egammaClusterHelpers Namespace Reference

Functions
std::pair< const double, const double >	etaphi_range (const CaloDetDescrManager &mgr, double eta, double phi, CaloCell_ID::CaloSample sampling, const CaloDetDescrElement *elt)
	Duplicate code.
void	fillPositionsInCalo (xAOD::CaloCluster *cluster, const CaloDetDescrManager &mgr)
	Function to decorate the calo cluster with position variables.
void	makeCorrection1 (xAOD::CaloCluster *cluster, const CaloDetDescrManager &mgr, const CaloSampling::CaloSample sample)
	functions to make 1st sampling (strips) specific corrections
void	refineEta1Position (xAOD::CaloCluster *cluster, const CaloDetDescrManager &mgr)
	function to refine position in eta1

Function Documentation

etaphi_range()

std::pair< const double, const double > egammaClusterHelpers::etaphi_range	(	const CaloDetDescrManager &	mgr,
		double	eta,
		double	phi,
		CaloCell_ID::CaloSample	sampling,
		const CaloDetDescrElement *	elt )

Duplicate code.

Return eta/phi ranges encompassing +- 1 cell.

Parameters

	eta	Central eta value.
	phi	Central phi value.
	sampling	The sampling to use.
[out]	deta	Range in eta.
[out]	dphi	Range in phi.

This can be a little tricky due to misalignments and the fact that cells have different sizes in different regions. Also, CaloLayerCalculator takes only a symmetric eta range. We try to find the neighboring cells by starting from the center cell and looking a little bit more than half its width in either direction, and finding the centers of those cells. Then we use the larger of these for the symmetric range.

Definition at line 13 of file egammaClusterHelpers.cxx.

  {
    // Should be smaller than the eta half-width of any cell.
    constexpr double eps = 0.001;
    
    // Now look in the negative eta direction, on the low (left) side.
    const CaloDetDescrElement* elt_l = mgr.get_element_raw(sampling, eta - elt->deta() - eps, phi);
    double deta_l = elt_l ? std::abs(eta - elt_l->eta_raw()) + eps : 0.;
    
    // Now look in the positive eta direction, on the high (right) side.
    const CaloDetDescrElement* elt_r = mgr.get_element_raw(sampling, eta + elt->deta() + eps, phi);
    double deta_r = elt_r ? std::abs(eta - elt_r->eta_raw()) + eps : 0.; 
    
    // Now for the phi variation.
    // The phi size can change as a function of eta, but not of phi.
    // Thus we have to look again at the adjacent eta cells, and
    // take the largest variation.
    
    // Now look in the negative eta direction, on the low-eta () side.
    elt_l = mgr.get_element_raw(sampling, eta - elt->deta() - eps, CaloPhiRange::fix(phi - elt->dphi() - eps));
    double dphi_l = elt_l ? std::abs(CaloPhiRange::fix(phi - elt_l->phi_raw())) + eps : 0.; 
    
    // Now look in the positive eta direction, on the positive (down) side.
    elt_r = mgr.get_element_raw(sampling, eta + elt->deta() + eps, CaloPhiRange::fix(phi - elt->dphi() - eps));
    double dphi_r = elt_r ? std::abs(CaloPhiRange::fix(phi - elt_r->phi_raw())) + eps : 0.; 
  
    // Total is twice the maximum.
    return {2 * std::max(deta_r, deta_l), 2 * std::max(dphi_l, dphi_r)};
}

fillPositionsInCalo()

void egammaClusterHelpers::fillPositionsInCalo	(	xAOD::CaloCluster *	cluster,
		const CaloDetDescrManager &	mgr )

Function to decorate the calo cluster with position variables.

Filling eta phi in calo-frame:

• xAOD::CaloCluster::ETACALOFRAME
• xAOD::CaloCluster::PHICALOFRAME
• xAOD::CaloCluster::ETA2CALOFRAME
• xAOD::CaloCluster::PHI2CALOFRAME
• xAOD::CaloCluster::ETA1CALOFRAME
• xAOD::CaloCluster::PHI1CALOFRAME

Definition at line 48 of file egammaClusterHelpers.cxx.

  {
    bool isBarrel = cluster->inBarrel();
    const bool isEndcap = cluster->inEndcap();
    if (isBarrel && isEndcap) {
      isBarrel = cluster->eSample(CaloSampling::EMB2)
    >= cluster->eSample(CaloSampling::EME2);
    }
    CaloCell_ID::CaloSample sample =
      isBarrel ? CaloCell_ID::EMB2 : CaloCell_ID::EME2;
    // eta and phi of the cluster in the calorimeter frame
    double eta;
    double phi;
    CaloCellDetPos::getDetPosition(
                   mgr, sample, cluster->eta(), cluster->phi(), eta, phi);
    cluster->insertMoment(xAOD::CaloCluster::ETACALOFRAME, eta);
    cluster->insertMoment(xAOD::CaloCluster::PHICALOFRAME, phi);
    //  eta in the second sampling
    CaloCellDetPos::getDetPosition(
                   mgr, sample, cluster->etaBE(2), cluster->phiBE(2), eta, phi);
    cluster->insertMoment(xAOD::CaloCluster::ETA2CALOFRAME, eta);
    cluster->insertMoment(xAOD::CaloCluster::PHI2CALOFRAME, phi);
    //  eta in the first sampling
    sample = isBarrel ? CaloCell_ID::EMB1 : CaloCell_ID::EME1;
    CaloCellDetPos::getDetPosition(
                   mgr, sample, cluster->etaBE(1), cluster->phiBE(1), eta, phi);
    cluster->insertMoment(xAOD::CaloCluster::ETA1CALOFRAME, eta);
    cluster->insertMoment(xAOD::CaloCluster::PHI1CALOFRAME, phi);
  }

makeCorrection1()

void egammaClusterHelpers::makeCorrection1	(	xAOD::CaloCluster *	cluster,
		const CaloDetDescrManager &	mgr,
		const CaloSampling::CaloSample	sample )

functions to make 1st sampling (strips) specific corrections

Definition at line 79 of file egammaClusterHelpers.cxx.

  {
    const double clusterEtaMax = cluster->etamax(sample);
    const double clusterPhiMax = cluster->phimax(sample);
    
    // Protections.
    if (clusterEtaMax == -999. || clusterPhiMax == -999.) {
      return;
    }
    if (std::abs(clusterEtaMax) < 1E-6 && std::abs(clusterPhiMax) < 1E-6) {
      return;
    }
    
    // Get the hottest in raw co-ordinates
    // We have two kinds of enums ...
    const CaloCell_ID::CaloSample xsample = 
                  (sample == CaloSampling::EMB1) ? CaloCell_ID::EMB1 : CaloCell_ID::EME1;
    
    const CaloDetDescrElement* dde = mgr.get_element(xsample, 
                                                   clusterEtaMax, 
                             clusterPhiMax);
 
    if (!dde) {
      return;
    }
    
    double etamax = dde->eta_raw();
    double phimax = dde->phi_raw();
    
    const CaloDetDescrElement* elt = mgr.get_element_raw(xsample, etamax, phimax);
    if (!elt) {
      return;
    }
    
  // Now Locate the +-1 range, use raw co-ordinates here.
    auto [detastr, dphistr] = etaphi_range(mgr, etamax, phimax, xsample, elt);
    
    // Given the range refine the position employing the smaller window
    if (detastr > 0 && dphistr > 0) {
      CaloLayerCalculator helper;
      const auto* const cellLink = cluster->getCellLinks();
      helper.fill(cellLink->begin(),
          cellLink->end(),
          etamax,
          phimax,
          detastr,
          dphistr,
          sample);
      
      // Here is where we (re-)fill the eta in the 1st sampling
      if (helper.etam() != -999.) {
    // This is "real" atlas co-ordinates
      cluster->setEta(sample, helper.etam());
      }
    }
  }

refineEta1Position()

void egammaClusterHelpers::refineEta1Position	(	xAOD::CaloCluster *	cluster,
		const CaloDetDescrManager &	mgr )

function to refine position in eta1

Definition at line 139 of file egammaClusterHelpers.cxx.

  {
    // This only makes sense if we have cells there
    if (!cluster->hasSampling(CaloSampling::EMB1) &&
    !cluster->hasSampling(CaloSampling::EME1)) {
      return;
    }
    // Now calculare the position using cells in barrel or endcap or both
    const double aeta = std::abs(cluster->etaBE(2));
    if (aeta < 1.6 && cluster->hasSampling(CaloSampling::EMB1)) {
      makeCorrection1(cluster, mgr, CaloSampling::EMB1);
    }
    if (aeta > 1.3 && cluster->hasSampling(CaloSampling::EME1)) {
      makeCorrection1(cluster, mgr, CaloSampling::EME1);
    }
  }