MuonSelectors.cc

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#include "DataFormats/MuonReco/interface/MuonSelectors.h"
#include "DataFormats/TrackReco/interface/Track.h"
#include "DataFormats/MuonDetId/interface/MuonSubdetId.h"
#include "DataFormats/MuonDetId/interface/CSCDetId.h"
#include "DataFormats/VertexReco/interface/Vertex.h"
#include "DataFormats/MuonReco/interface/MuonRPCHitMatch.h"

namespace muon {
SelectionType selectionTypeFromString( const std::string &label )
{
   static const SelectionTypeStringToEnum selectionTypeStringToEnumMap[] = {
      { "All", All },
      { "AllGlobalMuons", AllGlobalMuons },
      { "AllStandAloneMuons", AllStandAloneMuons },
      { "AllTrackerMuons", AllTrackerMuons },
      { "TrackerMuonArbitrated", TrackerMuonArbitrated },
      { "AllArbitrated", AllArbitrated },
      { "GlobalMuonPromptTight", GlobalMuonPromptTight },
      { "TMLastStationLoose", TMLastStationLoose },
      { "TMLastStationTight", TMLastStationTight },
      { "TM2DCompatibilityLoose", TM2DCompatibilityLoose },
      { "TM2DCompatibilityTight", TM2DCompatibilityTight },
      { "TMOneStationLoose", TMOneStationLoose },
      { "TMOneStationTight", TMOneStationTight },
      { "TMLastStationOptimizedLowPtLoose", TMLastStationOptimizedLowPtLoose },
      { "TMLastStationOptimizedLowPtTight", TMLastStationOptimizedLowPtTight },
      { "GMTkChiCompatibility", GMTkChiCompatibility },
      { "GMStaChiCompatibility", GMStaChiCompatibility},
      { "GMTkKinkTight", GMTkKinkTight},
      { "TMLastStationAngLoose", TMLastStationAngLoose },
      { "TMLastStationAngTight", TMLastStationAngTight },
      { "TMOneStationAngLoose", TMOneStationAngLoose },
      { "TMOneStationAngTight", TMOneStationAngTight },
      { "TMLastStationOptimizedBarrelLowPtLoose", TMLastStationOptimizedBarrelLowPtLoose },
      { "TMLastStationOptimizedBarrelLowPtTight", TMLastStationOptimizedBarrelLowPtTight },
      { "RPCMuLoose", RPCMuLoose },
      { "AllME0Muons", AllME0Muons },
      { "ME0MuonArbitrated", ME0MuonArbitrated },
      { "AllGEMMuons", AllGEMMuons },
      { "GEMMuonArbitrated", GEMMuonArbitrated },
      { 0, (SelectionType)-1 }
   };

   SelectionType value = (SelectionType)-1;
   bool found = false;
   for(int i = 0; selectionTypeStringToEnumMap[i].label && (! found); ++i)
      if (! strcmp(label.c_str(), selectionTypeStringToEnumMap[i].label)) {
         found = true;
         value = selectionTypeStringToEnumMap[i].value;
      }

   // in case of unrecognized selection type
   if (! found) throw cms::Exception("MuonSelectorError") << label << " is not a recognized SelectionType";
   return value;
}
}

unsigned int muon::RequiredStationMask( const reco::Muon& muon,
                      double maxChamberDist,
                      double maxChamberDistPull,
                      reco::Muon::ArbitrationType arbitrationType )
{
   unsigned int theMask = 0;

   for(int stationIdx = 1; stationIdx < 5; ++stationIdx)
      for(int detectorIdx = 1; detectorIdx < 3; ++detectorIdx)
         if(muon.trackDist(stationIdx,detectorIdx,arbitrationType) < maxChamberDist &&
               muon.trackDist(stationIdx,detectorIdx,arbitrationType)/muon.trackDistErr(stationIdx,detectorIdx,arbitrationType) < maxChamberDistPull)
            theMask += 1<<((stationIdx-1)+4*(detectorIdx-1));

   return theMask;
}

// ------------ method to calculate the calo compatibility for a track with matched muon info  ------------
float muon::caloCompatibility(const reco::Muon& muon) {
  return muon.caloCompatibility();
}

// ------------ method to calculate the segment compatibility for a track with matched muon info  ------------
float muon::segmentCompatibility(const reco::Muon& muon,reco::Muon::ArbitrationType arbitrationType) {
  bool use_weight_regain_at_chamber_boundary = true;
  bool use_match_dist_penalty = true;

  int nr_of_stations_crossed = 0;
  int nr_of_stations_with_segment = 0;
  std::vector<int> stations_w_track(8);
  std::vector<int> station_has_segmentmatch(8);
  std::vector<int> station_was_crossed(8);
  std::vector<float> stations_w_track_at_boundary(8);
  std::vector<float> station_weight(8);
  int position_in_stations = 0;
  float full_weight = 0.;

  for(int i = 1; i<=8; ++i) {
    // ********************************************************;
    // *** fill local info for this muon (do some counting) ***;
    // ************** begin ***********************************;
    if(i<=4) { // this is the section for the DTs
      if( muon.trackDist(i,1,arbitrationType) < 999999 ) { //current "raw" info that a track is close to a chamber
    ++nr_of_stations_crossed;
    station_was_crossed[i-1] = 1;
    if(muon.trackDist(i,1,arbitrationType) > -10. ) stations_w_track_at_boundary[i-1] = muon.trackDist(i,1,arbitrationType); 
    else stations_w_track_at_boundary[i-1] = 0.;
      }
      if( muon.segmentX(i,1,arbitrationType) < 999999 ) { //current "raw" info that a segment is matched to the current track
    ++nr_of_stations_with_segment;
    station_has_segmentmatch[i-1] = 1;
      }
    }
    else     { // this is the section for the CSCs
      if( muon.trackDist(i-4,2,arbitrationType) < 999999 ) { //current "raw" info that a track is close to a chamber
    ++nr_of_stations_crossed;
    station_was_crossed[i-1] = 1;
    if(muon.trackDist(i-4,2,arbitrationType) > -10. ) stations_w_track_at_boundary[i-1] = muon.trackDist(i-4,2,arbitrationType);
    else stations_w_track_at_boundary[i-1] = 0.;
      }
      if( muon.segmentX(i-4,2,arbitrationType) < 999999 ) { //current "raw" info that a segment is matched to the current track
    ++nr_of_stations_with_segment;
    station_has_segmentmatch[i-1] = 1;
      }
    }
    // rough estimation of chamber border efficiency (should be parametrized better, this is just a quick guess):
    // TF1 * merf = new TF1("merf","-0.5*(TMath::Erf(x/6.)-1)",-100,100);
    // use above value to "unpunish" missing segment if close to border, i.e. rather than not adding any weight, add
    // the one from the function. Only for dist ~> -10 cm, else full punish!.

    // ********************************************************;
    // *** fill local info for this muon (do some counting) ***;
    // ************** end *************************************;
  }

  // ********************************************************;
  // *** calculate weights for each station *****************;
  // ************** begin ***********************************;
  //    const float slope = 0.5;
  //    const float attenuate_weight_regain = 1.;
  // if attenuate_weight_regain < 1., additional punishment if track is close to boundary and no segment
  const float attenuate_weight_regain = 0.5; 

  for(int i = 1; i<=8; ++i) { // loop over all possible stations

    // first set all weights if a station has been crossed
    // later penalize if a station did not have a matching segment

    //old logic      if(station_has_segmentmatch[i-1] > 0 ) { // the track has an associated segment at the current station
    if( station_was_crossed[i-1] > 0 ) { // the track crossed this chamber (or was nearby)
      // - Apply a weight depending on the "depth" of the muon passage. 
      // - The station_weight is later reduced for stations with badly matched segments. 
      // - Even if there is no segment but the track passes close to a chamber boundary, the
      //   weight is set non zero and can go up to 0.5 of the full weight if the track is quite
      //   far from any station.
      ++position_in_stations;

      switch ( nr_of_stations_crossed ) { // define different weights depending on how many stations were crossed
      case 1 : 
    station_weight[i-1] =  1.;
    break;
      case 2 :
    if     ( position_in_stations == 1 ) station_weight[i-1] =  0.33;
    else                                 station_weight[i-1] =  0.67;
    break;
      case 3 : 
    if     ( position_in_stations == 1 ) station_weight[i-1] =  0.23;
    else if( position_in_stations == 2 ) station_weight[i-1] =  0.33;
    else                                 station_weight[i-1] =  0.44;
    break;
      case 4 : 
    if     ( position_in_stations == 1 ) station_weight[i-1] =  0.10;
    else if( position_in_stations == 2 ) station_weight[i-1] =  0.20;
    else if( position_in_stations == 3 ) station_weight[i-1] =  0.30;
    else                                 station_weight[i-1] =  0.40;
    break;
      
      default : 
//  LogTrace("MuonIdentification")<<"            // Message: A muon candidate track has more than 4 stations with matching segments.";
//  LogTrace("MuonIdentification")<<"            // Did not expect this - please let me know: ibloch@fnal.gov";
    // for all other cases
    station_weight[i-1] = 1./nr_of_stations_crossed;
      }

      if( use_weight_regain_at_chamber_boundary ) { // reconstitute some weight if there is no match but the segment is close to a boundary:
    if(station_has_segmentmatch[i-1] <= 0 && stations_w_track_at_boundary[i-1] != 0. ) {
      // if segment is not present but track in inefficient region, do not count as "missing match" but add some reduced weight. 
      // original "match weight" is currently reduced by at least attenuate_weight_regain, variing with an error function down to 0 if the track is 
      // inside the chamber.
      station_weight[i-1] = station_weight[i-1]*attenuate_weight_regain*0.5*(TMath::Erf(stations_w_track_at_boundary[i-1]/6.)+1.); // remark: the additional scale of 0.5 normalizes Err to run from 0 to 1 in y
    }
    else if(station_has_segmentmatch[i-1] <= 0 && stations_w_track_at_boundary[i-1] == 0.) { // no segment match and track well inside chamber
      // full penalization
      station_weight[i-1] = 0.;
    }
      }
      else { // always fully penalize tracks with no matching segment, whether the segment is close to the boundary or not.
    if(station_has_segmentmatch[i-1] <= 0) station_weight[i-1] = 0.;
      }

      if( station_has_segmentmatch[i-1] > 0 && 42 == 42 ) { // if track has matching segment, but the matching is not high quality, penalize
    if(i<=4) { // we are in the DTs
      if( muon.dY(i,1,arbitrationType) < 999999 && muon.dX(i,1,arbitrationType) < 999999) { // have both X and Y match
        if(
           TMath::Sqrt(TMath::Power(muon.pullX(i,1,arbitrationType),2.)+TMath::Power(muon.pullY(i,1,arbitrationType),2.))> 1. ) {
          // reduce weight
          if(use_match_dist_penalty) {
        // only use pull if 3 sigma is not smaller than 3 cm
        if(TMath::Sqrt(TMath::Power(muon.dX(i,1,arbitrationType),2.)+TMath::Power(muon.dY(i,1,arbitrationType),2.)) < 3. && TMath::Sqrt(TMath::Power(muon.pullX(i,1,arbitrationType),2.)+TMath::Power(muon.pullY(i,1,arbitrationType),2.)) > 3. ) { 
          station_weight[i-1] *= 1./TMath::Power(
                             TMath::Max((double)TMath::Sqrt(TMath::Power(muon.dX(i,1,arbitrationType),2.)+TMath::Power(muon.dY(i,1,arbitrationType),2.)),(double)1.),.25); 
        }
        else {
          station_weight[i-1] *= 1./TMath::Power(
                             TMath::Sqrt(TMath::Power(muon.pullX(i,1,arbitrationType),2.)+TMath::Power(muon.pullY(i,1,arbitrationType),2.)),.25); 
        }
          }
        }
      }
      else if (muon.dY(i,1,arbitrationType) >= 999999) { // has no match in Y
        if( muon.pullX(i,1,arbitrationType) > 1. ) { // has a match in X. Pull larger that 1 to avoid increasing the weight (just penalize, don't anti-penalize)
          // reduce weight
          if(use_match_dist_penalty) {
        // only use pull if 3 sigma is not smaller than 3 cm
        if( muon.dX(i,1,arbitrationType) < 3. && muon.pullX(i,1,arbitrationType) > 3. ) { 
          station_weight[i-1] *= 1./TMath::Power(TMath::Max((double)muon.dX(i,1,arbitrationType),(double)1.),.25);
        }
        else {
          station_weight[i-1] *= 1./TMath::Power(muon.pullX(i,1,arbitrationType),.25);
        }
          }
        }
      }
      else { // has no match in X
        if( muon.pullY(i,1,arbitrationType) > 1. ) { // has a match in Y. Pull larger that 1 to avoid increasing the weight (just penalize, don't anti-penalize)
          // reduce weight
          if(use_match_dist_penalty) {
        // only use pull if 3 sigma is not smaller than 3 cm
        if( muon.dY(i,1,arbitrationType) < 3. && muon.pullY(i,1,arbitrationType) > 3. ) { 
          station_weight[i-1] *= 1./TMath::Power(TMath::Max((double)muon.dY(i,1,arbitrationType),(double)1.),.25);
        }
        else {
          station_weight[i-1] *= 1./TMath::Power(muon.pullY(i,1,arbitrationType),.25);
        }
          }
        }
      }
    }
    else { // We are in the CSCs
      if(
         TMath::Sqrt(TMath::Power(muon.pullX(i-4,2,arbitrationType),2.)+TMath::Power(muon.pullY(i-4,2,arbitrationType),2.)) > 1. ) {
        // reduce weight
        if(use_match_dist_penalty) {
          // only use pull if 3 sigma is not smaller than 3 cm
          if(TMath::Sqrt(TMath::Power(muon.dX(i-4,2,arbitrationType),2.)+TMath::Power(muon.dY(i-4,2,arbitrationType),2.)) < 3. && TMath::Sqrt(TMath::Power(muon.pullX(i-4,2,arbitrationType),2.)+TMath::Power(muon.pullY(i-4,2,arbitrationType),2.)) > 3. ) { 
        station_weight[i-1] *= 1./TMath::Power(
                               TMath::Max((double)TMath::Sqrt(TMath::Power(muon.dX(i-4,2,arbitrationType),2.)+TMath::Power(muon.dY(i-4,2,arbitrationType),2.)),(double)1.),.25);
          }
          else {
        station_weight[i-1] *= 1./TMath::Power(
                               TMath::Sqrt(TMath::Power(muon.pullX(i-4,2,arbitrationType),2.)+TMath::Power(muon.pullY(i-4,2,arbitrationType),2.)),.25);
          }
        }
      }
    }
      }
    
      // Thoughts:
      // - should penalize if the segment has only x OR y info
      // - should also use the segment direction, as it now works!
    
    }
    else { // track did not pass a chamber in this station - just reset weight
      station_weight[i-1] = 0.;
    }
      
    //increment final weight for muon:
    full_weight += station_weight[i-1];
  }

  // if we don't expect any matches, we set the compatibility to
  // 0.5 as the track is as compatible with a muon as it is with
  // background - we should maybe rather set it to -0.5!
  if( nr_of_stations_crossed == 0 ) {
    //      full_weight = attenuate_weight_regain*0.5;
    full_weight = 0.5;
  }

  // ********************************************************;
  // *** calculate weights for each station *****************;
  // ************** end *************************************;

  return full_weight;

}

bool muon::isGoodMuon( const reco::Muon& muon, 
             AlgorithmType type,
             double minCompatibility,
             reco::Muon::ArbitrationType arbitrationType ) {
  if (!muon.isMatchesValid()) return false;
  bool goodMuon = false;
  
  switch( type ) {
  case TM2DCompatibility:
    // Simplistic first cut in the 2D segment- vs calo-compatibility plane. Will have to be refined!
    if( ( (0.8*caloCompatibility( muon ))+(1.2*segmentCompatibility( muon, arbitrationType )) ) > minCompatibility ) goodMuon = true;
    else goodMuon = false;
    return goodMuon;
    break;
  default : 
    //  LogTrace("MuonIdentification")<<"            // Invalid Algorithm Type called!";
    goodMuon = false;
    return goodMuon;
    break;
  }
}

bool muon::isGoodMuon( const reco::Muon& muon,
             AlgorithmType type,
             int minNumberOfMatches,
             double maxAbsDx,
             double maxAbsPullX,
             double maxAbsDy,
             double maxAbsPullY,
             double maxChamberDist,
             double maxChamberDistPull,
             reco::Muon::ArbitrationType arbitrationType,
             bool   syncMinNMatchesNRequiredStationsInBarrelOnly,
             bool   applyAlsoAngularCuts)
{
   if (!muon.isMatchesValid()) return false;
   bool goodMuon = false;

   if (type == TMLastStation) {
      // To satisfy my own paranoia, if the user specifies that the
      // minimum number of matches is zero, then return true.
      if(minNumberOfMatches == 0) return true;

      unsigned int theStationMask = muon.stationMask(arbitrationType);
      unsigned int theRequiredStationMask = RequiredStationMask(muon, maxChamberDist, maxChamberDistPull, arbitrationType);

      // Require that there be at least a minimum number of segments
      int numSegs = 0;
      int numRequiredStations = 0;
      for(int it = 0; it < 8; ++it) {
         if(theStationMask & 1<<it) ++numSegs;
         if(theRequiredStationMask & 1<<it) ++numRequiredStations;
      }

      // Make sure the minimum number of matches is not greater than
      // the number of required stations but still greater than zero
      if (syncMinNMatchesNRequiredStationsInBarrelOnly) {
         // Note that we only do this in the barrel region!
         if (fabs(muon.eta()) < 1.2) {
            if(minNumberOfMatches > numRequiredStations)
               minNumberOfMatches = numRequiredStations;
            if(minNumberOfMatches < 1) //SK: this only happens for negative values
               minNumberOfMatches = 1;
         }
      } else {
         if(minNumberOfMatches > numRequiredStations)
            minNumberOfMatches = numRequiredStations;
         if(minNumberOfMatches < 1) //SK: this only happens for negative values
            minNumberOfMatches = 1;
      }

      if(numSegs >= minNumberOfMatches) goodMuon = 1;

      // Require that last required station have segment
      // If there are zero required stations keep track
      // of the last station with a segment so that we may
      // apply the quality cuts below to it instead
      int lastSegBit = 0;
      if(theRequiredStationMask) {
         for(int stationIdx = 7; stationIdx >= 0; --stationIdx)
       if(theRequiredStationMask & 1<<stationIdx){
               if(theStationMask & 1<<stationIdx) {
                  lastSegBit = stationIdx;
                  goodMuon &= 1;
                  break;
               } else {
                  goodMuon = false;
                  break;
               }
       }
      } else {
         for(int stationIdx = 7; stationIdx >= 0; --stationIdx)
            if(theStationMask & 1<<stationIdx) {
               lastSegBit = stationIdx;
               break;
            }
      }

      if(!goodMuon) return false;

      // Impose pull cuts on last segment
      int station = 0, detector = 0;
      station  = lastSegBit < 4 ? lastSegBit+1 : lastSegBit-3;
      detector = lastSegBit < 4 ? 1 : 2;

      // Check x information
      if(fabs(muon.pullX(station,detector,arbitrationType,1)) > maxAbsPullX &&
            fabs(muon.dX(station,detector,arbitrationType)) > maxAbsDx)
         return false;

      if(applyAlsoAngularCuts && fabs(muon.pullDxDz(station,detector,arbitrationType,1)) > maxAbsPullX)
         return false;

      // Is this a tight algorithm, i.e. do we bother to check y information?
      if (maxAbsDy < 999999) { // really if maxAbsDy < 1E9 as currently defined

         // Check y information
         if (detector == 2) { // CSC
            if(fabs(muon.pullY(station,2,arbitrationType,1)) > maxAbsPullY &&
                  fabs(muon.dY(station,2,arbitrationType)) > maxAbsDy)
               return false;

            if(applyAlsoAngularCuts && fabs(muon.pullDyDz(station,2,arbitrationType,1)) > maxAbsPullY)
               return false;
         } else {
            //
            // In DT, if this is a "Tight" algorithm and the last segment is
            // missing y information (always the case in station 4!!!), impose
            // respective cuts on the next station in the stationMask that has
            // a segment with y information.  If there are no segments with y
            // information then there is nothing to penalize. Should we
            // penalize in Tight for having zero segments with y information?
            // That is the fundamental question.  Of course I am being uber
            // paranoid; if this is a good muon then there will probably be at
            // least one segment with y information but not always.  Suppose
            // somehow a muon only creates segments in station 4, then we
            // definitely do not want to require that there be at least one
            // segment with y information because we will lose it completely.
            //

            for (int stationIdx = station; stationIdx > 0; --stationIdx) {
               if(! (theStationMask & 1<<(stationIdx-1)))  // don't bother if the station is not in the stationMask
                  continue;

               if(muon.dY(stationIdx,1,arbitrationType) > 999998) // no y-information
                  continue;

               if(fabs(muon.pullY(stationIdx,1,arbitrationType,1)) > maxAbsPullY &&
                     fabs(muon.dY(stationIdx,1,arbitrationType)) > maxAbsDy) {
                  return false;
               }

               if(applyAlsoAngularCuts && fabs(muon.pullDyDz(stationIdx,1,arbitrationType,1)) > maxAbsPullY)
                  return false;

               // If we get this far then great this is a good muon
               return true;
            }
         }
      }

      return goodMuon;
   } // TMLastStation

   // TMOneStation requires only that there be one "good" segment, regardless
   // of the required stations.  We do not penalize if there are absolutely zero
   // segments with y information in the Tight algorithm.  Maybe I'm being
   // paranoid but so be it.  If it's really a good muon then we will probably
   // find at least one segment with both x and y information but you never
   // know, and I don't want to deal with a potential inefficiency in the DT
   // like we did with the original TMLastStation.  Incidentally, not penalizing
   // for total lack of y information in the Tight algorithm is what is done in
   // the new TMLastStation
   //                   
   if (type == TMOneStation) {
      unsigned int theStationMask = muon.stationMask(arbitrationType);

      // Of course there must be at least one segment
      if (! theStationMask) return false;

      int  station = 0, detector = 0;
      // Keep track of whether or not there is a DT segment with y information.
      // In the end, if it turns out there are absolutely zero DT segments with
      // y information, require only that there was a segment with good x info.
      // This of course only applies to the Tight algorithms.
      bool existsGoodDTSegX = false;
      bool existsDTSegY = false;

      // Impose cuts on the segments in the station mask until we find a good one
      // Might as well start with the lowest bit to speed things up.
      for(int stationIdx = 0; stationIdx <= 7; ++stationIdx)
         if(theStationMask & 1<<stationIdx) {
            station  = stationIdx < 4 ? stationIdx+1 : stationIdx-3;
            detector = stationIdx < 4 ? 1 : 2;

            if((fabs(muon.pullX(station,detector,arbitrationType,1)) > maxAbsPullX &&
                  fabs(muon.dX(station,detector,arbitrationType)) > maxAbsDx) ||
                  (applyAlsoAngularCuts && fabs(muon.pullDxDz(station,detector,arbitrationType,1)) > maxAbsPullX))
               continue;
            else if (detector == 1)
               existsGoodDTSegX = true;

            // Is this a tight algorithm?  If yes, use y information
            if (maxAbsDy < 999999) {
               if (detector == 2) { // CSC
                  if((fabs(muon.pullY(station,2,arbitrationType,1)) > maxAbsPullY &&
                        fabs(muon.dY(station,2,arbitrationType)) > maxAbsDy) ||
                        (applyAlsoAngularCuts && fabs(muon.pullDyDz(station,2,arbitrationType,1)) > maxAbsPullY))
                     continue;
               } else {

                  if(muon.dY(station,1,arbitrationType) > 999998) // no y-information
                     continue;
                  else
                     existsDTSegY = true;

                  if((fabs(muon.pullY(station,1,arbitrationType,1)) > maxAbsPullY &&
                        fabs(muon.dY(station,1,arbitrationType)) > maxAbsDy) ||
                        (applyAlsoAngularCuts && fabs(muon.pullDyDz(station,1,arbitrationType,1)) > maxAbsPullY)) {
                     continue;
                  }
               }
            }

            // If we get this far then great this is a good muon
            return true;
         }

      // If we get this far then for sure there are no "good" CSC segments. For
      // DT, check if there were any segments with y information.  If there
      // were none, but there was a segment with good x, then we're happy. If 
      // there WERE segments with y information, then they must have been shit
      // since we are here so fail it.  Of course, if this is a Loose algorithm
      // then fail immediately since if we had good x we would already have
      // returned true
      if (maxAbsDy < 999999) {
         if (existsDTSegY)
            return false;
         else if (existsGoodDTSegX)
            return true;
      } else
         return false;
   } // TMOneStation

  if ( type == RPCMu )
  {
    if ( minNumberOfMatches == 0 ) return true;
    
    int nMatch = 0;
    for ( std::vector<reco::MuonChamberMatch>::const_iterator chamberMatch = muon.matches().begin();
          chamberMatch != muon.matches().end(); ++chamberMatch )
    {
      if ( chamberMatch->detector() != 3 ) continue;

      const double trkX = chamberMatch->x;
      const double errX = chamberMatch->xErr;

      for ( std::vector<reco::MuonRPCHitMatch>::const_iterator rpcMatch = chamberMatch->rpcMatches.begin();
            rpcMatch != chamberMatch->rpcMatches.end(); ++rpcMatch )
      {
        const double rpcX = rpcMatch->x;

        const double dX = fabs(rpcX-trkX);
        if ( dX < maxAbsDx or dX/errX < maxAbsPullX )
        {
          ++nMatch;
          break;
        }
      }
    }

    if ( nMatch >= minNumberOfMatches ) return true;
    else return false;
  } // RPCMu
    
  if ( type == ME0Mu )
  {
    if ( minNumberOfMatches == 0 ) return true;
    
    int nMatch = 0;
    for ( const auto& chamberMatch : muon.matches() )
    {
      if ( chamberMatch.detector() != MuonSubdetId::ME0 ) continue;

      const double trkX = chamberMatch.x;
      const double errX = chamberMatch.xErr;
      const double trkY = chamberMatch.y;
      const double errY = chamberMatch.yErr;

      for ( const auto& segment : chamberMatch.me0Matches )
      {
          
        const double me0X = segment.x;
        const double me0ErrX = segment.xErr;
        const double me0Y = segment.y;
        const double me0ErrY = segment.yErr;

        const double dX   = fabs(me0X - trkX);
        const double dY   = fabs(me0Y - trkY);
        const double pullX   = dX/std::sqrt(errX + me0ErrX);
        const double pullY   = dY/std::sqrt(errY + me0ErrY);
          
        if ( (dX < maxAbsDx or pullX < maxAbsPullX) and (dY < maxAbsDy or pullY < maxAbsPullY) )
        {
          ++nMatch;
          break;
        }
      }
    }

  return ( nMatch >= minNumberOfMatches );
  } // ME0Mu
    
  if ( type == GEMMu )
  {
    if ( minNumberOfMatches == 0 ) return true;
    
    int nMatch = 0;
    for ( const auto& chamberMatch : muon.matches() )
    {
      if ( chamberMatch.detector() != MuonSubdetId::GEM ) continue;

      const double trkX = chamberMatch.x;
      const double errX = chamberMatch.xErr;
      const double trkY = chamberMatch.y;
      const double errY = chamberMatch.yErr;

      for ( const auto& segment : chamberMatch.gemMatches )
      {
          
        const double gemX = segment.x;
        const double gemErrX = segment.xErr;
        const double gemY = segment.y;
        const double gemErrY = segment.yErr;

        const double dX   = fabs(gemX - trkX);
        const double dY   = fabs(gemY - trkY);
        const double pullX   = dX/std::sqrt(errX + gemErrX);
        const double pullY   = dY/std::sqrt(errY + gemErrY);
          
        if ( (dX < maxAbsDx or pullX < maxAbsPullX) and (dY < maxAbsDy or pullY < maxAbsPullY) )
        {
          ++nMatch;
          break;
        }
      }
    }

   return ( nMatch >= minNumberOfMatches );
   } // GEMMu

   return goodMuon;
}

bool muon::isGoodMuon( const reco::Muon& muon, SelectionType type,
               reco::Muon::ArbitrationType arbitrationType)
{
  switch (type)
    {
    case muon::All:
      return true;
      break;
    case muon::AllGlobalMuons:
      return muon.isGlobalMuon();
      break;
    case muon::AllTrackerMuons:
      return muon.isTrackerMuon();
      break;
    case muon::AllStandAloneMuons:
      return muon.isStandAloneMuon();
      break;
    case muon::TrackerMuonArbitrated:
      return muon.isTrackerMuon() && muon.numberOfMatches(arbitrationType)>0;
      break;
    case muon::AllArbitrated:
      return ! muon.isTrackerMuon() || muon.numberOfMatches(arbitrationType)>0;
      break;
    case muon::GlobalMuonPromptTight:
      return muon.isGlobalMuon() && muon.globalTrack()->normalizedChi2()<10. && muon.globalTrack()->hitPattern().numberOfValidMuonHits() >0;
      break;
      // For "Loose" algorithms we choose maximum y quantity cuts of 1E9 instead of
      // 9999 as before.  We do this because the muon methods return 999999 (note
      // there are six 9's) when the requested information is not available.  For
      // example, if a muon fails to traverse the z measuring superlayer in a station
      // in the DT, then all methods involving segmentY in this station return
      // 999999 to demonstrate that the information is missing.  In order to not
      // penalize muons for missing y information in Loose algorithms where we do
      // not care at all about y information, we raise these limits.  In the
      // TMLastStation and TMOneStation algorithms we actually use this huge number
      // to determine whether to consider y information at all.
    case muon::TMLastStationLoose:
      return muon.isTrackerMuon() && isGoodMuon(muon,TMLastStation,2,3,3,1E9,1E9,-3,-3,arbitrationType,true,false);
      break;
    case muon::TMLastStationTight:
      return muon.isTrackerMuon() && isGoodMuon(muon,TMLastStation,2,3,3,3,3,-3,-3,arbitrationType,true,false);
      break;
    case muon::TMOneStationLoose:
      return muon.isTrackerMuon() && isGoodMuon(muon,TMOneStation,1,3,3,1E9,1E9,1E9,1E9,arbitrationType,false,false);
      break;
    case muon::TMOneStationTight:
      return muon.isTrackerMuon() && isGoodMuon(muon,TMOneStation,1,3,3,3,3,1E9,1E9,arbitrationType,false,false);
      break;
    case muon::TMLastStationOptimizedLowPtLoose:
      if (muon.pt() < 8. && fabs(muon.eta()) < 1.2)
    return muon.isTrackerMuon() && isGoodMuon(muon,TMOneStation,1,3,3,1E9,1E9,1E9,1E9,arbitrationType,false,false);
      else
    return muon.isTrackerMuon() && isGoodMuon(muon,TMLastStation,2,3,3,1E9,1E9,-3,-3,arbitrationType,false,false);
      break;
    case muon::TMLastStationOptimizedLowPtTight:
      if (muon.pt() < 8. && fabs(muon.eta()) < 1.2)
    return muon.isTrackerMuon() && isGoodMuon(muon,TMOneStation,1,3,3,3,3,1E9,1E9,arbitrationType,false,false);
      else
    return muon.isTrackerMuon() && isGoodMuon(muon,TMLastStation,2,3,3,3,3,-3,-3,arbitrationType,false,false);
      break;
      //compatibility loose
    case muon::TM2DCompatibilityLoose:
      return muon.isTrackerMuon() && isGoodMuon(muon,TM2DCompatibility,0.7,arbitrationType);
      break;
      //compatibility tight
    case muon::TM2DCompatibilityTight:
      return muon.isTrackerMuon() && isGoodMuon(muon,TM2DCompatibility,1.0,arbitrationType);
      break;
    case muon::GMTkChiCompatibility:
      return muon.isGlobalMuon() && muon.isQualityValid() && fabs(muon.combinedQuality().trkRelChi2 - muon.innerTrack()->normalizedChi2()) < 2.0;
      break;
    case muon::GMStaChiCompatibility:
      return muon.isGlobalMuon() && muon.isQualityValid() && fabs(muon.combinedQuality().staRelChi2 - muon.outerTrack()->normalizedChi2()) < 2.0;
      break;
    case muon::GMTkKinkTight:
      return muon.isGlobalMuon() && muon.isQualityValid() && muon.combinedQuality().trkKink < 100.0;
      break;
    case muon::TMLastStationAngLoose:
      return muon.isTrackerMuon() && isGoodMuon(muon,TMLastStation,2,3,3,1E9,1E9,-3,-3,arbitrationType,false,true);
      break;
    case muon::TMLastStationAngTight:
      return muon.isTrackerMuon() && isGoodMuon(muon,TMLastStation,2,3,3,3,3,-3,-3,arbitrationType,false,true);
      break;
    case muon::TMOneStationAngLoose:
      return muon.isTrackerMuon() && isGoodMuon(muon,TMOneStation,1,3,3,1E9,1E9,1E9,1E9,arbitrationType,false,true);
      break;
    case muon::TMOneStationAngTight:
      return muon.isTrackerMuon() && isGoodMuon(muon,TMOneStation,1,3,3,3,3,1E9,1E9,arbitrationType,false,true);
      break;
    case muon::TMLastStationOptimizedBarrelLowPtLoose:
      if (muon.pt() < 8. && fabs(muon.eta()) < 1.2)
    return muon.isTrackerMuon() && isGoodMuon(muon,TMOneStation,1,3,3,1E9,1E9,1E9,1E9,arbitrationType,false,false);
      else
    return muon.isTrackerMuon() && isGoodMuon(muon,TMLastStation,2,3,3,1E9,1E9,-3,-3,arbitrationType,true,false);
      break;
    case muon::TMLastStationOptimizedBarrelLowPtTight:
      if (muon.pt() < 8. && fabs(muon.eta()) < 1.2)
    return muon.isTrackerMuon() && isGoodMuon(muon,TMOneStation,1,3,3,3,3,1E9,1E9,arbitrationType,false,false);
      else
    return muon.isTrackerMuon() && isGoodMuon(muon,TMLastStation,2,3,3,3,3,-3,-3,arbitrationType,true,false);
      break;
    case muon::RPCMuLoose:
    return muon.isRPCMuon() && isGoodMuon(muon, RPCMu, 2, 20, 4, 1e9, 1e9, 1e9, 1e9, arbitrationType, false, false);
      break;
    case muon::AllME0Muons:
      return muon.isME0Muon();
      break;
    case muon::ME0MuonArbitrated:
      return muon.isME0Muon() && isGoodMuon(muon, ME0Mu, 1, 1e9, 1e9, 1e9, 1e9, 1e9, 1e9, arbitrationType, false, false);
      break;
    case muon::AllGEMMuons:
      return muon.isGEMMuon();
      break;
    case muon::GEMMuonArbitrated:
      return muon.isGEMMuon() && isGoodMuon(muon, GEMMu, 1, 1e9, 1e9, 1e9, 1e9, 1e9, 1e9, arbitrationType, false, false);
      break;
    default:
      return false;
    }
}

bool muon::overlap( const reco::Muon& muon1, const reco::Muon& muon2, 
            double pullX, double pullY, bool checkAdjacentChambers)
{
  unsigned int nMatches1 = muon1.numberOfMatches(reco::Muon::SegmentAndTrackArbitration);
  unsigned int nMatches2 = muon2.numberOfMatches(reco::Muon::SegmentAndTrackArbitration);
  unsigned int betterMuon = ( muon1.pt() > muon2.pt() ? 1 : 2 );
  for ( std::vector<reco::MuonChamberMatch>::const_iterator chamber1 = muon1.matches().begin();
       chamber1 != muon1.matches().end(); ++chamber1 )
    for ( std::vector<reco::MuonChamberMatch>::const_iterator chamber2 = muon2.matches().begin();
      chamber2 != muon2.matches().end(); ++chamber2 )
      {
    
    // if ( (chamber1->segmentMatches.empty() || chamber2->segmentMatches.empty()) ) continue;
    
    // handle case where both muons have information about the same chamber
    // here we know how close they are 
    if ( chamber1->id == chamber2->id ){
      // found the same chamber
      if ( fabs(chamber1->x-chamber2->x) < 
           pullX * sqrt(chamber1->xErr*chamber1->xErr+chamber2->xErr*chamber2->xErr) )
        {
          if ( betterMuon == 1 )
        nMatches2--;
          else
        nMatches1--;
          if ( nMatches1==0 || nMatches2==0 ) return true;
          continue;
        }
      if ( fabs(chamber1->y-chamber2->y) < 
           pullY * sqrt(chamber1->yErr*chamber1->yErr+chamber2->yErr*chamber2->yErr) )
        {
          if ( betterMuon == 1 )
        nMatches2--;
          else
        nMatches1--;
          if ( nMatches1==0 || nMatches2==0 ) return true;
        }
    } else {
      if ( ! checkAdjacentChambers ) continue;
      // check if tracks are pointing into overlaping region of the CSC detector
      if ( chamber1->id.subdetId() != MuonSubdetId::CSC || 
           chamber2->id.subdetId() != MuonSubdetId::CSC ) continue;
      CSCDetId id1(chamber1->id);
      CSCDetId id2(chamber2->id);
      if ( id1.endcap()  != id2.endcap() )  continue;
      if ( id1.station() != id2.station() ) continue;
      if ( id1.ring()    != id2.ring() )    continue;
      if ( abs(id1.chamber() - id2.chamber())>1 ) continue;
      // FIXME: we don't handle 18->1; 36->1 transitions since 
      // I don't know how to check for sure how many chambers
      // are there. Probably need to hard code some checks.
      
      // Now we have to make sure that both tracks are close to an edge
      // FIXME: ignored Y coordinate for now
      if ( fabs(chamber1->edgeX) > chamber1->xErr*pullX ) continue;
      if ( fabs(chamber2->edgeX) > chamber2->xErr*pullX ) continue;
      if ( chamber1->x * chamber2->x < 0 ) { // check if the same edge
        if ( betterMuon == 1 )
          nMatches2--;
        else
          nMatches1--;
        if ( nMatches1==0 || nMatches2==0 ) return true;
      }
    }
      }
  return false;
}


bool muon::isTightMuon(const reco::Muon& muon, const reco::Vertex& vtx){

  if(!muon.isPFMuon() || !muon.isGlobalMuon() ) return false;

  bool muID = isGoodMuon(muon,GlobalMuonPromptTight) && (muon.numberOfMatchedStations() > 1);
    
  
  bool hits = muon.innerTrack()->hitPattern().trackerLayersWithMeasurement() > 5 &&
    muon.innerTrack()->hitPattern().numberOfValidPixelHits() > 0; 

  
  bool ip = fabs(muon.muonBestTrack()->dxy(vtx.position())) < 0.2 && fabs(muon.muonBestTrack()->dz(vtx.position())) < 0.5;
  
  return muID && hits && ip;
}


bool muon::isLooseMuon(const reco::Muon& muon){
  return muon.isPFMuon() && ( muon.isGlobalMuon() || muon.isTrackerMuon());
}


bool muon::isMediumMuon(const reco::Muon& muon){
  if( !( isLooseMuon(muon) && muon.innerTrack()->validFraction() > 0.8 )) return false; 

  bool goodGlb = muon.isGlobalMuon() && 
    muon.globalTrack()->normalizedChi2() < 3. && 
    muon.combinedQuality().chi2LocalPosition < 12. && 
    muon.combinedQuality().trkKink < 20.; 

  return (segmentCompatibility(muon) > (goodGlb ? 0.303 : 0.451)); 
}


bool muon::isSoftMuon(const reco::Muon& muon, const reco::Vertex& vtx){

  bool muID = muon::isGoodMuon(muon, TMOneStationTight);

  if(!muID) return false;
  
  bool layers = muon.innerTrack()->hitPattern().trackerLayersWithMeasurement() > 5 &&
    muon.innerTrack()->hitPattern().pixelLayersWithMeasurement() > 0;

  bool ishighq = muon.innerTrack()->quality(reco::Track::highPurity); 
  
  bool ip = fabs(muon.innerTrack()->dxy(vtx.position())) < 0.3 && fabs(muon.innerTrack()->dz(vtx.position())) < 20.;
  
  return layers && ip && ishighq;
}



bool muon::isHighPtMuon(const reco::Muon& muon, const reco::Vertex& vtx){
  bool muID =   muon.isGlobalMuon() && muon.globalTrack()->hitPattern().numberOfValidMuonHits() >0 && (muon.numberOfMatchedStations() > 1);
  if(!muID) return false;

  bool hits = muon.innerTrack()->hitPattern().trackerLayersWithMeasurement() > 5 &&
    muon.innerTrack()->hitPattern().numberOfValidPixelHits() > 0; 

  bool momQuality = muon.tunePMuonBestTrack()->ptError()/muon.tunePMuonBestTrack()->pt() < 0.3;

  bool ip = fabs(muon.innerTrack()->dxy(vtx.position())) < 0.2 && fabs(muon.innerTrack()->dz(vtx.position())) < 0.5;
  
  return muID && hits && momQuality && ip;

}

int muon::sharedSegments( const reco::Muon& mu, const reco::Muon& mu2, unsigned int segmentArbitrationMask ) {
    int ret = 0;
   
    // Will do with a stupid double loop, since creating and filling a map is probably _more_ inefficient for a single lookup.
    for(std::vector<reco::MuonChamberMatch>::const_iterator chamberMatch = mu.matches().begin();
        chamberMatch != mu.matches().end(); ++chamberMatch) {
        if (chamberMatch->segmentMatches.empty()) continue;
        for(std::vector<reco::MuonChamberMatch>::const_iterator chamberMatch2 = mu2.matches().begin();
            chamberMatch2 != mu2.matches().end(); ++chamberMatch2) {
            if (chamberMatch2->segmentMatches.empty()) continue;
            if (chamberMatch2->id() != chamberMatch->id()) continue;
            for(std::vector<reco::MuonSegmentMatch>::const_iterator segmentMatch = chamberMatch->segmentMatches.begin(); 
                segmentMatch != chamberMatch->segmentMatches.end(); ++segmentMatch) {
                if (!segmentMatch->isMask(segmentArbitrationMask)) continue;
                for(std::vector<reco::MuonSegmentMatch>::const_iterator segmentMatch2 = chamberMatch2->segmentMatches.begin(); 
                    segmentMatch2 != chamberMatch2->segmentMatches.end(); ++segmentMatch2) {
                    if (!segmentMatch2->isMask(segmentArbitrationMask)) continue;
                    if ((segmentMatch->cscSegmentRef.isNonnull() && segmentMatch->cscSegmentRef == segmentMatch2->cscSegmentRef) ||
                        (segmentMatch-> dtSegmentRef.isNonnull() && segmentMatch-> dtSegmentRef == segmentMatch2-> dtSegmentRef) ) {
                        ++ret;
                    } // is the same
                } // segment of mu2 in chamber
            } // segment of mu1 in chamber
        } // chamber of mu2
    } // chamber of mu1
  
    return ret; 
}