CSCSegFit Class Reference

#include <CSCSegFit.h>

Inheritance diagram for CSCSegFit:

Public Types
typedef std::vector< const CSCRecHit2D * >	CSCSetOfHits
typedef ROOT::Math::SMatrix < double, 12, 4 >	SMatrix12by4
typedef ROOT::Math::SMatrix < double, 4 >	SMatrix4
typedef ROOT::Math::SMatrix < double, 12, 12, ROOT::Math::MatRepSym < double, 12 > >	SMatrixSym12
typedef ROOT::Math::SMatrix < double, 2, 2, ROOT::Math::MatRepSym < double, 2 > >	SMatrixSym2
typedef ROOT::Math::SMatrix < double, 4, 4, ROOT::Math::MatRepSym < double, 4 > >	SMatrixSym4
typedef ROOT::Math::SVector < double, 4 >	SVector4

Public Member Functions
const CSCChamber *	chamber () const
double	chi2 (void) const
AlgebraicSymMatrix	covarianceMatrix (void)
	CSCSegFit (const CSCChamber *csc, CSCSetOfHits hits)
void	fit (void)
bool	fitdone () const
CSCSetOfHits	hits (void) const
LocalPoint	intercept () const
LocalVector	localdir () const
int	ndof (void) const
size_t	nhits (void) const
float	Rdev (float x, float y, float z) const
double	scaleXError (void) const
void	setScaleXError (double factor)
float	xdev (float x, float z) const
float	xfit (float z) const
float	ydev (float y, float z) const
float	yfit (float z) const
virtual	~CSCSegFit ()

Protected Member Functions
SMatrix12by4	derivativeMatrix (void)
AlgebraicSymMatrix	flipErrors (const SMatrixSym4 &)
void	setOutFromIP (void)
SMatrixSym12	weightMatrix (void)

Protected Attributes
const CSCChamber *	chamber_
double	chi2_
bool	fitdone_
CSCSetOfHits	hits_
LocalPoint	intercept_
LocalVector	localdir_
int	ndof_
double	scaleXError_
float	uslope_
float	vslope_

Private Member Functions
void	fit2 (void)
void	fitlsq (void)
void	setChi2 (void)

Detailed Description

Definition at line 30 of file CSCSegFit.h.

Member Typedef Documentation

typedef std::vector<const CSCRecHit2D*> CSCSegFit::CSCSetOfHits

Definition at line 36 of file CSCSegFit.h.

typedef ROOT::Math::SMatrix<double,12,4 > CSCSegFit::SMatrix12by4

Definition at line 42 of file CSCSegFit.h.

typedef ROOT::Math::SMatrix<double, 4 > CSCSegFit::SMatrix4

Definition at line 45 of file CSCSegFit.h.

typedef ROOT::Math::SMatrix<double,12,12,ROOT::Math::MatRepSym<double,12> > CSCSegFit::SMatrixSym12

Definition at line 39 of file CSCSegFit.h.

typedef ROOT::Math::SMatrix<double,2,2,ROOT::Math::MatRepSym<double,2> > CSCSegFit::SMatrixSym2

Definition at line 49 of file CSCSegFit.h.

typedef ROOT::Math::SMatrix<double,4,4,ROOT::Math::MatRepSym<double,4> > CSCSegFit::SMatrixSym4

Definition at line 46 of file CSCSegFit.h.

typedef ROOT::Math::SVector<double,4> CSCSegFit::SVector4

Definition at line 52 of file CSCSegFit.h.

Constructor & Destructor Documentation

CSCSegFit::CSCSegFit ( const CSCChamber *  csc, CSCSetOfHits  hits  )

inline

Definition at line 58 of file CSCSegFit.h.

                                                       : 
  chamber_( csc ), hits_( hits ), scaleXError_( 1.0 ), fitdone_( false ) {}

virtual CSCSegFit::~CSCSegFit ( )

inlinevirtual

Definition at line 61 of file CSCSegFit.h.

{}

Member Function Documentation

const CSCChamber* CSCSegFit::chamber ( ) const

inline

Definition at line 89 of file CSCSegFit.h.

References chamber_.

Referenced by CSCCondSegFit::correctTheCovX(), derivativeMatrix(), CSCCondSegFit::fit(), fit2(), fitlsq(), geometryXMLparser.CSCAlignable::index(), CSCCondSegFit::setChi2(), setChi2(), and setOutFromIP().

{ return chamber_; }

double CSCSegFit::chi2 ( void  ) const

inline

Definition at line 85 of file CSCSegFit.h.

References chi2_.

Referenced by CSCSegAlgoST::buildSegments(), CSCSegAlgoTC::buildSegments(), CSCSegAlgoSK::buildSegments(), CSCSegAlgoDF::buildSegments(), CSCSegAlgoShowering::compareProtoSegment(), CSCSegAlgoTC::compareProtoSegment(), CSCSegAlgoDF::compareProtoSegment(), CSCSegAlgoSK::compareProtoSegment(), CSCSegAlgoTC::increaseProtoSegment(), CSCSegAlgoSK::increaseProtoSegment(), CSCSegAlgoST::prune_bad_hits(), and CSCSegAlgoShowering::showerSeg().

{ return chi2_; }

AlgebraicSymMatrix CSCSegFit::covarianceMatrix

(

void

)

Definition at line 378 of file CSCSegFit.cc.

References HLT_25ns14e33_v1_cff::A, derivativeMatrix(), flipErrors(), convertSQLiteXML::ok, query::result, weightMatrix(), and create_public_pileup_plots::weights.

Referenced by CSCSegAlgoST::buildSegments(), CSCSegAlgoTC::buildSegments(), CSCSegAlgoSK::buildSegments(), CSCSegAlgoDF::buildSegments(), CSCSegAlgoST::prune_bad_hits(), and CSCSegAlgoShowering::showerSeg().

                                               {
  
  SMatrixSym12 weights = weightMatrix();
  SMatrix12by4 A = derivativeMatrix();
  //  LogTrace("CSCSegFit") << "[CSCSegFit::covarianceMatrix] weights matrix W: \n" << weights;      
  //  LogTrace("CSCSegFit") << "[CSCSegFit::covarianceMatrix] derivatives matrix A: \n" << A;      

  // (AT W A)^-1
  // e.g. See http://www.phys.ufl.edu/~avery/fitting.html, part I

  bool ok;
  SMatrixSym4 result =  ROOT::Math::SimilarityT(A, weights);
  //  LogTrace("CSCSegFit") << "[CSCSegFit::covarianceMatrix] (AT W A): \n" << result;      
  ok = result.Invert(); // inverts in place
  if ( !ok ) {
    edm::LogVerbatim("CSCSegment|CSCSegFit") << "[CSCSegFit::calculateError] Failed to invert matrix: \n" << result;      
    //    return ok;  //@@ SHOULD PASS THIS BACK TO CALLER?
  }
  //  LogTrace("CSCSegFit") << "[CSCSegFit::covarianceMatrix] (AT W A)^-1: \n" << result;      
  
  // reorder components to match TrackingRecHit interface (CSCSegment isa TrackingRecHit)
  // i.e. slopes first, then positions 
  AlgebraicSymMatrix flipped = flipErrors( result );
    
  return flipped;
}

CSCSegFit::SMatrix12by4 CSCSegFit::derivativeMatrix ( void  )

protected

Definition at line 331 of file CSCSegFit.cc.

References chamber(), CSCRecHit2D::cscDetId(), hits_, CSCChamber::layer(), CSCDetId::layer(), CSCRecHit2D::localPosition(), makeMuonMisalignmentScenario::matrix, GeomDet::toGlobal(), GeomDet::toLocal(), z, and PV3DBase< T, PVType, FrameType >::z().

Referenced by covarianceMatrix().

                                                  {
  
  SMatrix12by4 matrix; // 12x4, init to 0
  int row = 0;
  
  for( CSCSetOfHits::const_iterator it = hits_.begin(); it != hits_.end(); ++it) {
    
    const CSCRecHit2D& hit = (**it);
    const CSCLayer* layer = chamber()->layer(hit.cscDetId().layer());
    GlobalPoint gp = layer->toGlobal(hit.localPosition());      
    LocalPoint lp = chamber()->toLocal(gp); 
    float z = lp.z();

    matrix(row, 0) = 1.;
    matrix(row, 2) = z;
    ++row;
    matrix(row, 1) = 1.;
    matrix(row, 3) = z;
    ++row;
  }
  return matrix;
}

void CSCSegFit::fit

(

void

)

Definition at line 14 of file CSCSegFit.cc.

References fit2(), fitdone(), fitlsq(), gen::n, and nhits().

Referenced by CSCSegAlgoShowering::compareProtoSegment(), CSCSegAlgoDF::compareProtoSegment(), CSCSegAlgoShowering::updateParameters(), CSCSegAlgoDF::updateParameters(), CSCSegAlgoSK::updateParameters(), and CSCSegAlgoTC::updateParameters().

                        {
  if ( fitdone() ) return; // don't redo fit unnecessarily
  short n = nhits();
  switch ( n ) {
  case 1:
    edm::LogVerbatim("CSCSegFit") << "[CSCSegFit::fit] - cannot fit just 1 hit!!";
    break;
  case 2:
    fit2();
    break;
  case 3:
  case 4:
  case 5:
  case 6:
    fitlsq();
    break;
  default:
    edm::LogVerbatim("CSCSegFit") << "[CSCSegFit::fit] - cannot fit more than 6 hits!!";
  }  
}

void CSCSegFit::fit2 ( void  )

private

Definition at line 35 of file CSCSegFit.cc.

References chamber(), chi2_, CSCRecHit2D::cscDetId(), fitdone_, hits_, intercept_, CSCChamber::layer(), CSCDetId::layer(), CSCRecHit2D::localPosition(), ndof_, setOutFromIP(), GeomDet::toGlobal(), GeomDet::toLocal(), uslope_, vslope_, PV3DBase< T, PVType, FrameType >::x(), PV3DBase< T, PVType, FrameType >::y(), and PV3DBase< T, PVType, FrameType >::z().

Referenced by fit().

                         {

  // Just join the two points
  // Equation of straight line between (x1, y1) and (x2, y2) in xy-plane is
  //       y = mx + c
  // with m = (y2-y1)/(x2-x1)
  // and  c = (y1*x2-x2*y1)/(x2-x1)

  CSCSetOfHits::const_iterator ih = hits_.begin();
  int il1 = (*ih)->cscDetId().layer();
  const CSCRecHit2D& h1 = (**ih);
  ++ih;    
  int il2 = (*ih)->cscDetId().layer();
  const CSCRecHit2D& h2 = (**ih);
    
  // Skip if on same layer, but should be impossible :)
  if (il1 == il2) {
    edm::LogVerbatim("CSCSegFit") << "[CSCSegFit:fit]2 - 2 hits on same layer!!";
    return;
  }
    
  const CSCLayer* layer1 = chamber()->layer(il1);
  const CSCLayer* layer2 = chamber()->layer(il2);
    
  GlobalPoint h1glopos = layer1->toGlobal(h1.localPosition());
  GlobalPoint h2glopos = layer2->toGlobal(h2.localPosition());
    
  // We want hit wrt chamber (and local z will be != 0)
  LocalPoint h1pos = chamber()->toLocal(h1glopos);  
  LocalPoint h2pos = chamber()->toLocal(h2glopos);  
    
  float dz = h2pos.z()-h1pos.z();

  uslope_ = ( h2pos.x() - h1pos.x() ) / dz ;
  vslope_ = ( h2pos.y() - h1pos.y() ) / dz ;

  float uintercept = ( h1pos.x()*h2pos.z() - h2pos.x()*h1pos.z() ) / dz;
  float vintercept = ( h1pos.y()*h2pos.z() - h2pos.y()*h1pos.z() ) / dz;
  intercept_ = LocalPoint( uintercept, vintercept, 0.);

  setOutFromIP();

  //@@ NOT SURE WHAT IS SENSIBLE FOR THESE...
  chi2_ = 0.;
  ndof_ = 0;

  fitdone_ = true;
}

bool CSCSegFit::fitdone ( ) const

inline

Definition at line 90 of file CSCSegFit.h.

References fitdone_.

Referenced by fit().

{ return fitdone_; }

void CSCSegFit::fitlsq ( void  )

private

Definition at line 85 of file CSCSegFit.cc.

References chamber(), CSCRecHit2D::cscDetId(), fitdone_, hits_, intercept_, CSCChamber::layer(), CSCDetId::layer(), CSCRecHit2D::localPosition(), CSCRecHit2D::localPositionError(), convertSQLiteXML::ok, AlCaHLTBitMon_ParallelJobs::p, setChi2(), setOutFromIP(), GeomDet::toGlobal(), GeomDet::toLocal(), uslope_, findQualityFiles::v, vslope_, PV3DBase< T, PVType, FrameType >::x(), LocalError::xx(), LocalError::xy(), PV3DBase< T, PVType, FrameType >::y(), LocalError::yy(), z, and PV3DBase< T, PVType, FrameType >::z().

Referenced by fit().

                           {
  
  // Linear least-squares fit to up to 6 CSC rechits, one per layer in a CSC.
  // Comments adapted from  mine in original  CSCSegAlgoSK algorithm.
  
  // Fit to the local x, y rechit coordinates in z projection
  // The strip measurement controls the precision of x
  // The wire measurement controls the precision of y.
  // Typical precision: u (strip, sigma~200um), v (wire, sigma~1cm)
  
  // Set up the normal equations for the least-squares fit as a matrix equation
  
  // We have a vector of measurements m, which is a 2n x 1 dim matrix
  // The transpose mT is (u1, v1, u2, v2, ..., un, vn) where
  // ui is the strip-associated measurement and 
  // vi is the wire-associated measurement 
  // for a given rechit i.
  
  // The fit is to
  // u = u0 + uz * z
  // v = v0 + vz * z
  // where u0, uz, v0, vz are the parameters to be obtained from the fit.
  
  // These are contained in a vector p which is a 4x1 dim matrix, and
  // its transpose pT is (u0, v0, uz, vz). Note the ordering!
  
  // The covariance matrix for each pair of measurements is 2 x 2 and
  // the inverse of this is the error matrix E.
  // The error matrix for the whole set of n measurements is a diagonal
  // matrix with diagonal elements the individual 2 x 2 error matrices
  // (because the inverse of a diagonal matrix is a diagonal matrix
  // with each element the inverse of the original.)
  
  // In function 'weightMatrix()', the variable 'matrix' is filled with this
  // block-diagonal overall covariance matrix. Then 'matrix' is inverted to the 
  // block-diagonal error matrix, and returned.
  
  // Define the matrix A as
  //    1   0   z1  0
  //    0   1   0   z1
  //    1   0   z2  0
  //    0   1   0   z2
  //    ..  ..  ..  ..
  //    1   0   zn  0
  //    0   1   0   zn
  
  // This matrix A is set up and returned by function 'derivativeMatrix()'.
  
  // Then the normal equations are described by the matrix equation
  //
  //    (AT E A)p = (AT E)m
  //
  // where AT is the transpose of A.
  
  // Call the combined matrix on the LHS, M, and that on the RHS, B:
  //     M p = B
  
  // We solve this for the parameter vector, p.
  // The elements of M and B then involve sums over the hits
  
  // The covariance matrix of the parameters is obtained by 
  // (AT E A)^-1 calculated in 'covarianceMatrix()'.
  

  // NOTE
  // We need local position of a RecHit w.r.t. the CHAMBER
  // and the RecHit itself only knows its local position w.r.t.
  // the LAYER, so we must explicitly transform global position.
  

  SMatrix4 M; // 4x4, init to 0
  SVector4 B; // 4x1, init to 0; 

  CSCSetOfHits::const_iterator ih = hits_.begin();
  
  for (ih = hits_.begin(); ih != hits_.end(); ++ih) {
    const CSCRecHit2D& hit = (**ih);
    const CSCLayer* layer  = chamber()->layer(hit.cscDetId().layer());
    GlobalPoint gp         = layer->toGlobal(hit.localPosition());
    LocalPoint  lp         = chamber()->toLocal(gp); 
    
    // Local position of hit w.r.t. chamber
    double u = lp.x();
    double v = lp.y();
    double z = lp.z();
    
    // Covariance matrix of local errors 
    SMatrixSym2 IC; // 2x2, init to 0
    
    IC(0,0) = hit.localPositionError().xx();
    IC(1,1) = hit.localPositionError().yy();
    //@@ NOT SURE WHICH OFF-DIAGONAL ELEMENT MUST BE DEFINED BUT (1,0) WORKS
    //@@ (and SMatrix enforces symmetry)
    IC(1,0) = hit.localPositionError().xy();
    // IC(0,1) = IC(1,0);
    
    // Invert covariance matrix (and trap if it fails!)
    bool ok = IC.Invert();
    if ( !ok ) {
      edm::LogVerbatim("CSCSegment|CSCSegFit") << "[CSCSegFit::fit] Failed to invert covariance matrix: \n" << IC;      
      //      return ok;  //@@ SHOULD PASS THIS BACK TO CALLER?
    }

    M(0,0) += IC(0,0);
    M(0,1) += IC(0,1);
    M(0,2) += IC(0,0) * z;
    M(0,3) += IC(0,1) * z;
    B(0)   += u * IC(0,0) + v * IC(0,1);
 
    M(1,0) += IC(1,0);
    M(1,1) += IC(1,1);
    M(1,2) += IC(1,0) * z;
    M(1,3) += IC(1,1) * z;
    B(1)   += u * IC(1,0) + v * IC(1,1);
 
    M(2,0) += IC(0,0) * z;
    M(2,1) += IC(0,1) * z;
    M(2,2) += IC(0,0) * z * z;
    M(2,3) += IC(0,1) * z * z;
    B(2)   += ( u * IC(0,0) + v * IC(0,1) ) * z;
 
    M(3,0) += IC(1,0) * z;
    M(3,1) += IC(1,1) * z;
    M(3,2) += IC(1,0) * z * z;
    M(3,3) += IC(1,1) * z * z;
    B(3)   += ( u * IC(1,0) + v * IC(1,1) ) * z;

  }

  SVector4 p;
  bool ok = M.Invert();
  if (!ok ){
    edm::LogVerbatim("CSCSegment|CSCSegFit") << "[CSCSegFit::fit] Failed to invert matrix: \n" << M;
    //    return ok; //@@ SHOULD PASS THIS BACK TO CALLER?
  }
  else {
    p = M * B;
  }

  //  LogTrace("CSCSegFit") << "[CSCSegFit::fit] p = " 
  //        << p(0) << ", " << p(1) << ", " << p(2) << ", " << p(3);
  
  // fill member variables  (note origin has local z = 0)
  //  intercept_
  intercept_ = LocalPoint(p(0), p(1), 0.);
  
  // localdir_ - set so segment points outwards from IP
  uslope_ = p(2);
  vslope_ = p(3);
  setOutFromIP();
  
  // calculate chi2 of fit
  setChi2( );

  // flag fit has been done
  fitdone_ = true;

}

AlgebraicSymMatrix CSCSegFit::flipErrors ( const SMatrixSym4 &  a )

protected

Definition at line 406 of file CSCSegFit.cc.

References a, i, and j.

Referenced by covarianceMatrix().

                                                               { 
    
  // The CSCSegment needs the error matrix re-arranged to match
  // parameters in order (uz, vz, u0, v0) 
  // where uz, vz = slopes, u0, v0 = intercepts
    
  //  LogTrace("CSCSegFit") << "[CSCSegFit::flipErrors] input: \n" << a;      

  AlgebraicSymMatrix hold(4, 0. ); 
      
  for ( short j=0; j!=4; ++j) {
    for (short i=0; i!=4; ++i) {
      hold(i+1,j+1) = a(i,j); // SMatrix counts from 0, AlgebraicMatrix from 1
    }
  }

  //  LogTrace("CSCSegFit") << "[CSCSegFit::flipErrors] after copy:";
  //  LogTrace("CSCSegFit") << "(" << hold(1,1) << "  " << hold(1,2) << "  " << hold(1,3) << "  " << hold(1,4);
  //  LogTrace("CSCSegFit") << " " << hold(2,1) << "  " << hold(2,2) << "  " << hold(2,3) << "  " << hold(2,4);
  //  LogTrace("CSCSegFit") << " " << hold(3,1) << "  " << hold(3,2) << "  " << hold(3,3) << "  " << hold(3,4);
  //  LogTrace("CSCSegFit") << " " << hold(4,1) << "  " << hold(4,2) << "  " << hold(4,3) << "  " << hold(4,4) << ")";

  // errors on slopes into upper left 
  hold(1,1) = a(2,2); 
  hold(1,2) = a(2,3); 
  hold(2,1) = a(3,2); 
  hold(2,2) = a(3,3); 
    
  // errors on positions into lower right 
  hold(3,3) = a(0,0); 
  hold(3,4) = a(0,1); 
  hold(4,3) = a(1,0); 
  hold(4,4) = a(1,1); 
    
  // must also interchange off-diagonal elements of off-diagonal 2x2 submatrices
  hold(4,1) = a(1,2);
  hold(3,2) = a(0,3);
  hold(2,3) = a(3,0); // = a(0,3)
  hold(1,4) = a(2,1); // = a(1,2)

  //  LogTrace("CSCSegFit") << "[CSCSegFit::flipErrors] after flip:";
  //  LogTrace("CSCSegFit") << "(" << hold(1,1) << "  " << hold(1,2) << "  " << hold(1,3) << "  " << hold(1,4);
  //  LogTrace("CSCSegFit") << " " << hold(2,1) << "  " << hold(2,2) << "  " << hold(2,3) << "  " << hold(2,4);
  //  LogTrace("CSCSegFit") << " " << hold(3,1) << "  " << hold(3,2) << "  " << hold(3,3) << "  " << hold(3,4);
  //  LogTrace("CSCSegFit") << " " << hold(4,1) << "  " << hold(4,2) << "  " << hold(4,3) << "  " << hold(4,4) << ")";

  return hold;
}

CSCSetOfHits CSCSegFit::hits ( void  ) const

inline

Definition at line 82 of file CSCSegFit.h.

References hits_.

Referenced by CSCSegAlgoTC::buildSegments(), CSCSegAlgoSK::buildSegments(), CSCSegAlgoDF::buildSegments(), and CSCSegAlgoShowering::showerSeg().

{ return hits_; }

LocalPoint CSCSegFit::intercept ( ) const

inline

Definition at line 87 of file CSCSegFit.h.

References intercept_.

Referenced by CSCSegAlgoST::buildSegments(), CSCSegAlgoTC::buildSegments(), CSCSegAlgoSK::buildSegments(), CSCSegAlgoDF::buildSegments(), CSCSegAlgoSK::phiAtZ(), CSCSegAlgoTC::phiAtZ(), CSCSegAlgoST::prune_bad_hits(), and CSCSegAlgoShowering::showerSeg().

{ return intercept_;}

LocalVector CSCSegFit::localdir ( ) const

inline

Definition at line 88 of file CSCSegFit.h.

References localdir_.

Referenced by CSCSegAlgoST::buildSegments(), CSCSegAlgoTC::buildSegments(), CSCSegAlgoSK::buildSegments(), CSCSegAlgoDF::buildSegments(), CSCSegAlgoSK::phiAtZ(), CSCSegAlgoTC::phiAtZ(), CSCSegAlgoST::prune_bad_hits(), and CSCSegAlgoShowering::showerSeg().

{ return localdir_;}

int CSCSegFit::ndof ( void  ) const

inline

Definition at line 86 of file CSCSegFit.h.

References ndof_.

Referenced by CSCSegAlgoST::buildSegments(), CSCSegAlgoTC::increaseProtoSegment(), CSCSegAlgoSK::increaseProtoSegment(), and CSCSegAlgoST::prune_bad_hits().

{ return ndof_; }

size_t CSCSegFit::nhits ( void  ) const

inline

Definition at line 84 of file CSCSegFit.h.

References hits_.

Referenced by CSCSegAlgoST::buildSegments(), fit(), and CSCSegAlgoShowering::showerSeg().

{ return hits_.size(); }

float CSCSegFit::Rdev	(	float	x,
		float	y,
		float	z
	)		const

Definition at line 473 of file CSCSegFit.cc.

References mathSSE::sqrt(), xdev(), and ydev().

Referenced by CSCSegAlgoShowering::pruneFromResidual(), and CSCSegAlgoDF::pruneFromResidual().

                                                     {
  return sqrt ( xdev(x,z)*xdev(x,z) + ydev(y,z)*ydev(y,z) );
}

double CSCSegFit::scaleXError ( void  ) const

inline

Definition at line 83 of file CSCSegFit.h.

References scaleXError_.

Referenced by CSCSegAlgoST::buildSegments(), CSCSegAlgoST::prune_bad_hits(), and weightMatrix().

{ return scaleXError_; }

void CSCSegFit::setChi2 ( void  )

private

Definition at line 246 of file CSCSegFit.cc.

References chamber(), chi2_, CSCRecHit2D::cscDetId(), hits_, intercept_, CSCChamber::layer(), CSCDetId::layer(), CSCRecHit2D::localPosition(), CSCRecHit2D::localPositionError(), ndof_, convertSQLiteXML::ok, GeomDet::toGlobal(), GeomDet::toLocal(), uslope_, findQualityFiles::v, vslope_, PV3DBase< T, PVType, FrameType >::x(), LocalError::xx(), LocalError::xy(), PV3DBase< T, PVType, FrameType >::y(), LocalError::yy(), z, and PV3DBase< T, PVType, FrameType >::z().

Referenced by CSCCondSegFit::fit(), and fitlsq().

                            {
  
  double chsq = 0.;

  CSCSetOfHits::const_iterator ih;
  for (ih = hits_.begin(); ih != hits_.end(); ++ih) {

    const CSCRecHit2D& hit = (**ih);
    const CSCLayer* layer  = chamber()->layer(hit.cscDetId().layer());
    GlobalPoint gp         = layer->toGlobal(hit.localPosition());
    LocalPoint lp          = chamber()->toLocal(gp);
    
    double u = lp.x();
    double v = lp.y();
    double z = lp.z();
    
    double du = intercept_.x() + uslope_ * z - u;
    double dv = intercept_.y() + vslope_ * z - v;
    
    //    LogTrace("CSCSegFit") << "[CSCSegFit::setChi2] u, v, z = " << u << ", " << v << ", " << z;

    SMatrixSym2 IC; // 2x2, init to 0

    IC(0,0) = hit.localPositionError().xx();
    //    IC(0,1) = hit.localPositionError().xy();
    IC(1,0) = hit.localPositionError().xy();
    IC(1,1) = hit.localPositionError().yy();
    //    IC(1,0) = IC(0,1);

    //    LogTrace("CSCSegFit") << "[CSCSegFit::setChi2] IC before = \n" << IC;

    // Invert covariance matrix
    bool ok = IC.Invert();
    if (!ok ){
      edm::LogVerbatim("CSCSegment|CSCSegFit") << "[CSCSegFit::setChi2] Failed to invert covariance matrix: \n" << IC;
      //      return ok;
    }
    //    LogTrace("CSCSegFit") << "[CSCSegFit::setChi2] IC after = \n" << IC;
    chsq += du*du*IC(0,0) + 2.*du*dv*IC(0,1) + dv*dv*IC(1,1);
  }
  
  // fill member variables
  chi2_ = chsq;
  ndof_ = 2.*hits_.size() - 4;

  //  LogTrace("CSCSegFit") << "[CSCSegFit::setChi2] chi2 = " << chi2_ << "/" << ndof_ << " dof";

}

void CSCSegFit::setOutFromIP ( void  )

protected

Definition at line 355 of file CSCSegFit.cc.

References chamber(), intercept_, localdir_, mathSSE::sqrt(), GeomDet::toGlobal(), csvLumiCalc::unit, uslope_, vslope_, and z.

Referenced by CSCCondSegFit::fit(), fit2(), and fitlsq().

                             {
  // Set direction of segment to point from IP outwards
  // (Incorrect for particles not coming from IP, of course.)
  
  double dxdz = uslope_;
  double dydz = vslope_;
  double dz   = 1./sqrt(1. + dxdz*dxdz + dydz*dydz);
  double dx   = dz*dxdz;
  double dy   = dz*dydz;
  LocalVector localDir(dx,dy,dz);

  // localDir sometimes needs a sign flip 
  // Examine its direction and origin in global z: to point outward
  // the localDir should always have same sign as global z...
  
  double globalZpos    = ( chamber()->toGlobal( intercept_ ) ).z();
  double globalZdir    = ( chamber()->toGlobal( localDir  ) ).z();
  double directionSign = globalZpos * globalZdir;
  localdir_ = (directionSign * localDir ).unit();
}

void CSCSegFit::setScaleXError ( double  factor )

inline

Definition at line 70 of file CSCSegFit.h.

References scaleXError_.

Referenced by CSCSegAlgoST::buildSegments(), CSCCondSegFit::correctTheCovX(), and CSCSegAlgoST::prune_bad_hits().

{ scaleXError_ = factor; }

CSCSegFit::SMatrixSym12 CSCSegFit::weightMatrix ( void  )

protected

Definition at line 298 of file CSCSegFit.cc.

References hits_, CSCRecHit2D::localPositionError(), makeMuonMisalignmentScenario::matrix, convertSQLiteXML::ok, scaleXError(), LocalError::xx(), LocalError::xy(), and LocalError::yy().

Referenced by covarianceMatrix().

                                              {
  
  bool ok = true;

  SMatrixSym12 matrix = ROOT::Math::SMatrixIdentity(); // 12x12, init to 1's on diag

  int row = 0;
  
  for (CSCSetOfHits::const_iterator it = hits_.begin(); it != hits_.end(); ++it) {
    
    const CSCRecHit2D& hit = (**it);

// Note scaleXError allows rescaling the x error if necessary

    matrix(row, row)   = scaleXError()*hit.localPositionError().xx();
    matrix(row, row+1) = hit.localPositionError().xy();
    ++row;
    matrix(row, row-1) = hit.localPositionError().xy();
    matrix(row, row)   = hit.localPositionError().yy();
    ++row;
  }

  ok = matrix.Invert(); // invert in place
  if ( !ok ) {
    edm::LogVerbatim("CSCSegment|CSCSegFit") << "[CSCSegFit::weightMatrix] Failed to invert matrix: \n" << matrix;      
    //    return ok; //@@ SHOULD PASS THIS BACK TO CALLER?
  }
  return matrix;
}

float CSCSegFit::xdev	(	float	x,
		float	z
	)		const

Definition at line 465 of file CSCSegFit.cc.

References intercept_, uslope_, x, and PV3DBase< T, PVType, FrameType >::x().

Referenced by Rdev().

                                              {
  return intercept_.x() + uslope_ * z - x;
}

float CSCSegFit::xfit

(

float

z

)

const

Definition at line 455 of file CSCSegFit.cc.

References intercept_, uslope_, PV3DBase< T, PVType, FrameType >::x(), and z.

Referenced by CSCSegAlgoShowering::isHitNearSegment(), and CSCSegAlgoDF::isHitNearSegment().

                                     {
  //@@ ADD THIS TO EACH ACCESSOR OF FIT RESULTS?
  //  if ( !fitdone() ) fit();
  return intercept_.x() + uslope_ * z;
}

float CSCSegFit::ydev	(	float	y,
		float	z
	)		const

Definition at line 469 of file CSCSegFit.cc.

References intercept_, vslope_, y, and PV3DBase< T, PVType, FrameType >::y().

Referenced by Rdev().

                                              {
  return intercept_.y() + vslope_ * z - y;
}

float CSCSegFit::yfit

(

float

z

)

const

Definition at line 461 of file CSCSegFit.cc.

References intercept_, vslope_, PV3DBase< T, PVType, FrameType >::y(), and z.

Referenced by CSCSegAlgoShowering::isHitNearSegment(), and CSCSegAlgoDF::isHitNearSegment().

                                     {
  return intercept_.y() + vslope_ * z;
}

Member Data Documentation

const CSCChamber* CSCSegFit::chamber_

protected

Definition at line 114 of file CSCSegFit.h.

Referenced by chamber().

double CSCSegFit::chi2_

protected

Definition at line 120 of file CSCSegFit.h.

Referenced by chi2(), fit2(), CSCCondSegFit::setChi2(), and setChi2().

bool CSCSegFit::fitdone_

protected

Definition at line 123 of file CSCSegFit.h.

Referenced by fit2(), fitdone(), and fitlsq().

CSCSetOfHits CSCSegFit::hits_

protected

Definition at line 115 of file CSCSegFit.h.

Referenced by CSCCondSegFit::correctTheCovX(), derivativeMatrix(), CSCCondSegFit::fit(), fit2(), fitlsq(), hits(), nhits(), CSCCondSegFit::setChi2(), setChi2(), and weightMatrix().

LocalPoint CSCSegFit::intercept_

protected

Definition at line 118 of file CSCSegFit.h.

Referenced by CSCCondSegFit::fit(), fit2(), fitlsq(), intercept(), CSCCondSegFit::setChi2(), setChi2(), setOutFromIP(), xdev(), xfit(), ydev(), and yfit().

LocalVector CSCSegFit::localdir_

protected

Definition at line 119 of file CSCSegFit.h.

Referenced by localdir(), and setOutFromIP().

int CSCSegFit::ndof_

protected

Definition at line 121 of file CSCSegFit.h.

Referenced by fit2(), ndof(), CSCCondSegFit::setChi2(), and setChi2().

double CSCSegFit::scaleXError_

protected

Definition at line 122 of file CSCSegFit.h.

Referenced by scaleXError(), and setScaleXError().

float CSCSegFit::uslope_

protected

Definition at line 116 of file CSCSegFit.h.

Referenced by CSCCondSegFit::fit(), fit2(), fitlsq(), CSCCondSegFit::setChi2(), setChi2(), setOutFromIP(), xdev(), and xfit().

float CSCSegFit::vslope_

protected

Definition at line 117 of file CSCSegFit.h.

Referenced by CSCCondSegFit::fit(), fit2(), fitlsq(), CSCCondSegFit::setChi2(), setChi2(), setOutFromIP(), ydev(), and yfit().