StRoot: StGammaMaker/StGammaTrack.cxx Source File

00001 #include "StMuDSTMaker/COMMON/StMuTrack.h"
00002 #include "StGammaTrack.h"
00003 
00004 ClassImp(StGammaTrack);
00005 
00007 //                 Constructor                  //
00009 StGammaTrack::StGammaTrack()
00010 {
00011     id = 0;
00012     flag = -1;
00013     charge = 0;
00014     nhits = 0;
00015     dEdx = 0;
00016 }
00017 
00019 //             Overloaded Constructor           //
00021 StGammaTrack::StGammaTrack(StMuTrack* track)
00022 {
00023 
00024     id = track->id();
00025     flag = track->flag();
00026     charge = track->charge();
00027     nhits = track->nHitsFit();
00028     dEdx = track->dEdx() / keV; 
00029     type = track->type();
00030     momentum = track->momentum().xyz();
00031     dca = track->dcaGlobal().xyz();
00032     helix = track->helix();
00033     outerHelix = track->outerHelix();
00034     
00035 }
00036 
00038 //                  Destructor                  //
00040 StGammaTrack::~StGammaTrack()
00041 {}
00042 
00043 
00045 //   Project the track out to radius R.  See    //
00046 //  StRoot/StEmcUtil/projection/StEmcPosition.h //
00048 TVector3 StGammaTrack::positionAtRadius(Double_t radius) const
00049 {
00050     
00051     static const pair<double, double> VALUE(999999999., 999999999.); // No solution
00052     
00053     if(outerHelix.origin().perp() < radius) 
00054     {
00055     
00056         pair<double, double> ss = outerHelix.pathLength(radius);
00057         
00058         if(finite(ss.first) && finite(ss.second) && ss != VALUE) 
00059         {
00060         
00061             double s = 0;
00062             
00063             if(ss.first > 0 && ss.second > 0 || ss.first >= 0 && ss.second < 0)
00064             {
00065                 s = ss.first;
00066             }
00067             else if(ss.first < 0 && ss.second >= 0)
00068             {
00069                 s = ss.second;
00070             }
00071             
00072             if(s > 0) return outerHelix.at(s).xyz();
00073             
00074         }
00075     }
00076 
00077     return TVector3(0,0,0);
00078 
00079 }
00080         
00081 
00083 //      Project the track out to distance z     //
00085 TVector3 StGammaTrack::positionAtZ(Double_t z) const
00086 {
00087 
00088     if( fabs(outerHelix.origin().z()) < fabs(z) ) 
00089     {
00090     
00091         StThreeVector<double> r(0, 0, z);
00092         StThreeVector<double> n(0, 0, 1);
00093         
00094         double s = outerHelix.pathLength(r, n);
00095         
00096         if (finite(s) && s != StHelix::NoSolution && s > 0)
00097         { 
00098             return outerHelix.at(s).xyz();
00099         }
00100         
00101     }
00102     
00103     return TVector3(0, 0, 0);
00104   
00105 }