StiNodePars.h

#ifndef __StiNodePars_h_
#define __StiNodePars_h_
#include "Rtypes.h"

#define kEC       2.99792458e-4
#define kZEROHZ   2e-6                  //minimal/zero mag field
#define kZEROPTI  1e-3                  //minimal/zero 1/pt
#define kZEROCURV (kZEROHZ*kZEROPTI)    //minimal/zero curvature
#define kBIGPT    10                    //Pt when energy loss ignored



class StiNodePars {
 public:        
  enum {kX=0,kY=1,kZ=2,kPhi=3,kPtin=4,kTan=5,kCurv=6,kHz=7};
  void reset(){memset(this,0,sizeof(StiNodePars));_cosCA=1;}
  void ready();
   int isZeroH() const { return fabs(P[kHz]) <= kZEROHZ;}
  StiNodePars &merge(double wt,StiNodePars &other);
  StiNodePars &operator=(const StiNodePars& fr);
  void rotate(double alfa);
  int  nan() const;
  double  operator[](Int_t idx) const {return P[idx];}
  double &operator[](Int_t idx)       {return P[idx];}
  double x()    const   {return P[kX];} 
  double y()    const   {return P[kY];}//  local Y-coordinate of this track (reference plane)                                
  double z()    const   {return P[kZ];}//  local Z-coordinate of this track (reference plane)                        
  double eta()  const   {return P[kPhi];}//  phi angle
  double phi()  const   {return P[kPhi];}//  phi angle again
  double ptin() const   {return P[kPtin];}//  signed invert pt [sign = sign(-qB)]                                            
  double tanl() const   {return P[kTan];}//  tangent of the track momentum dip angle
  double curv() const   {return P[kCurv];}//  signed curvature [sign = sign(-qB)]                                            
  double rxy2() const   {return     (P[kX]*P[kX]+P[kY]*P[kY]);}
  double rxy()  const   {return sqrt(P[kX]*P[kX]+P[kY]*P[kY]);}
  double hz()   const   {return P[kHz];}//  Z component magnetic field in units Pt(Gev) = Hz * RCurv(cm)                  
  double &x()           {return P[kX];}
  double &y()           {return P[kY];}
  double &z()           {return P[kZ];}
  double &eta()         {return P[kPhi];} 
  double &ptin()        {return P[kPtin];}
  double &tanl()        {return P[kTan];}
  double &curv()        {return P[kCurv];}
  double &hz()          {return P[kHz];}
  double *A(Int_t i)    {return &P[i];}
  
  Int_t     check(const char *pri=0) const;
  void      print() const;

  double _cosCA;
  double _sinCA;
  double P[8]; // array of parameters. see below
};

class StiELoss 
{
public:
float mELoss,mLen,mDens,mX0;
};

inline void StiNodePars::ready()
{
_cosCA=cos(P[kPhi]);_sinCA=sin(P[kPhi]); 
 if (fabs(P[kHz])<= kZEROHZ) {
   P[kCurv] =  kZEROCURV; P[kPtin]= kZEROPTI;
 } else {
   P[kCurv]  = P[kHz]*P[kPtin];
 }
}


#endif