#include <PixelFitterByConformalMappingAndLine.h>

Inheritance diagram for PixelFitterByConformalMappingAndLine:

Public Member Functions
	PixelFitterByConformalMappingAndLine (const TransientTrackingRecHitBuilder ttrhBuilder, const TrackerGeometry tracker, const MagneticField *field, double fixImpactParameter, bool useFixImpactParameter)

std::unique_ptr< reco::Track >	run (const std::vector< const TrackingRecHit * > &hits, const TrackingRegion &region, const edm::EventSetup &setup) const override

	~PixelFitterByConformalMappingAndLine () override

Public Member Functions inherited from PixelFitterBase
virtual	~PixelFitterBase ()

Private Attributes
const MagneticField *	theField

const double	theFixImpactParameter

const TrackerGeometry *	theTracker

const TransientTrackingRecHitBuilder *	theTTRHBuilder

const bool	theUseFixImpactParameter

Detailed Description

Definition at line 14 of file PixelFitterByConformalMappingAndLine.h.

Constructor & Destructor Documentation

PixelFitterByConformalMappingAndLine::PixelFitterByConformalMappingAndLine	(	const TransientTrackingRecHitBuilder *	ttrhBuilder,
		const TrackerGeometry *	tracker,
		const MagneticField *	field,
		double	fixImpactParameter,
		bool	useFixImpactParameter
	)

explicit

Definition at line 35 of file PixelFitterByConformalMappingAndLine.cc.

                                                                                                       :
   theTTRHBuilder(ttrhBuilder),
   theTracker(tracker),
   theField(field),
   theFixImpactParameter(fixImpactParameter),
   theUseFixImpactParameter(useFixImpactParameter)
 { }

PixelFitterByConformalMappingAndLine::~PixelFitterByConformalMappingAndLine ( )

inlineoverride

Definition at line 17 of file PixelFitterByConformalMappingAndLine.h.

References hfClusterShapes_cfi::hits, run(), and GeneralSetup::setup().

17 { }

Member Function Documentation

std::unique_ptr< reco::Track > PixelFitterByConformalMappingAndLine::run	(	const std::vector< const TrackingRecHit * > &	hits,
		const TrackingRegion &	region,
		const edm::EventSetup &	setup
	)		const

overridevirtual

Implements PixelFitterBase.

Definition at line 47 of file PixelFitterByConformalMappingAndLine.cc.

References TransientTrackingRecHitBuilder::build(), PixelTrackBuilder::build(), ConformalMappingFit::charge(), ALCARECOTkAlJpsiMuMu_cff::charge, ConformalMappingFit::chi2(), vertices_cff::chi2, RZLine::chi2(), RZLine::cotTheta(), RZLine::covii(), RZLine::covss(), ConformalMappingFit::curvature(), GlobalErrorBase< T, ErrorWeightType >::czz(), ConformalMappingFit::directionPhi(), vertexPlots::e4, Measurement1D::error(), relativeConstraints::error, benchmark_cfg::errors, fftjetvertexadder_cfi::errZ, ConformalMappingFit::fixImpactParmaeter(), mps_fire::i, ConformalMappingFit::impactParameter(), RZLine::intercept(), PixelRecoUtilities::inversePt(), GeomDetEnumerators::isBarrel(), nhits, TrackingRegion::origin(), PV3DBase< T, PVType, FrameType >::perp2(), phi, point, hiPixelPairStep_cff::points, EnergyCorrector::pt, alignCSCRings::r, rpcPointValidation_cfi::recHit, GlobalErrorBase< T, ErrorWeightType >::rerr(), GeneralSetup::setup(), sqr(), mathSSE::sqrt(), theField, theFixImpactParameter, theTTRHBuilder, theUseFixImpactParameter, btvTracks_cfi::tip, Measurement1D::value(), PV3DBase< T, PVType, FrameType >::x(), geometryCSVtoXML::xy, PV3DBase< T, PVType, FrameType >::y(), z, PV3DBase< T, PVType, FrameType >::z(), and ComparisonHelper::zip().

Referenced by ~PixelFitterByConformalMappingAndLine().

 {
 
   int nhits = hits.size();
 
   vector<GlobalPoint> points;
   vector<GlobalError> errors;
   vector<bool> isBarrel;
   
 
   for (vector<const TrackingRecHit*>::const_iterator ih=hits.begin();  ih!=hits.end(); ih++) {
     TransientTrackingRecHit::RecHitPointer recHit = theTTRHBuilder->build(*ih);
     points.push_back( recHit->globalPosition() );
     errors.push_back( recHit->globalPositionError() );
     isBarrel.push_back( recHit->detUnit()->type().isBarrel() );
   }
 
 //    if (useMultScatt) {
 //      MultipleScatteringParametrisation ms(hits[i].layer());
 //      float cotTheta = (p.z()-zVtx)/p.perp();
 //      err += sqr( ms( pt, cotTheta, PixelRecoPointRZ(0.,zVtx) ) );
 //    }
 
   //
   // simple fit to get pt, phi0 used for precise calcul.
   //
   typedef ConformalMappingFit::PointXY PointXY;
   vector<PointXY> xy; vector<float> errRPhi2;
   for (int i=0; i < nhits; ++i) {
     const GlobalPoint & point = points[i];
     xy.push_back(PointXY( point.x()-region.origin().x(), point.y()-region.origin().y()));
     float phiErr2 = errors[i].phierr(point);
     errRPhi2.push_back( point.perp2()*phiErr2);
   }
   ConformalMappingFit parabola(xy, errRPhi2);
   if (theUseFixImpactParameter) 
     parabola.fixImpactParmaeter(theFixImpactParameter);
   else if (nhits < 3) parabola.fixImpactParmaeter(0.);
  
 
   Measurement1D curv = parabola.curvature();
   float invPt = PixelRecoUtilities::inversePt( curv.value(), setup);
   float valPt =  (invPt > 1.e-4) ? 1./invPt : 1.e4;
   float errPt =PixelRecoUtilities::inversePt(curv.error(), setup) * sqr(valPt);
   Measurement1D pt (valPt,errPt);
   Measurement1D phi = parabola.directionPhi();
   Measurement1D tip = parabola.impactParameter();
 
   //
   // precalculate theta to correct errors:
   //
   vector<float> r(nhits),z(nhits),errZ(nhits);
   float simpleCot = ( points.back().z()-points.front().z() )/ (points.back().perp() - points.front().perp() );
   for (int i=0; i< nhits; ++i) {
     const GlobalPoint & point = points[i]; 
     const GlobalError & error = errors[i];
     r[i] = sqrt( sqr(point.x()-region.origin().x()) + sqr(point.y()-region.origin().y()) );
     r[i] += pixelrecoutilities::LongitudinalBendingCorrection(pt.value(), setup)(r[i]);
     z[i] = point.z()-region.origin().z();  
     errZ[i] =  (isBarrel[i]) ? sqrt(error.czz()) : sqrt( error.rerr(point) )*simpleCot;
   }
 
   //
   // line fit (R-Z plane)
   //
   RZLine rzLine(r,z,errZ);
   
 //
 // parameters for track builder 
 //
   Measurement1D zip(rzLine.intercept(), sqrt(rzLine.covii()));
   Measurement1D cotTheta(rzLine.cotTheta(), sqrt(rzLine.covss()));
   float chi2 = parabola.chi2() +  rzLine.chi2();
   int charge = parabola.charge();
 
 
   PixelTrackBuilder builder;
   return std::unique_ptr<reco::Track>(builder.build(pt, phi, cotTheta, tip, zip, chi2, charge, hits,  theField, region.origin()));
 }