diff --git a/Reconstruction/eflowRec/eflowRec/IPFClusterSelectorTool.h b/Reconstruction/eflowRec/eflowRec/IPFClusterSelectorTool.h
new file mode 100644
index 0000000000000000000000000000000000000000..47a1415a4e23d500d670a3030efeb322463ffc4c
--- /dev/null
+++ b/Reconstruction/eflowRec/eflowRec/IPFClusterSelectorTool.h
@@ -0,0 +1,21 @@
+/*
+ Copyright (C) 2002-2018 CERN for the benefit of the ATLAS collaboration
+*/
+
+#ifndef IPFCLUSTERSELECTIONTOOL_H
+#define IPFCLUSTERSELECTORTOOL_H
+
+#include "GaudiKernel/IAlgTool.h"
+#include "xAODCaloEvent/CaloClusterContainer.h"
+
+class IPFClusterSelectorTool : virtual public IAlgTool {
+
+ public:
+
+ /** Execute method to modify xAOD::CaloClusterContainer */
+ virtual StatusCode execute(xAOD::CaloClusterContainer&) = 0;
+
+ DeclareInterfaceID(IPFClusterSelectorTool,1,0);
+
+};
+#endif
diff --git a/Reconstruction/eflowRec/eflowRec/PFClusterSelectorTool.h b/Reconstruction/eflowRec/eflowRec/PFClusterSelectorTool.h
new file mode 100644
index 0000000000000000000000000000000000000000..def29509865ce7ca5b767393283da71ae745032f
--- /dev/null
+++ b/Reconstruction/eflowRec/eflowRec/PFClusterSelectorTool.h
@@ -0,0 +1,42 @@
+#ifndef PFCLUSTERSELECTORTOOL_H
+#define PFCLUSTERSELECTORTOOL_H
+
+#include "AthenaBaseComps/AthAlgTool.h"
+#include "eflowRec/IPFClusterSelectorTool.h"
+#include "GaudiKernel/ToolHandle.h"
+#include "xAODCaloEvent/CaloClusterContainer.h"
+
+#include <map>
+
+class eflowRecClusterContainer;
+
+class PFClusterSelectorTool : public extends<AthAlgTool, IPFClusterSelectorTool> {
+
+public:
+ /** Default constructor */
+ PFClusterSelectorTool(const std::string& type,const std::string& name,const IInterface* parent);
+ /** Default destructor */
+ ~PFClusterSelectorTool() {};
+
+ /** Gaudi AthAlgorithm hooks */
+ StatusCode initialize();
+ StatusCode execute(xAOD::CaloClusterContainer&);
+ StatusCode finalize();
+
+private:
+ /** for EM mode, LC weight for cells are retrieved before doing any subtraction; they will be used after subtraction */
+ void retrieveLCCalCellWeight(const double& energy, const unsigned& index, std::map<IdentifierHash,double>& cellsWeight,const xAOD::CaloClusterContainer& caloCalClustersContainer);
+
+ /** ReadHandleKey for the CaloClusterContainer to be used as input */
+ SG::ReadHandleKey<xAOD::CaloClusterContainer> m_caloClustersReadHandleKey{this,"clustersName","CaloTopoCluster","ReadHandleKey for the CaloClusterContainer to be used as input"};
+
+ /** ReadHandleKey for the CaloClusterContainer, at LC scale, to be used as input */
+ SG::ReadHandleKey<xAOD::CaloClusterContainer> m_caloCalClustersReadHandleKey{this,"calClustersName","CaloCalTopoClusters","ReadHandleKey for the CaloClusterContainer, at LC scale, to be used as input"};
+
+ /** WriteHandleKey for the eflowRecClusterContainer to write out */
+ SG::WriteHandleKey<eflowRecClusterContainer> m_eflowRecClustersWriteHandleKey{this,"eflowRecClustersOutputName","eflowRecClusters","WriteHandleKey for the eflowRecClusterContainer to write out"};
+
+
+
+};
+#endif
diff --git a/Reconstruction/eflowRec/src/PFClusterSelectorTool.cxx b/Reconstruction/eflowRec/src/PFClusterSelectorTool.cxx
new file mode 100644
index 0000000000000000000000000000000000000000..7a033a60c36f5d02316f529c08c23a26ae16e5ff
--- /dev/null
+++ b/Reconstruction/eflowRec/src/PFClusterSelectorTool.cxx
@@ -0,0 +1,113 @@
+#include "CaloDetDescr/CaloDetDescrManager.h"
+#include "CaloIdentifier/CaloCell_ID.h"
+#include "eflowRec/eflowRecCluster.h"
+#include "eflowRec/PFClusterSelectorTool.h"
+#include "xAODCaloEvent/CaloCluster.h"
+
+PFClusterSelectorTool::PFClusterSelectorTool(const std::string& type,const std::string& name,const IInterface* parent):
+ base_class(type, name, parent)
+{
+}
+
+StatusCode PFClusterSelectorTool::initialize(){
+
+ ATH_CHECK(m_caloClustersReadHandleKey.initialize());
+ ATH_CHECK(m_caloCalClustersReadHandleKey.initialize());
+
+ ATH_CHECK(m_eflowRecClustersWriteHandleKey.initialize());
+
+ return StatusCode::SUCCESS;
+}
+
+StatusCode PFClusterSelectorTool::execute(xAOD::CaloClusterContainer&){
+
+ SG::ReadHandle<xAOD::CaloClusterContainer> caloClustersReadHandle(m_caloClustersReadHandleKey);
+
+ /* Verify the read handle has a valid pointer, and if not return */
+ if (!caloClustersReadHandle.isValid()){
+ ATH_MSG_WARNING(" Invalid ReadHandle for xAOD::CaloCluster with key: " << caloClustersReadHandle.key());
+ return StatusCode::SUCCESS;
+ }
+ /* Record the eflowRecCluster output container */
+ SG::WriteHandle<eflowRecClusterContainer> eflowRecClustersWriteHandle(m_eflowRecClustersWriteHandleKey);
+ ATH_CHECK(eflowRecClustersWriteHandle.record(std::make_unique<eflowRecClusterContainer>()));
+
+ SG::ReadHandle<xAOD::CaloClusterContainer> caloCalClustersReadHandle(m_caloCalClustersReadHandleKey);
+
+ /* Fill the vector of eflowRecClusters */
+ unsigned int nClusters = caloClustersReadHandle->size();
+ for (unsigned int iCluster = 0; iCluster < nClusters; ++iCluster) {
+ /* Create the eflowRecCluster and put it in the container */
+ std::unique_ptr<eflowRecCluster> thisEFRecCluster = std::make_unique<eflowRecCluster>(ElementLink<xAOD::CaloClusterContainer>(*caloClustersReadHandle, iCluster));
+
+ if (caloCalClustersReadHandle.isValid()){
+ std::map<IdentifierHash,double> cellsWeightMap;
+ retrieveLCCalCellWeight(caloClustersReadHandle->at(iCluster)->e(), iCluster, cellsWeightMap, *caloCalClustersReadHandle);
+
+ if (msgLvl(MSG::DEBUG)) {
+ //zhangr
+ std::map<IdentifierHash, double>::iterator it = cellsWeightMap.begin();
+ for (; it != cellsWeightMap.end(); ++it) {
+ ATH_MSG_DEBUG("zhangrui eflowPreparation " << iCluster << "/" << nClusters << ": e="
+ << caloClustersReadHandle->at(iCluster)->e() << " (" << it->first << " "
+ << it->second << ")");
+ }
+ }
+
+ thisEFRecCluster->setCellsWeight(cellsWeightMap);
+ }
+
+ thisEFRecCluster->setClusterId(iCluster);
+ eflowRecClustersWriteHandle->push_back(std::move(thisEFRecCluster));
+
+ if (msgLvl(MSG::DEBUG)) {
+ const xAOD::CaloCluster* thisCluster = caloClustersReadHandle->at(iCluster);
+ ATH_MSG_DEBUG("eflowPreparation clus = " << thisCluster->eta() << " " << thisCluster->phi() << " " << thisCluster->e()/cosh(thisCluster->eta()));
+ }
+ }
+
+ return StatusCode::SUCCESS;
+}
+
+StatusCode PFClusterSelectorTool::finalize(){
+ return StatusCode::SUCCESS;
+}
+
+void PFClusterSelectorTool::retrieveLCCalCellWeight(const double& energy, const unsigned& index, std::map<IdentifierHash,double>& cellsWeight, const xAOD::CaloClusterContainer& caloCalClustersContainer) {
+
+ /* match CaloCluster with CaloCalCluster to obtain cell weight */
+ /* first try the position at 'index'. If we are lucky, the loop can be avoided. */
+ /* Note the read handle has been tested to be valid prior to the call of this function */
+ const xAOD::CaloCluster* matchedCalCluster = caloCalClustersContainer.at(index);
+
+ if (matchedCalCluster){
+
+ if (!(fabs(energy - matchedCalCluster->rawE()) < 0.001)) {
+ matchedCalCluster = nullptr;
+ for (unsigned iCalCalCluster = 0; iCalCalCluster < caloCalClustersContainer.size();
+ ++iCalCalCluster) {
+ matchedCalCluster = caloCalClustersContainer.at(iCalCalCluster);
+ if (fabs(energy - matchedCalCluster->rawE()) < 0.001) {
+ break;
+ }
+ }
+ if (!matchedCalCluster) ATH_MSG_WARNING("Invalid pointer to matched cluster - failed to find cluster match");
+ }
+ assert(matchedCalCluster);
+
+ /* obtain cell index and cell weight */
+ const CaloDetDescrManager* calo_dd_man = CaloDetDescrManager::instance();
+ const CaloCell_ID* calo_id = calo_dd_man->getCaloCell_ID();
+ xAOD::CaloCluster::const_cell_iterator itCell = matchedCalCluster->cell_begin();
+ xAOD::CaloCluster::const_cell_iterator endCell = matchedCalCluster->cell_end();
+ for (; itCell != endCell; ++itCell) {
+ const CaloCell* pCell = *itCell;
+ Identifier myId = pCell->ID();
+ IdentifierHash myHashId = calo_id->calo_cell_hash(myId);
+ cellsWeight[myHashId] = itCell.weight();
+ }
+ }
+ else ATH_MSG_WARNING("Invalid pointer to matched cluster - could not look up local hadron cell weights");
+
+ return ;
+}