'weight method cleanup' (PFlowUtils-00-00-10)

Reconstruction/PFlow/PFlowUtils/Changelog

+2016-09-12 Teng Jian Khoo <khoo@cern.ch>
+	* Reorganise the weight method and fix the 60 GeV track case again
+	* Tagging as PFlowUtils-00-00-10
+
+2016-09-11 Teng Jian Khoo <khoo@cern.ch>
+	* Don't weight 60 GeV tracks to 0 unless in dense environment
+	* Set tiny but non-zero weights to ensure high-pt cPFOs that are weighted down become jet constituents
+	* Needed for PF MET
+	* Tagging as PFlowUtils-00-00-09
+
+2016-08-04 Teng Jian Khoo <khoo@cern.ch>
+	* Added WeightPFOTool for extraction of charged PFO weights
+	* Tagging as PFlowUtils-00-00-08 (missed files in 07 tag)
+
 2016-04-16 Attila Krasznahorkay <Attila.Krasznahorkay@cern.ch>
 	* Created a new tag with a slightly adjusted CMakeLists.txt
 	  file.

Reconstruction/PFlow/PFlowUtils/PFlowUtils/IWeightPFOTool.h

+/*
+  Copyright (C) 2002-2017 CERN for the benefit of the ATLAS collaboration
+*/
+
+#ifndef IWEIGHTPFOTOOL_H
+#define IWEIGHTPFOTOOL_H
+
+/** Simple class to retrieve PFO for jets and met in the two possible configurations we provide */
+
+#include "AsgTools/IAsgTool.h"
+
+#include "xAODPFlow/PFOContainer.h"
+#include "PFlowUtils/PFODefs.h"
+
+namespace CP {
+
+  class IWeightPFOTool : public virtual asg::IAsgTool {
+
+    /** Declare the interface that the class provides */
+    ASG_TOOL_INTERFACE( CP::IWeightPFOTool )
+      
+    public:
+
+    /** given a PFO, extract weight */
+    virtual StatusCode fillWeight( const xAOD::PFO& cpfo, float& weight ) = 0;
+
+  };
+
+}
+#endif

Reconstruction/PFlow/PFlowUtils/PFlowUtils/WeightPFOTool.h

+/*
+  Copyright (C) 2002-2017 CERN for the benefit of the ATLAS collaboration
+*/
+
+#ifndef WEIGHTPFOTOOL_H
+#define WEIGHTPFOTOOL_H
+
+/** Simple class to weight charged PFO for jets and met */
+
+#include "AsgTools/AsgTool.h"
+
+#include "PFlowUtils/IWeightPFOTool.h"
+
+#include <string>
+
+namespace CP {
+
+  class WeightPFOTool : public virtual IWeightPFOTool, public asg::AsgTool {
+
+    /** Athena constructor */
+    ASG_TOOL_CLASS( WeightPFOTool, IWeightPFOTool );
+
+  public:
+    /** Rootcore constructor */
+    WeightPFOTool(const std::string& name);
+
+    // given a PFO, extract weight
+    StatusCode fillWeight( const xAOD::PFO& cpfo, float& weight );
+
+  private:
+
+  };
+
+}
+#endif

Reconstruction/PFlow/PFlowUtils/Root/WeightPFOTool.cxx

+/*
+  Copyright (C) 2002-2017 CERN for the benefit of the ATLAS collaboration
+*/
+
+#include "PFlowUtils/WeightPFOTool.h"
+
+namespace CP {
+
+  WeightPFOTool::WeightPFOTool(const std::string& name) : asg::AsgTool( name ) { }
+
+  // The intended result:
+  // 
+  // Subtraction applied (inDenseEnvironment==false)
+  // pt < 30 GeV: Ptrk [weight = 1]
+  // 30 <= pt < 60 GeV: Ptrk ( E/P + (1-E/P)(1 - (pt - 30)/30 ) ) [weight = E/P + (1-E/P)(1 - (pt - 30)/30 )]
+  // pt >= 60 GeV: Ptrk * E/P [weight = E/P]
+  // 
+  // Subtraction not applied (inDenseEnvironment==true)
+  // pt < 30 GeV: Ptrk (1 - E/P) + Ecal [weight = (1-E/P]
+  // 30 <= pt < 60 GeV: Ptrk ( (1-E/P)(1 - (pt - 30)/30 ) ) + Ecal [weight = (1-E/P)(1 - (pt - 30)/30 )]
+  // pt >= 60 GeV: Ecal [weight = 0]
+
+  StatusCode WeightPFOTool::fillWeight( const xAOD::PFO& cpfo, float& weight ) {
+    // Compute the weights internally
+    weight = 0.;
+    if(cpfo.pt()>100e3) {
+      ATH_MSG_WARNING("PFO with invalid pt " << cpfo.pt() << ", quitting.");
+      return StatusCode::FAILURE;
+    }
+	
+    int isInDenseEnvironment = false;
+    float expectedEnergy = 0.0;
+    bool gotVariable = cpfo.attribute(xAOD::PFODetails::PFOAttributes::eflowRec_isInDenseEnvironment,isInDenseEnvironment);
+    gotVariable &= cpfo.attribute(xAOD::PFODetails::PFOAttributes::eflowRec_tracksExpectedEnergyDeposit,expectedEnergy);
+    if (!gotVariable) {
+      ATH_MSG_WARNING("This charged PFO did not have eflowRec_isInDenseEnvironment or eflowRec_tracksExpectedEnergyDeposit set");
+      return StatusCode::FAILURE;
+    } else {
+      // Start by computing the correction as though we subtracted the calo energy
+      // This interpolates between the full track P and the expected calo E
+      float EoverP = expectedEnergy/cpfo.e(); // divide once only
+      if(cpfo.pt()<30e3) {        // take full track
+	weight = 1.;
+      } else if(cpfo.pt()<60e3) { // linearly interpolate between 1 and E/P
+	float interpolf = (1.0 - (cpfo.pt()-30000)/30000);
+	weight = EoverP + interpolf * (1-EoverP);
+      } else {                    // take the expected energy
+	weight = EoverP;
+      }
+
+      if(isInDenseEnvironment) {
+	// In this case we further remove the expected deposited energy from the track
+	weight -= EoverP;
+      }
+      // If the weight went to 0, set it to the ghost scale, so that the cPFOs
+      // are always added to the track.
+      if (weight<1e-9) {weight = 1e-40;}
+    }
+	
+    return StatusCode::SUCCESS;
+  }
+
+}

Reconstruction/PFlow/PFlowUtils/src/components/PFlowUtils_entries.cxx

 #include "GaudiKernel/DeclareFactoryEntries.h"
 #include "PFlowUtils/RetrievePFOTool.h"
+#include "PFlowUtils/WeightPFOTool.h"
 #include "PFlowUtils/ParticleFlowEventFilter_r207.h"
 
 DECLARE_NAMESPACE_TOOL_FACTORY( CP, RetrievePFOTool)
+DECLARE_NAMESPACE_TOOL_FACTORY( CP, WeightPFOTool)
 DECLARE_ALGORITHM_FACTORY(ParticleFlowEventFilter_r207)
 
 DECLARE_FACTORY_ENTRIES(PFlowUtils){
   DECLARE_NAMESPACE_TOOL (CP, RetrievePFOTool)
+  DECLARE_NAMESPACE_TOOL (CP, WeightPFOTool)
   DECLARE_ALGORITHM(ParticleFlowEventFilter_r207)  
 }