3 /* Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
4 * See cxx source for full Copyright notice */
6 // Class for global helix fit of a track
8 // This class uses decomposition of the chi2 based on the fact that
9 // one can rotate the coordinate system and provide xi >> yi for each
13 #include <TMatrixDSymfwd.h>
15 class AliRieman : public TObject{
18 AliRieman(Int_t capacity);
19 AliRieman(const AliRieman &rieman);
22 void AddPoint(Double_t x, Double_t y, Double_t z, Double_t sy, Double_t sz);
23 Int_t GetN() const {return fN;}
24 Int_t GetCapacity() const {return fCapacity;}
25 Double_t * GetX() const {return fX;}
26 Double_t * GetY() const {return fY;}
27 Double_t * GetZ() const {return fZ;}
28 Double_t * GetSy() const {return fSy;}
29 Double_t * GetSz() const {return fSz;}
32 Double_t* GetParam(){return fParams;}
33 const TMatrixDSym & GetCovariance() const {return *fCovar;}
34 Double_t GetC() const;
35 Double_t GetYat(Double_t x) const;
36 Double_t GetZat(Double_t x) const;
37 Double_t GetDYat(Double_t x) const;
38 Double_t GetDZat(Double_t x) const;
39 Bool_t GetXYZat(Double_t r, Double_t alpha, Float_t *xyz) const;
41 Bool_t IsValid(){ return fConv;}
42 Double_t GetChi2Y() const { return fChi2Y;}
43 Double_t GetChi2Z() const { return fChi2Z;}
44 Double_t GetChi2() const { return fChi2; }
45 Double_t CalcChi2Y() const;
46 Double_t CalcChi2Z() const;
47 Double_t CalcChi2() const;
48 AliRieman * MakeResiduals() const;
52 Int_t fCapacity; // capacity
53 Int_t fN; // numebr of points
54 Double_t *fX; //[fN] x coordinate
55 Double_t *fY; //[fN] y coordinate
56 Double_t *fZ; //[fN] z coordinate
57 Double_t *fSy; //[fN] sigma y coordinate
58 Double_t *fSz; //[fN] sigma z coordinate
59 Double_t fParams[6]; //Parameters
60 TMatrixDSym *fCovar; //Covariance
61 Double_t fSumXY[9]; //sums for XY part
62 Double_t fSumXZ[9]; //sums for XZ part
63 Double_t fSumZZ; //sums of Z2
64 Double_t fChi2; //sums of chi2
65 Double_t fChi2Y; //sums of chi2 for y coord
66 Double_t fChi2Z; //sums of chi2 foz z coord
67 Bool_t fConv; // indicates convergation
70 AliRieman& operator=(const AliRieman &rieman);
71 ClassDef(AliRieman,1) // Fast fit of helices on ITS RecPoints