CbmKFMath.h

/** Collection of mathematical routines for the CbmKF Kalman Filter 
 *
 * @author  S.Gorbunov
 * @version 0.0
 * @since   02.12.05
 * 
 * Description will be here 
 *
 */

#ifndef CBMKFMATH_H
#define CBMKFMATH_H 1

#include "TObject.h"

class FairField;
class FairTrackParam;

class CbmKFMath : public TObject {
public:
  CbmKFMath() {}
  ~CbmKFMath() {}

  static Bool_t GetThickness(Double_t z1,
                             Double_t z2,
                             Double_t mz,
                             Double_t mthick,
                             Double_t* mz_out,
                             Double_t* mthick_out);

  static Bool_t intersectCone(Double_t zCone,
                              Double_t ZCone,
                              Double_t rCone,
                              Double_t RCone,
                              const Double_t x[],
                              Double_t* z1,
                              Double_t* z2);

  static Int_t indexS(Int_t i, Int_t j) {
    return (j <= i) ? i * (i + 1) / 2 + j : j * (j + 1) / 2 + i;
  }

  static void
  multQSQt(Int_t N, const Double_t Q[], const Double_t S[], Double_t S_out[]);
  static void
  multQtSQ(Int_t N, const Double_t Q[], const Double_t S[], Double_t S_out[]);
  static void
  multSSQ(const Double_t* A, const Double_t* B, Double_t* C, Int_t n);
  static void four_dim_inv(Double_t a[4][4]);
  static void five_dim_inv(Double_t a[5][5]);
  static Bool_t invS(Double_t A[], Int_t N);
  static Double_t getDeviation(Double_t x,
                               Double_t y,
                               Double_t C[],
                               Double_t vx,
                               Double_t vy,
                               Double_t Cv[] = 0);
  static Double_t
  AnalyticQP(const Double_t T[],       // track parameters (x,y,tx,ty,Q/p,z)
             const Double_t V[],       // vertex parameters (x,y,z)
             FairField* MagneticField  // magnetic field
  );

  static Int_t GetNoise(Double_t Lrl,
                        Double_t F,
                        Double_t Fe,
                        Double_t tx,
                        Double_t ty,
                        Double_t qp,
                        Double_t mass,
                        Bool_t is_electron,
                        Bool_t downstream_direction,
                        Double_t* Q5,
                        Double_t* Q8,
                        Double_t* Q9,
                        Double_t* Ecor);

  static void
  CopyTrackParam2TC(const FairTrackParam* par, Double_t T[], Double_t C[]);
  static void
  CopyTC2TrackParam(FairTrackParam* par, Double_t T[], Double_t C[]);

  ClassDef(CbmKFMath, 1)
};

#endif /* ! CBMKFMATH_H */