RPCRecHit/plugins/RPCRecHitStandardAlgo.cc

0001 /*
0002  *  See header file for a description of this class.
0003  *
0004  *  \author M. Maggi -- INFN
0005  */
0006
0007 #include "RPCCluster.h"
0008 #include "RPCRecHitStandardAlgo.h"
0009 #include "DataFormats/MuonDetId/interface/RPCDetId.h"
0010 #include "Geometry/RPCGeometry/interface/RPCRoll.h"
0011 #include "Geometry/CommonTopologies/interface/StripTopology.h"
0012 #include "FWCore/ParameterSet/interface/ParameterSet.h"
0013 #include "FWCore/Framework/interface/EventSetup.h"
0014 #include "FWCore/Utilities/interface/Exception.h"
0015 #include "Geometry/CommonTopologies/interface/TrapezoidalStripTopology.h"
0016
0017 // First Step
0018 bool RPCRecHitStandardAlgo::compute(const RPCRoll& roll,
0019                                     const RPCCluster& cluster,
0020                                     LocalPoint& Point,
0021                                     LocalError& error,
0022                                     float& time,
0023                                     float& timeErr) const {
0024   // Get Average Strip position
0025   const float fstrip = (roll.centreOfStrip(cluster.firstStrip())).x();
0026   const float lstrip = (roll.centreOfStrip(cluster.lastStrip())).x();
0027   const float centreOfCluster = (fstrip + lstrip) / 2;
0028   const double y = cluster.hasY() ? cluster.y() : 0;
0029   Point = LocalPoint(centreOfCluster, y, 0);
0030
0031   if (!cluster.hasY()) {
0032     error = LocalError(roll.localError((cluster.firstStrip() + cluster.lastStrip()) / 2.));
0033   } else {
0034     // Use the default one for local x error
0035     float ex2 = roll.localError((cluster.firstStrip() + cluster.lastStrip()) / 2.).xx();
0036     // Maximum estimate of local y error, (distance to the boundary)/sqrt(3)
0037     // which gives consistent error to the default one at y=0
0038     const float stripLen = roll.specificTopology().stripLength();
0039     const float maxDy = stripLen / 2 - std::abs(cluster.y());
0040
0041     // Apply x-position correction for the endcap
0042     if (roll.id().region() != 0) {
0043       const auto& topo = dynamic_cast<const TrapezoidalStripTopology&>(roll.topology());
0044       const double angle = topo.stripAngle((cluster.firstStrip() + cluster.lastStrip()) / 2.);
0045       const double x = centreOfCluster - y * std::tan(angle);
0046       Point = LocalPoint(x, y, 0);
0047
0048       // rescale x-error by the change of local pitch
0049       const double scale = topo.localPitch(Point) / topo.pitch();
0050       ex2 *= scale * scale;
0051     }
0052
0053     error = LocalError(ex2, 0, maxDy * maxDy / 3.);
0054   }
0055
0056   if (cluster.hasTime()) {
0057     time = cluster.time();
0058     timeErr = cluster.timeRMS();
0059   } else {
0060     time = 0;
0061     timeErr = -1;
0062   }
0063
0064   return true;
0065 }
0066
0067 bool RPCRecHitStandardAlgo::compute(const RPCRoll& roll,
0068                                     const RPCCluster& cl,
0069                                     const float& angle,
0070                                     const GlobalPoint& globPos,
0071                                     LocalPoint& Point,
0072                                     LocalError& error,
0073                                     float& time,
0074                                     float& timeErr) const {
0075   this->compute(roll, cl, Point, error, time, timeErr);
0076   return true;
0077 }