Changeset c24ad79 in git for examples/ExamplePVtxFit.C

Timestamp:

Mar 4, 2021, 10:20:54 AM (4 years ago)

Author:

Franco BEDESCHI <bed@…>

Branches:

master

Children:

3dc190c

Parents:

85aa1f4

Message:

Add comments/authors

File:

• examples/ExamplePVtxFit.C (modified) (7 diffs)

examples/ExamplePVtxFit.C

@@ -1 +1 @@
 /*
 Example of using vertex fitter class to fit primary vertex
-assumed to be generated in (0,0,0)
+assumed to be generated in (0,0,0).
+To run compiled version:
+root
+root> .L examples/LoadPvtxFit.C+
+root> LoadPVtxFit()
+root> ExamplePVtxFit("infile.root", Nevents)
+
+March 4, 2021
+F. Bedeschi, INFN-Pisa, Italy
 */
 
@@ -12 +20 @@
 #include <TClonesArray.h>
 #include <TChain.h>
-#include <TVector3.h>
 #include <TVectorD.h>
 #include <TMatrixDSym.h>
@@ -49 +56 @@
                 treeReader->ReadEntry(entry);
                 Int_t Ntr = 0;  // # of tracks from primary vertex
-                Int_t NtrG = branchTrack->GetEntries();
+                Int_t NtrG = branchTrack->GetEntries(); // Total # of tracks
                 TVectorD** pr = new TVectorD * [NtrG];
                 TMatrixDSym** cv = new TMatrixDSym * [NtrG];
@@ -64 +71 @@
                                 GenParticle* gp = (GenParticle*)trk->Particle.GetObject();
                                 //
-                                // Position of origin in meters
-                                Double_t x = 1.0e-3 * gp->X;
-                                Double_t y = 1.0e-3 * gp->Y;
-                                Double_t z = 1.0e-3 * gp->Z;
+                                // Position of origin (mm)
+                                Double_t x = gp->X;
+                                Double_t y = gp->Y;
+                                Double_t z = gp->Z;
                                 //
-                                // group tracks originating from the primary vertex
+                                // Select group of tracks originating from the primary vertex
                                 if (x == 0.0 && y == 0.0)
                                 {
@@ -81 +88 @@
                                         Double_t oPar[5] = { obsD0, obsPhi, obsC, obsZ0, obsCtg };
                                         TVectorD obsPar(5, oPar);       // Fill observed parameters
-                                        TVector3 xv(x, y, z);
                                         //
                                         pr[Ntr] = new TVectorD(obsPar);
@@ -88 +94 @@
                                 }
                         }               // End loop on tracks
-                        //std::cout << "Total of " << Ntr << " primary tracks out of " << NtrG << " tracks" << std::endl;
                 }
                 //
@@ -110 +115 @@
                 }
 
-                //std::cout << "Vertex chi2/Ndof = " << Chi2 / Ndof << std::endl;
                 //
                 // Cleanup