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 delta, geometryDiff::epsilon, relativeConstraints::error, f, i, j, mathSSE::sqrt(), and findQualityFiles::v.

Referenced by tauImpactParameter::TrackTools::lorentzParticleAtPosition().

                                                                                                                                  {
  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;
}