tauImpactParameter::ErrorMatrixPropagator Class Reference

#include <ErrorMatrixPropagator.h>

Public Member Functions
	ErrorMatrixPropagator ()
virtual	~ErrorMatrixPropagator ()

Static Public Member Functions
static TMatrixTSym< double >	propagateError (std::function< TVectorT< double >(const TVectorT< double > &)> f, const TVectorT< double > &inPar, TMatrixTSym< double > &inCov, double epsilon=0.001, double errorEpsilonRatio=1000)

Detailed Description

Definition at line 17 of file ErrorMatrixPropagator.h.

Constructor & Destructor Documentation

tauImpactParameter::ErrorMatrixPropagator::ErrorMatrixPropagator ( )

inline

Definition at line 19 of file ErrorMatrixPropagator.h.

{};

virtual tauImpactParameter::ErrorMatrixPropagator::~ErrorMatrixPropagator ( )

inlinevirtual

Definition at line 20 of file ErrorMatrixPropagator.h.

{};

Member Function Documentation

TMatrixTSym< double > ErrorMatrixPropagator::propagateError ( std::function< TVectorT< double >(const TVectorT< double > &)>  f, const TVectorT< double > &  inPar, TMatrixTSym< double > &  inCov, double  epsilon = 0.001, double  errorEpsilonRatio = 1000  )

static

Definition at line 12 of file ErrorMatrixPropagator.cc.

References CommonMethods::delta(), geometryDiff::epsilon, relativeConstraints::error, validate-o2o-wbm::f, mps_fire::i, dqmiolumiharvest::j, mathSSE::sqrt(), and findQualityFiles::v.

Referenced by tauImpactParameter::ParticleBuilder::createLorentzVectorParticle(), tauImpactParameter::ParticleBuilder::createTrackParticle(), tauImpactParameter::TauA1NuConstrainedFitter::fit(), tauImpactParameter::TauA1NuConstrainedFitter::getMother(), tauImpactParameter::TrackHelixVertexFitter::getMother(), tauImpactParameter::TauA1NuConstrainedFitter::getRefitDaughters(), tauImpactParameter::TrackHelixVertexFitter::getRefitLorentzVectorParticles(), tauImpactParameter::TrackHelixVertexFitter::getRefitTracks(), tauImpactParameter::TauA1NuConstrainedFitter::getTauRotationSignificance(), tauImpactParameter::TrackTools::lorentzParticleAtPosition(), and tauImpactParameter::TauA1NuConstrainedFitter::TauA1NuConstrainedFitter().

                                                                                    {
  TVectorT<double> v = f(inPar);
  TMatrixT<double> Jacobian(inPar.GetNrows(), v.GetNrows());
  for (int i = 0; i < inPar.GetNrows(); i++) {
    TVectorT<double> ParPlusEpsilon = inPar;
    double error = sqrt(fabs(inCov(i, i)));
    double delta = epsilon;
    if (delta * errorEpsilonRatio < error)
      delta = error / errorEpsilonRatio;
    ParPlusEpsilon(i) += delta;
    TVectorT<double> vp = f(ParPlusEpsilon);
    for (int j = 0; j < v.GetNrows(); j++) {
      Jacobian(i, j) = (vp(j) - v(j)) / delta;
    }  // Newtons approx.
  }
  TMatrixTSym<double> newCov = inCov.SimilarityT(Jacobian);
  return newCov;
}