[u/mrichter/AliRoot.git] / STEER / AliTracker.cxx

/**************************************************************************
 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
 *                                                                        *
 * Author: The ALICE Off-line Project.                                    *
 * Contributors are mentioned in the code where appropriate.              *
 *                                                                        *
 * Permission to use, copy, modify and distribute this software and its   *
 * documentation strictly for non-commercial purposes is hereby granted   *
 * without fee, provided that the above copyright notice appears in all   *
 * copies and that both the copyright notice and this permission notice   *
 * appear in the supporting documentation. The authors make no claims     *
 * about the suitability of this software for any purpose. It is          *
 * provided "as is" without express or implied warranty.                  *
 **************************************************************************/

/* $Id$ */

//-------------------------------------------------------------------------
//               Implementation of the AliTracker class
//  that is the base for AliTPCtracker, AliITStrackerV2 and AliTRDtracker    
//        Origin: Iouri Belikov, CERN, Jouri.Belikov@cern.ch
//-------------------------------------------------------------------------
#include <TClass.h>
#include <TMath.h>
#include <TH1F.h>
#include <TGeoManager.h>

#include "AliMagF.h"
#include "AliTracker.h"
#include "AliGeomManager.h"
#include "AliCluster.h"
#include "AliKalmanTrack.h"

extern TGeoManager *gGeoManager;

Bool_t AliTracker::fgUniformField=kTRUE;
Double_t AliTracker::fgBz=kAlmost0Field;
const AliMagF *AliTracker::fgkFieldMap=0;
Bool_t AliTracker::fFillResiduals=kFALSE;
TObjArray *AliTracker::fResiduals=0;

ClassImp(AliTracker)

AliTracker::AliTracker():
  TObject(),
  fX(0),
  fY(0),
  fZ(0),
  fSigmaX(0.005),
  fSigmaY(0.005),
  fSigmaZ(0.010)
{
  //--------------------------------------------------------------------
  // The default constructor.
  //--------------------------------------------------------------------
  if (!fgkFieldMap) AliWarning("Field map is not set. Call AliTracker::SetFieldMap before creating a tracker!");
}

//__________________________________________________________________________
AliTracker::AliTracker(const AliTracker &atr):
  TObject(atr),
  fX(atr.fX),
  fY(atr.fY),
  fZ(atr.fZ),
  fSigmaX(atr.fSigmaX),
  fSigmaY(atr.fSigmaY),
  fSigmaZ(atr.fSigmaZ)
{
  //--------------------------------------------------------------------
  // The default constructor.
  //--------------------------------------------------------------------
  if (!fgkFieldMap) AliWarning("Field map is not set. Call AliTracker::SetFieldMap before creating a tracker!");
}

//__________________________________________________________________________
void AliTracker::SetFieldMap(const AliMagF* map, Bool_t uni) {
  //--------------------------------------------------------------------
  //This passes the field map to the reconstruction.
  //--------------------------------------------------------------------
  if (map==0) AliFatalClass("Can't access the field map !");

  if (fgkFieldMap) {
     AliWarningClass("The magnetic field map has been already set !");
     return;
  }

  fgUniformField=uni;
  fgkFieldMap=map;

  //Float_t r[3]={0.,0.,0.},b[3]; map->Field(r,b);
  //Double_t bz=-b[2];
 
  Double_t bz=-map->SolenoidField();
  fgBz=TMath::Sign(kAlmost0Field,bz) + bz;

}

//__________________________________________________________________________
void AliTracker::CookLabel(AliKalmanTrack *t, Float_t wrong) const {
  //--------------------------------------------------------------------
  //This function "cooks" a track label. If label<0, this track is fake.
  //--------------------------------------------------------------------
  Int_t noc=t->GetNumberOfClusters();
  if (noc<1) return;
  Int_t *lb=new Int_t[noc];
  Int_t *mx=new Int_t[noc];
  AliCluster **clusters=new AliCluster*[noc];

  Int_t i;
  for (i=0; i<noc; i++) {
     lb[i]=mx[i]=0;
     Int_t index=t->GetClusterIndex(i);
     clusters[i]=GetCluster(index);
  }

  Int_t lab=123456789;
  for (i=0; i<noc; i++) {
    AliCluster *c=clusters[i];
    lab=TMath::Abs(c->GetLabel(0));
    Int_t j;
    for (j=0; j<noc; j++) if (lb[j]==lab || mx[j]==0) break;
    lb[j]=lab;
    (mx[j])++;
  }

  Int_t max=0;
  for (i=0; i<noc; i++) if (mx[i]>max) {max=mx[i]; lab=lb[i];}
    
  for (i=0; i<noc; i++) {
    AliCluster *c=clusters[i];
    //if (TMath::Abs(c->GetLabel(1)) == lab ||
    //    TMath::Abs(c->GetLabel(2)) == lab ) max++;
    if (TMath::Abs(c->GetLabel(0)!=lab))
	if (TMath::Abs(c->GetLabel(1)) == lab ||
	    TMath::Abs(c->GetLabel(2)) == lab ) max++;
  }

  if ((1.- Float_t(max)/noc) > wrong) lab=-lab;
  t->SetFakeRatio((1.- Float_t(max)/noc));
  t->SetLabel(lab);

  delete[] lb;
  delete[] mx;
  delete[] clusters;
}

//____________________________________________________________________________
void AliTracker::UseClusters(const AliKalmanTrack *t, Int_t from) const {
  //------------------------------------------------------------------
  //This function marks clusters associated with the track.
  //------------------------------------------------------------------
  Int_t noc=t->GetNumberOfClusters();
  for (Int_t i=from; i<noc; i++) {
     Int_t index=t->GetClusterIndex(i);
     AliCluster *c=GetCluster(index); 
     c->Use();   
  }
}

Double_t AliTracker::GetBz(Float_t *r) {
  //------------------------------------------------------------------
  // Returns Bz (kG) at the point "r" .
  //------------------------------------------------------------------
    Float_t b[3]; fgkFieldMap->Field(r,b);
    Double_t bz=-Double_t(b[2]);
    return  (TMath::Sign(kAlmost0Field,bz) + bz);
}

Double_t 
AliTracker::MeanMaterialBudget(Double_t *start,Double_t *end,Double_t *mparam)
{
  // 
  // Calculate mean material budget and material properties between 
  //    the points "start" and "end".
  //
  // "mparam" - parameters used for the energy and multiple scattering
  //  corrections: 
  //
  // mparam[0] - mean density: sum(x_i*rho_i)/sum(x_i) [g/cm3]
  // mparam[1] - equivalent rad length fraction: sum(x_i/X0_i) [adimensional]
  // mparam[2] - mean A: sum(x_i*A_i)/sum(x_i) [adimensional]
  // mparam[3] - mean Z: sum(x_i*Z_i)/sum(x_i) [adimensional]
  // mparam[4] - length: sum(x_i) [cm]
  // mparam[5] - Z/A mean: sum(x_i*Z_i/A_i)/sum(x_i) [adimensional]
  // mparam[6] - number of boundary crosses
  //
  //  Origin:  Marian Ivanov, Marian.Ivanov@cern.ch
  //
  //  Corrections and improvements by
  //        Andrea Dainese, Andrea.Dainese@lnl.infn.it,
  //        Andrei Gheata,  Andrei.Gheata@cern.ch
  //

  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]; // total parameters
  Double_t lparam[6]; // 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) {
    AliErrorClass(Form("start point out of geometry: x %f, y %f, z %f",
		  start[0],start[1],start[2]));
    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()) {
    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;
  }

  // Locate next boundary within length without computing safety.
  // Propagate either with length (if no boundary found) or just cross boundary
  gGeoManager->FindNextBoundaryAndStep(length, kFALSE);
  Double_t step = 0.0; // Step made
  Double_t snext = gGeoManager->GetStep();
  // If no boundary within proposed length, return current density
  if (!gGeoManager->IsOnBoundary()) {
    mparam[0] = lparam[0];
    mparam[1] = lparam[4]/lparam[1];
    mparam[2] = lparam[2];
    mparam[3] = lparam[3];
    mparam[4] = lparam[4];
    return lparam[0];
  }
  // Try to cross the boundary and see what is next
  Int_t nzero = 0;
  while (length>TGeoShape::Tolerance()) {
    currentnode = gGeoManager->GetCurrentNode();
    if (snext<2.*TGeoShape::Tolerance()) nzero++;
    else nzero = 0;
    if (nzero>3) {
      // This means navigation has problems on one boundary
      // Try to cross by making a small step
      printf("ERROR: cannot cross boundary\n");
      mparam[0] = bparam[0]/step;
      mparam[1] = bparam[1];
      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;
    }
    mparam[6]+=1.;
    step += snext;
    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;
    length -= snext;
    //printf("%s snext=%f length=%f\n", currentnode->GetName(),snext,length);
    material = currentnode->GetVolume()->GetMedium()->GetMaterial();
    lparam[0] = material->GetDensity();
    lparam[1]  = material->GetRadLen();
    lparam[2]  = material->GetA();
    lparam[3]  = material->GetZ();
    //printf("       %f %f %f %f\n",lparam[0],lparam[1],lparam[2],lparam[3]); 
    lparam[5]   = lparam[3]/lparam[2];
    if (material->IsMixture()) {
      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->FindNextBoundaryAndStep(length, kFALSE);
    snext = gGeoManager->GetStep();
    //printf("snext %f\n",snext);
  }
  mparam[0] = bparam[0]/step;
  mparam[1] = bparam[1];
  mparam[2] = bparam[2]/step;
  mparam[3] = bparam[3]/step;
  mparam[5] = bparam[5]/step;
  return bparam[0]/step;
}


Bool_t 
AliTracker::PropagateTrackTo(AliExternalTrackParam *track, Double_t xToGo, 
Double_t mass, Double_t maxStep, Bool_t rotateTo, Double_t maxSnp){
  //----------------------------------------------------------------
  //
  // Propagates the track to the plane X=xk (cm) using the magnetic field map 
  // and correcting for the crossed material.
  //
  // mass     - mass used in propagation - used for energy loss correction
  // maxStep  - maximal step for propagation
  //
  //  Origin: Marian Ivanov,  Marian.Ivanov@cern.ch
  //
  //----------------------------------------------------------------
  const Double_t kEpsilon = 0.00001;
  Double_t xpos     = track->GetX();
  Double_t dir      = (xpos<xToGo) ? 1.:-1.;
  //
  while ( (xToGo-xpos)*dir > kEpsilon){
    Double_t step = dir*TMath::Min(TMath::Abs(xToGo-xpos), maxStep);
    Double_t x    = xpos+step;
    Double_t xyz0[3],xyz1[3],param[7];
    track->GetXYZ(xyz0);   //starting global position

    Double_t bz=GetBz(xyz0); // getting the local Bz

    if (!track->GetXYZAt(x,bz,xyz1)) return kFALSE;   // no prolongation
    xyz1[2]+=kEpsilon; // waiting for bug correction in geo

    if (TMath::Abs(track->GetSnpAt(x,bz)) >= maxSnp) return kFALSE;
    if (!track->PropagateTo(x,bz))  return kFALSE;

    MeanMaterialBudget(xyz0,xyz1,param);	
    Double_t xrho=param[0]*param[4], xx0=param[1];

    if (!track->CorrectForMeanMaterial(xx0,xrho,mass)) return kFALSE;
    if (rotateTo){
      if (TMath::Abs(track->GetSnp()) >= maxSnp) return kFALSE;
      track->GetXYZ(xyz0);   // global position
      Double_t alphan = TMath::ATan2(xyz0[1], xyz0[0]); 
      //
      Double_t ca=TMath::Cos(alphan-track->GetAlpha()), 
               sa=TMath::Sin(alphan-track->GetAlpha());
      Double_t sf=track->GetSnp(), cf=TMath::Sqrt(1.- sf*sf);
      Double_t sinNew =  sf*ca - cf*sa;
      if (TMath::Abs(sinNew) >= maxSnp) return kFALSE;
      if (!track->Rotate(alphan)) return kFALSE;
    }
    xpos = track->GetX();
  }
  return kTRUE;
}

void AliTracker::FillResiduals(const AliExternalTrackParam *t,
			      Double_t *p, Double_t *cov, 
                              UShort_t id, Bool_t updated) {
  //
  // This function fills the histograms of residuals 
  // The array of these histos is external for this AliTracker class.
  // Normally, this array belong to AliGlobalQADataMaker class.  
  // 
  if (!fFillResiduals) return; 
  if (!fResiduals) return; 

  const Double_t *residuals=t->GetResiduals(p,cov,updated);
  if (!residuals) return;

  TH1F *h=0;
  AliGeomManager::ELayerID layer=AliGeomManager::VolUIDToLayer(id);
  h=(TH1F*)fResiduals->At(2*layer-2);
  h->Fill(residuals[0]);
  h=(TH1F*)fResiduals->At(2*layer-1);
  h->Fill(residuals[1]);
}
Commit	Line	Data
be9c5115	1	/**************************************************************************
	2	* Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
	3	* *
	4	* Author: The ALICE Off-line Project. *
	5	* Contributors are mentioned in the code where appropriate. *
	6	* *
	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	**************************************************************************/
	15
acd84897	16	/* $Id$ */
fb17acd4	17
be9c5115	18	//-------------------------------------------------------------------------
be9c5115	19	// Implementation of the AliTracker class
9b83b8cc	20	// that is the base for AliTPCtracker, AliITStrackerV2 and AliTRDtracker
9b83b8cc	21	// Origin: Iouri Belikov, CERN, Jouri.Belikov@cern.ch
be9c5115	22	//-------------------------------------------------------------------------
7d0f8548	23	#include <TClass.h>
be9c5115	24	#include <TMath.h>
e23a38cb	25	#include <TH1F.h>
6e440ee5	26	#include <TGeoManager.h>
be9c5115	27
7b5ef2e6	28	#include "AliMagF.h"
be9c5115	29	#include "AliTracker.h"
e23a38cb	30	#include "AliGeomManager.h"
c84a5e9e	31	#include "AliCluster.h"
7d0f8548	32	#include "AliKalmanTrack.h"
41377c29	33
6e440ee5	34	extern TGeoManager *gGeoManager;
6e440ee5	35
7d0f8548	36	Bool_t AliTracker::fgUniformField=kTRUE;
7b5ef2e6	37	Double_t AliTracker::fgBz=kAlmost0Field;
3b242889	38	const AliMagF *AliTracker::fgkFieldMap=0;
e23a38cb	39	Bool_t AliTracker::fFillResiduals=kFALSE;
e23a38cb	40	TObjArray *AliTracker::fResiduals=0;
3b242889	41
be9c5115	42	ClassImp(AliTracker)
be9c5115	43
3b242889	44	AliTracker::AliTracker():
fe12e09c	45	TObject(),
3b242889	46	fX(0),
	47	fY(0),
	48	fZ(0),
	49	fSigmaX(0.005),
	50	fSigmaY(0.005),
	51	fSigmaZ(0.010)
	52	{
	53	//--------------------------------------------------------------------
	54	// The default constructor.
	55	//--------------------------------------------------------------------
c9b9861a	56	if (!fgkFieldMap) AliWarning("Field map is not set. Call AliTracker::SetFieldMap before creating a tracker!");
3b242889	57	}
3b242889	58
fe12e09c	59	//__________________________________________________________________________
	60	AliTracker::AliTracker(const AliTracker &atr):
	61	TObject(atr),
	62	fX(atr.fX),
	63	fY(atr.fY),
	64	fZ(atr.fZ),
	65	fSigmaX(atr.fSigmaX),
	66	fSigmaY(atr.fSigmaY),
	67	fSigmaZ(atr.fSigmaZ)
	68	{
	69	//--------------------------------------------------------------------
	70	// The default constructor.
	71	//--------------------------------------------------------------------
	72	if (!fgkFieldMap) AliWarning("Field map is not set. Call AliTracker::SetFieldMap before creating a tracker!");
	73	}
	74
	75	//__________________________________________________________________________
7d0f8548	76	void AliTracker::SetFieldMap(const AliMagF* map, Bool_t uni) {
	77	//--------------------------------------------------------------------
	78	//This passes the field map to the reconstruction.
	79	//--------------------------------------------------------------------
	80	if (map==0) AliFatalClass("Can't access the field map !");
	81
729c2fa2	82	if (fgkFieldMap) {
	83	AliWarningClass("The magnetic field map has been already set !");
	84	return;
	85	}
	86
7d0f8548	87	fgUniformField=uni;
	88	fgkFieldMap=map;
	89
	90	//Float_t r[3]={0.,0.,0.},b[3]; map->Field(r,b);
7ebb06c3	91	//Double_t bz=-b[2];
7d0f8548	92
7ebb06c3	93	Double_t bz=-map->SolenoidField();
7b5ef2e6	94	fgBz=TMath::Sign(kAlmost0Field,bz) + bz;
7d0f8548	95
	96	}
	97
be9c5115	98	//__________________________________________________________________________
	99	void AliTracker::CookLabel(AliKalmanTrack *t, Float_t wrong) const {
	100	//--------------------------------------------------------------------
	101	//This function "cooks" a track label. If label<0, this track is fake.
	102	//--------------------------------------------------------------------
	103	Int_t noc=t->GetNumberOfClusters();
9b4aca55	104	if (noc<1) return;
be9c5115	105	Int_t *lb=new Int_t[noc];
	106	Int_t *mx=new Int_t[noc];
	107	AliCluster *clusters=new AliCluster[noc];
	108
	109	Int_t i;
	110	for (i=0; i<noc; i++) {
	111	lb[i]=mx[i]=0;
	112	Int_t index=t->GetClusterIndex(i);
	113	clusters[i]=GetCluster(index);
	114	}
	115
	116	Int_t lab=123456789;
	117	for (i=0; i<noc; i++) {
	118	AliCluster *c=clusters[i];
	119	lab=TMath::Abs(c->GetLabel(0));
	120	Int_t j;
	121	for (j=0; j<noc; j++) if (lb[j]==lab \|\| mx[j]==0) break;
	122	lb[j]=lab;
	123	(mx[j])++;
	124	}
	125
	126	Int_t max=0;
	127	for (i=0; i<noc; i++) if (mx[i]>max) {max=mx[i]; lab=lb[i];}
	128
	129	for (i=0; i<noc; i++) {
	130	AliCluster *c=clusters[i];
babd135a	131	//if (TMath::Abs(c->GetLabel(1)) == lab \|\|
	132	// TMath::Abs(c->GetLabel(2)) == lab ) max++;
	133	if (TMath::Abs(c->GetLabel(0)!=lab))
	134	if (TMath::Abs(c->GetLabel(1)) == lab \|\|
	135	TMath::Abs(c->GetLabel(2)) == lab ) max++;
be9c5115	136	}
	137
	138	if ((1.- Float_t(max)/noc) > wrong) lab=-lab;
babd135a	139	t->SetFakeRatio((1.- Float_t(max)/noc));
be9c5115	140	t->SetLabel(lab);
	141
	142	delete[] lb;
	143	delete[] mx;
	144	delete[] clusters;
	145	}
	146
	147	//____________________________________________________________________________
	148	void AliTracker::UseClusters(const AliKalmanTrack *t, Int_t from) const {
	149	//------------------------------------------------------------------
	150	//This function marks clusters associated with the track.
	151	//------------------------------------------------------------------
	152	Int_t noc=t->GetNumberOfClusters();
	153	for (Int_t i=from; i<noc; i++) {
	154	Int_t index=t->GetClusterIndex(i);
	155	AliCluster *c=GetCluster(index);
	156	c->Use();
	157	}
	158	}
7b5ef2e6	159
	160	Double_t AliTracker::GetBz(Float_t *r) {
	161	//------------------------------------------------------------------
	162	// Returns Bz (kG) at the point "r" .
	163	//------------------------------------------------------------------
	164	Float_t b[3]; fgkFieldMap->Field(r,b);
	165	Double_t bz=-Double_t(b[2]);
	166	return (TMath::Sign(kAlmost0Field,bz) + bz);
	167	}
6e440ee5	168
	169	Double_t
	170	AliTracker::MeanMaterialBudget(Double_t start,Double_t end,Double_t *mparam)
	171	{
	172	//
	173	// Calculate mean material budget and material properties between
	174	// the points "start" and "end".
	175	//
	176	// "mparam" - parameters used for the energy and multiple scattering
	177	// corrections:
	178	//
	179	// mparam[0] - mean density: sum(x_i*rho_i)/sum(x_i) [g/cm3]
	180	// mparam[1] - equivalent rad length fraction: sum(x_i/X0_i) [adimensional]
	181	// mparam[2] - mean A: sum(x_i*A_i)/sum(x_i) [adimensional]
	182	// mparam[3] - mean Z: sum(x_i*Z_i)/sum(x_i) [adimensional]
	183	// mparam[4] - length: sum(x_i) [cm]
	184	// mparam[5] - Z/A mean: sum(x_i*Z_i/A_i)/sum(x_i) [adimensional]
	185	// mparam[6] - number of boundary crosses
	186	//
0c4ea33b	187	// Origin: Marian Ivanov, Marian.Ivanov@cern.ch
	188	//
	189	// Corrections and improvements by
	190	// Andrea Dainese, Andrea.Dainese@lnl.infn.it,
	191	// Andrei Gheata, Andrei.Gheata@cern.ch
	192	//
6e440ee5	193
	194	mparam[0]=0; mparam[1]=1; mparam[2] =0; mparam[3] =0;
	195	mparam[4]=0; mparam[5]=0; mparam[6]=0;
	196	//
	197	Double_t bparam[6]; // total parameters
	198	Double_t lparam[6]; // local parameters
	199
	200	for (Int_t i=0;i<6;i++) bparam[i]=0;
	201
	202	if (!gGeoManager) {
	203	printf("ERROR: no TGeo\n");
	204	return 0.;
	205	}
	206	//
	207	Double_t length;
	208	Double_t dir[3];
	209	length = TMath::Sqrt((end[0]-start[0])*(end[0]-start[0])+
	210	(end[1]-start[1])*(end[1]-start[1])+
	211	(end[2]-start[2])*(end[2]-start[2]));
	212	mparam[4]=length;
	213	if (length<TGeoShape::Tolerance()) return 0.0;
	214	Double_t invlen = 1./length;
	215	dir[0] = (end[0]-start[0])*invlen;
	216	dir[1] = (end[1]-start[1])*invlen;
	217	dir[2] = (end[2]-start[2])*invlen;
	218
	219	// Initialize start point and direction
	220	TGeoNode *currentnode = 0;
	221	TGeoNode *startnode = gGeoManager->InitTrack(start, dir);
	222	//printf("%s length=%f\n",gGeoManager->GetPath(),length);
	223	if (!startnode) {
f3b4b060	224	AliErrorClass(Form("start point out of geometry: x %f, y %f, z %f",
ff0051ed	225	start[0],start[1],start[2]));
6e440ee5	226	return 0.0;
	227	}
	228	TGeoMaterial *material = startnode->GetVolume()->GetMedium()->GetMaterial();
	229	lparam[0] = material->GetDensity();
	230	lparam[1] = material->GetRadLen();
	231	lparam[2] = material->GetA();
	232	lparam[3] = material->GetZ();
	233	lparam[4] = length;
	234	lparam[5] = lparam[3]/lparam[2];
	235	if (material->IsMixture()) {
	236	TGeoMixture * mixture = (TGeoMixture*)material;
	237	lparam[5] =0;
	238	Double_t sum =0;
	239	for (Int_t iel=0;iel<mixture->GetNelements();iel++){
	240	sum += mixture->GetWmixt()[iel];
	241	lparam[5]+= mixture->GetZmixt()[iel]*mixture->GetWmixt()[iel]/mixture->GetAmixt()[iel];
	242	}
	243	lparam[5]/=sum;
	244	}
	245
	246	// Locate next boundary within length without computing safety.
	247	// Propagate either with length (if no boundary found) or just cross boundary
	248	gGeoManager->FindNextBoundaryAndStep(length, kFALSE);
	249	Double_t step = 0.0; // Step made
	250	Double_t snext = gGeoManager->GetStep();
	251	// If no boundary within proposed length, return current density
	252	if (!gGeoManager->IsOnBoundary()) {
	253	mparam[0] = lparam[0];
	254	mparam[1] = lparam[4]/lparam[1];
	255	mparam[2] = lparam[2];
	256	mparam[3] = lparam[3];
	257	mparam[4] = lparam[4];
	258	return lparam[0];
	259	}
	260	// Try to cross the boundary and see what is next
	261	Int_t nzero = 0;
	262	while (length>TGeoShape::Tolerance()) {
	263	currentnode = gGeoManager->GetCurrentNode();
	264	if (snext<2.*TGeoShape::Tolerance()) nzero++;
	265	else nzero = 0;
	266	if (nzero>3) {
	267	// This means navigation has problems on one boundary
	268	// Try to cross by making a small step
	269	printf("ERROR: cannot cross boundary\n");
	270	mparam[0] = bparam[0]/step;
	271	mparam[1] = bparam[1];
	272	mparam[2] = bparam[2]/step;
	273	mparam[3] = bparam[3]/step;
	274	mparam[5] = bparam[5]/step;
	275	mparam[4] = step;
	276	mparam[0] = 0.; // if crash of navigation take mean density 0
	277	mparam[1] = 1000000; // and infinite rad length
	278	return bparam[0]/step;
	279	}
	280	mparam[6]+=1.;
	281	step += snext;
	282	bparam[1] += snext/lparam[1];
	283	bparam[2] += snext*lparam[2];
	284	bparam[3] += snext*lparam[3];
	285	bparam[5] += snext*lparam[5];
	286	bparam[0] += snext*lparam[0];
	287
	288	if (snext>=length) break;
	289	if (!currentnode) break;
290	length -= snext;
291	//printf("%s snext=%f length=%f\n", currentnode->GetName(),snext,length);
292	material = currentnode->GetVolume()->GetMedium()->GetMaterial();
293	lparam[0] = material->GetDensity();
294	lparam[1] = material->GetRadLen();
295	lparam[2] = material->GetA();
296	lparam[3] = material->GetZ();
297	//printf(" %f %f %f %f\n",lparam[0],lparam[1],lparam[2],lparam[3]);
298	lparam[5] = lparam[3]/lparam[2];
299	if (material->IsMixture()) {
300	TGeoMixture * mixture = (TGeoMixture*)material;
301	lparam[5]=0;
302	Double_t sum =0;
303	for (Int_t iel=0;iel<mixture->GetNelements();iel++){
304	sum+= mixture->GetWmixt()[iel];
305	lparam[5]+= mixture->GetZmixt()[iel]*mixture->GetWmixt()[iel]/mixture->GetAmixt()[iel];
306	}
307	lparam[5]/=sum;
308	}
309	gGeoManager->FindNextBoundaryAndStep(length, kFALSE);
310	snext = gGeoManager->GetStep();
311	//printf("snext %f\n",snext);
312	}
313	mparam[0] = bparam[0]/step;
314	mparam[1] = bparam[1];
315	mparam[2] = bparam[2]/step;
316	mparam[3] = bparam[3]/step;
317	mparam[5] = bparam[5]/step;
318	return bparam[0]/step;
319	}
0c4ea33b	320
	321
	322	Bool_t
	323	AliTracker::PropagateTrackTo(AliExternalTrackParam *track, Double_t xToGo,
	324	Double_t mass, Double_t maxStep, Bool_t rotateTo, Double_t maxSnp){
	325	//----------------------------------------------------------------
	326	//
	327	// Propagates the track to the plane X=xk (cm) using the magnetic field map
	328	// and correcting for the crossed material.
	329	//
	330	// mass - mass used in propagation - used for energy loss correction
	331	// maxStep - maximal step for propagation
	332	//
	333	// Origin: Marian Ivanov, Marian.Ivanov@cern.ch
	334	//
	335	//----------------------------------------------------------------
	336	const Double_t kEpsilon = 0.00001;
	337	Double_t xpos = track->GetX();
	338	Double_t dir = (xpos<xToGo) ? 1.:-1.;
	339	//
	340	while ( (xToGo-xpos)*dir > kEpsilon){
	341	Double_t step = dir*TMath::Min(TMath::Abs(xToGo-xpos), maxStep);
	342	Double_t x = xpos+step;
	343	Double_t xyz0[3],xyz1[3],param[7];
	344	track->GetXYZ(xyz0); //starting global position
	345
	346	Double_t bz=GetBz(xyz0); // getting the local Bz
	347
	348	if (!track->GetXYZAt(x,bz,xyz1)) return kFALSE; // no prolongation
	349	xyz1[2]+=kEpsilon; // waiting for bug correction in geo
	350
	351	if (TMath::Abs(track->GetSnpAt(x,bz)) >= maxSnp) return kFALSE;
	352	if (!track->PropagateTo(x,bz)) return kFALSE;
	353
	354	MeanMaterialBudget(xyz0,xyz1,param);
	355	Double_t xrho=param[0]*param[4], xx0=param[1];
	356
	357	if (!track->CorrectForMeanMaterial(xx0,xrho,mass)) return kFALSE;
	358	if (rotateTo){
	359	if (TMath::Abs(track->GetSnp()) >= maxSnp) return kFALSE;
	360	track->GetXYZ(xyz0); // global position
	361	Double_t alphan = TMath::ATan2(xyz0[1], xyz0[0]);
	362	//
	363	Double_t ca=TMath::Cos(alphan-track->GetAlpha()),
	364	sa=TMath::Sin(alphan-track->GetAlpha());
	365	Double_t sf=track->GetSnp(), cf=TMath::Sqrt(1.- sf*sf);
	366	Double_t sinNew = sfca - cfsa;
	367	if (TMath::Abs(sinNew) >= maxSnp) return kFALSE;
	368	if (!track->Rotate(alphan)) return kFALSE;
	369	}
	370	xpos = track->GetX();
	371	}
	372	return kTRUE;
	373	}
	374
e23a38cb	375	void AliTracker::FillResiduals(const AliExternalTrackParam *t,
	376	Double_t p, Double_t cov,
	377	UShort_t id, Bool_t updated) {
	378	//
	379	// This function fills the histograms of residuals
	380	// The array of these histos is external for this AliTracker class.
	381	// Normally, this array belong to AliGlobalQADataMaker class.
	382	//
	383	if (!fFillResiduals) return;
	384	if (!fResiduals) return;
	385
	386	const Double_t *residuals=t->GetResiduals(p,cov,updated);
	387	if (!residuals) return;
	388
	389	TH1F *h=0;
	390	AliGeomManager::ELayerID layer=AliGeomManager::VolUIDToLayer(id);
	391	h=(TH1F)fResiduals->At(2layer-2);
	392	h->Fill(residuals[0]);
	393	h=(TH1F)fResiduals->At(2layer-1);
	394	h->Fill(residuals[1]);
	395	}
	396