MdcSegInfoAxialO.cxx

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//--------------------------------------------------------------------------
// File and Version Information:
//      $Id: MdcSegInfoAxialO.cxx,v 1.2 2005/07/18 02:34:42 zhangy Exp $
//
// Description:
//
//
// Environment:
//      Software developed for the BaBar Detector at the SLAC B-Factory.
//
// Authors:
//
//------------------------------------------------------------------------
// #include "BaBar/BaBar.h"
#include "MdcTrkRecon/MdcSegInfoAxialO.h"
#include "MdcGeom/BesAngle.h"
#include "MdcGeom/MdcSuperLayer.h"
#include "MdcTrkRecon/MdcSeg.h"
#include "MdcTrkRecon/mdcTwoInv.h"
#include <assert.h>
#include <math.h>
// #include "ErrLogger/ErrLog.h"
using std::endl;
 
//--------------------------------------------------------------------------
bool MdcSegInfoAxialO::parIsAngle( int i ) const {
  //---------------------------------------------------------------------------
  assert( i >= 0 && i < 2 );
  return ( 0 == i ); // i.e., 0th parameter is an angle
}
//------------------------------------------------------------------
void MdcSegInfoAxialO::calcFromOrigin( double phi, double slope, double radius,
                                       const double* inErr ) {
  //------------------------------------------------------------------
 
  if ( slope == 0. ) slope = 0.00000001;
  double slinv = 1. / slope;
  _par1        = slope / sqrt( 1. + radius * radius * slope * slope ); // curve
  double temp  = 1. - _par1 * _par1 * radius * radius;
  if ( temp < 0. ) temp = 0.;
  double   dphi0ds = -radius * _par1 * sqrt( temp ) * slinv;
  BesAngle phi0    = phi - asin( _par1 * radius );
  _par0            = phi0.posRad();
 
  // phi0:
  _errmat[0] = inErr[2] * dphi0ds * dphi0ds + inErr[0] + inErr[1] * 2. * dphi0ds;
  if ( _errmat[0] < 0. ) _errmat[0] = 0.;
  // curv:
  _errmat[2] = inErr[2] * _par1 * _par1 * temp * temp * slinv * slinv;
  if ( _errmat[2] < 0. ) _errmat[2] = 0.;
  // phi0|curv:
  _errmat[1] = inErr[2] * _par1 * slinv * temp * dphi0ds + inErr[1] * _par1 * slinv * temp;
  int error  = mdcTwoInv( _errmat, _inverr );
  if ( error )
  {
    std::cout << " ErrMsg(warning) "
              << "Failed to invert matrix -- MdcSegInfo::calcFromOrigin" << endl
              << _errmat[0] << " " << _errmat[1] << " " << _errmat[2] << endl;
  }
}
 
//-------------------------------------------------------------------
void MdcSegInfoAxialO::calcFromOrigin( const MdcSeg* parentSeg ) {
  //-------------------------------------------------------------------
  double        slope  = parentSeg->slope();
  double        radius = parentSeg->superlayer()->rad0();
  double        phi    = parentSeg->phi();
  const double* inErr  = parentSeg->errmat();
 
  calcFromOrigin( phi, slope, radius, inErr );
}
 
//-------------------------------------------------------------------
double MdcSegInfoAxialO::sigPhi0() const {
  //-------------------------------------------------------------------
  return sqrt( _errmat[0] );
}
 
//-------------------------------------------------------------------
double MdcSegInfoAxialO::sigCurv() const {
  //-------------------------------------------------------------------
  return sqrt( _errmat[2] );
}