* provided "as is" without express or implied warranty. *
**************************************************************************/
+/* $Id$ */
+
//-------------------------------------------------------------------------
// Implementation of the AliKalmanTrack class
-//
+// that is the base for AliTPCtrack, AliITStrackV2 and AliTRDtrack
// Origin: Iouri Belikov, CERN, Jouri.Belikov@cern.ch
//-------------------------------------------------------------------------
-
+#include <TGeoManager.h>
#include "AliKalmanTrack.h"
ClassImp(AliKalmanTrack)
-Double_t AliKalmanTrack::fConvConst;
+//_______________________________________________________________________
+ AliKalmanTrack::AliKalmanTrack():AliExternalTrackParam(),
+ fLab(-3141593),
+ fFakeRatio(0),
+ fChi2(0),
+ fMass(AliPID::ParticleMass(AliPID::kPion)),
+ fN(0),
+ fStartTimeIntegral(kFALSE),
+ fIntegratedLength(0)
+{
+ //
+ // Default constructor
+ //
+
+ for(Int_t i=0; i<AliPID::kSPECIES; i++) fIntegratedTime[i] = 0;
+}
+
+//_______________________________________________________________________
+AliKalmanTrack::AliKalmanTrack(const AliKalmanTrack &t):
+ AliExternalTrackParam(t),
+ fLab(t.fLab),
+ fFakeRatio(t.fFakeRatio),
+ fChi2(t.fChi2),
+ fMass(t.fMass),
+ fN(t.fN),
+ fStartTimeIntegral(t.fStartTimeIntegral),
+ fIntegratedLength(t.fIntegratedLength)
+{
+ //
+ // Copy constructor
+ //
+
+ for (Int_t i=0; i<AliPID::kSPECIES; i++)
+ fIntegratedTime[i] = t.fIntegratedTime[i];
+}
+
+//_______________________________________________________________________
+void AliKalmanTrack::StartTimeIntegral()
+{
+ // Sylwester Radomski, GSI
+ // S.Radomski@gsi.de
+ //
+ // Start time integration
+ // To be called at Vertex by ITS tracker
+ //
+
+ //if (fStartTimeIntegral)
+ // AliWarning("Reseting Recorded Time.");
+
+ fStartTimeIntegral = kTRUE;
+ for(Int_t i=0; i<AliPID::kSPECIES; i++) fIntegratedTime[i] = 0;
+ fIntegratedLength = 0;
+}
+
+//_______________________________________________________________________
+void AliKalmanTrack:: AddTimeStep(Double_t length)
+{
+ //
+ // Add step to integrated time
+ // this method should be called by a sublasses at the end
+ // of the PropagateTo function or by a tracker
+ // each time step is made.
+ //
+ // If integration not started function does nothing
+ //
+ // Formula
+ // dt = dl * sqrt(p^2 + m^2) / p
+ // p = pT * (1 + tg^2 (lambda) )
+ //
+ // pt = 1/external parameter [4]
+ // tg lambda = external parameter [3]
+ //
+ //
+ // Sylwester Radomski, GSI
+ // S.Radomski@gsi.de
+ //
+
+ static const Double_t kcc = 2.99792458e-2;
+
+ if (!fStartTimeIntegral) return;
+
+ fIntegratedLength += length;
+
+ Double_t xr, param[5];
+ Double_t pt, tgl;
+
+ GetExternalParameters(xr, param);
+ pt = 1/param[4] ;
+ tgl = param[3];
+
+ Double_t p = TMath::Abs(pt * TMath::Sqrt(1+tgl*tgl));
+
+ if (length > 100) return;
+
+ for (Int_t i=0; i<AliPID::kSPECIES; i++) {
+
+ Double_t mass = AliPID::ParticleMass(i);
+ Double_t correction = TMath::Sqrt( pt*pt * (1 + tgl*tgl) + mass * mass ) / p;
+ Double_t time = length * correction / kcc;
+
+ fIntegratedTime[i] += time;
+ }
+}
+
+//_______________________________________________________________________
+Double_t AliKalmanTrack::GetIntegratedTime(Int_t pdg) const
+{
+ // Sylwester Radomski, GSI
+ // S.Radomski@gsi.de
+ //
+ // Return integrated time hypothesis for a given particle
+ // type assumption.
+ //
+ // Input parameter:
+ // pdg - Pdg code of a particle type
+ //
+
+
+ if (!fStartTimeIntegral) {
+ AliWarning("Time integration not started");
+ return 0.;
+ }
+
+ for (Int_t i=0; i<AliPID::kSPECIES; i++)
+ if (AliPID::ParticleCode(i) == TMath::Abs(pdg)) return fIntegratedTime[i];
+
+ AliWarning(Form("Particle type [%d] not found", pdg));
+ return 0;
+}
+
+void AliKalmanTrack::GetIntegratedTimes(Double_t *times) const {
+ for (Int_t i=0; i<AliPID::kSPECIES; i++) times[i]=fIntegratedTime[i];
+}
+
+void AliKalmanTrack::SetIntegratedTimes(const Double_t *times) {
+ for (Int_t i=0; i<AliPID::kSPECIES; i++) fIntegratedTime[i]=times[i];
+}
+
+Double_t AliKalmanTrack::MeanMaterialBudget(Double_t *start, Double_t *end, Double_t *mparam)
+{
+ //
+ // calculate mean material budget and material properties beween point start and end
+ // mparam - returns parameters used for dEdx and multiple scatering
+ //
+ // mparam[0] - density mean
+ // mparam[1] - rad length
+ // mparam[2] - A mean
+ // mparam[3] - Z mean
+ // mparam[4] - length
+ // mparam[5] - Z/A mean
+ // mparam[6] - number of boundary crosses
+ //
+ mparam[0]=0; mparam[1]=1; mparam[2] =0; mparam[3] =0, mparam[4]=0, mparam[5]=0; mparam[6]=0;
+ //
+ Double_t bparam[6], lparam[6]; // bparam - total param - lparam - local parameters
+ for (Int_t i=0;i<6;i++) bparam[i]=0; //
+
+ if (!gGeoManager) {
+ printf("ERROR: no TGeo\n");
+ return 0.;
+ }
+ //
+ Double_t length;
+ Double_t dir[3];
+ length = TMath::Sqrt((end[0]-start[0])*(end[0]-start[0])+
+ (end[1]-start[1])*(end[1]-start[1])+
+ (end[2]-start[2])*(end[2]-start[2]));
+ mparam[4]=length;
+ if (length<TGeoShape::Tolerance()) return 0.0;
+ Double_t invlen = 1./length;
+ dir[0] = (end[0]-start[0])*invlen;
+ dir[1] = (end[1]-start[1])*invlen;
+ dir[2] = (end[2]-start[2])*invlen;
+ // Initialize start point and direction
+ TGeoNode *currentnode = 0;
+ TGeoNode *startnode = gGeoManager->InitTrack(start, dir);
+ // printf("%s length=%f\n",gGeoManager->GetPath(),length);
+ if (!startnode) {
+ printf("ERROR: start point out of geometry\n");
+ return 0.0;
+ }
+ TGeoMaterial *material = startnode->GetVolume()->GetMedium()->GetMaterial();
+ lparam[0] = material->GetDensity();
+ lparam[1] = material->GetRadLen();
+ lparam[2] = material->GetA();
+ lparam[3] = material->GetZ();
+ lparam[4] = length;
+ lparam[5] = lparam[3]/lparam[2];
+ if (material->IsMixture()) {
+ lparam[1]*=lparam[0]; // different normalization in the modeler for mixture
+ TGeoMixture * mixture = (TGeoMixture*)material;
+ lparam[5] =0;
+ Double_t sum =0;
+ for (Int_t iel=0;iel<mixture->GetNelements();iel++){
+ sum += mixture->GetWmixt()[iel];
+ lparam[5]+= mixture->GetZmixt()[iel]*mixture->GetWmixt()[iel]/mixture->GetAmixt()[iel];
+ }
+ lparam[5]/=sum;
+ }
+ gGeoManager->FindNextBoundary(length);
+ Double_t snext = gGeoManager->GetStep();
+ Double_t step = 0.0;
+ // If no boundary within proposed length, return current density
+ if (snext>=length) {
+ for (Int_t ip=0;ip<5;ip++) mparam[ip] = lparam[ip];
+ return lparam[0];
+ }
+ // Try to cross the boundary and see what is next
+ while (length>TGeoShape::Tolerance()) {
+ mparam[6]+=1.;
+ currentnode = gGeoManager->Step();
+ step += snext+1.E-6;
+ bparam[1] += snext*lparam[1];
+ bparam[2] += snext*lparam[2];
+ bparam[3] += snext*lparam[3];
+ bparam[5] += snext*lparam[5];
+ bparam[0] += snext*lparam[0];
+
+ if (snext>=length) break;
+ if (!currentnode) break;
+ // printf("%s snext=%f density=%f bparam[0]=%f\n", gGeoManager->GetPath(),snext,density,bparam[0]);
+ if (!gGeoManager->IsEntering()) {
+ gGeoManager->SetStep(1.E-3);
+ currentnode = gGeoManager->Step();
+ if (!gGeoManager->IsEntering() || !currentnode) {
+ // printf("ERROR: cannot cross boundary\n");
+ mparam[0] = bparam[0]/step;
+ mparam[1] = bparam[1]/step;
+ mparam[2] = bparam[2]/step;
+ mparam[3] = bparam[3]/step;
+ mparam[5] = bparam[5]/step;
+ mparam[4] = step;
+ mparam[0] = 0.; // if crash of navigation take mean density 0
+ mparam[1] = 1000000; // and infinite rad length
+ return bparam[0]/step;
+ }
+ step += 1.E-3;
+ snext += 1.E-3;
+ bparam[0] += lparam[0]*1.E-3;
+ bparam[1] += lparam[1]*1.E-3;
+ bparam[2] += lparam[2]*1.E-3;
+ bparam[3] += lparam[3]*1.E-3;
+ bparam[5] += lparam[5]*1.E-3;
+ }
+ length -= snext;
+ material = currentnode->GetVolume()->GetMedium()->GetMaterial();
+ lparam[0] = material->GetDensity();
+ lparam[1] = material->GetRadLen();
+ lparam[2] = material->GetA();
+ lparam[3] = material->GetZ();
+ lparam[5] = lparam[3]/lparam[2];
+ if (material->IsMixture()) {
+ lparam[1]*=lparam[0];
+ TGeoMixture * mixture = (TGeoMixture*)material;
+ lparam[5]=0;
+ Double_t sum =0;
+ for (Int_t iel=0;iel<mixture->GetNelements();iel++){
+ sum+= mixture->GetWmixt()[iel];
+ lparam[5]+= mixture->GetZmixt()[iel]*mixture->GetWmixt()[iel]/mixture->GetAmixt()[iel];
+ }
+ lparam[5]/=sum;
+ }
+ gGeoManager->FindNextBoundary(length);
+ snext = gGeoManager->GetStep();
+ }
+ mparam[0] = bparam[0]/step;
+ mparam[1] = bparam[1]/step;
+ mparam[2] = bparam[2]/step;
+ mparam[3] = bparam[3]/step;
+ mparam[5] = bparam[5]/step;
+ return bparam[0]/step;
+
+}
git://git.uio.no / u / mrichter / AliRoot.git / blobdiff