Minor improvements (cms-sw#120)

* Minor improvements

* Added comments

L1Trigger/TrackFindingTracklet/interface/PurgeDuplicate.h

@@ -7,6 +7,13 @@
 
 #include <vector>
 
+// Run algorithm to remove duplicate tracks.
+// Returns Track object that represent output at end of L1 track chain, 
+// (and are later converted to TTTrack). Duplicate Track objects are flagged,
+// but only deleted if using the Hybrid algo.
+// Also writes to memory the same tracks in more detailed Tracklet format,
+// where duplicates are all deleted.
+
 namespace trklet {
 
   class Settings;

L1Trigger/TrackFindingTracklet/interface/Settings.h

@@ -298,6 +298,7 @@ namespace trklet {
     double phicritminmc() const { return phicritmin() - dphicritmc_; }
     double phicritmaxmc() const { return phicritmax() + dphicritmc_; }
 
+    // Stub digitization granularities
     double kphi() const { return dphisectorHG() / (1 << nphibitsstub(0)); }
     double kphi1() const { return dphisectorHG() / (1 << nphibitsstub(N_LAYER - 1)); }
     double kphi(unsigned int layerdisk) const { return dphisectorHG() / (1 << nphibitsstub(layerdisk)); }
@@ -383,6 +384,7 @@ namespace trklet {
     int chisqphifactbits() const { return chisqphifactbits_; }
     int chisqzfactbits() const { return chisqzfactbits_; }
 
+    // Helix param digisation granularities
     //0.02 here is the maximum range in rinv values that can be represented
     double krinvpars() const {
       int shift = ceil(-log2(0.02 * rmaxdisk_ / ((1 << nbitsrinv_) * dphisectorHG())));
@@ -775,6 +777,7 @@ namespace trklet {
                                                            {"PR", 108},
                                                            {"ME", 108},
                                                            {"MC", 105},
+                                                           {"TB", 108},
                                                            {"MP", 108},
                                                            {"TP", 108},
                                                            {"TRE", 108}};

L1Trigger/TrackFindingTracklet/interface/Track.h

@@ -17,8 +17,9 @@ namespace trklet {
 
   class Track {
   public:
-    Track(TrackPars<int> ipars,
-          int ichisqrphi,
+    // Create track from digitized helix params & stubs
+    Track(TrackPars<int> ipars, // digi helix
+          int ichisqrphi, // digi chi2
           int ichisqrz,
           double chisqrphi,
           double chisqrz,
@@ -54,6 +55,7 @@ namespace trklet {
       return (settings.c() * settings.bfield() * 0.01) / (ipars_.rinv() * settings.krinvpars());
     }
 
+    // Get floating point helix params by undigitized digi helix params
     double phi0(Settings const& settings) const;
 
     double eta(Settings const& settings) const { return asinh(ipars_.t() * settings.ktpars()); }

L1Trigger/TrackFindingTracklet/interface/Tracklet.h

@@ -157,6 +157,7 @@ namespace trklet {
       return FPGAWord(ichisqrphifit_.value() + ichisqrzfit_.value(), ichisqrphifit_.nbits());
     }
 
+    // Note floating & digitized helix params after track fit.
     void setFitPars(double rinvfit,
                     double phi0fit,
                     double d0fit,
@@ -185,6 +186,7 @@ namespace trklet {
     const std::string diskstubstr(const unsigned disk) const;
     std::string trackfitstr() const;
 
+    // Create a Track object from stubs & digitized track helix params
     Track makeTrack(const std::vector<const L1TStub*>& l1stubs);
 
     Track* getTrack() {

L1Trigger/TrackFindingTracklet/src/FitTrack.cc

@@ -124,13 +124,15 @@ void FitTrack::trackFitKF(Tracklet* tracklet,
         stubidslist.push_back(std::make_pair(layer, it->phiregionaddress()));
       }
 
-      // And that's all we need! The rest is just for fitting (in PurgeDuplicate)
-      return;
-    }
+      // And that's all we need! The rest is just for track fit (done in PurgeDuplicate)
 
-    HybridFit hybridFitter(iSector_, settings_, globals_);
-    hybridFitter.Fit(tracklet, trackstublist);
-    return;
+    } else {
+
+      // Track fit only called here if not running duplicate removal 
+      // before fit. (e.g. If skipping duplicate removal).
+      HybridFit hybridFitter(iSector_, settings_, globals_);
+      hybridFitter.Fit(tracklet, trackstublist);
+    }
   }
 }
 #endif
@@ -889,8 +891,8 @@ void FitTrack::execute(unsigned int iSector) {
     indexArray[i] = 0;
   }
 
-  int countAll = 0;
-  int countFit = 0;
+  unsigned int countAll = 0;
+  unsigned int countFit = 0;
 
   Tracklet* bestTracklet = nullptr;
   do {
@@ -989,6 +991,7 @@ void FitTrack::execute(unsigned int iSector) {
 
     std::vector<const Stub*> trackstublist;
     std::vector<std::pair<int, int>> stubidslist;
+    // Track Builder cut of >= 4 layers with stubs.
     if ((bestTracklet->getISeed() >= (int)N_SEED_PROMPT && nMatchesUniq >= 1) ||
         nMatchesUniq >= 2) {  //For seeds index >=8 (triplet seeds), there are three stubs associated from start.
       countFit++;
@@ -1021,7 +1024,7 @@ void FitTrack::execute(unsigned int iSector) {
       }
     }
 
-  } while (bestTracklet != nullptr);
+  } while (bestTracklet != nullptr && countAll < settings_.maxStep("TB"));
 
   if (settings_.writeMonitorData("FT")) {
     globals_->ofstream("fittrack.txt") << getName() << " " << countAll << " " << countFit << endl;

L1Trigger/TrackFindingTracklet/src/PurgeDuplicate.cc

@@ -323,26 +323,29 @@ void PurgeDuplicate::execute(std::vector<Track>& outputtracks_, unsigned int iSe
 
     // Make the final track objects, fit with KF, and send to output
     for (unsigned int itrk = 0; itrk < numStublists; itrk++) {
-      Tracklet* tracklet = inputtracklets_[itrk];
-      std::vector<const Stub*> trackstublist = inputstublists_[itrk];
-
-      HybridFit hybridFitter(iSector, settings_, globals_);
-      hybridFitter.Fit(tracklet, trackstublist);
-
-      // If the track was accepted (and thus fit), add to output
-      if (tracklet->fit()) {
-        // Add track to output if it wasn't merged into another
-        Track* outtrack = tracklet->getTrack();
-        outtrack->setSector(iSector);
-        if (trackInfo[itrk].second == true)
-          outtrack->setDuplicate(true);
-        else
+      bool duplicateTrack = trackInfo[itrk].second;
+      if (not duplicateTrack) { // Don't waste CPU by calling KF for duplicates
+
+        Tracklet* tracklet = inputtracklets_[itrk];
+        std::vector<const Stub*> trackstublist = inputstublists_[itrk];
+
+        // Run KF track fit 
+        HybridFit hybridFitter(iSector, settings_, globals_);
+        hybridFitter.Fit(tracklet, trackstublist);
+
+        // If the track was accepted (and thus fit), add to output
+        if (tracklet->fit()) {
+          // Add fitted Track to output (later converted to TTTrack)
+          Track* outtrack = tracklet->getTrack();
+          outtrack->setSector(iSector);
+          // Also store fitted track as more detailed Tracklet object.
           outputtracklets_[trackInfo[itrk].first]->addTrack(tracklet);
 
-        // Add all tracks to standalone root file output
-        outtrack->setStubIDpremerge(inputstubidslists_[itrk]);
-        outtrack->setStubIDprefit(mergedstubidslists_[itrk]);
-        outputtracks_.push_back(*outtrack);
+          // Add all tracks to standalone root file output
+          outtrack->setStubIDpremerge(inputstubidslists_[itrk]);
+          outtrack->setStubIDprefit(mergedstubidslists_[itrk]);
+          outputtracks_.push_back(*outtrack);
+        }
       }
     }
   }

L1Trigger/TrackFindingTracklet/src/Sector.cc

@@ -410,12 +410,17 @@ void Sector::executeMP() {
   }
 }
 
+// Order here reflects Tracklet algo that calls FitTrack before PurgeDuplicates.
+// If using Hybrid, then PurgeDuplicates runs both duplicate removal & KF steps.
+// (unless duplicate removal disabled, in which case FitTrack runs KF).
+
 void Sector::executeFT() {
   for (auto& i : FT_) {
     i->execute(isector_);
   }
 }
 
+// Returns tracks reconstructed by L1 track chain.
 void Sector::executePD(std::vector<Track>& tracks) {
   for (auto& i : PD_) {
     i->execute(tracks, isector_);

L1Trigger/TrackFindingTracklet/src/Tracklet.cc

@@ -735,9 +735,12 @@ std::string Tracklet::trackfitstr() const {
   return oss;
 }
 
+// Create a Track object from stubs & digitized track helix params
+
 Track Tracklet::makeTrack(const vector<const L1TStub*>& l1stubs) {
   assert(fit());
 
+  // Digitized track helix params
   TrackPars<int> ipars(fpgafitpars_.rinv().value(),
                        fpgafitpars_.phi0().value(),
                        fpgafitpars_.d0().value(),