self-explaining text of matchsvdmt.C function :

//--------------------------------------------------------------------
// Created: 02.09.97 by   Olya Igonkina
// see http://www-hera-b.desy.de/subgroup/software/arte/MARPLE/    

// MARPLE function for matching of segments 
// reconstructed in the SVD and Main Tracker area

//--------------------------------------------------------------------

#include "marple/marple.hh"
#include "marple/RcMatchBuilder.hh"

#include "arte/RSEG_cmp.hh"
#include "arte/ArteMessage.hh"

//definition of constants for SVD-MT matching ( see \Ref{RcMatchConst})
// flag, z_plane, z_min, z_max, use_pair_cut, n_pair_left, n_pair_right, 
// use_delta_cut, delta_x, delta_y, delta_tx, delta_ty, delta_pe, chi2

RcMatchConst rcSvdMtConst = { 
  11110,     160.,   -30.,  700.,      0,          2,            2,
            1,      1,      1.5,      0.01,      0.01,   1.e+10,   1.e+10  
};

RcMatchConst rcSvdMtSoftConst = { 
  11110,     160.,   -30.,  700.,      1,          2,            1,
            1,      3.,      6.,      0.015,      0.02,   1.e+10,   1.e+10  
};

// Constants optimized on SUSI :
//RcMatchConst rcSvdMtConst = { 
//  11110,     160.,   -10.,  300.,      1,          2,            1,
//            1,      1.,      2.,      0.005,      0.008,   1.e+10,   100  
//};



extern "C"  
void FORTRAN_ROUTINE(matchsvdmt)() 
{
  RcMatchBuilder< RcSegPoint, RcSegPoint> SvdMtMatch;

  //--------------------------------------------------------------------
  // put constants to the MatchBuilder
  //--------------------------------------------------------------------
  if( MARPLE_SOFT )
    SvdMtMatch.setConst(rcSvdMtSoftConst);
  else
    SvdMtMatch.setConst(rcSvdMtConst);

  //--------------------------------------------------------------------
  // create vector of segments from SVD
  //--------------------------------------------------------------------

  int iErr =0;
  for( ArteTable<RSEG>::iterator irseg = ArteTable<RSEG>::begin();
       irseg != ArteTable<RSEG>::end(); ++irseg )
    {
      if( (*irseg)->fit != 0 ) continue;
      if( ((*irseg)->cmp & Rsegc::bitsign) != 0 ) continue;
      if( (*irseg)->cmp != Rsegc::vxd && 
	  (*irseg)->cmp != 65537) continue;
      if( SvdMtMatch.ptToMatchConst()->geomAccept(HepDouble((*irseg)->ze)) )
	{ 	  
	  RcSegPoint * ptToPoint = new RcSegPoint( (*irseg) , 1); // endPoint

	  // prolongate to the plane of matching
	  ptToPoint->prolongate( SvdMtMatch.ptToMatchConst()->z_plane, iErr);
	  if( iErr ) 
	    { 
	      delete ptToPoint; 
	    }else{
	      SvdMtMatch.addPointLeft( *ptToPoint);
	    }
	  ptToPoint = 0;
	}
    }
  //--------------------------------------------------------------------
  // create vector of Main Tracker segments
  //--------------------------------------------------------------------

  
  for( ArteTable<RSEG>::iterator irseg2 = ArteTable<RSEG>::begin(); 
       irseg2 != ArteTable<RSEG>::end(); ++irseg2 )
    {
      if( (*irseg2)->fit != 0 ) continue;
      if( ((*irseg2)->cmp & Rsegc::bitsign) != 0 ) continue;
      if(  (*irseg2)->cmp & Rsegc::magt && 
	  SvdMtMatch.ptToMatchConst()->geomAccept(HepDouble((*irseg2)->zf)) )
	{
	  RcSegPoint * ptToPoint = new RcSegPoint( (*irseg2),0 );// firstPoint
	  (*ptToPoint).prolongate( SvdMtMatch.ptToMatchConst()->z_plane, iErr);
	  if( iErr ) 
	    {
	      delete ptToPoint;
	    }else{
	      SvdMtMatch.addPointRight( *ptToPoint);
	    }
	  ptToPoint = 0;	      
	}
    }  
  
  //--------------------------------------------------------------------
  // do Matching 
  //--------------------------------------------------------------------
  SvdMtMatch.doMatch();

  //--------------------------------------------------------------------
  // print result of matching
  //--------------------------------------------------------------------

  
  SvdMtMatch.stat();
   
      
  if( MARPLE_DEBUG >= 20)
    {
      SvdMtMatch.fillMatch(8112);
      SvdMtMatch.fillDeltas(8212,8312);
    }else  if( MARPLE_DEBUG >= 10 ){
      SvdMtMatch.fillDeltas(8212);
    }
  //--------------------------------------------------------------------
  // save found relation to the table
  //--------------------------------------------------------------------
  if( MARPLE_MAKERSEG ) SvdMtMatch.saveRSEG(iErr);
  SvdMtMatch.saveRelation(iErr);
  if( iErr )
    { arteMsg << "MARPLE: some relations were not saved "; arteMsg.allp();}

  //    refit information
  //SvdMtMatch.refitLeftFound(       iErr);
  //SvdMtMatch.refitRightFound(      iErr);
  //    and update RSEG tables
  //SvdMtMatch.updateARTELeftFound(  iErr);
  //SvdMtMatch.updateARTERightFound( iErr);

  //--------------------------------------------------------------------
  // clean everything
  //--------------------------------------------------------------------
  SvdMtMatch.deleteAll();  
}