CSCComparatorDigiFitter Class Reference

#include <CSCComparatorDigiFitter.h>

Public Member Functions
	CSCComparatorDigiFitter ()
void	fit (const CSCDetId &ch_id, const CSCCorrelatedLCTDigi &, const CSCComparatorDigiCollection &, std::vector< float > &fit_phi_layers, std::vector< float > &fit_z_layers, float &keyRadius)
void	setGeometry (const CSCGeometry *csc_g)
void	setStripBits (int bits)
void	useKeyRadius (bool useKeyRadius)
	~CSCComparatorDigiFitter ()

Private Member Functions
void	calculateSlopeIntercept (float &alpha, float &beta)
bool	comparatorInLCTPattern (int keyStrip, int pattern, int layer, int halfStrip) const
float	cscHalfStripWidth (const CSCDetId &id) const
void	getComparatorDigiCoordinates (const CSCDetId &ch_id, const CSCCorrelatedLCTDigi &stub)
void	matchingComparatorDigisLCT (const CSCDetId &ch_id, const CSCCorrelatedLCTDigi &, const CSCComparatorDigiCollection &)

Private Attributes
CSCComparatorDigiContainerIds	compDigisIds_
const CSCGeometry *	cscGeometry_
const std::vector< float >	degrees_ = {10., 10., 10., 10., 20., 10., 20., 10., 20., 10.}
std::vector< float >	ephis_
std::vector< float >	ezs_
int	nStripBits_
std::vector< float >	phis_
float	radius_
const std::vector< int >	strips_ = {48, 64, 80, 64, 80, 80, 80, 80, 80, 80}
bool	useKeyRadius_
std::vector< float >	zs_

Detailed Description

Definition at line 38 of file CSCComparatorDigiFitter.h.

Constructor & Destructor Documentation

CSCComparatorDigiFitter()

CSCComparatorDigiFitter::CSCComparatorDigiFitter ( )

inline

Definition at line 40 of file CSCComparatorDigiFitter.h.

{}

~CSCComparatorDigiFitter()

CSCComparatorDigiFitter::~CSCComparatorDigiFitter ( )

inline

Definition at line 41 of file CSCComparatorDigiFitter.h.

{}

Member Function Documentation

calculateSlopeIntercept()

void CSCComparatorDigiFitter::calculateSlopeIntercept ( float &  alpha, float &  beta  )

private

Definition at line 213 of file CSCComparatorDigiFitter.cc.

                                                                               {
  // if there are at least 3 hits in the chamber, do a linear fit to the
  // comparator digi positions with the chi2 method
  if (phis_.size() >= 3) {
    float Sxx = 0, Sxy = 0, Sx = 0, Sy = 0, S = 0;
    for (unsigned i = 0; i < phis_.size(); ++i) {
      float sigma2_inv = 1. / ephis_[i] * ephis_[i];
      Sxx += zs_[i] * zs_[i] * sigma2_inv;
      Sxy += zs_[i] * phis_[i] * sigma2_inv;
      Sx += zs_[i] * zs_[i] * sigma2_inv;
      Sy += phis_[i] * sigma2_inv;
      S += sigma2_inv;
    }
    float delta = S * Sxx - Sx * Sx;
    alpha = (Sxx * Sy - Sx * Sxy) / delta;
    beta = (S * Sxy - Sx * Sy) / delta;
  } else {
    alpha = -99;
    beta = 0.0;
  }
}

References zMuMuMuonUserData::alpha, zMuMuMuonUserData::beta, dumpMFGeometry_cfg::delta, ephis_, mps_fire::i, phis_, and zs_.

Referenced by fit().

comparatorInLCTPattern()

bool CSCComparatorDigiFitter::comparatorInLCTPattern ( int  keyStrip, int  pattern, int  layer, int  halfStrip  ) const

private

Definition at line 243 of file CSCComparatorDigiFitter.cc.

                                                                                                              {
  // get the (sub)pattern
  const std::vector<int>& subpat = patIndexToPatternDelta[pattern].at(layer - 1);
 
  // due to comparator digi time extension in the CLCT processor we need to
  // search a bigger region around the key HS. +/-1, 0 should be sufficient
  const int halfStripDelta = halfStrip - keyStrip;
  return (std::find(subpat.begin(), subpat.end(), halfStripDelta + 1) != subpat.end() or
          std::find(subpat.begin(), subpat.end(), halfStripDelta) != subpat.end() or
          std::find(subpat.begin(), subpat.end(), halfStripDelta - 1) != subpat.end());
}

References spr::find(), or, and topSingleLeptonDQM_PU_cfi::pattern.

Referenced by matchingComparatorDigisLCT().

cscHalfStripWidth()

float CSCComparatorDigiFitter::cscHalfStripWidth ( const CSCDetId &  id ) const

private

Definition at line 235 of file CSCComparatorDigiFitter.cc.

                                                                         {
  // what is the chamber type?
  int index = id.iChamberType() - 1;
 
  // calculate the half strip width of this chamber
  return degrees_[index] * M_PI / 180. / (2. * strips_[index]);
}

References degrees_, M_PI, and strips_.

Referenced by getComparatorDigiCoordinates().

fit()

void CSCComparatorDigiFitter::fit	(	const CSCDetId &	ch_id,
		const CSCCorrelatedLCTDigi &	stub,
		const CSCComparatorDigiCollection &	hCSCComparators,
		std::vector< float > &	fit_phi_layers,
		std::vector< float > &	fit_z_layers,
		float &	keyRadius
	)

Definition at line 150 of file CSCComparatorDigiFitter.cc.

                                                    {
  // clear fit results
  fit_phi_layers.clear();
  fit_z_layers.clear();
  keyRadius = 0;
 
  // first, match the comparator digis to the LCT
  matchingComparatorDigisLCT(ch_id, stub, hCSCComparators);
 
  // second, get the coordinates
  getComparatorDigiCoordinates(ch_id, stub);
 
  // get radius of the stub from key layer
  const CSCDetId key_id(ch_id.endcap(), ch_id.station(), ch_id.ring(), ch_id.chamber(), CSCConstants::KEY_CLCT_LAYER);
  const float fractional_strip = stub.getFractionalStrip();
 
  const auto& cscChamber = cscGeometry_->chamber(ch_id);
  const auto& layer_geo = cscChamber->layer(CSCConstants::KEY_CLCT_LAYER)->geometry();
 
  // LCT::getKeyWG() also starts from 0
  const float wire = layer_geo->middleWireOfGroup(stub.getKeyWG() + 1);
  const LocalPoint& csc_intersect = layer_geo->intersectionOfStripAndWire(fractional_strip, wire);
  const GlobalPoint& csc_gp = cscGeometry_->idToDet(key_id)->surface().toGlobal(csc_intersect);
 
  // get radius from key layer
  if (useKeyRadius_)
    radius_ = radius_ / phis_.size();
  else
    radius_ = csc_gp.perp();
 
  float alpha = -99., beta = 0.;
  // do a fit to the comparator digis
  calculateSlopeIntercept(alpha, beta);
  if (phis_.size() <= 2 or std::abs(alpha) >= 99) {
    alpha = csc_gp.phi();
    beta = 0.0;
  }
 
  // determine the pitch of the chamber
  // option to discretize the pitch
  float stripPhiPitch = layer_geo->stripPhiPitch();
  if (nStripBits_)
    stripPhiPitch = stripPhiPitch / nStripBits_;
 
  // get the fit results
  // option to discretize the fitted phi value
  keyRadius = radius_;
 
  for (int i = 0; i < CSCConstants::NUM_LAYERS; i++) {
    const float fit_z = cscChamber->layer(i + 1)->centerOfStrip(20).z();
    const float fit_phi = normalizedPhi(alpha + beta * fit_z);
    fit_z_layers.push_back(fit_z);
    fit_phi_layers.push_back(fit_phi);
    if (nStripBits_)
      fit_phi_layers.push_back((std::floor(fit_phi / stripPhiPitch) + 0.5) * stripPhiPitch);
  }
}

References funct::abs(), zMuMuMuonUserData::alpha, zMuMuMuonUserData::beta, calculateSlopeIntercept(), CSCDetId::chamber(), CSCGeometry::chamber(), cscGeometry_, CSCDetId::endcap(), CSCLayer::geometry(), getComparatorDigiCoordinates(), CSCCorrelatedLCTDigi::getFractionalStrip(), CSCCorrelatedLCTDigi::getKeyWG(), mps_fire::i, CSCGeometry::idToDet(), CSCConstants::KEY_CLCT_LAYER, CSCChamber::layer(), matchingComparatorDigisLCT(), CSCLayerGeometry::middleWireOfGroup(), normalizedPhi(), nStripBits_, CSCConstants::NUM_LAYERS, or, PV3DBase< T, PVType, FrameType >::perp(), PV3DBase< T, PVType, FrameType >::phi(), phis_, radius_, CSCDetId::ring(), CSCDetId::station(), GeomDet::surface(), Surface::toGlobal(), and useKeyRadius_.

Referenced by trackingPlots.Iteration::modules().

getComparatorDigiCoordinates()

void CSCComparatorDigiFitter::getComparatorDigiCoordinates ( const CSCDetId &  ch_id, const CSCCorrelatedLCTDigi &  stub  )

private

Definition at line 94 of file CSCComparatorDigiFitter.cc.

                                                                                                                  {
  const auto& cscChamber = cscGeometry_->chamber(ch_id);
 
  // get the z and phi positions of the comparator digis
  float radius_ = 0.0;
 
  // loop on all matching digis
  for (const auto& p : compDigisIds_) {
    const auto& detId = p.first;
 
    float phi_tmp = 0.0;
    float radius_tmp = 0.0;
    float z_tmp = 0.0;
 
    // ignore layers with no digis
    if (p.second.empty())
      continue;
 
    // loop on all matching digis in this layer
    for (const auto& hit : p.second) {
      const float fractional_strip = hit.getFractionalStrip();
      const auto& layer_geo = cscChamber->layer(detId.layer())->geometry();
      const float wire = layer_geo->middleWireOfGroup(stub.getKeyWG() + 1);
 
      // get the phi of each comparator digi
      const LocalPoint& csc_intersect = layer_geo->intersectionOfStripAndWire(fractional_strip, wire);
      const GlobalPoint& csc_gp = cscGeometry_->idToDet(detId)->surface().toGlobal(csc_intersect);
      const float gpphi = csc_gp.phi();
 
      // normalize phi values according to first one
      if (!phis_.empty() and gpphi > 0 and phis_[0] < 0 and (gpphi - phis_[0]) > M_PI)
        phi_tmp += (gpphi - 2 * M_PI);
      else if (!phis_.empty() and gpphi < 0 and phis_[0] > 0 and (gpphi - phis_[0]) < -M_PI)
        phi_tmp += (gpphi + 2 * M_PI);
      else
        phi_tmp += (csc_gp.phi());
 
      z_tmp = csc_gp.z();
      radius_tmp += csc_gp.perp();
    }
 
    //in case there are more than one comparator digis in one layer
    radius_tmp = radius_tmp / (p.second).size();
    radius_ += radius_tmp;
 
    zs_.push_back(z_tmp);
    ezs_.push_back(0);
 
    phi_tmp = phi_tmp / (p.second).size();
    phis_.push_back(phi_tmp);
    // assume that the charge is flat distributed across the half-strip
    // this is only approximately valid, but good enough for now
    ephis_.push_back(cscHalfStripWidth(detId) / sqrt(12));
  }
}

References CSCGeometry::chamber(), compDigisIds_, cscGeometry_, cscHalfStripWidth(), ephis_, ezs_, geometry, CSCCorrelatedLCTDigi::getKeyWG(), CSCGeometry::idToDet(), M_PI, AlCaHLTBitMon_ParallelJobs::p, PV3DBase< T, PVType, FrameType >::perp(), PV3DBase< T, PVType, FrameType >::phi(), phis_, radius_, findQualityFiles::size, mathSSE::sqrt(), GeomDet::surface(), Surface::toGlobal(), PV3DBase< T, PVType, FrameType >::z(), and zs_.

Referenced by fit().

matchingComparatorDigisLCT()

void CSCComparatorDigiFitter::matchingComparatorDigisLCT ( const CSCDetId &  ch_id, const CSCCorrelatedLCTDigi &  stub, const CSCComparatorDigiCollection &  hCSCComparators  )

private

Definition at line 64 of file CSCComparatorDigiFitter.cc.

                                                                                                             {
  // fetch the CSC comparator digis in this chamber
  for (int iLayer = 1; iLayer <= CSCConstants::NUM_LAYERS; ++iLayer) {
    const CSCDetId layerId(ch_id.endcap(), ch_id.station(), ch_id.ring(), ch_id.chamber(), iLayer);
 
    // get the digis per layer
    const auto& compRange = hCSCComparators.get(layerId);
    CSCComparatorDigiContainer compDigis;
 
    for (auto compDigiItr = compRange.first; compDigiItr != compRange.second; compDigiItr++) {
      const auto& compDigi = *compDigiItr;
 
      //if (stub.getTimeBin() < 4 or stub.getTimeBin() > 8) continue;
      const int stubHalfStrip(compDigi.getHalfStrip());
 
      // these comparator digis never fit the pattern anyway!
      if (std::abs(stubHalfStrip - stub.getStrip()) > 5)
        continue;
 
      // check if this comparator digi fits the pattern
      if (comparatorInLCTPattern(stub.getStrip(), stub.getPattern(), iLayer, stubHalfStrip)) {
        compDigis.push_back(compDigi);
      }
    }
    compDigisIds_.emplace_back(layerId, compDigis);
  }
}

References funct::abs(), CSCDetId::chamber(), comparatorInLCTPattern(), compDigisIds_, CSCDetId::endcap(), CSCCorrelatedLCTDigi::getPattern(), CSCCorrelatedLCTDigi::getStrip(), CSCConstants::NUM_LAYERS, CSCDetId::ring(), and CSCDetId::station().

Referenced by fit().

setGeometry()

void CSCComparatorDigiFitter::setGeometry ( const CSCGeometry *  csc_g )

inline

Definition at line 44 of file CSCComparatorDigiFitter.h.

{ cscGeometry_ = csc_g; }

References cscGeometry_.

setStripBits()

void CSCComparatorDigiFitter::setStripBits ( int  bits )

inline

Definition at line 47 of file CSCComparatorDigiFitter.h.

{ nStripBits_ = bits; }

References bits, and nStripBits_.

useKeyRadius()

void CSCComparatorDigiFitter::useKeyRadius ( bool  useKeyRadius )

inline

Definition at line 50 of file CSCComparatorDigiFitter.h.

{ useKeyRadius_ = useKeyRadius; }

References useKeyRadius(), and useKeyRadius_.

Referenced by useKeyRadius().

Member Data Documentation

compDigisIds_

CSCComparatorDigiContainerIds CSCComparatorDigiFitter::compDigisIds_

private

Definition at line 85 of file CSCComparatorDigiFitter.h.

Referenced by getComparatorDigiCoordinates(), and matchingComparatorDigisLCT().

cscGeometry_

const CSCGeometry* CSCComparatorDigiFitter::cscGeometry_

private

Definition at line 80 of file CSCComparatorDigiFitter.h.

Referenced by fit(), getComparatorDigiCoordinates(), and setGeometry().

degrees_

const std::vector<float> CSCComparatorDigiFitter::degrees_ = {10., 10., 10., 10., 20., 10., 20., 10., 20., 10.}

private

Definition at line 98 of file CSCComparatorDigiFitter.h.

Referenced by cscHalfStripWidth().

ephis_

std::vector<float> CSCComparatorDigiFitter::ephis_

private

Definition at line 90 of file CSCComparatorDigiFitter.h.

Referenced by calculateSlopeIntercept(), and getComparatorDigiCoordinates().

ezs_

std::vector<float> CSCComparatorDigiFitter::ezs_

private

Definition at line 91 of file CSCComparatorDigiFitter.h.

Referenced by getComparatorDigiCoordinates().

nStripBits_

int CSCComparatorDigiFitter::nStripBits_

private

Definition at line 83 of file CSCComparatorDigiFitter.h.

Referenced by fit(), and setStripBits().

phis_

std::vector<float> CSCComparatorDigiFitter::phis_

private

Definition at line 88 of file CSCComparatorDigiFitter.h.

Referenced by calculateSlopeIntercept(), fit(), and getComparatorDigiCoordinates().

radius_

float CSCComparatorDigiFitter::radius_

private

Definition at line 92 of file CSCComparatorDigiFitter.h.

Referenced by fit(), and getComparatorDigiCoordinates().

strips_

const std::vector<int> CSCComparatorDigiFitter::strips_ = {48, 64, 80, 64, 80, 80, 80, 80, 80, 80}

private

Definition at line 97 of file CSCComparatorDigiFitter.h.

Referenced by cscHalfStripWidth().

useKeyRadius_

bool CSCComparatorDigiFitter::useKeyRadius_

private

Definition at line 93 of file CSCComparatorDigiFitter.h.

Referenced by fit(), and useKeyRadius().

zs_

std::vector<float> CSCComparatorDigiFitter::zs_

private

Definition at line 89 of file CSCComparatorDigiFitter.h.

Referenced by calculateSlopeIntercept(), and getComparatorDigiCoordinates().