[u/mrichter/AliRoot.git] / HLT / hough / AliL3HoughTrack.cxx

//$Id$

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

#include <math.h>

#include "AliL3Logging.h"
#include "AliL3Transform.h"
#include "AliL3Defs.h"
#include "AliL3HoughTrack.h"

//_____________________________________________________________
// AliL3HoughTrack
//
// Track class for Hough tracklets

ClassImp(AliL3HoughTrack)


AliL3HoughTrack::AliL3HoughTrack()
{
  //Constructor
  
  fWeight = 0;
  fMinDist=0;
  fTransform = new AliL3Transform();
  fDLine = 0;
  fPsiLine = 0;
  fIsHelix = true;
  fEtaIndex = -1;
}


AliL3HoughTrack::~AliL3HoughTrack()
{
  //Destructor
  if(fTransform)
    delete fTransform;
}

void AliL3HoughTrack::Set(AliL3Track *track)
{
  
  AliL3HoughTrack *tpt = (AliL3HoughTrack*)track;
  SetTrackParameters(tpt->GetKappa(),tpt->GetPhi0(),tpt->GetWeight());
  SetEtaIndex(tpt->GetEtaIndex());
  SetEta(tpt->GetEta());
  SetTgl(tpt->GetTgl());
  SetPsi(tpt->GetPsi());
  SetCenterX(tpt->GetCenterX());
  SetCenterY(tpt->GetCenterY());
  SetFirstPoint(tpt->GetFirstPointX(),tpt->GetFirstPointY(),tpt->GetFirstPointZ());
  SetLastPoint(tpt->GetLastPointX(),tpt->GetLastPointY(),tpt->GetLastPointZ());
  SetCharge(tpt->GetCharge());
  SetRowRange(tpt->GetFirstRow(),tpt->GetLastRow());
  SetSlice(tpt->GetSlice());
  return;

  fWeight = tpt->GetWeight();
  fDLine = tpt->GetDLine();
  fPsiLine = tpt->GetPsiLine();
  SetNHits(tpt->GetWeight());
  SetRowRange(tpt->GetFirstRow(),tpt->GetLastRow());
  fIsHelix = false;


}

Int_t AliL3HoughTrack::Compare(const AliL3Track *tpt) const
{
  AliL3HoughTrack *track = (AliL3HoughTrack*)tpt;
  if(track->GetWeight() < GetWeight()) return 1;
  if(track->GetWeight() > GetWeight()) return -1;
  return 0;
}

void AliL3HoughTrack::SetEta(Double_t f)
{
  //Set eta, and calculate fTanl, which is the tan of dipangle

  fEta = f;
  Double_t theta = 2*atan(exp(-1.*fEta));
  Double_t dipangle = Pi/2 - theta;
  Double_t tgl = tan(dipangle);
  SetTgl(tgl);
}

void AliL3HoughTrack::CalculateHelix()
{
  return;
}

void AliL3HoughTrack::UpdateToFirstRow()
{
  //Update the track parameters to the point where track cross
  //its first padrow.
  
  //Get the crossing point with the first padrow:
  Float_t xyz[3];
  if(!GetCrossingPoint(GetFirstRow(),xyz))
    LOG(AliL3Log::kWarning,"AliL3HoughTrack::UpdateToFirstRow()","Track parameters")
      <<AliL3Log::kDec<<"Track does not cross padrow "<<GetFirstRow()<<" centerx "
      <<GetCenterX()<<" centery "<<GetCenterY()<<" Radius "<<GetRadius()<<" tgl "<<GetTgl()<<ENDLOG;
  
  //printf("Track with eta %f tgl %f crosses at x %f y %f z %f on padrow %d\n",GetEta(),GetTgl(),xyz[0],xyz[1],xyz[2],GetFirstRow());
  //printf("Before: first %f %f %f tgl %f center %f %f charge %d\n",GetFirstPointX(),GetFirstPointY(),GetFirstPointZ(),GetTgl(),GetCenterX(),GetCenterY(),GetCharge());
  
  Double_t radius = sqrt(xyz[0]*xyz[0] + xyz[1]*xyz[1]);

  //Get the track parameters
  
  /*
    Double_t x0    = GetR0() * cos(GetPhi0()) ;
    Double_t y0    = GetR0() * sin(GetPhi0()) ;
  */
  Double_t rc    = GetRadius();//fabs(GetPt()) / ( BFACT * BField )  ;
  Double_t tPhi0 = GetPsi() + GetCharge() * 0.5 * pi / fabs(GetCharge()) ;
  Double_t xc    = GetCenterX();//x0 - rc * cos(tPhi0) ;
  Double_t yc    = GetCenterY();//y0 - rc * sin(tPhi0) ;
  
  //Check helix and cylinder intersect
  Double_t fac1 = xc*xc + yc*yc ;
  Double_t sfac = sqrt( fac1 ) ;
  
  if ( fabs(sfac-rc) > radius || fabs(sfac+rc) < radius ) {
    LOG(AliL3Log::kError,"AliL3HoughTrack::UpdateToFirstRow","Tracks")<<AliL3Log::kDec<<
      "Track does not intersect"<<ENDLOG;
    return;
  }
  
  //Find intersection
  Double_t fac2   = ( radius*radius + fac1 - rc*rc) / (2.00 * radius * sfac ) ;
  Double_t phi    = atan2(yc,xc) + GetCharge()*acos(fac2) ;
  Double_t td     = atan2(radius*sin(phi) - yc,radius*cos(phi) - xc) ;
  
  //Intersection in z
  if ( td < 0 ) td = td + 2. * pi ;
  Double_t deltat = fmod((-GetCharge()*td + GetCharge()*tPhi0),2*pi) ;
  if ( deltat < 0.      ) deltat += 2. * pi ;
  if ( deltat > 2.*pi ) deltat -= 2. * pi ;
  Double_t z = GetZ0() + rc * GetTgl() * deltat ;
  
  
  Double_t xExtra = radius * cos(phi) ;
  Double_t yExtra = radius * sin(phi) ;
  
  Double_t tPhi = atan2(yExtra-yc,xExtra-xc);
  
  //if ( tPhi < 0 ) tPhi += 2. * M_PI ;
  
  Double_t tPsi = tPhi - GetCharge() * 0.5 * pi / fabs(GetCharge()) ;
  if ( tPsi > 2. * pi ) tPsi -= 2. * pi ;
  if ( tPsi < 0.        ) tPsi += 2. * pi ;
  
  //And finally, update the track parameters
  SetR0(radius);
  SetPhi0(phi);
  SetZ0(z);
  SetPsi(tPsi);
  SetFirstPoint(xyz[0],xyz[1],z);
  //printf("After: first %f %f %f tgl %f center %f %f charge %d\n",GetFirstPointX(),GetFirstPointY(),GetFirstPointZ(),GetTgl(),GetCenterX(),GetCenterY(),GetCharge());
  
  //printf("First point set %f %f %f\n",xyz[0],xyz[1],z);
  
  //Also, set the coordinates of the point where track crosses last padrow:
  GetCrossingPoint(GetLastRow(),xyz);
  SetLastPoint(xyz[0],xyz[1],xyz[2]);
  //printf("last point %f %f %f\n",xyz[0],xyz[1],xyz[2]);
}

void AliL3HoughTrack::SetTrackParameters(Double_t kappa,Double_t phi,Int_t weight)
{

  fWeight = weight;
  fMinDist = 100000;
  SetKappa(kappa);
  SetPhi0(phi);
  Double_t pt = fabs(BFACT*BField/kappa);
  SetPt(pt);
  Double_t radius = 1/fabs(kappa);
  SetRadius(radius);
  SetFirstPoint(0,0,0);
  SetPsi(phi); //Psi = Phi when first point is vertex
  SetR0(0);
  Double_t charge = -1.*kappa;
  SetCharge((Int_t)copysign(1.,charge));
  
  Double_t trackPhi0 = GetPsi() + charge*0.5*Pi/fabs(charge);
  Double_t xc = GetFirstPointX() - GetRadius() * cos(trackPhi0) ;
  Double_t yc = GetFirstPointY() - GetRadius() * sin(trackPhi0) ;
  SetCenterX(xc);
  SetCenterY(yc);
  fIsHelix = true;
  
}

void AliL3HoughTrack::SetLineParameters(Double_t psi,Double_t D,Int_t weight,Int_t *rowrange,Int_t ref_row)
{
  //Initialize a track piece, not yet a track
  //Used in case of straight line transformation

  //Transform line parameters to coordinate system of slice:
  
  D = D + fTransform->Row2X(ref_row)*cos(psi);

  fDLine = D;
  fPsiLine = psi;
  fWeight = weight;
  SetNHits(weight);
  SetRowRange(rowrange[0],rowrange[1]);
  fIsHelix = false;

}

void AliL3HoughTrack::SetBestMCid(Int_t mcid,Double_t min_dist)
{
  
  if(min_dist < fMinDist)
    {
      fMinDist = min_dist;
      SetMCid(mcid);
    }
  
}

void AliL3HoughTrack::GetLineCrossingPoint(Int_t padrow,Double_t *xy)
{
  

  if(fIsHelix)
    {
      printf("AliL3HoughTrack::GetLineCrossingPoint : Track is not a line\n");
      return;
    }

  Double_t xhit = fTransform->Row2X(padrow);
  Double_t a = -1/tan(fPsiLine);
  Double_t b = fDLine/sin(fPsiLine);
  
  Double_t yhit = a*xhit + b;
  xy[0] = xhit;
  xy[1] = yhit;

}

/*
Double_t AliL3HoughTrack::GetCrossingAngle(Int_t padrow)
{
  //Calculate the crossing angle between track and given padrow.

  if(!fIsHelix)
    {
      printf("AliL3HoughTrack::GetCrossingAngle : Track is not a helix\n");
      return 0;
    }

  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");
  
  
  //Convert center of curvature to local coordinates:
  //Float_t xyz_coc[3] = {GetCenterX(),GetCenterY(),0};
  //fTransform->Global2Local(xyz_coc,slice);
  
  //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] - xyz_coc[0])/GetRadius();
  //tangent[0] = -1.*(xyz[1] - xyz_coc[1])/GetRadius();
  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 AliL3HoughTrack::GetCrossingPoint(Int_t padrow,Float_t *xyz)
{
  //Assumes the track is given in local coordinates

  if(!fIsHelix)
    {
      printf("AliL3HoughTrack::GetCrossingPoint : Track is not a helix\n");
      return 0;
    }
    

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

  //xyz[0] = fTransform->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;
  xyz[2] = 0; //only consider transverse plane
  
  return true;
}


Bool_t AliL3HoughTrack::GetCrossingPoint(Int_t slice,Int_t padrow,Float_t *xyz)
{
  //Calculate the crossing point in transverse plane of this track and given 
  //padrow (y = a*x + b). Point is given in local coordinates in slice.
  //Assumes the track is given in global coordinates.

  if(!fIsHelix)
    {
      printf("AliL3HoughTrack::GetCrossingPoint : Track is not a helix\n");
      return 0;
    }

  
  if(IsLocal())
    {
      printf("GetCrossingPoint: Track is given in local coordintes!!!\n");
      return false;
    }

  Double_t padrowradii = fTransform->Row2X(padrow);


  Float_t rotation_angle = (slice*20)*ToRad;
  
  Float_t cs,sn;
  cs = cos(rotation_angle);
  sn = sin(rotation_angle);

  Double_t a = -1.*cs/sn;
  Double_t b = padrowradii/sn;

  Double_t ycPrime = GetCenterY() - b ;
  Double_t aa = ( 1. + a * a ) ;
  Double_t bb = -2. * ( GetCenterX() + a * ycPrime ) ;
  Double_t cc = ( GetCenterX() * GetCenterX() + ycPrime * ycPrime - GetRadius() * GetRadius() ) ;

  Double_t racine = bb * bb - 4. * aa * cc ;
  if ( racine < 0 ) return false ;
  Double_t rootRacine = sqrt(racine) ;
  
  Double_t oneOverA = 1./aa;
//
//   First solution
//
   Double_t x1 = 0.5 * oneOverA * ( -1. * bb + rootRacine ) ; 
   Double_t y1 = a * x1 + b ;
   Double_t r1 = sqrt(x1*x1+y1*y1);
//
//   Second solution
//
   Double_t x2 = 0.5 * oneOverA * ( -1. * bb - rootRacine ) ; 
   Double_t y2 = a * x2 + b ;
   Double_t r2 = sqrt(x2*x2+y2*y2);
//
//    Choose close to (0,0) 
//
   Double_t xHit ;
   Double_t yHit ;
   if ( r1 < r2 ) {
      xHit = x1 ;
      yHit = y1 ;
   }
   else {
      xHit = x2 ;
      yHit = y2 ;
   }
  
   xyz[0] = xHit;
   xyz[1] = yHit;
   xyz[2] = 0;
   
   fTransform->Global2Local(xyz,slice);
   
   return true;
}
*/
Commit	Line	Data
b1886074	1	//$Id$
	2
	3	// Author: Anders Vestbo <mailto:vestbo@fi.uib.no>
	4	//*-- Copyright &copy ASV
d712b5b8	5
	6	#include <math.h>
	7
	8	#include "AliL3Logging.h"
	9	#include "AliL3Transform.h"
	10	#include "AliL3Defs.h"
	11	#include "AliL3HoughTrack.h"
	12
b1886074	13	//_____________________________________________________________
	14	// AliL3HoughTrack
	15	//
	16	// Track class for Hough tracklets
	17
d712b5b8	18	ClassImp(AliL3HoughTrack)
	19
	20
	21	AliL3HoughTrack::AliL3HoughTrack()
	22	{
	23	//Constructor
	24
	25	fWeight = 0;
	26	fMinDist=0;
	27	fTransform = new AliL3Transform();
	28	fDLine = 0;
	29	fPsiLine = 0;
	30	fIsHelix = true;
	31	fEtaIndex = -1;
	32	}
	33
	34
	35	AliL3HoughTrack::~AliL3HoughTrack()
	36	{
	37	//Destructor
	38	if(fTransform)
	39	delete fTransform;
	40	}
	41
	42	void AliL3HoughTrack::Set(AliL3Track *track)
	43	{
	44
	45	AliL3HoughTrack tpt = (AliL3HoughTrack)track;
	46	SetTrackParameters(tpt->GetKappa(),tpt->GetPhi0(),tpt->GetWeight());
	47	SetEtaIndex(tpt->GetEtaIndex());
	48	SetEta(tpt->GetEta());
ae4d5136	49	SetTgl(tpt->GetTgl());
d712b5b8	50	SetPsi(tpt->GetPsi());
	51	SetCenterX(tpt->GetCenterX());
	52	SetCenterY(tpt->GetCenterY());
	53	SetFirstPoint(tpt->GetFirstPointX(),tpt->GetFirstPointY(),tpt->GetFirstPointZ());
	54	SetLastPoint(tpt->GetLastPointX(),tpt->GetLastPointY(),tpt->GetLastPointZ());
	55	SetCharge(tpt->GetCharge());
	56	SetRowRange(tpt->GetFirstRow(),tpt->GetLastRow());
b1886074	57	SetSlice(tpt->GetSlice());
d712b5b8	58	return;
	59
	60	fWeight = tpt->GetWeight();
	61	fDLine = tpt->GetDLine();
	62	fPsiLine = tpt->GetPsiLine();
	63	SetNHits(tpt->GetWeight());
	64	SetRowRange(tpt->GetFirstRow(),tpt->GetLastRow());
	65	fIsHelix = false;
	66
	67
	68	}
	69
	70	Int_t AliL3HoughTrack::Compare(const AliL3Track *tpt) const
	71	{
	72	AliL3HoughTrack track = (AliL3HoughTrack)tpt;
	73	if(track->GetWeight() < GetWeight()) return 1;
	74	if(track->GetWeight() > GetWeight()) return -1;
	75	return 0;
	76	}
	77
	78	void AliL3HoughTrack::SetEta(Double_t f)
	79	{
b1886074	80	//Set eta, and calculate fTanl, which is the tan of dipangle
b1886074	81
d712b5b8	82	fEta = f;
d712b5b8	83	Double_t theta = 2atan(exp(-1.fEta));
8b007a2d	84	Double_t dipangle = Pi/2 - theta;
8b007a2d	85	Double_t tgl = tan(dipangle);
d712b5b8	86	SetTgl(tgl);
	87	}
	88
	89	void AliL3HoughTrack::CalculateHelix()
	90	{
	91	return;
	92	}
	93
	94	void AliL3HoughTrack::UpdateToFirstRow()
	95	{
	96	//Update the track parameters to the point where track cross
	97	//its first padrow.
	98
	99	//Get the crossing point with the first padrow:
	100	Float_t xyz[3];
	101	if(!GetCrossingPoint(GetFirstRow(),xyz))
	102	LOG(AliL3Log::kWarning,"AliL3HoughTrack::UpdateToFirstRow()","Track parameters")
	103	<<AliL3Log::kDec<<"Track does not cross padrow "<<GetFirstRow()<<" centerx "
	104	<<GetCenterX()<<" centery "<<GetCenterY()<<" Radius "<<GetRadius()<<" tgl "<<GetTgl()<<ENDLOG;
	105
8b007a2d	106	//printf("Track with eta %f tgl %f crosses at x %f y %f z %f on padrow %d\n",GetEta(),GetTgl(),xyz[0],xyz[1],xyz[2],GetFirstRow());
	107	//printf("Before: first %f %f %f tgl %f center %f %f charge %d\n",GetFirstPointX(),GetFirstPointY(),GetFirstPointZ(),GetTgl(),GetCenterX(),GetCenterY(),GetCharge());
	108
d712b5b8	109	Double_t radius = sqrt(xyz[0]xyz[0] + xyz[1]xyz[1]);
	110
	111	//Get the track parameters
b1886074	112
	113	/*
	114	Double_t x0 = GetR0() * cos(GetPhi0()) ;
	115	Double_t y0 = GetR0() * sin(GetPhi0()) ;
	116	*/
	117	Double_t rc = GetRadius();//fabs(GetPt()) / ( BFACT * BField ) ;
d712b5b8	118	Double_t tPhi0 = GetPsi() + GetCharge() * 0.5 * pi / fabs(GetCharge()) ;
b1886074	119	Double_t xc = GetCenterX();//x0 - rc * cos(tPhi0) ;
b1886074	120	Double_t yc = GetCenterY();//y0 - rc * sin(tPhi0) ;
d712b5b8	121
	122	//Check helix and cylinder intersect
	123	Double_t fac1 = xcxc + ycyc ;
	124	Double_t sfac = sqrt( fac1 ) ;
b1886074	125
d712b5b8	126	if ( fabs(sfac-rc) > radius \|\| fabs(sfac+rc) < radius ) {
	127	LOG(AliL3Log::kError,"AliL3HoughTrack::UpdateToFirstRow","Tracks")<<AliL3Log::kDec<<
	128	"Track does not intersect"<<ENDLOG;
	129	return;
	130	}
	131
	132	//Find intersection
	133	Double_t fac2 = ( radiusradius + fac1 - rcrc) / (2.00 * radius * sfac ) ;
	134	Double_t phi = atan2(yc,xc) + GetCharge()*acos(fac2) ;
	135	Double_t td = atan2(radiussin(phi) - yc,radiuscos(phi) - xc) ;
	136
	137	//Intersection in z
	138	if ( td < 0 ) td = td + 2. * pi ;
	139	Double_t deltat = fmod((-GetCharge()td + GetCharge()tPhi0),2*pi) ;
	140	if ( deltat < 0. ) deltat += 2. * pi ;
	141	if ( deltat > 2.pi ) deltat -= 2. pi ;
	142	Double_t z = GetZ0() + rc * GetTgl() * deltat ;
8b007a2d	143
d712b5b8	144
	145	Double_t xExtra = radius * cos(phi) ;
	146	Double_t yExtra = radius * sin(phi) ;
	147
	148	Double_t tPhi = atan2(yExtra-yc,xExtra-xc);
	149
	150	//if ( tPhi < 0 ) tPhi += 2. * M_PI ;
	151
	152	Double_t tPsi = tPhi - GetCharge() * 0.5 * pi / fabs(GetCharge()) ;
	153	if ( tPsi > 2. * pi ) tPsi -= 2. * pi ;
	154	if ( tPsi < 0. ) tPsi += 2. * pi ;
	155
	156	//And finally, update the track parameters
d712b5b8	157	SetR0(radius);
	158	SetPhi0(phi);
	159	SetZ0(z);
	160	SetPsi(tPsi);
	161	SetFirstPoint(xyz[0],xyz[1],z);
8b007a2d	162	//printf("After: first %f %f %f tgl %f center %f %f charge %d\n",GetFirstPointX(),GetFirstPointY(),GetFirstPointZ(),GetTgl(),GetCenterX(),GetCenterY(),GetCharge());
	163
	164	//printf("First point set %f %f %f\n",xyz[0],xyz[1],z);
d712b5b8	165
	166	//Also, set the coordinates of the point where track crosses last padrow:
	167	GetCrossingPoint(GetLastRow(),xyz);
	168	SetLastPoint(xyz[0],xyz[1],xyz[2]);
8b007a2d	169	//printf("last point %f %f %f\n",xyz[0],xyz[1],xyz[2]);
d712b5b8	170	}
	171
	172	void AliL3HoughTrack::SetTrackParameters(Double_t kappa,Double_t phi,Int_t weight)
	173	{
	174
	175	fWeight = weight;
	176	fMinDist = 100000;
	177	SetKappa(kappa);
	178	SetPhi0(phi);
b1886074	179	Double_t pt = fabs(BFACT*BField/kappa);
d712b5b8	180	SetPt(pt);
	181	Double_t radius = 1/fabs(kappa);
	182	SetRadius(radius);
	183	SetFirstPoint(0,0,0);
8b007a2d	184	SetPsi(phi); //Psi = Phi when first point is vertex
8b007a2d	185	SetR0(0);
d712b5b8	186	Double_t charge = -1.*kappa;
8b007a2d	187	SetCharge((Int_t)copysign(1.,charge));
	188
	189	Double_t trackPhi0 = GetPsi() + charge0.5Pi/fabs(charge);
	190	Double_t xc = GetFirstPointX() - GetRadius() * cos(trackPhi0) ;
	191	Double_t yc = GetFirstPointY() - GetRadius() * sin(trackPhi0) ;
d712b5b8	192	SetCenterX(xc);
	193	SetCenterY(yc);
	194	fIsHelix = true;
8b007a2d	195
d712b5b8	196	}
	197
	198	void AliL3HoughTrack::SetLineParameters(Double_t psi,Double_t D,Int_t weight,Int_t *rowrange,Int_t ref_row)
	199	{
	200	//Initialize a track piece, not yet a track
	201	//Used in case of straight line transformation
	202
	203	//Transform line parameters to coordinate system of slice:
	204
	205	D = D + fTransform->Row2X(ref_row)*cos(psi);
	206
	207	fDLine = D;
	208	fPsiLine = psi;
	209	fWeight = weight;
	210	SetNHits(weight);
	211	SetRowRange(rowrange[0],rowrange[1]);
	212	fIsHelix = false;
	213
	214	}
	215
	216	void AliL3HoughTrack::SetBestMCid(Int_t mcid,Double_t min_dist)
	217	{
	218
	219	if(min_dist < fMinDist)
	220	{
	221	fMinDist = min_dist;
	222	SetMCid(mcid);
	223	}
	224
	225	}
	226
	227	void AliL3HoughTrack::GetLineCrossingPoint(Int_t padrow,Double_t *xy)
	228	{
	229
	230
	231	if(fIsHelix)
	232	{
	233	printf("AliL3HoughTrack::GetLineCrossingPoint : Track is not a line\n");
	234	return;
	235	}
	236
	237	Double_t xhit = fTransform->Row2X(padrow);
	238	Double_t a = -1/tan(fPsiLine);
	239	Double_t b = fDLine/sin(fPsiLine);
	240
	241	Double_t yhit = a*xhit + b;
	242	xy[0] = xhit;
	243	xy[1] = yhit;
	244
	245	}
	246
	247	/*
	248	Double_t AliL3HoughTrack::GetCrossingAngle(Int_t padrow)
	249	{
	250	//Calculate the crossing angle between track and given padrow.
	251
	252	if(!fIsHelix)
	253	{
	254	printf("AliL3HoughTrack::GetCrossingAngle : Track is not a helix\n");
	255	return 0;
	256	}
	257
	258	if(!IsLocal())
	259	{
260	printf("Track is not given in local coordinates\n");
261	return 0;
262	}
263
264	Float_t xyz[3];
265	if(!GetCrossingPoint(padrow,xyz))
266	printf("AliL3HoughTrack::GetCrossingPoint : Track does not cross line!!\n");
267
268
269	//Convert center of curvature to local coordinates:
270	//Float_t xyz_coc[3] = {GetCenterX(),GetCenterY(),0};
271	//fTransform->Global2Local(xyz_coc,slice);
272
273	//Take the dot product of the tangent vector of the track, and
274	//vector perpendicular to the padrow.
275
276	Double_t tangent[2];
277	//tangent[1] = (xyz[0] - xyz_coc[0])/GetRadius();
278	//tangent[0] = -1.*(xyz[1] - xyz_coc[1])/GetRadius();
279	tangent[1] = (xyz[0] - GetCenterX())/GetRadius();
280	tangent[0] = -1.*(xyz[1] - GetCenterY())/GetRadius();
281
282	Double_t perp_padrow[2] = {1,0}; //locally in slice
283
284	Double_t cos_beta = fabs(tangent[0]perp_padrow[0] + tangent[1]perp_padrow[1]);
285	return acos(cos_beta);
286
287	}
288
289	Bool_t AliL3HoughTrack::GetCrossingPoint(Int_t padrow,Float_t *xyz)
290	{
291	//Assumes the track is given in local coordinates
292
293	if(!fIsHelix)
294	{
295	printf("AliL3HoughTrack::GetCrossingPoint : Track is not a helix\n");
296	return 0;
297	}
298
299
300	if(!IsLocal())
301	{
302	printf("GetCrossingPoint: Track is given on global coordinates\n");
303	return false;
304	}
305
306	Double_t xHit = fTransform->Row2X(padrow);
307
308	//xyz[0] = fTransform->Row2X(padrow);
309	xyz[0] = xHit;
310	Double_t aa = (xHit - GetCenterX())*(xHit - GetCenterX());
311	Double_t r2 = GetRadius()*GetRadius();
312	if(aa > r2)
313	return false;
314
315	Double_t aa2 = sqrt(r2 - aa);
316	Double_t y1 = GetCenterY() + aa2;
317	Double_t y2 = GetCenterY() - aa2;
318	xyz[1] = y1;
319	if(fabs(y2) < fabs(y1)) xyz[1] = y2;
320	xyz[2] = 0; //only consider transverse plane
321
322	return true;
323	}
324
325
326	Bool_t AliL3HoughTrack::GetCrossingPoint(Int_t slice,Int_t padrow,Float_t *xyz)
327	{
328	//Calculate the crossing point in transverse plane of this track and given
329	//padrow (y = a*x + b). Point is given in local coordinates in slice.
330	//Assumes the track is given in global coordinates.
331
332	if(!fIsHelix)
333	{
334	printf("AliL3HoughTrack::GetCrossingPoint : Track is not a helix\n");
335	return 0;
336	}
337
338
339	if(IsLocal())
340	{
341	printf("GetCrossingPoint: Track is given in local coordintes!!!\n");
342	return false;
343	}
344
345	Double_t padrowradii = fTransform->Row2X(padrow);
346
347
348	Float_t rotation_angle = (slice20)ToRad;
349
350	Float_t cs,sn;
351	cs = cos(rotation_angle);
352	sn = sin(rotation_angle);
353
354	Double_t a = -1.*cs/sn;
355	Double_t b = padrowradii/sn;
356
357	Double_t ycPrime = GetCenterY() - b ;
358	Double_t aa = ( 1. + a * a ) ;
359	Double_t bb = -2. * ( GetCenterX() + a * ycPrime ) ;
360	Double_t cc = ( GetCenterX() * GetCenterX() + ycPrime * ycPrime - GetRadius() * GetRadius() ) ;
361
362	Double_t racine = bb * bb - 4. * aa * cc ;
363	if ( racine < 0 ) return false ;
364	Double_t rootRacine = sqrt(racine) ;
365
366	Double_t oneOverA = 1./aa;
367	//
368	// First solution
369	//
370	Double_t x1 = 0.5 * oneOverA * ( -1. * bb + rootRacine ) ;
371	Double_t y1 = a * x1 + b ;
372	Double_t r1 = sqrt(x1x1+y1y1);
373	//
374	// Second solution
375	//
376	Double_t x2 = 0.5 * oneOverA * ( -1. * bb - rootRacine ) ;
377	Double_t y2 = a * x2 + b ;
378	Double_t r2 = sqrt(x2x2+y2y2);
379	//
380	// Choose close to (0,0)
381	//
382	Double_t xHit ;
383	Double_t yHit ;
384	if ( r1 < r2 ) {
385	xHit = x1 ;
386	yHit = y1 ;
387	}
388	else {
389	xHit = x2 ;
390	yHit = y2 ;
391	}
392
393	xyz[0] = xHit;
394	xyz[1] = yHit;
395	xyz[2] = 0;
396
397	fTransform->Global2Local(xyz,slice);
398
399	return true;
400	}
401	*/