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DTTopology.cc

Go to the documentation of this file.

#include "Geometry/DTGeometry/interface/DTTopology.h"
#include <FWCore/Utilities/interface/Exception.h>

#include <iostream>

// FIXME now put by hand, check the number!

const float DTTopology::theWidth  = 4.2;  // cm 
const float DTTopology::theHeight = 1.3; // cm ...

const float DTTopology::IBeamWingThickness = 0.13;   // cm 
const float DTTopology::IBeamWingLength    = 0.635; // cm

const float DTTopology::plateThickness = 0.15;  // aluminium plate:  1.5 mm
const float DTTopology::IBeamThickness = 0.13;  // I-beam thickness: 1.3 mm
  
DTTopology::DTTopology(int firstWire, int nChannels,float semilenght): theFirstChannel(firstWire),
                                                                   theNChannels(nChannels),
                                                                   theLength(semilenght*2){
  theOffSet = Local2DPoint(-theNChannels/2. * theWidth, -theLength/2.);
  
#ifdef VERBOSE
  cout <<"Constructing DTTopology with:"<<endl
       <<"number of wires = "<<theNChannels
       <<", first wire number = "<<theFirstChannel<<endl
       <<", width = "<<theWidth
       <<", height = "<<theHeight
       <<", length = "<<theLength
       <<endl;
#endif
}

const float DTTopology::sensibleWidth() const{
  return theWidth-IBeamThickness;
}

const float DTTopology::sensibleHeight() const{
  return theHeight-plateThickness;
}

LocalPoint DTTopology::localPosition( const MeasurementPoint& mp) const{
    return LocalPoint( (mp.x() - theFirstChannel)*theWidth + theOffSet.x() , 
                       (1-mp.y())*theLength + theOffSet.y());
}

LocalError DTTopology::localError( const MeasurementPoint& mp, const MeasurementError& me) const{
  return LocalError(me.uu()*(theWidth*theWidth), 0,
                    me.vv()*(theLength*theLength));
}

MeasurementPoint DTTopology::measurementPosition( const LocalPoint& lp) const{
  return MeasurementPoint( static_cast<int>( (lp.x()-theOffSet.x())/theWidth + theFirstChannel),
                           1 - (lp.y()-theOffSet.y())/theLength);
}

MeasurementError DTTopology::measurementError( const LocalPoint& lp, const LocalError& le) const{
  return MeasurementError(le.xx()/(theWidth*theWidth),0,
                          le.yy()/(theLength*theLength));
}

int DTTopology::channel( const LocalPoint& lp) const{
  return static_cast<int>( (lp.x()-theOffSet.x())/theWidth + theFirstChannel);
}

// return the x wire position in the layer, starting from its wire number.
float DTTopology::wirePosition(int wireNumber) const{
  if (wireNumber - (theFirstChannel-1) <= 0 || wireNumber > lastChannel() )
    throw cms::Exception("InvalidWireNumber") << "DTTopology::wirePosition:" 
                                              << " Requested wire number: "<< wireNumber 
                                              << " ,but the first wire number is "<< theFirstChannel
                                              << " and the last wire number is "<< lastChannel()
                                              << std::endl;
  else
    return  (wireNumber - (theFirstChannel-1) - 0.5)*theWidth + theOffSet.x();
}

/*
// return the x wire position in the layer r.f., starting from its wire number.
float DTTopology::wirePosition(int wireNumber) const{
  int layerCoord = theNChannels - wireNumber + theFirstChannel;
  return  (layerCoord - 0.5)*theWidth + theOffSet.x();
}
*/


//New cell geometry
DTTopology::Side DTTopology::onWhichBorder(float x, float y, float z) const{
  
  // epsilon = Tolerance to determine if a hit starts/ends on the cell border.
  // Current value comes from CMSIM, where hit position is
  // always ~10um far from surface. For OSCAR the discrepancy is < 1um.
  const float epsilon = 0.0015; // 15 um
  
  // with new geometry the cell shape is not rectangular, but is a
  // rectangular with the I-beam "Wing" subtracted.
  // The height of the Wing is 1.0 mm and the length is 6.35 mm: these 4
  // volumens must be taken into account when the border is computed
   
  Side side = none;
  
  if ( fabs(z) > ( sensibleHeight()/2.-epsilon) ||
       (fabs(x) > ( sensibleWidth()/2.-IBeamWingLength-epsilon) &&
        fabs(z) > ( sensibleHeight()/2.-IBeamWingThickness-epsilon) ) ){ //FIXME 

    if (z > 0.) side = zMax; // This is currently the INNER surface.
    else side = zMin;
  }
  
  else if ( fabs(x) > ( sensibleWidth()/2.-epsilon) ){ 
    if (x > 0.) side = xMax;
    else side = xMin;
  }   // FIXME: else if ymax, ymin...

  return side;
}
  

//Old geometry of the DT
DTTopology::Side DTTopology::onWhichBorder_old(float x, float y, float z) const{

  // epsilon = Tolerance to determine if a hit starts/ends on the cell border.
  // Current value comes from CMSIM, where hit position is
  // always ~10um far from surface. For OSCAR the discrepancy is < 1um.
  const float epsilon = 0.0015; // 15 um

  Side side = none;

  if ( fabs(z) > ( sensibleHeight()/2.-epsilon)) {
    if (z > 0.) { 
      side = zMax; // This is currently the INNER surface.
    } else {
      side = zMin;
    }
  } else if ( fabs(x) > ( sensibleWidth()/2.-epsilon)) {
    if (x > 0.) {
      side = xMax; 
    } else {
      side = xMin;
    }
  }   // FIXME: else if ymax, ymin...
  
  return side;
}

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