Algorithm corrected
[u/mrichter/AliRoot.git] / ITS / AliITSTPArrayFit.h
CommitLineData
6be22b3f 1/* Copyright(c) 2009-2011, ALICE Experiment at CERN, All rights reserved. *
2 * See cxx source for full Copyright notice */
3
4/* $Id$ */
5
6
7#ifndef ALIITSTPARRAYFIT_H
8#define ALIITSTPARRAYFIT_H
9
10///////////////////////////////////////////////////////////////////////////////////////////////
11// //
12// The line is defined by equations (1) //
13// a0*z+a1*x-a0*a1=0 and //
14// b0*z+b1*y-b0*b1=0 //
15// where x,y,z are NOT the lab axes but z is the lab axis along which the track //
16// has the largest lever arm and x,y are the remaining 2 axis in //
17// the order of fgkAxisID[z][0], fgkAxisID[z][1] //
18// The parameters are fParams[kA0,kB0,kA1,kB1] and the axis chosen as the independent //
19// var. is fParAxis (i.e. if fParAxis==kZ, then a0=ax,b0=bx, a1=ay,b1=by) //
20// //
21// //
22// The helix is defined by the equations (2) //
23// X(t) = (dr+R)*cos(phi0) - (R+sum{dRi})*cos(t+phi0) + sum{dRi*cos(phi0+ti)} //
24// Y(t) = (dr+R)*sin(phi0) - (R+sum{dRi})*sin(t+phi0) + sum{dRi*sin(phi0+ti)} //
25// Z(t) = dz - (R+sum{dRi})*t*tg(dip) + sum{dRi*ti}*tg(dip) //
26// where dRi is the change of the radius due to the ELoss at parameter ti //
27// //
28// Author: ruben.shahoyan@cern.ch //
29// //
30///////////////////////////////////////////////////////////////////////////////////////////////
31
32
33#include <TObject.h>
34#include <TMath.h>
35#include "AliTrackPointArray.h"
36class AliSymMatrix;
37class AliLog;
38class AliParamSolver;
39
40
41class AliITSTPArrayFit : public TObject
42{
43 public:
44 enum {kFitDoneBit=BIT(14),kCovInvBit=BIT(15),
45 kCosmicsBit=BIT(16),kELossBit=BIT(17),
46 kIgnoreCovBit=BIT(18),
47 kMask=BIT(24)-1};
48 enum {kXX=0,kXY=1,kXZ=2,kYX=kXY,kYY=3,kYZ=4,kZX=kXZ,kZY=kYZ,kZZ=5};
49 enum {kA0,kB0,kA1,kB1}; // line params
50 enum {kD0,kPhi0,kR0,kDZ,kDip}; // helix params
51 enum {kX,kY,kZ};
52 enum {kMaxParam=6,kMaxParamSq = kMaxParam*(kMaxParam+1)/2};
53 enum {kLrBeamPime, kLrSPD1,kLrSPD2, kLrShield1, kLrSDD1,kLrSDD2, kLrShield2, kLrSSD1,kLrSSD2,kMaxLrITS};
54 //
55 public:
56 AliITSTPArrayFit();
57 AliITSTPArrayFit(Int_t npoints);
58 AliITSTPArrayFit(const AliITSTPArrayFit &fit);
59 AliITSTPArrayFit& operator= (const AliITSTPArrayFit& src);
60 virtual ~AliITSTPArrayFit();
61 //
62 void AttachPoints(const AliTrackPointArray* points, Int_t pfirst=-1,Int_t plast=-1);
63 Bool_t SetFirstLast(Int_t pfirst=-1,Int_t plast=-1);
64 AliTrackPointArray* GetPoints() const {return (AliTrackPointArray*)fPoints;}
65 //
66 void SetBz(Double_t bz) {fBz = bz;}
67 Double_t GetBz() const {return fBz;}
68 Bool_t IsFieldON() const {return TMath::Abs(fBz)>1e-5;}
69 Bool_t IsTypeCosmics() const {return TestBit(kCosmicsBit);}
70 Bool_t IsTypeCollision() const {return !IsTypeCosmics();}
71 Int_t GetCharge() const {return fCharge;}
72 Int_t GetSignQB() const {return fBz<0 ? -fCharge:fCharge;}
73 void GetResiduals(Double_t *res, Int_t ipnt) const;
74 void GetResiduals(Double_t *resPCA, const Double_t* xyz, const Double_t* covI=0) const;
75 Double_t GetPosition( Double_t *xyzPCA, const Double_t* xyz, const Double_t* covI=0) const;
76 Double_t GetPosition( Double_t *xyzPCA, const AliTrackPoint *pntCovInv) const;
77 void GetResiduals(Double_t *xyzPCA, const AliTrackPoint *pntCovInv) const;
78 void GetPosition(Double_t *xyz, Double_t t) const;
79 void GetPosition(Double_t *xyz, Int_t pnt) const;
80 void GetDirCos(Double_t *dircos, Double_t t) const;
81 Double_t GetPCA2PlaneInfo(Double_t *xyz, Double_t *dir=0, Int_t axis=kY, Double_t axval=0) const;
66214d86 82 void GetT0Info(Double_t *xyz, Double_t *dir=0) const;
6be22b3f 83 Double_t CalcChi2NDF() const;
84 Double_t GetChi2NDF() const {return fChi2NDF;}
85 Double_t GetParPCA(const double *xyz, const double *covI=0) const;
66214d86 86 Bool_t CalcErrorMatrix();
6be22b3f 87 //
88 void GetDResDParamsLine (Double_t *dXYZdP, const Double_t *xyz, const Double_t *covI=0) const;
89 void GetDResDParamsLine (Double_t *dXYZdP, Int_t ipnt) const;
90 void GetDResDParams(Double_t *dXYZdP, const Double_t *xyz, const Double_t *covI=0);
91 void GetDResDParams(Double_t *dXYZdP, Int_t ipnt);
92 //
93 void GetDResDPosLine (Double_t *dXYZdP,/*const Double_t *xyz,*/ const Double_t *covI=0) const;
94 void GetDResDPosLine (Double_t *dXYZdP, Int_t ipnt) const;
95 void GetDResDPos(Double_t *dXYZdP, const Double_t *xyz, const Double_t *covI=0);
96 void GetDResDPos(Double_t *dXYZdP, Int_t ipnt);
97 //
98 Double_t* GetPoint(int ip) const;
99 Bool_t Converged() const {return fIter<fMaxIter;}
100 //
101 Double_t Fit(Int_t extQ=0, Double_t extPT=-1,Double_t extPTerr=0);
102 Double_t FitLine();
103 Double_t FitHelix(Int_t extQ=0, Double_t extPT=-1,Double_t extPTerr=0);
104 Bool_t FitLineCrude();
105 Bool_t FitHelixCrude(Int_t imposedQ=0);
106 //
107 Int_t GetParAxis() const {return fParAxis;}
108 Int_t GetAxID(Int_t id) const {return fkAxID ? fkAxID[id] : -1;}
109 Int_t GetAxCID(Int_t id) const {return fkAxCID ? fkAxCID[id] : -1;}
110 Int_t GetFirst() const {return fPntFirst;}
111 Int_t GetLast() const {return fPntLast;}
112 //
113 Int_t GetNParams() const {return IsFieldON() ? 5:4;}
114 Bool_t InvertPointsCovMat();
115 //
116 Int_t* GetElsId() const {return fElsId;}
117 Double_t* GetElsDR() const {return fElsDR;}
118 //
119 Double_t* GetCovI(Int_t ip) const {return fCovI + ip*6;}
120 Double_t* GetCovI() const {return fCovI;}
121 Double_t* GetParams() const {return (Double_t*)&fParams[0];}
122 Double_t GetParam(Int_t ip) const {return fParams[ip];}
123 Double_t* GetTs() const {return (Double_t*)fCurT;}
124 Double_t GetT(Int_t ip) const {return fCurT[ip];}
125 Double_t GetLineOffset(Int_t axis) const;
126 Double_t GetLineSlope(Int_t axis) const;
127 //
128 Bool_t IsELossON() const {return TestBit(kELossBit)&&IsFieldON();}
129 Bool_t IsFitDone() const {return TestBit(kFitDoneBit);}
130 Bool_t IsCovInv() const {return TestBit(kCovInvBit);}
131 Bool_t IsCovIgnored() const {return TestBit(kIgnoreCovBit);}
132 Int_t GetMaxIterations() const {return fMaxIter;}
133 Int_t GetNIterations() const {return fIter;}
134 Double_t GetEps() const {return fEps;}
135 Double_t GetMass() const {return fMass;}
136 //
137 void SetCharge(Int_t q=1) {fCharge = q<0 ? -1:1;}
138 void SetELossON(Bool_t v=kTRUE) {SetBit(kELossBit,v);}
139 void SetTypeCosmics(Bool_t v=kTRUE) {SetBit(kCosmicsBit,v);}
140 void SetTypeCollision(Bool_t v=kTRUE) {SetTypeCosmics(!v);}
141 void SetFitDone(Bool_t v=kTRUE) {SetBit(kFitDoneBit,v);}
142 void SetCovInv(Bool_t v=kTRUE) {SetBit(kCovInvBit,v);}
143 void SetIgnoreCov(Bool_t v=kTRUE) {SetBit(kIgnoreCovBit,v);}
144 void SetParAxis(Int_t ax);
145 void SetMaxIterations(Int_t n=20) {fMaxIter = n<2 ? 2:n;}
146 void SetEps(Double_t eps=1e-6) {fEps = eps<0 ? GetMachinePrec() : eps;}
147 void SetMass(Double_t m=0.13957) {fMass = m<5E-4 ? 5E-4 : m;}
148 void Reset();
149 void BuildMaterialLUT(Int_t ntri=3000);
150 //
151 virtual void Print(Option_t *opt="") const;
152 //
153 static void GetNormal(Double_t *norm,const Float_t *covMat);
154 //
155 protected:
156 void InitAux();
157 Double_t GetMachinePrec();
158 Int_t ChoseParAxis() const;
159 Double_t GetParPCALine(const Double_t *xyz, const Double_t *covI=0) const;
160 Double_t GetParPCAHelix(const Double_t *xyz, const Double_t *covI=0) const;
161 Double_t GetParPCACircle(Double_t x, Double_t y) const;
162 Double_t GetHelixParAtR(Double_t r) const;
163 //
164 void GetDtDPosLine(Double_t *dtpos,/*const Double_t *xyz,*/ const Double_t *covI=0) const;
165 Double_t GetDtDParamsLine(Double_t *dtparam,const Double_t *xyz, const Double_t *covI=0) const;
166 //
167 Double_t GetDRofELoss(Double_t t,Double_t cdip,Double_t rhoL,
168 const Double_t *normS, Double_t &p,Double_t &e) const;
169 static Bool_t IsZero(Double_t v,Double_t threshold = 1e-16) {return TMath::Abs(v)<threshold; }
170
171 //
172 protected:
173 const AliTrackPointArray *fPoints; // current points
174 AliParamSolver* fParSol; // solver for parametric linearized systems
175 //
176 Double_t fBz; // magnetic field
177 Int_t fCharge; // track charge +1=+, -1=-
178 Int_t fPntFirst; // first point to fit
179 Int_t fPntLast; // last point to fit
180 Int_t fNPBooked; // number of points booked
181 Int_t fParAxis; // parameterization axis
182 Double_t *fCovI; //! inverted cov.matrix for each point
183 Double_t fParams[kMaxParam]; // fitted params
184 Double_t fParamsCov[kMaxParamSq]; // fit cov matrix
185 Double_t fChi2NDF; // fit chi2/NDF
186 Int_t fMaxIter; // max number of iterations
187 Int_t fIter; // real number of iterations
188 Double_t fEps; // precision
189 Double_t fMass; // assumed particle mass for ELoss Calculation
190 //
191 const Int_t *fkAxID; // axis IDs
192 const Int_t *fkAxCID; // axis combinations IDs
193 //
194 // internal storage
195 Double_t *fCurT; // track parameter for each point
196 //
197 // storage to account e-loss
198 Int_t fFirstPosT; // id of the first positive t index in fElsId
199 Int_t fNElsPnt; // number of e-loss layers seen by the track
200 Int_t *fElsId; // index of increasing t-ordering in the fCurT
201 Double_t *fElsDR; // delta_Radius for each e-loss layer
202 //
203 static Double_t fgRhoLITS[kMaxLrITS]; // <rho*L> for each material layer
204 static const Double_t fgkRLayITS[kMaxLrITS]; // radii of material layers
205 static const Double_t fgkZSpanITS[kMaxLrITS]; // half Z span of the material layer
206 static const Int_t fgkPassivLrITS[3]; // list of passive layer enums
207 static const Int_t fgkActiveLrITS[6]; // list of active layer enums
208 static const Double_t fgkAlmostZero; // tiny double
209 static const Double_t fgkCQConv; // R = PT/Bz/fgkCQConv with GeV,kGauss,cm
210 static const Int_t fgkAxisID[3][3]; // permutations of axis
211 static const Int_t fgkAxisCID[3][6]; // cov matrix elements for axis selection
212
213 ClassDef(AliITSTPArrayFit,0);
214};
215
216//____________________________________________________
217inline void AliITSTPArrayFit::GetPosition(Double_t *xyz, Int_t pnt) const
218{
219 // track position at measured point pnt
220 GetPosition(xyz,fCurT[pnt]);
221}
222
223//____________________________________________________
224inline Double_t AliITSTPArrayFit::GetParPCA(const double *xyz, const double *covI) const
225{
226 // get parameter for the point with least weighted distance to the point
227 if (IsFieldON()) return GetParPCAHelix(xyz,covI);
228 else return GetParPCALine(xyz,covI);
229}
230
231//____________________________________________________
232inline Double_t* AliITSTPArrayFit::GetPoint(Int_t ip) const
233{
234 static double xyz[3];
235 xyz[kX] = fPoints->GetX()[ip];
236 xyz[kY] = fPoints->GetY()[ip];
237 xyz[kZ] = fPoints->GetZ()[ip];
238 return &xyz[0];
239}
240
241//____________________________________________________
242inline Double_t AliITSTPArrayFit::Fit(Int_t extQ,Double_t extPT,Double_t extPTerr)
243{
244 if (IsFieldON()) return FitHelix(extQ,extPT,extPTerr);
245 else return FitLine();
246}
247
248
249#endif