[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());
  SetNHits(1);
  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);
  SetNHits(1); //just for the trackarray IO
  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());
242c143e	58	SetNHits(1);
d712b5b8	59	return;
	60
	61	fWeight = tpt->GetWeight();
	62	fDLine = tpt->GetDLine();
	63	fPsiLine = tpt->GetPsiLine();
	64	SetNHits(tpt->GetWeight());
	65	SetRowRange(tpt->GetFirstRow(),tpt->GetLastRow());
	66	fIsHelix = false;
	67
	68
	69	}
	70
	71	Int_t AliL3HoughTrack::Compare(const AliL3Track *tpt) const
	72	{
	73	AliL3HoughTrack track = (AliL3HoughTrack)tpt;
	74	if(track->GetWeight() < GetWeight()) return 1;
	75	if(track->GetWeight() > GetWeight()) return -1;
	76	return 0;
	77	}
	78
	79	void AliL3HoughTrack::SetEta(Double_t f)
	80	{
b1886074	81	//Set eta, and calculate fTanl, which is the tan of dipangle
b1886074	82
d712b5b8	83	fEta = f;
d712b5b8	84	Double_t theta = 2atan(exp(-1.fEta));
8b007a2d	85	Double_t dipangle = Pi/2 - theta;
8b007a2d	86	Double_t tgl = tan(dipangle);
d712b5b8	87	SetTgl(tgl);
	88	}
	89
	90	void AliL3HoughTrack::CalculateHelix()
	91	{
	92	return;
	93	}
	94
	95	void AliL3HoughTrack::UpdateToFirstRow()
	96	{
	97	//Update the track parameters to the point where track cross
	98	//its first padrow.
	99
	100	//Get the crossing point with the first padrow:
	101	Float_t xyz[3];
	102	if(!GetCrossingPoint(GetFirstRow(),xyz))
	103	LOG(AliL3Log::kWarning,"AliL3HoughTrack::UpdateToFirstRow()","Track parameters")
	104	<<AliL3Log::kDec<<"Track does not cross padrow "<<GetFirstRow()<<" centerx "
	105	<<GetCenterX()<<" centery "<<GetCenterY()<<" Radius "<<GetRadius()<<" tgl "<<GetTgl()<<ENDLOG;
	106
8b007a2d	107	//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());
	108	//printf("Before: first %f %f %f tgl %f center %f %f charge %d\n",GetFirstPointX(),GetFirstPointY(),GetFirstPointZ(),GetTgl(),GetCenterX(),GetCenterY(),GetCharge());
	109
d712b5b8	110	Double_t radius = sqrt(xyz[0]xyz[0] + xyz[1]xyz[1]);
	111
	112	//Get the track parameters
b1886074	113
	114	/*
	115	Double_t x0 = GetR0() * cos(GetPhi0()) ;
	116	Double_t y0 = GetR0() * sin(GetPhi0()) ;
	117	*/
	118	Double_t rc = GetRadius();//fabs(GetPt()) / ( BFACT * BField ) ;
d712b5b8	119	Double_t tPhi0 = GetPsi() + GetCharge() * 0.5 * pi / fabs(GetCharge()) ;
b1886074	120	Double_t xc = GetCenterX();//x0 - rc * cos(tPhi0) ;
b1886074	121	Double_t yc = GetCenterY();//y0 - rc * sin(tPhi0) ;
d712b5b8	122
	123	//Check helix and cylinder intersect
	124	Double_t fac1 = xcxc + ycyc ;
	125	Double_t sfac = sqrt( fac1 ) ;
b1886074	126
d712b5b8	127	if ( fabs(sfac-rc) > radius \|\| fabs(sfac+rc) < radius ) {
	128	LOG(AliL3Log::kError,"AliL3HoughTrack::UpdateToFirstRow","Tracks")<<AliL3Log::kDec<<
	129	"Track does not intersect"<<ENDLOG;
	130	return;
	131	}
	132
	133	//Find intersection
	134	Double_t fac2 = ( radiusradius + fac1 - rcrc) / (2.00 * radius * sfac ) ;
	135	Double_t phi = atan2(yc,xc) + GetCharge()*acos(fac2) ;
	136	Double_t td = atan2(radiussin(phi) - yc,radiuscos(phi) - xc) ;
	137
	138	//Intersection in z
	139	if ( td < 0 ) td = td + 2. * pi ;
	140	Double_t deltat = fmod((-GetCharge()td + GetCharge()tPhi0),2*pi) ;
	141	if ( deltat < 0. ) deltat += 2. * pi ;
	142	if ( deltat > 2.pi ) deltat -= 2. pi ;
	143	Double_t z = GetZ0() + rc * GetTgl() * deltat ;
8b007a2d	144
d712b5b8	145
	146	Double_t xExtra = radius * cos(phi) ;
	147	Double_t yExtra = radius * sin(phi) ;
	148
	149	Double_t tPhi = atan2(yExtra-yc,xExtra-xc);
	150
	151	//if ( tPhi < 0 ) tPhi += 2. * M_PI ;
	152
	153	Double_t tPsi = tPhi - GetCharge() * 0.5 * pi / fabs(GetCharge()) ;
	154	if ( tPsi > 2. * pi ) tPsi -= 2. * pi ;
	155	if ( tPsi < 0. ) tPsi += 2. * pi ;
	156
	157	//And finally, update the track parameters
d712b5b8	158	SetR0(radius);
	159	SetPhi0(phi);
	160	SetZ0(z);
	161	SetPsi(tPsi);
	162	SetFirstPoint(xyz[0],xyz[1],z);
8b007a2d	163	//printf("After: first %f %f %f tgl %f center %f %f charge %d\n",GetFirstPointX(),GetFirstPointY(),GetFirstPointZ(),GetTgl(),GetCenterX(),GetCenterY(),GetCharge());
	164
	165	//printf("First point set %f %f %f\n",xyz[0],xyz[1],z);
d712b5b8	166
	167	//Also, set the coordinates of the point where track crosses last padrow:
	168	GetCrossingPoint(GetLastRow(),xyz);
	169	SetLastPoint(xyz[0],xyz[1],xyz[2]);
8b007a2d	170	//printf("last point %f %f %f\n",xyz[0],xyz[1],xyz[2]);
d712b5b8	171	}
	172
	173	void AliL3HoughTrack::SetTrackParameters(Double_t kappa,Double_t phi,Int_t weight)
	174	{
	175
	176	fWeight = weight;
	177	fMinDist = 100000;
	178	SetKappa(kappa);
	179	SetPhi0(phi);
b1886074	180	Double_t pt = fabs(BFACT*BField/kappa);
d712b5b8	181	SetPt(pt);
	182	Double_t radius = 1/fabs(kappa);
	183	SetRadius(radius);
	184	SetFirstPoint(0,0,0);
8b007a2d	185	SetPsi(phi); //Psi = Phi when first point is vertex
8b007a2d	186	SetR0(0);
d712b5b8	187	Double_t charge = -1.*kappa;
8b007a2d	188	SetCharge((Int_t)copysign(1.,charge));
	189
	190	Double_t trackPhi0 = GetPsi() + charge0.5Pi/fabs(charge);
	191	Double_t xc = GetFirstPointX() - GetRadius() * cos(trackPhi0) ;
	192	Double_t yc = GetFirstPointY() - GetRadius() * sin(trackPhi0) ;
d712b5b8	193	SetCenterX(xc);
d712b5b8	194	SetCenterY(yc);
242c143e	195	SetNHits(1); //just for the trackarray IO
d712b5b8	196	fIsHelix = true;
8b007a2d	197
242c143e	198
d712b5b8	199	}
	200
	201	void AliL3HoughTrack::SetLineParameters(Double_t psi,Double_t D,Int_t weight,Int_t *rowrange,Int_t ref_row)
	202	{
	203	//Initialize a track piece, not yet a track
	204	//Used in case of straight line transformation
	205
	206	//Transform line parameters to coordinate system of slice:
	207
	208	D = D + fTransform->Row2X(ref_row)*cos(psi);
	209
	210	fDLine = D;
	211	fPsiLine = psi;
	212	fWeight = weight;
	213	SetNHits(weight);
	214	SetRowRange(rowrange[0],rowrange[1]);
	215	fIsHelix = false;
	216
	217	}
	218
	219	void AliL3HoughTrack::SetBestMCid(Int_t mcid,Double_t min_dist)
	220	{
	221
	222	if(min_dist < fMinDist)
	223	{
	224	fMinDist = min_dist;
	225	SetMCid(mcid);
	226	}
	227
	228	}
	229
	230	void AliL3HoughTrack::GetLineCrossingPoint(Int_t padrow,Double_t *xy)
	231	{
	232
	233
	234	if(fIsHelix)
	235	{
	236	printf("AliL3HoughTrack::GetLineCrossingPoint : Track is not a line\n");
	237	return;
	238	}
	239
	240	Double_t xhit = fTransform->Row2X(padrow);
	241	Double_t a = -1/tan(fPsiLine);
	242	Double_t b = fDLine/sin(fPsiLine);
	243
	244	Double_t yhit = a*xhit + b;
	245	xy[0] = xhit;
	246	xy[1] = yhit;
	247
	248	}
	249
	250	/*
	251	Double_t AliL3HoughTrack::GetCrossingAngle(Int_t padrow)
	252	{
	253	//Calculate the crossing angle between track and given padrow.
	254
	255	if(!fIsHelix)
	256	{
	257	printf("AliL3HoughTrack::GetCrossingAngle : Track is not a helix\n");
	258	return 0;
	259	}
	260
	261	if(!IsLocal())
	262	{
263	printf("Track is not given in local coordinates\n");
264	return 0;
265	}
266
267	Float_t xyz[3];
268	if(!GetCrossingPoint(padrow,xyz))
269	printf("AliL3HoughTrack::GetCrossingPoint : Track does not cross line!!\n");
270
271
272	//Convert center of curvature to local coordinates:
273	//Float_t xyz_coc[3] = {GetCenterX(),GetCenterY(),0};
274	//fTransform->Global2Local(xyz_coc,slice);
275
276	//Take the dot product of the tangent vector of the track, and
277	//vector perpendicular to the padrow.
278
279	Double_t tangent[2];
280	//tangent[1] = (xyz[0] - xyz_coc[0])/GetRadius();
281	//tangent[0] = -1.*(xyz[1] - xyz_coc[1])/GetRadius();
282	tangent[1] = (xyz[0] - GetCenterX())/GetRadius();
283	tangent[0] = -1.*(xyz[1] - GetCenterY())/GetRadius();
284
285	Double_t perp_padrow[2] = {1,0}; //locally in slice
286
287	Double_t cos_beta = fabs(tangent[0]perp_padrow[0] + tangent[1]perp_padrow[1]);
288	return acos(cos_beta);
289
290	}
291
292	Bool_t AliL3HoughTrack::GetCrossingPoint(Int_t padrow,Float_t *xyz)
293	{
294	//Assumes the track is given in local coordinates
295
296	if(!fIsHelix)
297	{
298	printf("AliL3HoughTrack::GetCrossingPoint : Track is not a helix\n");
299	return 0;
300	}
301
302
303	if(!IsLocal())
304	{
305	printf("GetCrossingPoint: Track is given on global coordinates\n");
306	return false;
307	}
308
309	Double_t xHit = fTransform->Row2X(padrow);
310
311	//xyz[0] = fTransform->Row2X(padrow);
312	xyz[0] = xHit;
313	Double_t aa = (xHit - GetCenterX())*(xHit - GetCenterX());
314	Double_t r2 = GetRadius()*GetRadius();
315	if(aa > r2)
316	return false;
317
318	Double_t aa2 = sqrt(r2 - aa);
319	Double_t y1 = GetCenterY() + aa2;
320	Double_t y2 = GetCenterY() - aa2;
321	xyz[1] = y1;
322	if(fabs(y2) < fabs(y1)) xyz[1] = y2;
323	xyz[2] = 0; //only consider transverse plane
324
325	return true;
326	}
327
328
329	Bool_t AliL3HoughTrack::GetCrossingPoint(Int_t slice,Int_t padrow,Float_t *xyz)
330	{
331	//Calculate the crossing point in transverse plane of this track and given
332	//padrow (y = a*x + b). Point is given in local coordinates in slice.
333	//Assumes the track is given in global coordinates.
334
335	if(!fIsHelix)
336	{
337	printf("AliL3HoughTrack::GetCrossingPoint : Track is not a helix\n");
338	return 0;
339	}
340
341
342	if(IsLocal())
343	{
344	printf("GetCrossingPoint: Track is given in local coordintes!!!\n");
345	return false;
346	}
347
348	Double_t padrowradii = fTransform->Row2X(padrow);
349
350
351	Float_t rotation_angle = (slice20)ToRad;
352
353	Float_t cs,sn;
354	cs = cos(rotation_angle);
355	sn = sin(rotation_angle);
356
357	Double_t a = -1.*cs/sn;
358	Double_t b = padrowradii/sn;
359
360	Double_t ycPrime = GetCenterY() - b ;
361	Double_t aa = ( 1. + a * a ) ;
362	Double_t bb = -2. * ( GetCenterX() + a * ycPrime ) ;
363	Double_t cc = ( GetCenterX() * GetCenterX() + ycPrime * ycPrime - GetRadius() * GetRadius() ) ;
364
365	Double_t racine = bb * bb - 4. * aa * cc ;
366	if ( racine < 0 ) return false ;
367	Double_t rootRacine = sqrt(racine) ;
368
369	Double_t oneOverA = 1./aa;
370	//
371	// First solution
372	//
373	Double_t x1 = 0.5 * oneOverA * ( -1. * bb + rootRacine ) ;
374	Double_t y1 = a * x1 + b ;
375	Double_t r1 = sqrt(x1x1+y1y1);
376	//
377	// Second solution
378	//
379	Double_t x2 = 0.5 * oneOverA * ( -1. * bb - rootRacine ) ;
380	Double_t y2 = a * x2 + b ;
381	Double_t r2 = sqrt(x2x2+y2y2);
382	//
383	// Choose close to (0,0)
384	//
385	Double_t xHit ;
386	Double_t yHit ;
387	if ( r1 < r2 ) {
388	xHit = x1 ;
389	yHit = y1 ;
390	}
391	else {
392	xHit = x2 ;
393	yHit = y2 ;
394	}
395
396	xyz[0] = xHit;
397	xyz[1] = yHit;
398	xyz[2] = 0;
399
400	fTransform->Global2Local(xyz,slice);
401
402	return true;
403	}
404	*/