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#include <RecoPixelVertexing/PixelTrackFitting/interface/PixelFitterByConformalMappingAndLine.h>
Public Member Functions | |
| PixelFitterByConformalMappingAndLine () | |
| PixelFitterByConformalMappingAndLine (const edm::ParameterSet &cfg) | |
| virtual reco::Track * | run (const edm::EventSetup &es, const std::vector< const TrackingRecHit * > &hits, const TrackingRegion ®ion) const |
| virtual | ~PixelFitterByConformalMappingAndLine () |
Private Attributes | |
| edm::ParameterSet | theConfig |
Definition at line 12 of file PixelFitterByConformalMappingAndLine.h.
| PixelFitterByConformalMappingAndLine::PixelFitterByConformalMappingAndLine | ( | const edm::ParameterSet & | cfg | ) |
Definition at line 40 of file PixelFitterByConformalMappingAndLine.cc.
00041 : theConfig(cfg) 00042 { }
| PixelFitterByConformalMappingAndLine::PixelFitterByConformalMappingAndLine | ( | ) |
| virtual PixelFitterByConformalMappingAndLine::~PixelFitterByConformalMappingAndLine | ( | ) | [inline, virtual] |
| reco::Track * PixelFitterByConformalMappingAndLine::run | ( | const edm::EventSetup & | es, | |
| const std::vector< const TrackingRecHit * > & | hits, | |||
| const TrackingRegion & | region | |||
| ) | const [virtual] |
Implements PixelFitter.
Definition at line 47 of file PixelFitterByConformalMappingAndLine.cc.
References PixelTrackBuilder::build(), ConformalMappingFit::charge(), RZLine::chi2(), ConformalMappingFit::chi2(), ConformalMappingFit::curvature(), GlobalErrorBase< T, ErrorWeightType >::czz(), ConformalMappingFit::directionPhi(), e4, Measurement1D::error(), error, HLT_VtxMuL3::errors, edm::ParameterSet::exists(), RZLine::fit(), ConformalMappingFit::fixImpactParmaeter(), edm::EventSetup::get(), edm::ParameterSet::getParameter(), i, ConformalMappingFit::impactParameter(), PixelRecoUtilities::inversePt(), TrackingRegion::origin(), PV3DBase< T, PVType, FrameType >::perp2(), phi, edm::ESHandle< T >::product(), r, GlobalErrorBase< T, ErrorWeightType >::rerr(), sqr(), funct::sqrt(), theConfig, tip, Measurement1D::value(), PV3DBase< T, PVType, FrameType >::x(), PV3DBase< T, PVType, FrameType >::y(), PV3DBase< T, PVType, FrameType >::z(), and z.
00051 { 00052 00053 int nhits = hits.size(); 00054 00055 vector<GlobalPoint> points; 00056 vector<GlobalError> errors; 00057 vector<bool> isBarrel; 00058 00059 00060 edm::ESHandle<TrackerGeometry> tracker; 00061 es.get<TrackerDigiGeometryRecord>().get(tracker); 00062 00063 edm::ESHandle<MagneticField> field; 00064 es.get<IdealMagneticFieldRecord>().get(field); 00065 00066 edm::ESHandle<TransientTrackingRecHitBuilder> ttrhBuilder; 00067 string ttrhBuilderName = theConfig.getParameter<std::string>("TTRHBuilder"); 00068 es.get<TransientRecHitRecord>().get( ttrhBuilderName, ttrhBuilder); 00069 00070 for (vector<const TrackingRecHit*>::const_iterator ih=hits.begin(); ih!=hits.end(); ih++) { 00071 TransientTrackingRecHit::RecHitPointer recHit = ttrhBuilder->build(*ih); 00072 points.push_back( recHit->globalPosition() ); 00073 errors.push_back( recHit->globalPositionError() ); 00074 isBarrel.push_back( recHit->detUnit()->type().isBarrel() ); 00075 } 00076 00077 // if (useMultScatt) { 00078 // MultipleScatteringParametrisation ms(hits[i].layer()); 00079 // float cotTheta = (p.z()-zVtx)/p.perp(); 00080 // err += sqr( ms( pt, cotTheta, PixelRecoPointRZ(0.,zVtx) ) ); 00081 // } 00082 00083 // 00084 // simple fit to get pt, phi0 used for precise calcul. 00085 // 00086 typedef ConformalMappingFit::PointXY PointXY; 00087 vector<PointXY> xy; vector<float> errRPhi2; 00088 for (int i=0; i < nhits; ++i) { 00089 const GlobalPoint & point = points[i]; 00090 xy.push_back(PointXY( point.x()-region.origin().x(), point.y()-region.origin().y())); 00091 float phiErr2 = errors[i].phierr(point); 00092 errRPhi2.push_back( point.perp2()*phiErr2); 00093 } 00094 ConformalMappingFit parabola(xy, errRPhi2); 00095 if (theConfig.exists("fixImpactParameter") || nhits < 3) 00096 parabola.fixImpactParmaeter(theConfig.getParameter<double>("fixImpactParameter")); 00097 else if (nhits < 3) { 00098 parabola.fixImpactParmaeter(0.); 00099 } 00100 00101 Measurement1D curv = parabola.curvature(); 00102 float invPt = PixelRecoUtilities::inversePt( curv.value(), es); 00103 float valPt = (invPt > 1.e-4) ? 1./invPt : 1.e4; 00104 float errPt =PixelRecoUtilities::inversePt(curv.error(), es) * sqr(valPt); 00105 Measurement1D pt (valPt,errPt); 00106 Measurement1D phi = parabola.directionPhi(); 00107 Measurement1D tip = parabola.impactParameter(); 00108 00109 // 00110 // precalculate theta to correct errors: 00111 // 00112 vector<float> r(nhits),z(nhits),errZ(nhits); 00113 float simpleCot = ( points.back().z()-points.front().z() )/ (points.back().perp() - points.front().perp() ); 00114 for (int i=0; i< nhits; ++i) { 00115 const GlobalPoint & point = points[i]; 00116 const GlobalError & error = errors[i]; 00117 r[i] = sqrt( sqr(point.x()-region.origin().x()) + sqr(point.y()-region.origin().y()) ); 00118 r[i] += pixelrecoutilities::LongitudinalBendingCorrection(pt.value(),es)(r[i]); 00119 z[i] = point.z(); 00120 errZ[i] = (isBarrel[i]) ? sqrt(error.czz()) : sqrt( error.rerr(point) )*simpleCot; 00121 } 00122 00123 // 00124 // line fit (R-Z plane) 00125 // 00126 RZLine rzLine(r,z,errZ); 00127 float cottheta, intercept, covss, covii, covsi; 00128 rzLine.fit(cottheta, intercept, covss, covii, covsi); 00129 00130 // 00131 // parameters for track builder 00132 // 00133 Measurement1D zip(intercept, sqrt(covii)); 00134 Measurement1D cotTheta(cottheta, sqrt(covss)); 00135 float chi2 = parabola.chi2() + rzLine.chi2(cottheta, intercept); 00136 int charge = parabola.charge(); 00137 00138 00139 PixelTrackBuilder builder; 00140 return builder.build(pt, phi, cotTheta, tip, zip, chi2, charge, hits, field.product()); 00141 }
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