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File indexing completed on 2021-02-14 13:30:41

0001 #ifndef L1Trigger_TrackFindingTMTT_HTrphi_h
0002 #define L1Trigger_TrackFindingTMTT_HTrphi_h
0003 
0004 #include "L1Trigger/TrackFindingTMTT/interface/HTbase.h"
0005 
0006 #include <vector>
0007 #include <list>
0008 #include <utility>
0009 #include <atomic>
0010 
0011 //=== The r-phi Hough Transform array for a single (eta,phi) sector.
0012 //===
0013 //=== Its axes are (q/Pt, phiTrk), where phiTrk is the phi at which the track crosses a
0014 //=== user-configurable radius from the beam-line.
0015 
0016 namespace tmtt {
0017 
0018   class Settings;
0019   class Stub;
0020   class TP;
0021   class L1fittedTrack;
0022 
0023   class HTrphi : public HTbase {
0024   public:
0025     enum class HTshape { square, diamond, hexagon, brick };
0026 
0027     //--- Error monitoring
0028 
0029     struct ErrorMonitor {
0030       // Maximum |gradient| of line corresponding to any stub. FW assumes it's < 1.0.
0031       std::atomic<float> maxLineGradient;
0032       // Error count when stub added to cell not NE, E or SE of cell stub added to in previous HT column.
0033       std::atomic<unsigned int> numErrorsTypeA;
0034       // Error count when stub added to more than 2 cells in one HT column
0035       std::atomic<unsigned int> numErrorsTypeB;
0036       // Error count normalisation
0037       std::atomic<unsigned int> numErrorsNorm;
0038     };
0039 
0040     // Initialization with sector number, eta range covered by sector and phi coordinate of its centre.
0041     HTrphi(const Settings* settings,
0042            unsigned int iPhiSec,
0043            unsigned int iEtaReg,
0044            float etaMinSector,
0045            float etaMaxSector,
0046            float phiCentreSector,
0047            ErrorMonitor* errMon = nullptr);
0048 
0049     ~HTrphi() override = default;
0050 
0051     // Add stub to HT array.
0052     // If eta subsectors are being used within each sector, specify which ones the stub is compatible with.
0053     void store(Stub* stub, const std::vector<bool>& inEtaSubSecs);
0054 
0055     // Termination. Causes HT array to search for tracks etc.
0056     // ... function end() is in base class ...
0057 
0058     //=== Info about track candidates found.
0059 
0060     // ... is available via base class ...
0061 
0062     //=== Utilities
0063 
0064     // Get the values of the track helix params corresponding to middle of a specified HT cell (i,j).
0065     // The helix parameters returned will be those corresponding to the two axes of the HT array.
0066     // So they might be (q/pt, phi0) or (q/pt, phi65) etc. depending on the configuration.
0067     std::pair<float, float> helix2Dhough(unsigned int i, unsigned int j) const override;
0068 
0069     // Get the values of the track helix params corresponding to middle of a specified HT cell (i,j).
0070     // The helix parameters returned will be always be (q/pt, phi0), irrespective of how the axes
0071     // of the HT array are defined.
0072     std::pair<float, float> helix2Dconventional(unsigned int i, unsigned int j) const override;
0073 
0074     // Which cell in HT array should this TP be in, based on its true trajectory?
0075     // (If TP is outside HT array, it it put in the closest bin inside it).
0076     std::pair<unsigned int, unsigned int> trueCell(const TP* tp) const override;
0077 
0078     // Which cell in HT array should this fitted track be in, based on its fitted trajectory?
0079     // Always uses beam-spot constrained trajectory if available.
0080     // (If fitted track is outside HT array, it it put in the closest bin inside it).
0081     std::pair<unsigned int, unsigned int> cell(const L1fittedTrack* fitTrk) const override;
0082 
0083     // Check if specified cell has been merged with its 2x2 neighbours into a single cell,
0084     // as it is in low Pt region.
0085     bool mergedCell(unsigned int iQoverPtBin, unsigned int jPhiTrkBin) const;
0086 
0087     // Number of stubs received from GP, irrespective of whether the stub was actually stored in
0088     // a cell in the HT array.
0089     unsigned int nReceivedStubs() const { return nReceivedStubs_; }
0090 
0091     // Determine which m-bin (q/pt) range the specified track is in. (Used if outputting each m bin range on a different opto-link).
0092     unsigned int getMbinRange(const L1track2D& trk) const;
0093 
0094   private:
0095     // For a given Q/Pt bin, find the range of phi bins that a given stub is consistent with.
0096     std::pair<unsigned int, unsigned int> iPhiRange(const Stub* stub,
0097                                                     unsigned int iQoverPtBin,
0098                                                     bool debug = false) const;
0099 
0100     // Check that limitations of firmware would not prevent stub being stored correctly in this HT column.
0101     void countFirmwareErrors(unsigned int iQoverPtBin,
0102                              unsigned int iPhiTrkBinMin,
0103                              unsigned int iPhiTrkBinMax,
0104                              unsigned int jPhiTrkBinMinLast,
0105                              unsigned int jPhiTrkBinMaxLast);
0106 
0107     // Calculate line |gradient| of stubs in HT array, so can check it doesn't exceed 1.
0108     float calcLineGradArray(float r) const;
0109 
0110     // If requested, kill those tracks in this sector that can't be read out during the time-multiplexed period, because
0111     // the HT has associated too many stubs to tracks.
0112     std::list<L1track2D> killTracksBusySec(const std::list<L1track2D>& tracks) const override;
0113 
0114     // Define the order in which the hardware processes rows of the HT array when it outputs track candidates.
0115     // Currently corresponds to highest Pt tracks first.
0116     // If two tracks have the same Pt, the -ve charge one is output before the +ve charge one.
0117     std::vector<unsigned int> rowOrder(unsigned int numRows) const override;
0118 
0119   private:
0120     float invPtToDphi_;  // conversion constant.
0121 
0122     HTshape shape_;
0123     std::vector<std::vector<std::pair<float, float> > > cellCenters_;
0124 
0125     //--- Specifications of HT array.
0126 
0127     float maxAbsQoverPtAxis_;        // Max. |q/Pt| covered by  HT array.
0128     unsigned int nBinsQoverPtAxis_;  // Number of bins in HT array in q/Pt.
0129     float binSizeQoverPtAxis_;       // HT array bin size in q/Pt.
0130 
0131     float chosenRofPhi_;            // Use phi of track at radius="chosenRofPhi" to define one of the r-phi HT axes.
0132     float phiCentreSector_;         // phiTrk angle of centre of this (eta,phi) sector.
0133     float maxAbsPhiTrkAxis_;        // Half-width of phiTrk axis in HT array.
0134     unsigned int nBinsPhiTrkAxis_;  // Number of bins in HT array in phiTrk axis.
0135     float binSizePhiTrkAxis_;       // HT array bin size in phiTrk
0136     // Optionally merge 2x2 neighbouring cells into a single cell at low Pt, to reduce efficiency loss due to scattering. (Used also by mini-HT).
0137     bool enableMerge2x2_;
0138     float minInvPtToMerge2x2_;
0139 
0140     //--- Options when filling HT array.
0141 
0142     // Take all cells in HT array crossed by line corresponding to each stub (= 0) or take only some to reduce rate at cost of efficiency ( > 0)
0143     unsigned int killSomeHTCellsRphi_;
0144     // Options for killing stubs/tracks that cant be sent within time-multiplexed period.
0145     bool busyInputSectorKill_;
0146     bool busySectorKill_;
0147     unsigned int busyInputSectorNumStubs_;
0148     unsigned int busySectorNumStubs_;
0149     std::vector<unsigned int> busySectorMbinRanges_;
0150     std::vector<unsigned int> busySectorMbinOrder_;
0151     bool busySectorUseMbinRanges_;
0152     bool busySectorUseMbinOrder_;
0153     std::vector<unsigned int> busySectorMbinLow_;
0154     std::vector<unsigned int> busySectorMbinHigh_;
0155 
0156     // Number of stubs received from GP, irrespective of whether the stub was actually stored in
0157     // a cell in the HT array.
0158     unsigned int nReceivedStubs_;
0159 
0160     // Error monitoring.
0161     ErrorMonitor* errMon_;
0162 
0163     // ... The Hough transform array data is in the base class ...
0164 
0165     // ... The list of found track candidates is in the base class ...
0166   };
0167 
0168 }  // namespace tmtt
0169 
0170 #endif