Merge pull request #17687 from nickmccoll/ME0_updatedSegAlgo_90

CSC RU segment algorithm tuned for ME0

RecoLocalMuon/GEMSegment/plugins/ME0SegAlgoRU.h

@@ -0,0 +1,112 @@
+#ifndef ME0Segment_ME0SegAlgoRU_h
+#define ME0Segment_ME0SegAlgoRU_h
+
+/**
+ * \class ME0SegAlgoRU
+ * adapted from CSC to ME0 bt Marcello Maggi
+ *
+ * This is the original algorithm for building endcap muon track segments
+ * out of the rechit's in a ME0Chamber
+ * 'RU' = 'RUssia' = Road Usage
+ *
+ * A ME0Segment is a RecSegment4D, and is built from
+ * ME0RecHit2D objects, each of which is a RecHit2DLocalPos. <BR>
+ *
+ * This class is used by the ME0SegmentAlgorithm. <BR>
+ * Alternative algorithms can be used for the segment building
+ * by writing classes like this, and then selecting which one is actually
+ * used via the ME0SegmentBuilder. <BR>
+ *
+ * developed and implemented by Vladimir Palichik <Vladimir.Paltchik@cern.ch>
+ *                          and Nikolay Voytishin <nikolay.voytishin@cern.ch>
+ */
+
+#include <RecoLocalMuon/GEMSegment/plugins/ME0SegmentAlgorithmBase.h>
+#include <DataFormats/GEMRecHit/interface/ME0RecHit.h>
+#include "MuonSegFit.h"
+
+
+#include <vector>
+
+class MuonSegFit;
+class ME0SegAlgoRU : public ME0SegmentAlgorithmBase {
+
+public:
+	struct SegmentParameters {
+		float maxETASeeds       ;
+		float maxPhiSeeds       ;
+		float maxPhiAdditional  ;
+		float maxChi2Additional ;
+		float maxChi2Prune      ;
+		float maxChi2GoodSeg    ;
+		float maxTOFDiff        ;
+		unsigned int minNumberOfHits;
+		bool  requireBeamConstr  ;
+
+	};
+
+	// We need to be able to flag a hit as 'used' and so need a container of bool's.
+	typedef std::vector<bool> BoolContainer;
+	typedef std::vector<std::pair<float,HitAndPositionPtrContainer> > SegmentByMetricContainer;
+
+	/// Constructor
+	explicit ME0SegAlgoRU(const edm::ParameterSet& ps);
+	/// Destructor
+	virtual ~ME0SegAlgoRU() {};
+
+	/**
+	 * Here we must implement the algorithm
+	 */
+	std::vector<ME0Segment> run(const ME0Chamber * chamber, const HitAndPositionContainer& rechits);
+
+private:
+
+	//Look for segments that have at least "n_seg_min" consituents and following the associated paramters
+	void lookForSegments(const SegmentParameters& params, const unsigned int n_seg_min, const HitAndPositionContainer& rechits, const std::vector<unsigned int>& recHits_per_layer, BoolContainer& used, std::vector<ME0Segment>& segments) const;
+	//Look for any hits between the two seed hits consistent with a segment
+	void tryAddingHitsToSegment( const float maxTOF,const float maxETA,  const float maxPhi, const float maxChi2, std::unique_ptr<MuonSegFit>& current_fit, HitAndPositionPtrContainer& proto_segment,
+			const BoolContainer& used, HitAndPositionContainer::const_iterator i1, HitAndPositionContainer::const_iterator i2) const;
+	//Remove extra hits until the segment passes "maxChi2"
+	void pruneBadHits(const float maxChi2, HitAndPositionPtrContainer& proto_segment,  std::unique_ptr<MuonSegFit>& fit, const unsigned int n_seg_min) const;
+	//Remove any overlapping segments by which has the lowset chi2
+	void addUniqueSegments(SegmentByMetricContainer& proto_segments, std::vector<ME0Segment>& segments, BoolContainer& used) const;
+
+	//Are the two seed hits consistent spatially?
+	bool areHitsCloseInEta(const float maxETA, const bool beamConst,  const GlobalPoint& h1, const GlobalPoint& h2) const;
+	bool areHitsCloseInGlobalPhi(const float maxPHI, const unsigned int nLayDisp, const GlobalPoint& h1, const GlobalPoint& h2) const;
+
+	//Add a hit to a segment
+	std::unique_ptr<MuonSegFit> addHit(HitAndPositionPtrContainer& proto_segment, const HitAndPosition& aHit) const;
+	//Does the segment have any hits on this layer?
+	bool hasHitOnLayer(const HitAndPositionPtrContainer& proto_segment, const unsigned int layer) const;
+	//Produce a new fit
+	std::unique_ptr<MuonSegFit> makeFit(const HitAndPositionPtrContainer& proto_segment) const;
+
+	//Is this hit consistent in time with the other hits?
+	bool areHitsConsistentInTime(const float maxTOF, const HitAndPositionPtrContainer& proto_segment, const HitAndPosition& h)  const;
+	//Is this new hit btw the seeds near the segment fit?
+	bool isHitNearSegment(const float maxETA, const float maxPHI, const std::unique_ptr<MuonSegFit>& fit, const HitAndPositionPtrContainer& proto_segment, const HitAndPosition& h)  const;
+	//Return a chi2 for a hit and a predicted segment extrapolation
+	float getHitSegChi2(const std::unique_ptr<MuonSegFit>& fit, const ME0RecHit& hit) const;
+	//Global point of a segment extrapolated to a Z value
+	GlobalPoint globalAtZ(const std::unique_ptr<MuonSegFit>& fit, float z) const;
+
+	//Try adding a hit instead of another and return new or old, depending on which has the smallest chi2
+	void compareProtoSegment(std::unique_ptr<MuonSegFit>& current_fit, HitAndPositionPtrContainer& current_proto_segment, const HitAndPosition& new_hit) const;
+	//Try adding this hit to the segment, dont if the new chi2 is too big
+	void increaseProtoSegment(const float maxChi2,  std::unique_ptr<MuonSegFit>& current_fit, HitAndPositionPtrContainer& current_proto_segment, const HitAndPosition& new_hit) const;
+
+
+	const std::string myName;
+	bool doCollisions;
+	bool allowWideSegments;
+
+	SegmentParameters stdParameters;
+	SegmentParameters displacedParameters;
+	SegmentParameters wideParameters;
+
+	//Objects used to produce the segments
+	const ME0Chamber *theChamber;
+};
+
+#endif