[u/mrichter/AliRoot.git] / TRD / AliTRDltuTracklet.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.                  *
 **************************************************************************/

///////////////////////////////////////////////////////////////////////////////
//                                                                           //
//                                                                           //
//  TRD chamber local track (LTU, tracklet)                                  //
//                                                                           //
//                                                                           //
///////////////////////////////////////////////////////////////////////////////

#include <TMath.h>

#include "AliTRDltuTracklet.h"

ClassImp(AliTRDltuTracklet)

//_____________________________________________________________________________
AliTRDltuTracklet::AliTRDltuTracklet(Int_t det, 
				     Int_t row, 
				     Float_t rowz,
				     Float_t slope, 
				     Float_t offset, 
				     Float_t time, 
				     Int_t ncl,
				     Int_t label,
				     Float_t q) 
{
  //
  // AliTRDltuTracklet constructor
  //

  fDetector  = det;
  fRow       = row;
  fRowz      = rowz;
  fSlope     = slope;
  fX         = time;
  fY         = offset;
  fNclusters = ncl;
  fLabel     = label;
  fQ         = q;

}

//_____________________________________________________________________________
AliTRDltuTracklet::~AliTRDltuTracklet()
{
  //
  // destructor
  //

}

//_____________________________________________________________________________
Float_t AliTRDltuTracklet::GetPt(Float_t field) const
{
  // transverse momentum calculation
  // curvature R = (fX*fX + fY*fY) / (2 * sin(alpha))
  // alpha = angle deviation from "infinite momentum"
  //
  // consistent with AliTRDmcmTracklet::GetPt(...)

  Float_t infSlope = TMath::ATan(fY/fX)/TMath::Pi()*180.0;    
  Float_t alpha = fSlope - infSlope;
  Float_t r = TMath::Sqrt(fX*fX + fY*fY)/(2.0*TMath::Sin(alpha/180.0*TMath::Pi()));
  
  Float_t pt = 0.3 * field * 0.01 * r;
 
  return pt;
 
}

//_____________________________________________________________________________
Int_t AliTRDltuTracklet::Compare(const TObject * o) const
{
  //
  // compare two LTU tracklets according to the intercept point Y1
  //

  AliTRDltuTracklet *ltutrk = (AliTRDltuTracklet*)o;

  if (fRow      != ltutrk->fRow)      return +1;
  if (fDetector != ltutrk->fDetector) return +1;

  if (fY <  ltutrk->fY) return -1;
  if (fY == ltutrk->fY) return  0;

  return 1;

}

//_____________________________________________________________________________
Float_t AliTRDltuTracklet::GetYproj(Float_t xpl) const
{
  //
  // y-projection (bending plane) onto the median plane
  //

  Float_t yproj;

  yproj = fY + TMath::Tan(fSlope/180.0*TMath::Pi()) * (xpl - fX);

  return yproj;

}

//_____________________________________________________________________________
Float_t AliTRDltuTracklet::GetZproj(Float_t xpl) const
{
  //
  // z-projection (using pad row center) onto the median plane
  //

  Float_t zproj;

  zproj = fRowz * xpl / fX;

  return zproj;

}
Commit	Line	Data
e3b2b5e5	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
	16	///////////////////////////////////////////////////////////////////////////////
	17	// //
	18	// //
	19	// TRD chamber local track (LTU, tracklet) //
	20	// //
	21	// //
	22	///////////////////////////////////////////////////////////////////////////////
	23
	24	#include <TMath.h>
	25
	26	#include "AliTRDltuTracklet.h"
	27
	28	ClassImp(AliTRDltuTracklet)
	29
	30	//_____________________________________________________________________________
	31	AliTRDltuTracklet::AliTRDltuTracklet(Int_t det,
	32	Int_t row,
	33	Float_t rowz,
	34	Float_t slope,
	35	Float_t offset,
	36	Float_t time,
	37	Int_t ncl,
	38	Int_t label,
	39	Float_t q)
	40	{
	41	//
	42	// AliTRDltuTracklet constructor
	43	//
	44
	45	fDetector = det;
	46	fRow = row;
	47	fRowz = rowz;
	48	fSlope = slope;
	49	fX = time;
	50	fY = offset;
	51	fNclusters = ncl;
	52	fLabel = label;
	53	fQ = q;
	54
	55	}
	56
	57	//_____________________________________________________________________________
	58	AliTRDltuTracklet::~AliTRDltuTracklet()
	59	{
	60	//
	61	// destructor
	62	//
	63
	64	}
65
66	//_____________________________________________________________________________
67	Float_t AliTRDltuTracklet::GetPt(Float_t field) const
68	{
69	// transverse momentum calculation
70	// curvature R = (fXfX + fYfY) / (2 * sin(alpha))
71	// alpha = angle deviation from "infinite momentum"
72	//
73	// consistent with AliTRDmcmTracklet::GetPt(...)
74
75	Float_t infSlope = TMath::ATan(fY/fX)/TMath::Pi()*180.0;
76	Float_t alpha = fSlope - infSlope;
77	Float_t r = TMath::Sqrt(fXfX + fYfY)/(2.0TMath::Sin(alpha/180.0TMath::Pi()));
78
79	Float_t pt = 0.3 * field * 0.01 * r;
80
81	return pt;
82
83	}
84
85	//_____________________________________________________________________________
86	Int_t AliTRDltuTracklet::Compare(const TObject * o) const
87	{
88	//
89	// compare two LTU tracklets according to the intercept point Y1
90	//
91
92	AliTRDltuTracklet ltutrk = (AliTRDltuTracklet)o;
93
94	if (fRow != ltutrk->fRow) return +1;
95	if (fDetector != ltutrk->fDetector) return +1;
96
97	if (fY < ltutrk->fY) return -1;
98	if (fY == ltutrk->fY) return 0;
99
100	return 1;
101
102	}
103
104	//_____________________________________________________________________________
105	Float_t AliTRDltuTracklet::GetYproj(Float_t xpl) const
106	{
107	//
108	// y-projection (bending plane) onto the median plane
109	//
110
111	Float_t yproj;
112
113	yproj = fY + TMath::Tan(fSlope/180.0TMath::Pi()) (xpl - fX);
114
115	return yproj;
116
117	}
118
119	//_____________________________________________________________________________
120	Float_t AliTRDltuTracklet::GetZproj(Float_t xpl) const
121	{
122	//
123	// z-projection (using pad row center) onto the median plane
124	//
125
126	Float_t zproj;
127
128	zproj = fRowz * xpl / fX;
129
130	return zproj;
131
132	}
133