTrack(4)/2.;
563 Double_t tgl=(fvTrack(1)-Zv)*Cy/TMath::ASin(Cy*rtrack);
566 fvTrack(1)=rtrack*tgl;
571 newC(4,4)=(*fmCovariance)(4,4);
572 (*fmCovariance)=newC;
576 for (i=0; i<6; i++) {
577 Propagation(Rlayer[i]);
579 d2(i)=(*fmCovariance)(2,2);
580 tgl2(i)=(*fmCovariance)(3,3);
581 dtgl(i)=(*fmCovariance)(2,3);
588 Int_t AliITStrack::DoNotCross(Double_t rk) const{
589 Double_t C=fvTrack(4);
590 Double_t D=fvTrack(2);
592 return (TMath::Abs((Cy*rk+(1.+Cy*D)*D/rk)/(1.+2.*Cy*D))>=1.)?1:0;
596 Double_t AliITStrack::argA(Double_t rk) const {
597 Double_t C=fvTrack(4);
598 Double_t D=fvTrack(2);
600 Double_t arg=(Cy*rk + (1 + Cy*D)*D/rk)/(1.+ 2.*Cy*D);
601 if (TMath::Abs(arg) < 1.) return arg;
602 //cout<<"class AliITSTrack: argA out of range !\n";/* getchar();*/
603 return (arg>0) ? 0.99999999999 : -0.9999999999;
606 Double_t AliITStrack::arga(Double_t rk) const {
607 Double_t C=fvTrack(4);
608 Double_t D=fvTrack(2);
610 Double_t arg=(rk*rk - D*D)/(1.+ 2.*Cy*D);
611 if (arg<0.) {/*cout<<"class AliITSTrack: arga out of range !\n";*/ arg=0.;}
612 return Cy*TMath::Sqrt(arg);
615 Double_t AliITStrack::argB(Double_t rk) const {
616 Double_t C=fvTrack(4);
617 Double_t D=fvTrack(2);
619 return (rk*rk - D*D)/(rk*(1.+ 2.*Cy*D)*(1.+ 2.*Cy*D));
622 Double_t AliITStrack::argC(Double_t rk) const {
623 Double_t C=fvTrack(4);
624 Double_t D=fvTrack(2);
626 return (1./rk - 2.*Cy*argA(rk)/(1.+ 2.*Cy*D));
629 Double_t AliITStrack::PhiDef(Double_t x, Double_t y){
630 Double_t pigre= TMath::Pi();
632 if(y == 0. || x == 0.) {
633 if(y == 0. && x == 0.) {
634 cout << " Error in AliITStracking::PhiDef x=0 and y=0 \n"; getchar();
636 if(y==0. && x>0.) phi=0.;
637 if(y==0. && x<0.) phi=pigre;
638 if(x==0 && y>0.) phi=pigre/2.;
639 if(x==0 && y<0.) phi=1.5*pigre;
642 if (x>0. && y>0.) phi=TMath::ATan(y/x);
643 if (x<0. && y>0.) phi=pigre+TMath::ATan(y/x);
644 if (x<0. && y<0.) phi=pigre+TMath::ATan(y/x);
645 if (x>0. && y<0.) phi=(2.*pigre)+TMath::ATan(y/x);
647 if(phi<0. || phi>(2*pigre)) {
648 cout<<" Error on phi in AliITStracking::PhiDef \n"; getchar();