[u/mrichter/AliRoot.git] / HLT / src / AliL3Track.cxx

//$Id$

// Author: Anders Vestbo <mailto:vestbo$fi.uib.no>, Uli Frankenfeld <mailto:franken@fi.uib.no>
//*-- Copyright &copy ASV


#include "AliL3RootTypes.h"

#include "AliL3Defs.h"
#include "AliL3Logging.h"
#include "AliL3Track.h"
#include "AliL3Transform.h"
#include "AliL3Vertex.h"
#include <math.h>

//_____________________________________________________________
// AliL3Track
//
// Track base class
//Begin_Html
/*
<img src="track_coordinates.gif">
*/
//End_Html

ClassImp(AliL3Track)

Float_t AliL3Track::BFACT = 0.0029980;
Double_t AliL3Track::pi=3.14159265358979323846;

AliL3Track::AliL3Track()
{
  //Constructor

  fNHits = 0;
  fMCid = -1;
  fKappa=0;
  fRadius=0;
  fCenterX=0;
  fCenterY=0;
  ComesFromMainVertex(false);
  fQ = 0;
  fPhi0=0;
  fPsi=0;
  fR0=0;
  fTanl=0;
  fZ0=0;
  fPt=0;
  fLength=0;
  fIsLocal=true;
  fRowRange[0]=0;
  fRowRange[1]=0;
  memset(fHitNumbers,0,176*sizeof(UInt_t));
}

void AliL3Track::Set(AliL3Track *tpt){
  
  SetRowRange(tpt->GetFirstRow(),tpt->GetLastRow());
  SetPhi0(tpt->GetPhi0());
  SetKappa(tpt->GetKappa());
  SetNHits(tpt->GetNHits());
  SetFirstPoint(tpt->GetFirstPointX(),tpt->GetFirstPointY(),tpt->GetFirstPointZ());
  SetLastPoint(tpt->GetLastPointX(),tpt->GetLastPointY(),tpt->GetLastPointZ());
  SetPt(tpt->GetPt());
  SetPsi(tpt->GetPsi());
  SetTgl(tpt->GetTgl());
  SetCharge(tpt->GetCharge());
  SetHits(tpt->GetNHits(),(UInt_t *)tpt->GetHitNumbers());

}

Int_t AliL3Track::Compare(const AliL3Track *track) const
{
  if(track->GetNHits() < GetNHits()) return 1;
  if(track->GetNHits() > GetNHits()) return -1;
  return 0;
}

AliL3Track::~AliL3Track()
{
  //Nothing to do
}

Double_t AliL3Track::GetP() const
{
  // Returns total momentum.  
  return fabs(GetPt())*sqrt(1. + GetTgl()*GetTgl());

}

Double_t AliL3Track::GetPseudoRapidity() const
{
  return 0.5 * log((GetP() + GetPz()) / (GetP() - GetPz()));
}
/*
Double_t AliL3Track::GetEta() const
{
  return GetPseudoRapidity();
}
*/
Double_t AliL3Track::GetRapidity() const
{
  Double_t m_pi = 0.13957;
  return 0.5 * log((m_pi + GetPz()) / (m_pi - GetPz()));
}

void AliL3Track::Rotate(Int_t slice,Bool_t tolocal)
{
  //Rotate track to global parameters
  //If flag tolocal is set, the track is rotated
  //to local coordinates.

  
  Float_t psi[1] = {GetPsi()};
  if(!tolocal)
    AliL3Transform::Local2GlobalAngle(psi,slice);
  else
    AliL3Transform::Global2LocalAngle(psi,slice);
  SetPsi(psi[0]);
  Float_t first[3];
  first[0] = GetFirstPointX();
  first[1] = GetFirstPointY();
  first[2] = GetFirstPointZ();
  if(!tolocal)
    AliL3Transform::Local2Global(first,slice);
  else
    AliL3Transform::Global2Local(first,slice,kTRUE);
  
  SetFirstPoint(first[0],first[1],first[2]);
  Float_t last[3];
  last[0] = GetLastPointX();
  last[1] = GetLastPointY();
  last[2] = GetLastPointZ();
  if(!tolocal)
    AliL3Transform::Local2Global(last,slice);
  else
    AliL3Transform::Global2Local(last,slice,kTRUE);
  SetLastPoint(last[0],last[1],last[2]);
  
  Float_t center[3] = {GetCenterX(),GetCenterY(),0};
  if(!tolocal)
    AliL3Transform::Local2Global(center,slice);
  else
    AliL3Transform::Global2Local(center,slice,kTRUE);
  SetCenterX(center[0]);
  SetCenterY(center[1]);
  
  if(!tolocal)
    fIsLocal=kFALSE;
  else
    fIsLocal=kTRUE;
}

void AliL3Track::CalculateHelix(){
  //Calculate Radius, CenterX and Centery from Psi, X0, Y0
  //
  
  fRadius = fPt / (BFACT*AliL3Transform::GetBField());
  if(fRadius) fKappa = -fQ*1./fRadius;
  else fRadius = 999999;  //just zero
  Double_t trackPhi0 = fPsi + fQ *0.5 * pi;

  fCenterX = fFirstPoint[0] - fRadius *  cos(trackPhi0);
  fCenterY = fFirstPoint[1] - fRadius *  sin(trackPhi0);
}

Double_t AliL3Track::GetCrossingAngle(Int_t padrow) 
{
  //Calculate the crossing angle between track and given padrow.
  
  if(!IsLocal())
    {
      printf("Track is not given in local coordinates\n");
      return 0;
    }
  
  Float_t xyz[3];
  if(!GetCrossingPoint(padrow,xyz))
    printf("AliL3HoughTrack::GetCrossingPoint : Track does not cross line!!\n");
  
  //Take the dot product of the tangent vector of the track, and
  //vector perpendicular to the padrow.
  
  Double_t tangent[2];
  tangent[1] = (xyz[0] - GetCenterX())/GetRadius();
  tangent[0] = -1.*(xyz[1] - GetCenterY())/GetRadius();

  Double_t perp_padrow[2] = {1,0}; //locally in slice

  Double_t cos_beta = fabs(tangent[0]*perp_padrow[0] + tangent[1]*perp_padrow[1]);
  return acos(cos_beta);
  
}

Bool_t AliL3Track::GetCrossingPoint(Int_t padrow,Float_t *xyz) 
{
  //Assumes the track is given in local coordinates

  if(!IsLocal())
    {
      printf("GetCrossingPoint: Track is given on global coordinates\n");
      return false;
    }
  
  Double_t xHit = AliL3Transform::Row2X(padrow);

  xyz[0] = xHit;
  Double_t aa = (xHit - GetCenterX())*(xHit - GetCenterX());
  Double_t r2 = GetRadius()*GetRadius();
  if(aa > r2)
    return false;

  Double_t aa2 = sqrt(r2 - aa);
  Double_t y1 = GetCenterY() + aa2;
  Double_t y2 = GetCenterY() - aa2;
  xyz[1] = y1;
  if(fabs(y2) < fabs(y1)) xyz[1] = y2;
  
  Double_t yHit = xyz[1];
  Double_t angle1 = atan2((yHit - GetCenterY()),(xHit - GetCenterX()));
  if(angle1 < 0) angle1 += 2.*Pi;
  Double_t angle2 = atan2((GetFirstPointY() - GetCenterY()),(GetFirstPointX() - GetCenterX()));
  if(angle2 < 0) angle2 += 2.*Pi;
  Double_t diff_angle = angle1 - angle2;
  diff_angle = fmod(diff_angle,2*Pi);
  if((GetCharge()*diff_angle) > 0) diff_angle = diff_angle - GetCharge()*2.*Pi;
  Double_t s_tot = fabs(diff_angle)*GetRadius();
  Double_t zHit = GetFirstPointZ() + s_tot*GetTgl();
  xyz[2] = zHit;
  
  return true;
}


Bool_t AliL3Track::CalculateReferencePoint(Double_t angle,Double_t radius){
  // Global coordinate: crossing point with y = ax+ b; a=tan(angle-Pi/2);
  //
  const Double_t rr=radius;//132; //position of referece plane
  const Double_t xr = cos(angle) *rr;
  const Double_t yr = sin(angle) *rr;
  
  Double_t a = tan(angle-pi/2);
  Double_t b = yr - a * xr;

  Double_t pp=(fCenterX+a*fCenterY-a*b)/(1+pow(a,2));
  Double_t qq=(pow(fCenterX,2)+pow(fCenterY,2)-2*fCenterY*b+pow(b,2)-pow(fRadius,2))/(1+pow(a,2));

  Double_t racine = pp*pp-qq;
  if(racine<0) return IsPoint(kFALSE);      //no Point

  Double_t rootRacine = sqrt(racine);
  Double_t x0 = pp+rootRacine;
  Double_t x1 = pp-rootRacine;
  Double_t y0 = a*x0 + b;
  Double_t y1 = a*x1 + b;

  Double_t diff0 = sqrt(pow(x0-xr,2)+pow(y0-yr,2));
  Double_t diff1 = sqrt(pow(x1-xr,2)+pow(y1-yr,2));
 
  if(diff0<diff1){
    fPoint[0]=x0;
    fPoint[1]=y0;
  }
  else{
    fPoint[0]=x1;
    fPoint[1]=y1;
  }

  Double_t pointPhi0  = atan2(fPoint[1]-fCenterY,fPoint[0]-fCenterX);
  Double_t trackPhi0  = atan2(fFirstPoint[1]-fCenterY,fFirstPoint[0]-fCenterX);
  if(fabs(trackPhi0-pointPhi0)>pi){
    if(trackPhi0<pointPhi0) trackPhi0 += 2*pi;
    else                    pointPhi0 += 2*pi;
  }
  Double_t stot = -fQ * (pointPhi0-trackPhi0) * fRadius ;
  fPoint[2]   = fFirstPoint[2] + stot * fTanl;

  fPointPsi = pointPhi0 - fQ * 0.5 * pi;
  if(fPointPsi<0.)  fPointPsi+= 2*pi;
  fPointPsi = fmod(fPointPsi, 2*pi);

  return IsPoint(kTRUE);
}

Bool_t AliL3Track::CalculateEdgePoint(Double_t angle){
  // Global coordinate: crossing point with y = ax; a=tan(angle);
  //
  Double_t rmin=80;  //min Radius of TPC
  Double_t rmax=260; //max Radius of TPC

  Double_t a = tan(angle);
  Double_t pp=(fCenterX+a*fCenterY)/(1+pow(a,2));
  Double_t qq=(pow(fCenterX,2)+pow(fCenterY,2)-pow(fRadius,2))/(1+pow(a,2));
  Double_t racine = pp*pp-qq;
  if(racine<0) return IsPoint(kFALSE);     //no Point
  Double_t rootRacine = sqrt(racine);
  Double_t x0 = pp+rootRacine;
  Double_t x1 = pp-rootRacine;
  Double_t y0 = a*x0;
  Double_t y1 = a*x1;

  Double_t r0 = sqrt(pow(x0,2)+pow(y0,2));
  Double_t r1 = sqrt(pow(x1,2)+pow(y1,2)); 
  //find the right crossing point:
  //inside the TPC modules
  Bool_t ok0 = kFALSE;
  Bool_t ok1 = kFALSE;

  if(r0>rmin&&r0<rmax){
    Double_t da=atan2(y0,x0);
    if(da<0) da+=2*pi;
    if(fabs(da-angle)<0.5)
      ok0 = kTRUE;
  }
  if(r1>rmin&&r1<rmax){
    Double_t da=atan2(y1,x1);
    if(da<0) da+=2*pi;
    if(fabs(da-angle)<0.5)
      ok1 = kTRUE;
  }
  if(!(ok0||ok1)) return IsPoint(kFALSE);   //no Point
  
  if(ok0&&ok1){
    Double_t diff0 = sqrt(pow(fFirstPoint[0]-x0,2)+pow(fFirstPoint[1]-y0,2));
    Double_t diff1 = sqrt(pow(fFirstPoint[0]-x1,2)+pow(fFirstPoint[1]-y1,2));
    if(diff0<diff1) ok1 = kFALSE; //use ok0
    else ok0 = kFALSE;            //use ok1
  }
  if(ok0){fPoint[0]=x0; fPoint[1]=y0;}
  else   {fPoint[0]=x1; fPoint[1]=y1;}

  Double_t pointPhi0  = atan2(fPoint[1]-fCenterY,fPoint[0]-fCenterX);
  Double_t trackPhi0  = atan2(fFirstPoint[1]-fCenterY,fFirstPoint[0]-fCenterX);
  if(fabs(trackPhi0-pointPhi0)>pi){
    if(trackPhi0<pointPhi0) trackPhi0 += 2*pi;
    else                    pointPhi0 += 2*pi;
  }
  Double_t stot = -fQ * (pointPhi0-trackPhi0) * fRadius ;
  fPoint[2]   = fFirstPoint[2] + stot * fTanl;

  fPointPsi = pointPhi0 - fQ * 0.5 * pi;
  if(fPointPsi<0.)  fPointPsi+= 2*pi;
  fPointPsi = fmod(fPointPsi, 2*pi);

  return IsPoint(kTRUE);
}

Bool_t AliL3Track::CalculatePoint(Double_t xplane){
  // Local coordinate: crossing point with x plane
  //
  Double_t racine = pow(fRadius,2)-pow(xplane-fCenterX,2);
  if(racine<0) return IsPoint(kFALSE);
  Double_t rootRacine = sqrt(racine);

  Double_t y0 = fCenterY + rootRacine;
  Double_t y1 = fCenterY - rootRacine;
  //Double_t diff0 = sqrt(pow(fFirstPoint[0]-xplane)+pow(fFirstPoint[1]-y0));
  //Double_t diff1 = sqrt(pow(fFirstPoint[0]-xplane)+pow(fFirstPoint[1]-y1));
  Double_t diff0 = fabs(y0-fFirstPoint[1]);
  Double_t diff1 = fabs(y1-fFirstPoint[1]);

  fPoint[0]=xplane;
  if(diff0<diff1) fPoint[1]=y0;
  else            fPoint[1]=y1;

  Double_t pointPhi0  = atan2(fPoint[1]-fCenterY,fPoint[0]-fCenterX);
  Double_t trackPhi0  = atan2(fFirstPoint[1]-fCenterY,fFirstPoint[0]-fCenterX);
  if(fabs(trackPhi0-pointPhi0)>pi){
    if(trackPhi0<pointPhi0) trackPhi0 += 2*pi;
    else                    pointPhi0 += 2*pi;
  }
  Double_t stot = -fQ * (pointPhi0-trackPhi0) * fRadius ;  
  fPoint[2]   = fFirstPoint[2] + stot * fTanl;

  fPointPsi = pointPhi0 - fQ * 0.5 * pi;
  if(fPointPsi<0.)  fPointPsi+= 2*pi;
  fPointPsi = fmod(fPointPsi, 2*pi);

  return IsPoint(kTRUE);
}

void AliL3Track::GetClosestPoint(AliL3Vertex *vertex,Double_t &closest_x,Double_t &closest_y,Double_t &closest_z)
{
  //Calculate the point of closest approach to the vertex
  
  
  Double_t xc = GetCenterX() - vertex->GetX();//Shift the center of curvature with respect to the vertex
  Double_t yc = GetCenterY() - vertex->GetY();
  
  Double_t dist_x1 = xc*(1 + GetRadius()/sqrt(xc*xc + yc*yc));
  Double_t dist_y1 = yc*(1 + GetRadius()/sqrt(xc*xc + yc*yc));
  Double_t distance1 = sqrt(dist_x1*dist_x1 + dist_y1*dist_y1);
  
  Double_t dist_x2 = xc*(1 - GetRadius()/sqrt(xc*xc + yc*yc));
  Double_t dist_y2 = yc*(1 - GetRadius()/sqrt(xc*xc + yc*yc));
  Double_t distance2 = sqrt(dist_x2*dist_x2 + dist_y2*dist_y2);
  
  //Choose the closest:
  if(distance1 < distance2)
    {
      closest_x = dist_x1 + vertex->GetX();
      closest_y = dist_y1 + vertex->GetY();
    }
  else
    {
      closest_x = dist_x2 + vertex->GetX();
      closest_y = dist_y2 + vertex->GetY();
    }
  
  //Get the z coordinate:
  Double_t angle1 = atan2((closest_y-GetCenterY()),(closest_x-GetCenterX()));
  if(angle1 < 0) angle1 = angle1 + 2*Pi;
 
  Double_t angle2 = atan2((GetFirstPointY()-GetCenterY()),(GetFirstPointX()-GetCenterX()));
  if(angle2 < 0) angle2 = angle2 + 2*Pi;
  
  Double_t diff_angle = angle1 - angle2;
  diff_angle = fmod(diff_angle,2*Pi);
  
  if((GetCharge()*diff_angle) < 0) diff_angle = diff_angle + GetCharge()*2*Pi;
  Double_t s_tot = fabs(diff_angle)*GetRadius();
  
  closest_z = GetFirstPointZ() - s_tot*GetTgl();
}
Commit	Line	Data
6d4f1901	1	//$Id$
6d4f1901	2
2d04dcbf	3	// Author: Anders Vestbo <mailto:vestbo$fi.uib.no>, Uli Frankenfeld <mailto:franken@fi.uib.no>
2d04dcbf	4	//*-- Copyright &copy ASV
108615fc	5
108615fc	6
	7	#include "AliL3RootTypes.h"
	8
0391971c	9	#include "AliL3Defs.h"
108615fc	10	#include "AliL3Logging.h"
108615fc	11	#include "AliL3Track.h"
0391971c	12	#include "AliL3Transform.h"
6d4f1901	13	#include "AliL3Vertex.h"
108615fc	14	#include <math.h>
108615fc	15
2d04dcbf	16	//_____________________________________________________________
	17	// AliL3Track
	18	//
	19	// Track base class
02cb36b2	20	//Begin_Html
	21	/*
	22	<img src="track_coordinates.gif">
	23	*/
	24	//End_Html
0391971c	25
108615fc	26	ClassImp(AliL3Track)
	27
	28	Float_t AliL3Track::BFACT = 0.0029980;
108615fc	29	Double_t AliL3Track::pi=3.14159265358979323846;
	30
	31	AliL3Track::AliL3Track()
	32	{
	33	//Constructor
	34
	35	fNHits = 0;
	36	fMCid = -1;
	37	fKappa=0;
	38	fRadius=0;
	39	fCenterX=0;
	40	fCenterY=0;
	41	ComesFromMainVertex(false);
	42	fQ = 0;
	43	fPhi0=0;
	44	fPsi=0;
	45	fR0=0;
	46	fTanl=0;
	47	fZ0=0;
	48	fPt=0;
	49	fLength=0;
	50	fIsLocal=true;
	51	fRowRange[0]=0;
	52	fRowRange[1]=0;
ae97a0b9	53	memset(fHitNumbers,0,176*sizeof(UInt_t));
108615fc	54	}
	55
	56	void AliL3Track::Set(AliL3Track *tpt){
	57
3a735e00	58	SetRowRange(tpt->GetFirstRow(),tpt->GetLastRow());
	59	SetPhi0(tpt->GetPhi0());
	60	SetKappa(tpt->GetKappa());
	61	SetNHits(tpt->GetNHits());
	62	SetFirstPoint(tpt->GetFirstPointX(),tpt->GetFirstPointY(),tpt->GetFirstPointZ());
	63	SetLastPoint(tpt->GetLastPointX(),tpt->GetLastPointY(),tpt->GetLastPointZ());
	64	SetPt(tpt->GetPt());
	65	SetPsi(tpt->GetPsi());
	66	SetTgl(tpt->GetTgl());
	67	SetCharge(tpt->GetCharge());
	68	SetHits(tpt->GetNHits(),(UInt_t *)tpt->GetHitNumbers());
108615fc	69
108615fc	70	}
108615fc	71
203925a9	72	Int_t AliL3Track::Compare(const AliL3Track *track) const
	73	{
	74	if(track->GetNHits() < GetNHits()) return 1;
	75	if(track->GetNHits() > GetNHits()) return -1;
	76	return 0;
	77	}
108615fc	78
	79	AliL3Track::~AliL3Track()
	80	{
203925a9	81	//Nothing to do
108615fc	82	}
	83
	84	Double_t AliL3Track::GetP() const
	85	{
203925a9	86	// Returns total momentum.
108615fc	87	return fabs(GetPt())sqrt(1. + GetTgl()GetTgl());
	88
	89	}
	90
	91	Double_t AliL3Track::GetPseudoRapidity() const
	92	{
	93	return 0.5 * log((GetP() + GetPz()) / (GetP() - GetPz()));
	94	}
203925a9	95	/*
108615fc	96	Double_t AliL3Track::GetEta() const
	97	{
	98	return GetPseudoRapidity();
	99	}
203925a9	100	*/
108615fc	101	Double_t AliL3Track::GetRapidity() const
	102	{
	103	Double_t m_pi = 0.13957;
	104	return 0.5 * log((m_pi + GetPz()) / (m_pi - GetPz()));
	105	}
	106
203925a9	107	void AliL3Track::Rotate(Int_t slice,Bool_t tolocal)
0391971c	108	{
0391971c	109	//Rotate track to global parameters
203925a9	110	//If flag tolocal is set, the track is rotated
203925a9	111	//to local coordinates.
0391971c	112
0391971c	113
0391971c	114	Float_t psi[1] = {GetPsi()};
203925a9	115	if(!tolocal)
494fad94	116	AliL3Transform::Local2GlobalAngle(psi,slice);
203925a9	117	else
494fad94	118	AliL3Transform::Global2LocalAngle(psi,slice);
0391971c	119	SetPsi(psi[0]);
	120	Float_t first[3];
	121	first[0] = GetFirstPointX();
	122	first[1] = GetFirstPointY();
	123	first[2] = GetFirstPointZ();
203925a9	124	if(!tolocal)
494fad94	125	AliL3Transform::Local2Global(first,slice);
203925a9	126	else
494fad94	127	AliL3Transform::Global2Local(first,slice,kTRUE);
203925a9	128
0391971c	129	SetFirstPoint(first[0],first[1],first[2]);
	130	Float_t last[3];
	131	last[0] = GetLastPointX();
	132	last[1] = GetLastPointY();
	133	last[2] = GetLastPointZ();
203925a9	134	if(!tolocal)
494fad94	135	AliL3Transform::Local2Global(last,slice);
203925a9	136	else
494fad94	137	AliL3Transform::Global2Local(last,slice,kTRUE);
0391971c	138	SetLastPoint(last[0],last[1],last[2]);
203925a9	139
6d4f1901	140	Float_t center[3] = {GetCenterX(),GetCenterY(),0};
6d4f1901	141	if(!tolocal)
494fad94	142	AliL3Transform::Local2Global(center,slice);
6d4f1901	143	else
494fad94	144	AliL3Transform::Global2Local(center,slice,kTRUE);
6d4f1901	145	SetCenterX(center[0]);
	146	SetCenterY(center[1]);
	147
203925a9	148	if(!tolocal)
	149	fIsLocal=kFALSE;
	150	else
	151	fIsLocal=kTRUE;
0391971c	152	}
0391971c	153
108615fc	154	void AliL3Track::CalculateHelix(){
	155	//Calculate Radius, CenterX and Centery from Psi, X0, Y0
	156	//
	157
ef79795d	158	fRadius = fPt / (BFACT*AliL3Transform::GetBField());
3ceb3fe1	159	if(fRadius) fKappa = -fQ*1./fRadius;
108615fc	160	else fRadius = 999999; //just zero
	161	Double_t trackPhi0 = fPsi + fQ 0.5 pi;
	162
	163	fCenterX = fFirstPoint[0] - fRadius * cos(trackPhi0);
	164	fCenterY = fFirstPoint[1] - fRadius * sin(trackPhi0);
	165	}
	166
2d04dcbf	167	Double_t AliL3Track::GetCrossingAngle(Int_t padrow)
0391971c	168	{
0391971c	169	//Calculate the crossing angle between track and given padrow.
2d04dcbf	170
0391971c	171	if(!IsLocal())
	172	{
	173	printf("Track is not given in local coordinates\n");
	174	return 0;
	175	}
2d04dcbf	176
0391971c	177	Float_t xyz[3];
	178	if(!GetCrossingPoint(padrow,xyz))
	179	printf("AliL3HoughTrack::GetCrossingPoint : Track does not cross line!!\n");
	180
	181	//Take the dot product of the tangent vector of the track, and
	182	//vector perpendicular to the padrow.
	183
	184	Double_t tangent[2];
	185	tangent[1] = (xyz[0] - GetCenterX())/GetRadius();
	186	tangent[0] = -1.*(xyz[1] - GetCenterY())/GetRadius();
	187
	188	Double_t perp_padrow[2] = {1,0}; //locally in slice
	189
	190	Double_t cos_beta = fabs(tangent[0]perp_padrow[0] + tangent[1]perp_padrow[1]);
	191	return acos(cos_beta);
	192
	193	}
	194
2d04dcbf	195	Bool_t AliL3Track::GetCrossingPoint(Int_t padrow,Float_t *xyz)
0391971c	196	{
	197	//Assumes the track is given in local coordinates
	198
0391971c	199	if(!IsLocal())
	200	{
	201	printf("GetCrossingPoint: Track is given on global coordinates\n");
	202	return false;
	203	}
	204
494fad94	205	Double_t xHit = AliL3Transform::Row2X(padrow);
0391971c	206
	207	xyz[0] = xHit;
	208	Double_t aa = (xHit - GetCenterX())*(xHit - GetCenterX());
	209	Double_t r2 = GetRadius()*GetRadius();
	210	if(aa > r2)
	211	return false;
	212
	213	Double_t aa2 = sqrt(r2 - aa);
	214	Double_t y1 = GetCenterY() + aa2;
	215	Double_t y2 = GetCenterY() - aa2;
	216	xyz[1] = y1;
	217	if(fabs(y2) < fabs(y1)) xyz[1] = y2;
	218
	219	Double_t yHit = xyz[1];
	220	Double_t angle1 = atan2((yHit - GetCenterY()),(xHit - GetCenterX()));
	221	if(angle1 < 0) angle1 += 2.*Pi;
	222	Double_t angle2 = atan2((GetFirstPointY() - GetCenterY()),(GetFirstPointX() - GetCenterX()));
	223	if(angle2 < 0) angle2 += 2.*Pi;
	224	Double_t diff_angle = angle1 - angle2;
	225	diff_angle = fmod(diff_angle,2*Pi);
	226	if((GetCharge()diff_angle) > 0) diff_angle = diff_angle - GetCharge()2.*Pi;
	227	Double_t s_tot = fabs(diff_angle)*GetRadius();
	228	Double_t zHit = GetFirstPointZ() + s_tot*GetTgl();
	229	xyz[2] = zHit;
	230
0391971c	231	return true;
	232	}
	233
	234
6d4f1901	235	Bool_t AliL3Track::CalculateReferencePoint(Double_t angle,Double_t radius){
108615fc	236	// Global coordinate: crossing point with y = ax+ b; a=tan(angle-Pi/2);
108615fc	237	//
6d4f1901	238	const Double_t rr=radius;//132; //position of referece plane
108615fc	239	const Double_t xr = cos(angle) *rr;
108615fc	240	const Double_t yr = sin(angle) *rr;
6d4f1901	241
108615fc	242	Double_t a = tan(angle-pi/2);
	243	Double_t b = yr - a * xr;
	244
	245	Double_t pp=(fCenterX+afCenterY-ab)/(1+pow(a,2));
	246	Double_t qq=(pow(fCenterX,2)+pow(fCenterY,2)-2fCenterYb+pow(b,2)-pow(fRadius,2))/(1+pow(a,2));
	247
	248	Double_t racine = pp*pp-qq;
	249	if(racine<0) return IsPoint(kFALSE); //no Point
	250
	251	Double_t rootRacine = sqrt(racine);
	252	Double_t x0 = pp+rootRacine;
	253	Double_t x1 = pp-rootRacine;
	254	Double_t y0 = a*x0 + b;
	255	Double_t y1 = a*x1 + b;
	256
	257	Double_t diff0 = sqrt(pow(x0-xr,2)+pow(y0-yr,2));
	258	Double_t diff1 = sqrt(pow(x1-xr,2)+pow(y1-yr,2));
	259
	260	if(diff0<diff1){
	261	fPoint[0]=x0;
	262	fPoint[1]=y0;
	263	}
	264	else{
	265	fPoint[0]=x1;
	266	fPoint[1]=y1;
	267	}
	268
	269	Double_t pointPhi0 = atan2(fPoint[1]-fCenterY,fPoint[0]-fCenterX);
	270	Double_t trackPhi0 = atan2(fFirstPoint[1]-fCenterY,fFirstPoint[0]-fCenterX);
	271	if(fabs(trackPhi0-pointPhi0)>pi){
	272	if(trackPhi0<pointPhi0) trackPhi0 += 2*pi;
	273	else pointPhi0 += 2*pi;
	274	}
	275	Double_t stot = -fQ * (pointPhi0-trackPhi0) * fRadius ;
	276	fPoint[2] = fFirstPoint[2] + stot * fTanl;
	277
	278	fPointPsi = pointPhi0 - fQ * 0.5 * pi;
	279	if(fPointPsi<0.) fPointPsi+= 2*pi;
	280	fPointPsi = fmod(fPointPsi, 2*pi);
	281
	282	return IsPoint(kTRUE);
	283	}
	284
	285	Bool_t AliL3Track::CalculateEdgePoint(Double_t angle){
	286	// Global coordinate: crossing point with y = ax; a=tan(angle);
	287	//
	288	Double_t rmin=80; //min Radius of TPC
	289	Double_t rmax=260; //max Radius of TPC
	290
	291	Double_t a = tan(angle);
	292	Double_t pp=(fCenterX+a*fCenterY)/(1+pow(a,2));
	293	Double_t qq=(pow(fCenterX,2)+pow(fCenterY,2)-pow(fRadius,2))/(1+pow(a,2));
	294	Double_t racine = pp*pp-qq;
	295	if(racine<0) return IsPoint(kFALSE); //no Point
	296	Double_t rootRacine = sqrt(racine);
	297	Double_t x0 = pp+rootRacine;
	298	Double_t x1 = pp-rootRacine;
	299	Double_t y0 = a*x0;
	300	Double_t y1 = a*x1;
	301
	302	Double_t r0 = sqrt(pow(x0,2)+pow(y0,2));
	303	Double_t r1 = sqrt(pow(x1,2)+pow(y1,2));
	304	//find the right crossing point:
	305	//inside the TPC modules
306	Bool_t ok0 = kFALSE;
307	Bool_t ok1 = kFALSE;
472d9e24	308
108615fc	309	if(r0>rmin&&r0<rmax){
108615fc	310	Double_t da=atan2(y0,x0);
472d9e24	311	if(da<0) da+=2*pi;
108615fc	312	if(fabs(da-angle)<0.5)
	313	ok0 = kTRUE;
	314	}
	315	if(r1>rmin&&r1<rmax){
472d9e24	316	Double_t da=atan2(y1,x1);
472d9e24	317	if(da<0) da+=2*pi;
108615fc	318	if(fabs(da-angle)<0.5)
	319	ok1 = kTRUE;
	320	}
	321	if(!(ok0\|\|ok1)) return IsPoint(kFALSE); //no Point
	322
	323	if(ok0&&ok1){
	324	Double_t diff0 = sqrt(pow(fFirstPoint[0]-x0,2)+pow(fFirstPoint[1]-y0,2));
	325	Double_t diff1 = sqrt(pow(fFirstPoint[0]-x1,2)+pow(fFirstPoint[1]-y1,2));
	326	if(diff0<diff1) ok1 = kFALSE; //use ok0
	327	else ok0 = kFALSE; //use ok1
	328	}
	329	if(ok0){fPoint[0]=x0; fPoint[1]=y0;}
	330	else {fPoint[0]=x1; fPoint[1]=y1;}
	331
	332	Double_t pointPhi0 = atan2(fPoint[1]-fCenterY,fPoint[0]-fCenterX);
	333	Double_t trackPhi0 = atan2(fFirstPoint[1]-fCenterY,fFirstPoint[0]-fCenterX);
	334	if(fabs(trackPhi0-pointPhi0)>pi){
	335	if(trackPhi0<pointPhi0) trackPhi0 += 2*pi;
	336	else pointPhi0 += 2*pi;
	337	}
	338	Double_t stot = -fQ * (pointPhi0-trackPhi0) * fRadius ;
	339	fPoint[2] = fFirstPoint[2] + stot * fTanl;
	340
	341	fPointPsi = pointPhi0 - fQ * 0.5 * pi;
	342	if(fPointPsi<0.) fPointPsi+= 2*pi;
	343	fPointPsi = fmod(fPointPsi, 2*pi);
	344
	345	return IsPoint(kTRUE);
	346	}
	347
	348	Bool_t AliL3Track::CalculatePoint(Double_t xplane){
	349	// Local coordinate: crossing point with x plane
	350	//
	351	Double_t racine = pow(fRadius,2)-pow(xplane-fCenterX,2);
	352	if(racine<0) return IsPoint(kFALSE);
	353	Double_t rootRacine = sqrt(racine);
	354
	355	Double_t y0 = fCenterY + rootRacine;
	356	Double_t y1 = fCenterY - rootRacine;
	357	//Double_t diff0 = sqrt(pow(fFirstPoint[0]-xplane)+pow(fFirstPoint[1]-y0));
	358	//Double_t diff1 = sqrt(pow(fFirstPoint[0]-xplane)+pow(fFirstPoint[1]-y1));
	359	Double_t diff0 = fabs(y0-fFirstPoint[1]);
	360	Double_t diff1 = fabs(y1-fFirstPoint[1]);
	361
	362	fPoint[0]=xplane;
	363	if(diff0<diff1) fPoint[1]=y0;
	364	else fPoint[1]=y1;
	365
	366	Double_t pointPhi0 = atan2(fPoint[1]-fCenterY,fPoint[0]-fCenterX);
	367	Double_t trackPhi0 = atan2(fFirstPoint[1]-fCenterY,fFirstPoint[0]-fCenterX);
	368	if(fabs(trackPhi0-pointPhi0)>pi){
	369	if(trackPhi0<pointPhi0) trackPhi0 += 2*pi;
	370	else pointPhi0 += 2*pi;
	371	}
	372	Double_t stot = -fQ * (pointPhi0-trackPhi0) * fRadius ;
	373	fPoint[2] = fFirstPoint[2] + stot * fTanl;
	374
	375	fPointPsi = pointPhi0 - fQ * 0.5 * pi;
	376	if(fPointPsi<0.) fPointPsi+= 2*pi;
	377	fPointPsi = fmod(fPointPsi, 2*pi);
	378
	379	return IsPoint(kTRUE);
	380	}
	381
6d4f1901	382	void AliL3Track::GetClosestPoint(AliL3Vertex *vertex,Double_t &closest_x,Double_t &closest_y,Double_t &closest_z)
	383	{
	384	//Calculate the point of closest approach to the vertex
	385
	386
	387	Double_t xc = GetCenterX() - vertex->GetX();//Shift the center of curvature with respect to the vertex
	388	Double_t yc = GetCenterY() - vertex->GetY();
	389
	390	Double_t dist_x1 = xc(1 + GetRadius()/sqrt(xcxc + yc*yc));
	391	Double_t dist_y1 = yc(1 + GetRadius()/sqrt(xcxc + yc*yc));
	392	Double_t distance1 = sqrt(dist_x1dist_x1 + dist_y1dist_y1);
	393
	394	Double_t dist_x2 = xc(1 - GetRadius()/sqrt(xcxc + yc*yc));
	395	Double_t dist_y2 = yc(1 - GetRadius()/sqrt(xcxc + yc*yc));
	396	Double_t distance2 = sqrt(dist_x2dist_x2 + dist_y2dist_y2);
	397
	398	//Choose the closest:
	399	if(distance1 < distance2)
	400	{
	401	closest_x = dist_x1 + vertex->GetX();
	402	closest_y = dist_y1 + vertex->GetY();
	403	}
	404	else
	405	{
	406	closest_x = dist_x2 + vertex->GetX();
	407	closest_y = dist_y2 + vertex->GetY();
	408	}
	409
	410	//Get the z coordinate:
	411	Double_t angle1 = atan2((closest_y-GetCenterY()),(closest_x-GetCenterX()));
	412	if(angle1 < 0) angle1 = angle1 + 2*Pi;
	413
	414	Double_t angle2 = atan2((GetFirstPointY()-GetCenterY()),(GetFirstPointX()-GetCenterX()));
	415	if(angle2 < 0) angle2 = angle2 + 2*Pi;
	416
	417	Double_t diff_angle = angle1 - angle2;
	418	diff_angle = fmod(diff_angle,2*Pi);
	419
	420	if((GetCharge()diff_angle) < 0) diff_angle = diff_angle + GetCharge()2*Pi;
	421	Double_t s_tot = fabs(diff_angle)*GetRadius();
	422
	423	closest_z = GetFirstPointZ() - s_tot*GetTgl();
	424	}