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#include <CSCSegAlgoHitPruning.h>
Public Types | |
| typedef std::vector< const CSCRecHit2D * > | ChamberHitContainer |
Public Member Functions | |
| CSCSegAlgoHitPruning (const edm::ParameterSet &ps) | |
| constructor | |
| std::vector< CSCSegment > | pruneBadHits (const CSCChamber *aChamber, std::vector< CSCSegment > segments) |
| clusterize | |
| ~CSCSegAlgoHitPruning () | |
| destructor | |
Private Member Functions | |
| AlgebraicSymMatrix | calculateError (void) const |
| CLHEP::HepMatrix | derivativeMatrix (void) const |
| void | fillChiSquared (void) |
| void | fillLocalDirection (void) |
| void | fitSlopes (void) |
| void | flipErrors (AlgebraicSymMatrix &) const |
| AlgebraicSymMatrix | weightMatrix (void) const |
Private Attributes | |
| bool | BrutePruning |
| double | protoChi2 |
| LocalVector | protoDirection |
| LocalPoint | protoIntercept |
| ChamberHitContainer | protoSegment |
| float | protoSlope_u |
| float | protoSlope_v |
| const CSCChamber * | theChamber |
Definition at line 23 of file CSCSegAlgoHitPruning.h.
| typedef std::vector<const CSCRecHit2D*> CSCSegAlgoHitPruning::ChamberHitContainer |
Definition at line 27 of file CSCSegAlgoHitPruning.h.
| CSCSegAlgoHitPruning::CSCSegAlgoHitPruning | ( | const edm::ParameterSet & | ps | ) | [explicit] |
constructor
Definition at line 32 of file CSCSegAlgoHitPruning.cc.
References BrutePruning, and edm::ParameterSet::getParameter().
{
BrutePruning = ps.getParameter<bool>("BrutePruning");
}
| CSCSegAlgoHitPruning::~CSCSegAlgoHitPruning | ( | ) |
| AlgebraicSymMatrix CSCSegAlgoHitPruning::calculateError | ( | void | ) | const [private] |
Definition at line 421 of file CSCSegAlgoHitPruning.cc.
References funct::A, derivativeMatrix(), query::result, and weightMatrix().
Referenced by pruneBadHits().
{
AlgebraicSymMatrix weights = weightMatrix();
AlgebraicMatrix A = derivativeMatrix();
// (AT W A)^-1
// from https://www.phys.ufl.edu/~avery/fitting.html, part I
int ierr;
AlgebraicSymMatrix result = weights.similarityT(A);
result.invert(ierr);
// blithely assuming the inverting never fails...
return result;
}
| CLHEP::HepMatrix CSCSegAlgoHitPruning::derivativeMatrix | ( | void | ) | const [private] |
Definition at line 393 of file CSCSegAlgoHitPruning.cc.
References CSCRecHit2D::cscDetId(), CSCDetId::layer(), CSCChamber::layer(), CSCRecHit2D::localPosition(), protoSegment, theChamber, GeomDet::toGlobal(), GeomDet::toLocal(), PV3DBase< T, PVType, FrameType >::z(), and z.
Referenced by calculateError().
{
ChamberHitContainer::const_iterator it;
int nhits = protoSegment.size();
CLHEP::HepMatrix matrix(2*nhits, 4);
int row = 0;
for(it = protoSegment.begin(); it != protoSegment.end(); ++it) {
const CSCRecHit2D& hit = (**it);
const CSCLayer* layer = theChamber->layer(hit.cscDetId().layer());
GlobalPoint gp = layer->toGlobal(hit.localPosition());
LocalPoint lp = theChamber->toLocal(gp);
float z = lp.z();
++row;
matrix(row, 1) = 1.;
matrix(row, 3) = z;
++row;
matrix(row, 2) = 1.;
matrix(row, 4) = z;
}
return matrix;
}
| void CSCSegAlgoHitPruning::fillChiSquared | ( | void | ) | [private] |
Definition at line 298 of file CSCSegAlgoHitPruning.cc.
References CSCRecHit2D::cscDetId(), CSCDetId::layer(), CSCChamber::layer(), CSCRecHit2D::localPosition(), CSCRecHit2D::localPositionError(), LogDebug, protoChi2, protoIntercept, protoSegment, protoSlope_u, protoSlope_v, theChamber, GeomDet::toGlobal(), GeomDet::toLocal(), v, PV3DBase< T, PVType, FrameType >::x(), LocalError::xx(), LocalError::xy(), PV3DBase< T, PVType, FrameType >::y(), LocalError::yy(), PV3DBase< T, PVType, FrameType >::z(), and z.
Referenced by pruneBadHits().
{
double chsq = 0.;
ChamberHitContainer::const_iterator ih;
for (ih = protoSegment.begin(); ih != protoSegment.end(); ++ih) {
const CSCRecHit2D& hit = (**ih);
const CSCLayer* layer = theChamber->layer(hit.cscDetId().layer());
GlobalPoint gp = layer->toGlobal(hit.localPosition());
LocalPoint lp = theChamber->toLocal(gp);
double u = lp.x();
double v = lp.y();
double z = lp.z();
double du = protoIntercept.x() + protoSlope_u * z - u;
double dv = protoIntercept.y() + protoSlope_v * z - v;
CLHEP::HepMatrix IC(2,2);
IC(1,1) = hit.localPositionError().xx();
IC(1,2) = hit.localPositionError().xy();
IC(2,2) = hit.localPositionError().yy();
IC(2,1) = IC(1,2);
// Invert covariance matrix
int ierr = 0;
IC.invert(ierr);
if (ierr != 0) {
LogDebug("CSC") << "CSCSegment::fillChiSquared: failed to invert covariance matrix=\n" << IC << "\n";
// std::cout << "CSCSegment::fillChiSquared: failed to invert covariance matrix=\n" << IC << "\n";
}
chsq += du*du*IC(1,1) + 2.*du*dv*IC(1,2) + dv*dv*IC(2,2);
}
protoChi2 = chsq;
}
| void CSCSegAlgoHitPruning::fillLocalDirection | ( | void | ) | [private] |
Definition at line 342 of file CSCSegAlgoHitPruning.cc.
References protoDirection, protoIntercept, protoSlope_u, protoSlope_v, mathSSE::sqrt(), theChamber, GeomDet::toGlobal(), csvLumiCalc::unit, and z.
Referenced by pruneBadHits().
{
// Always enforce direction of segment to point from IP outwards
// (Incorrect for particles not coming from IP, of course.)
double dxdz = protoSlope_u;
double dydz = protoSlope_v;
double dz = 1./sqrt(1. + dxdz*dxdz + dydz*dydz);
double dx = dz*dxdz;
double dy = dz*dydz;
LocalVector localDir(dx,dy,dz);
// localDir may need sign flip to ensure it points outward from IP
// ptc: Examine its direction and origin in global z: to point outward
// the localDir should always have same sign as global z...
double globalZpos = ( theChamber->toGlobal( protoIntercept ) ).z();
double globalZdir = ( theChamber->toGlobal( localDir ) ).z();
double directionSign = globalZpos * globalZdir;
protoDirection = (directionSign * localDir).unit();
}
| void CSCSegAlgoHitPruning::fitSlopes | ( | void | ) | [private] |
Definition at line 232 of file CSCSegAlgoHitPruning.cc.
References CSCRecHit2D::cscDetId(), CSCDetId::layer(), CSCChamber::layer(), CSCRecHit2D::localPosition(), CSCRecHit2D::localPositionError(), LogDebug, L1TEmulatorMonitor_cff::p, protoIntercept, protoSegment, protoSlope_u, protoSlope_v, theChamber, GeomDet::toGlobal(), GeomDet::toLocal(), v, PV3DBase< T, PVType, FrameType >::x(), LocalError::xx(), LocalError::xy(), PV3DBase< T, PVType, FrameType >::y(), LocalError::yy(), PV3DBase< T, PVType, FrameType >::z(), and z.
Referenced by pruneBadHits().
{
CLHEP::HepMatrix M(4,4,0);
CLHEP::HepVector B(4,0);
ChamberHitContainer::const_iterator ih = protoSegment.begin();
for (ih = protoSegment.begin(); ih != protoSegment.end(); ++ih) {
const CSCRecHit2D& hit = (**ih);
const CSCLayer* layer = theChamber->layer(hit.cscDetId().layer());
GlobalPoint gp = layer->toGlobal(hit.localPosition());
LocalPoint lp = theChamber->toLocal(gp);
// ptc: Local position of hit w.r.t. chamber
double u = lp.x();
double v = lp.y();
double z = lp.z();
// ptc: Covariance matrix of local errors
CLHEP::HepMatrix IC(2,2);
IC(1,1) = hit.localPositionError().xx();
IC(1,2) = hit.localPositionError().xy();
IC(2,2) = hit.localPositionError().yy();
IC(2,1) = IC(1,2); // since Cov is symmetric
// ptc: Invert covariance matrix (and trap if it fails!)
int ierr = 0;
IC.invert(ierr); // inverts in place
if (ierr != 0) {
LogDebug("CSC") << "CSCSegment::fitSlopes: failed to invert covariance matrix=\n" << IC << "\n";
// std::cout<< "CSCSegment::fitSlopes: failed to invert covariance matrix=\n" << IC << "\n"<<std::endl;
}
M(1,1) += IC(1,1);
M(1,2) += IC(1,2);
M(1,3) += IC(1,1) * z;
M(1,4) += IC(1,2) * z;
B(1) += u * IC(1,1) + v * IC(1,2);
M(2,1) += IC(2,1);
M(2,2) += IC(2,2);
M(2,3) += IC(2,1) * z;
M(2,4) += IC(2,2) * z;
B(2) += u * IC(2,1) + v * IC(2,2);
M(3,1) += IC(1,1) * z;
M(3,2) += IC(1,2) * z;
M(3,3) += IC(1,1) * z * z;
M(3,4) += IC(1,2) * z * z;
B(3) += ( u * IC(1,1) + v * IC(1,2) ) * z;
M(4,1) += IC(2,1) * z;
M(4,2) += IC(2,2) * z;
M(4,3) += IC(2,1) * z * z;
M(4,4) += IC(2,2) * z * z;
B(4) += ( u * IC(2,1) + v * IC(2,2) ) * z;
}
CLHEP::HepVector p = solve(M, B);
// Update member variables
// Note that origin has local z = 0
protoIntercept = LocalPoint(p(1), p(2), 0.);
protoSlope_u = p(3);
protoSlope_v = p(4);
}
| void CSCSegAlgoHitPruning::flipErrors | ( | AlgebraicSymMatrix & | a | ) | const [private] |
Definition at line 437 of file CSCSegAlgoHitPruning.cc.
References a.
Referenced by pruneBadHits().
{
// The CSCSegment needs the error matrix re-arranged
AlgebraicSymMatrix hold( a );
// errors on slopes into upper left
a(1,1) = hold(3,3);
a(1,2) = hold(3,4);
a(2,1) = hold(4,3);
a(2,2) = hold(4,4);
// errors on positions into lower right
a(3,3) = hold(1,1);
a(3,4) = hold(1,2);
a(4,3) = hold(2,1);
a(4,4) = hold(2,2);
// off-diagonal elements remain unchanged
}
| std::vector< CSCSegment > CSCSegAlgoHitPruning::pruneBadHits | ( | const CSCChamber * | aChamber, |
| std::vector< CSCSegment > | segments | ||
| ) |
clusterize
Definition at line 49 of file CSCSegAlgoHitPruning.cc.
References begin, BrutePruning, calculateError(), CSCSegment::chi2(), ChiSquaredProbability(), fillChiSquared(), fillLocalDirection(), fitSlopes(), flipErrors(), CSCChamber::layer(), m, CSCSegment::nRecHits(), protoChi2, protoDirection, protoIntercept, protoSegment, CosmicsPD_Skims::radius, cond::rpcobtemp::temp, theChamber, GeomDet::toGlobal(), PV3DBase< T, PVType, FrameType >::x(), LocalError::xx(), PV3DBase< T, PVType, FrameType >::y(), and PV3DBase< T, PVType, FrameType >::z().
{
theChamber = aChamber;
std::vector<CSCSegment> segments_temp;
std::vector<ChamberHitContainer> rechits_clusters;
const float chi2ndfProbMin = 1.0e-4;
bool use_brute_force = BrutePruning;
int hit_nr = 0;
int hit_nr_worst = -1;
int hit_nr_2ndworst = -1;
for (std::vector<CSCSegment>::iterator it=segments.begin(); it != segments.end(); it++) {
if ( !use_brute_force ) {// find worst hit
float chisq = (*it).chi2();
int nhits = (*it).nRecHits();
LocalPoint localPos = (*it).localPosition();
LocalVector segDir = (*it).localDirection();
const CSCChamber* cscchamber = theChamber;
float globZ ;
GlobalPoint globalPosition = cscchamber->toGlobal(localPos);
globZ = globalPosition.z();
if ( ChiSquaredProbability((double)chisq,(double)(2*nhits-4)) < chi2ndfProbMin ) {
// find (rough) "residuals" (NOT excluding the hit from the fit - speed!) of hits on segment
std::vector<CSCRecHit2D> theseRecHits = (*it).specificRecHits();
std::vector<CSCRecHit2D>::const_iterator iRH_worst;
float xdist_local = -99999.;
float xdist_local_worst_sig = -99999.;
float xdist_local_2ndworst_sig = -99999.;
float xdist_local_sig = -99999.;
hit_nr = 0;
hit_nr_worst = -1;
hit_nr_2ndworst = -1;
for ( std::vector<CSCRecHit2D>::const_iterator iRH = theseRecHits.begin(); iRH != theseRecHits.end(); iRH++ ) {
//mark "worst" hit:
float z_at_target ;
float radius ;
float loc_x_at_target ;
float loc_y_at_target ;
float loc_z_at_target ;
z_at_target = 0.;
loc_x_at_target = 0.;
loc_y_at_target = 0.;
loc_z_at_target = 0.;
radius = 0.;
// set the z target in CMS global coordinates:
const CSCLayer* csclayerRH = theChamber->layer((*iRH).cscDetId().layer());
LocalPoint localPositionRH = (*iRH).localPosition();
GlobalPoint globalPositionRH = csclayerRH->toGlobal(localPositionRH);
LocalError rerrlocal = (*iRH).localPositionError();
float xxerr = rerrlocal.xx();
float target_z = globalPositionRH.z(); // target z position in cm (z pos of the hit)
loc_x_at_target = localPos.x() + (segDir.x()*( target_z - globZ ));
loc_y_at_target = localPos.y() + (segDir.y()*( target_z - globZ ));
loc_z_at_target = target_z;
// have to transform the segments coordinates back to the local frame... how?!!!!!!!!!!!!
xdist_local = fabs(localPositionRH.x() - loc_x_at_target);
xdist_local_sig = fabs((localPositionRH.x() -loc_x_at_target)/(xxerr));
if( xdist_local_sig > xdist_local_worst_sig ) {
xdist_local_2ndworst_sig = xdist_local_worst_sig;
xdist_local_worst_sig = xdist_local_sig;
iRH_worst = iRH;
hit_nr_2ndworst = hit_nr_worst;
hit_nr_worst = hit_nr;
}
else if(xdist_local_sig > xdist_local_2ndworst_sig) {
xdist_local_2ndworst_sig = xdist_local_sig;
hit_nr_2ndworst = hit_nr;
}
++hit_nr;
}
// reset worst hit number if certain criteria apply.
// Criteria: 2nd worst hit must be at least a factor of
// 1.5 better than the worst in terms of sigma:
if ( xdist_local_worst_sig / xdist_local_2ndworst_sig < 1.5 ) {
hit_nr_worst = -1;
hit_nr_2ndworst = -1;
}
}
}
// if worst hit was found, refit without worst hit and select if considerably better than original fit.
// Can also use brute force: refit all n-1 hit segments and choose one over the n hit if considerably "better"
std::vector< CSCRecHit2D > buffer;
std::vector< std::vector< CSCRecHit2D > > reduced_segments;
std::vector< CSCRecHit2D > theseRecHits = (*it).specificRecHits();
float best_red_seg_prob = 0.0;
// usefor chi2 1 diff float best_red_seg_prob = 99999.;
buffer.clear();
if( ChiSquaredProbability((double)(*it).chi2(),(double)((2*(*it).nRecHits())-4)) < chi2ndfProbMin ) {
buffer = theseRecHits;
// Dirty switch: here one can select to refit all possible subsets or just the one without the
// tagged worst hit:
if( use_brute_force ) { // Brute force method: loop over all possible segments:
for(size_t bi = 0; bi < buffer.size(); bi++) {
reduced_segments.push_back(buffer);
reduced_segments[bi].erase(reduced_segments[bi].begin()+(bi),reduced_segments[bi].begin()+(bi+1));
}
}
else { // More elegant but still biased: erase only worst hit
// Comment: There is not a very strong correlation of the worst hit with the one that one should remove...
if( hit_nr_worst >= 0 && hit_nr_worst <= int(buffer.size()) ) {
// fill segment in buffer, delete worst hit
buffer.erase(buffer.begin()+(hit_nr_worst),buffer.begin()+(hit_nr_worst+1));
reduced_segments.push_back(buffer);
}
else {
// only fill segment in array, do not delete anything
reduced_segments.push_back(buffer);
}
}
}
// Loop over the subsegments and fit (only one segment if "use_brute_force" is false):
for (size_t iSegment=0; iSegment<reduced_segments.size(); iSegment++ ) {
// loop over hits on given segment and push pointers to hits into protosegment
protoSegment.clear();
for (size_t m = 0; m<reduced_segments[iSegment].size(); ++m ) {
protoSegment.push_back(&reduced_segments[iSegment][m]);
}
fitSlopes();
fillChiSquared();
fillLocalDirection();
// calculate error matrix
AlgebraicSymMatrix protoErrors = calculateError();
// but reorder components to match what's required by TrackingRecHit interface
// i.e. slopes first, then positions
flipErrors( protoErrors );
//
CSCSegment temp(protoSegment, protoIntercept, protoDirection, protoErrors, protoChi2);
// replace n hit segment with n-1 hit segment, if segment probability is 1e3 better:
if( ( ChiSquaredProbability((double)(*it).chi2(),(double)((2*(*it).nRecHits())-4))
<
(1.e-3)*(ChiSquaredProbability((double)temp.chi2(),(double)(2*temp.nRecHits()-4))) )
&&
( (ChiSquaredProbability((double)temp.chi2(),(double)(2*temp.nRecHits()-4)))
> best_red_seg_prob
)
&&
( (ChiSquaredProbability((double)temp.chi2(),(double)(2*temp.nRecHits()-4))) > 1e-10 )
) {
best_red_seg_prob = ChiSquaredProbability((double)temp.chi2(),(double)(2*temp.nRecHits()-4));
// exchange current n hit segment (*it) with better n-1 hit segment:
(*it) = temp;
}
}
}
return segments;
}
| AlgebraicSymMatrix CSCSegAlgoHitPruning::weightMatrix | ( | void | ) | const [private] |
Definition at line 367 of file CSCSegAlgoHitPruning.cc.
References CSCRecHit2D::localPositionError(), protoSegment, LocalError::xx(), LocalError::xy(), and LocalError::yy().
Referenced by calculateError().
{
std::vector<const CSCRecHit2D*>::const_iterator it;
int nhits = protoSegment.size();
AlgebraicSymMatrix matrix(2*nhits, 0);
int row = 0;
for (it = protoSegment.begin(); it != protoSegment.end(); ++it) {
const CSCRecHit2D& hit = (**it);
++row;
matrix(row, row) = hit.localPositionError().xx();
matrix(row, row+1) = hit.localPositionError().xy();
++row;
matrix(row, row-1) = hit.localPositionError().xy();
matrix(row, row) = hit.localPositionError().yy();
}
int ierr;
matrix.invert(ierr);
return matrix;
}
bool CSCSegAlgoHitPruning::BrutePruning [private] |
Definition at line 56 of file CSCSegAlgoHitPruning.h.
Referenced by CSCSegAlgoHitPruning(), and pruneBadHits().
double CSCSegAlgoHitPruning::protoChi2 [private] |
Definition at line 53 of file CSCSegAlgoHitPruning.h.
Referenced by fillChiSquared(), and pruneBadHits().
Definition at line 54 of file CSCSegAlgoHitPruning.h.
Referenced by fillLocalDirection(), and pruneBadHits().
Definition at line 52 of file CSCSegAlgoHitPruning.h.
Referenced by fillChiSquared(), fillLocalDirection(), fitSlopes(), and pruneBadHits().
Definition at line 49 of file CSCSegAlgoHitPruning.h.
Referenced by derivativeMatrix(), fillChiSquared(), fitSlopes(), pruneBadHits(), and weightMatrix().
float CSCSegAlgoHitPruning::protoSlope_u [private] |
Definition at line 50 of file CSCSegAlgoHitPruning.h.
Referenced by fillChiSquared(), fillLocalDirection(), and fitSlopes().
float CSCSegAlgoHitPruning::protoSlope_v [private] |
Definition at line 51 of file CSCSegAlgoHitPruning.h.
Referenced by fillChiSquared(), fillLocalDirection(), and fitSlopes().
const CSCChamber* CSCSegAlgoHitPruning::theChamber [private] |
Definition at line 47 of file CSCSegAlgoHitPruning.h.
Referenced by derivativeMatrix(), fillChiSquared(), fillLocalDirection(), fitSlopes(), and pruneBadHits().
1.7.3