Merge pull request #37580 from trackreco/errorRescalePlusOverlapHits

MkFit TrackCandidate error rescale + relaxed selection for overlap hits

RecoTracker/MkFit/README.md

@@ -51,7 +51,7 @@ $ runTheMatrix.py -l <workflow(s)> --apply 2 --command "--procModifiers tracking
 * *maxHolesPerCand:* maximum number of allowed holes on a candidate
 * *maxConsecHoles:*  maximum number of allowed consecutive holes on a candidate
 * *chi2Cut_min:*     minimum chi2 cut for accepting a new hit
-* *chi2CutOverlap:*  chi2 cut for accepting an overlap hit
+* *chi2CutOverlap:*  chi2 cut for accepting an overlap hit (currently NOT used)
 * *pTCutOverlap:*    pT cut below which the overlap hits are not picked up
 
 #### Seed cleaning params (based on elliptical dR-dz cut)

RecoTracker/MkFit/plugins/MkFitOutputConverter.cc

@@ -110,6 +110,8 @@ class MkFitOutputConverter : public edm::global::EDProducer<> {
   const float qualityMaxZ_;
   const float qualityMaxPosErrSq_;
   const bool qualitySignPt_;
+
+  const bool doErrorRescale_;
 };
 
 MkFitOutputConverter::MkFitOutputConverter(edm::ParameterSet const& iConfig)
@@ -134,7 +136,8 @@ MkFitOutputConverter::MkFitOutputConverter(edm::ParameterSet const& iConfig)
       qualityMaxRsq_{float(pow(iConfig.getParameter<double>("qualityMaxR"), 2))},
       qualityMaxZ_{float(iConfig.getParameter<double>("qualityMaxZ"))},
       qualityMaxPosErrSq_{float(pow(iConfig.getParameter<double>("qualityMaxPosErr"), 2))},
-      qualitySignPt_{iConfig.getParameter<bool>("qualitySignPt")} {}
+      qualitySignPt_{iConfig.getParameter<bool>("qualitySignPt")},
+      doErrorRescale_{iConfig.getParameter<bool>("doErrorRescale")} {}
 
 void MkFitOutputConverter::fillDescriptions(edm::ConfigurationDescriptions& descriptions) {
   edm::ParameterSetDescription desc;
@@ -156,6 +159,8 @@ void MkFitOutputConverter::fillDescriptions(edm::ConfigurationDescriptions& desc
   desc.add<double>("qualityMaxPosErr", 100)->setComment("max position error for converted tracks");
   desc.add<bool>("qualitySignPt", true)->setComment("check sign of 1/pt for converted tracks");
 
+  desc.add<bool>("doErrorRescale", true)->setComment("rescale candidate error before final fit");
+
   descriptions.addWithDefaultLabel(desc);
 }
 
@@ -341,6 +346,12 @@ TrackCandidateCollection MkFitOutputConverter::convertCandidates(const MkFitOutp
     const auto seedIndex = cand.label();
     LogTrace("MkFitOutputConverter") << " from seed " << seedIndex << " seed hits";
 
+    // Rescale candidate error if candidate is already propagated to first layer,
+    // to be consistent with TransientInitialStateEstimator::innerState used in CkfTrackCandidateMakerBase
+    // Error is only rescaled for candidates propagated to first layer;
+    // otherwise, candidates undergo backwardFit where error is already rescaled
+    if (mkFitOutput.propagatedToFirstLayer() && doErrorRescale_)
+      fts.rescaleError(100.);
     auto tsosDet =
         mkFitOutput.propagatedToFirstLayer()
             ? convertInnermostState(fts, recHits, propagatorAlong, propagatorOpposite)

RecoTracker/MkFitCore/interface/IterationConfig.h

@@ -93,7 +93,7 @@ namespace mkfit {
     int maxConsecHoles = 1;
     float chi2Cut_min = 15.0;
     float chi2CutOverlap = 3.5;
-    float pTCutOverlap = 1.0;
+    float pTCutOverlap = 0.0;
 
     //seed cleaning params
     float c_ptthr_hpt = 2.0;

RecoTracker/MkFitCore/src/MkFinder.cc

@@ -1074,7 +1074,8 @@ namespace mkfit {
                 newcand.setScore(getScoreCand(newcand, true /*penalizeTailMissHits*/, true /*inFindCandidates*/));
                 newcand.setOriginIndex(m_CandIdx(itrack, 0, 0));
 
-                if (chi2 < m_iteration_params->chi2CutOverlap) {
+                // To apply a fixed cut instead of dynamic cut for overlap: m_iteration_params->chi2CutOverlap
+                if (chi2 < max_c2) {
                   CombCandidate &ccand = *newcand.combCandidate();
                   ccand[m_CandIdx(itrack, 0, 0)].considerHitForOverlap(
                       hit_idx, layer_of_hits.refHit(hit_idx).detIDinLayer(), chi2);
@@ -1231,8 +1232,9 @@ namespace mkfit {
               nHitsAdded[itrack]++;
               const int hit_idx = m_XHitArr.At(itrack, hit_cnt, 0);
 
-              // Register hit for overlap consideration, here we apply chi2 cut
-              if (chi2 < m_iteration_params->chi2CutOverlap) {
+              // Register hit for overlap consideration, if chi2 cut is passed
+              // To apply a fixed cut instead of dynamic cut for overlap: m_iteration_params->chi2CutOverlap
+              if (chi2 < max_c2) {
                 ccand[m_CandIdx(itrack, 0, 0)].considerHitForOverlap(
                     hit_idx, layer_of_hits.refHit(hit_idx).detIDinLayer(), chi2);
               }