CommonAlignmentParametrization/src/BeamSpotAlignmentDerivatives.cc

0001 /** \file BeamSpotAlignmentDerivatives.cc
0002  *
0003  *  $Date: 2007/05/02 21:01:53 $
0004  *  $Revision: 1.7 $
0005  *  (last update by $Author: cklae $)
0006  */
0007
0008 #include "DataFormats/GeometrySurface/interface/Surface.h"
0009
0010 #include "TrackingTools/PatternTools/interface/TwoTrackMinimumDistance.h"
0011
0012 #include "TrackingTools/TrajectoryState/interface/PerigeeConversions.h"
0013 #include "TrackingTools/TrajectoryState/interface/TrajectoryStateOnSurface.h"
0014
0015 #include "Alignment/CommonAlignmentParametrization/interface/BeamSpotAlignmentDerivatives.h"
0016
0017 AlgebraicMatrix BeamSpotAlignmentDerivatives::operator()(const TrajectoryStateOnSurface &tsos) const {
0018   AlgebraicMatrix aliderivs(4, 2);
0019
0020   if (!tsos.isValid())
0021     return aliderivs;
0022
0023   // lp.x = transverse impact parameter
0024   // lp.y = longitudinal impact parameter
0025   LocalPoint lp = tsos.localPosition();
0026   double phi = tsos.globalMomentum().phi();
0027   double dz = lp.y();
0028   double sinphi = sin(phi);
0029   double cosphi = cos(phi);
0030
0031   aliderivs[0][0] = sinphi;
0032   aliderivs[0][1] = 0.0;
0033   aliderivs[1][0] = -cosphi;
0034   aliderivs[1][1] = 0.0;
0035   aliderivs[2][0] = sinphi * dz;
0036   aliderivs[2][1] = 0.0;
0037   aliderivs[3][0] = -cosphi * dz;
0038   aliderivs[3][1] = 0.0;
0039
0040   return (aliderivs);
0041 }