Merge pull request #48148 from tcuisset/pr-fixSimToReco

TICL: change Trackster SimToReco score, to fix overlapping CaloParticle issues

Author: cmsbuild

SimCalorimetry/HGCalAssociatorProducers/plugins/AllTracksterToSimTracksterAssociatorsByHitsProducer.cc

@@ -391,18 +391,24 @@ void AllTracksterToSimTracksterAssociatorsByHitsProducer::produce(edm::StreamID,
           float simFraction = simFractions[i];
           const auto& recHit = rechitManager[hitIndex];
           float rechitEnergy = recHit.energy();
-          float squaredSimFraction = simFraction * simFraction;
           float squaredRecHitEnergy = rechitEnergy * rechitEnergy;
           float simSharedEnergy = rechitEnergy * simFraction;
           const auto& hitToRecoTracksterVec = hitToAssociatedRecoTracksterMap[i];
           for (const auto& recoTracksterElement : hitToRecoTracksterVec) {
             auto recoTracksterIndex = recoTracksterElement.index();
-            float recoFraction = recoTracksterElement.fraction();
+            float recoFraction =
+                recoTracksterElement.fraction();  // Either zero or one when no sharing of rechits between tracksters
             edm::Ref<std::vector<ticl::Trackster>> recoTracksterRef(recoTrackstersHandle, recoTracksterIndex);
             float sharedEnergy = std::min(recoFraction * rechitEnergy, simSharedEnergy);
-            float squaredFraction =
-                std::min(squaredSimFraction, (recoFraction - simFraction) * (recoFraction - simFraction));
-            float score = invDenominator * squaredFraction * squaredRecHitEnergy;
+            /* SimToReco score logic:
+             - simFraction = 0 && recoFraction >= 0 : trackster contains non-sim associated elements : ignore in simToReco
+             - simFraction > 0 && recoFraction == 0 : simhits not present in reco trackster : penalty in score by simFraction*E
+             - simFraction == 1 && recoFraction == 1 : good association
+             - 1 > simFraction > recoFraction > 0 :  we are missing some sim energy, penalty in score by the missing part : (simFraction-recoFraction)*E
+             - 1 > recoFraction > simFraction > 0 : consider as good association, as there is enough reco to cover the sim
+            */
+            float simMinusRecoFraction = std::max(0.f, simFraction - recoFraction);
+            float score = invDenominator * simMinusRecoFraction * simMinusRecoFraction * squaredRecHitEnergy;
             simTracksterToTracksterMap->insert(simTracksterRef, recoTracksterRef, sharedEnergy, score);
           }
         }

SimCalorimetry/HGCalAssociatorProducers/plugins/AllTracksterToSimTracksterAssociatorsByLCsProducer.cc

@@ -290,7 +290,6 @@ void AllTracksterToSimTracksterAssociatorsByLCsProducer::produce(edm::StreamID,
           unsigned int layerClusterId = layerClustersIds[i];
           const auto& layerCluster = layerClusters[layerClusterId];
           float simFraction = 1.f / simTrackster.vertex_multiplicity(i);
-          float squaredSimFraction = simFraction * simFraction;
           float squaredLayerClusterEnergy = layerCluster.energy() * layerCluster.energy();
           float simSharedEnergy = layerCluster.energy() * simFraction;
           float invLayerClusterEnergy = 1.f / layerCluster.energy();
@@ -300,10 +299,18 @@ void AllTracksterToSimTracksterAssociatorsByLCsProducer::produce(edm::StreamID,
             float recoSharedEnergy = recoTracksterElement.sharedEnergy();
             edm::Ref<std::vector<ticl::Trackster>> recoTracksterRef(recoTrackstersHandle, recoTracksterIndex);
             float sharedEnergy = std::min(recoSharedEnergy, simSharedEnergy);
-            float recoFraction = recoSharedEnergy * invLayerClusterEnergy;
-            float score = invDenominator *
-                          std::min(squaredSimFraction, (simFraction - recoFraction) * (simFraction - recoFraction)) *
-                          squaredLayerClusterEnergy;
+            float recoFraction =
+                recoSharedEnergy *
+                invLayerClusterEnergy;  // Either zero or one when no sharing of rechits between tracksters
+            /* SimToReco score logic:
+             - simFraction = 0 && recoFraction >= 0 : trackster contains non-sim associated elements : ignore in simToReco
+             - simFraction > 0 && recoFraction == 0 : simhits not present in reco trackster : penalty in score by simFraction*E
+             - simFraction == 1 && recoFraction == 1 : good association
+             - 1 > simFraction > recoFraction > 0 :  we are missing some sim energy, penalty in score by the missing part : (simFraction-recoFraction)*E
+             - 1 > recoFraction > simFraction > 0 : consider as good association, as there is enough reco to cover the sim
+            */
+            float simMinusRecoFraction = std::max(0.f, simFraction - recoFraction);
+            float score = invDenominator * simMinusRecoFraction * simMinusRecoFraction * squaredLayerClusterEnergy;
             simTracksterToTracksterMap->insert(tracksterIndex, recoTracksterIndex, sharedEnergy, score);
           }
         }