Go to the documentation of this file.00001 #include "RZLine.h"
00002 #include "CommonTools/Statistics/interface/LinearFit.h"
00003
00004 using namespace std;
00005 template <class T> inline T sqr( T t) {return t*t;}
00006
00007 RZLine::RZLine(const std::vector<float> & aR,
00008 const std::vector<float> & aZ,
00009 const std::vector<float> & aErrZ) :
00010 storage(3*aR.size()) {
00011 nPoints = aR.size();
00012 r = &storage.front();
00013 z = r+nPoints;
00014 errZ2 = z+nPoints;
00015 for (int i=0; i<nPoints; i++) {
00016 r[i] = aR[i];
00017 z[i]=aZ[i];
00018 errZ2[i] = aErrZ[i]*aErrZ[i];
00019 }
00020 }
00021
00022 RZLine::RZLine(const vector<GlobalPoint> & points,
00023 const vector<GlobalError> & errors,
00024 const vector<bool> isBarrel) :
00025 storage(3*points.size()) {
00026 nPoints = points.size();
00027 r = &storage.front();
00028 z = r+nPoints;
00029 errZ2 = z+nPoints;
00030 for (int i=0; i!=nPoints; ++i) {
00031 const GlobalPoint & p = points[i];
00032 r[i] = p.perp();
00033 z[i] = p.z();
00034 }
00035
00036 float simpleCot2 = ( z[nPoints-1]-z[0] )/ (r[nPoints-1] - r[0] );
00037 simpleCot2 *= simpleCot2;
00038 for (int i=0; i!=nPoints; ++i) {
00039 errZ2[i] = (isBarrel[i]) ? errors[i].czz() :
00040 errors[i].rerr(points[i]) * simpleCot2;
00041 }
00042 }
00043
00044 void RZLine::fit(float & cotTheta, float & intercept,
00045 float &covss, float &covii, float &covsi) const
00046 {
00047 linearFit( r, z, nPoints, errZ2, cotTheta, intercept, covss, covii, covsi);
00048 }
00049
00050 float RZLine::chi2(float cotTheta, float intercept) const
00051 {
00052 float chi2 = 0.f;
00053 for (int i=0; i!=nPoints; ++i) chi2 += sqr( ((z[i]-intercept) - cotTheta*r[i]) ) / errZ2[i];
00054 return chi2;
00055 }
1.7.3