mathcoreVectorIO.C: Example of I/O of a mathcore Lorentz Vectors in a Tree and comparison with a TLorentzVector
//
// Example of I/O of a mathcore Lorentz Vectors in a Tree and comparison with a TLorentzVector
// A ROOT tree is written and read in both using either a XYZTVector or /// a TLorentzVector.
//
// To execute the macro type in:
//
// root[0]: .x mathcoreVectorIO.C
//Author: Lorenzo Moneta
#include "TRandom2.h"
#include "TStopwatch.h"
#include "TSystem.h"
#include "TFile.h"
#include "TTree.h"
#include "TH1D.h"
#include "TCanvas.h"
#include <iostream>
#include "TLorentzVector.h"
#include "Math/Vector4D.h"
using namespace ROOT::Math;
void write(int n) {
TRandom2 R;
TStopwatch timer;
R.SetSeed(1);
timer.Start();
double s = 0;
for (int i = 0; i < n; ++i) {
s += R.Gaus(0,10);
s += R.Gaus(0,10);
s += R.Gaus(0,10);
s += R.Gaus(100,10);
}
timer.Stop();
std::cout << s/double(n) << std::endl;
std::cout << " Time for Random gen " << timer.RealTime() << " " << timer.CpuTime() << std::endl;
TFile f1("mathcoreVectorIO_1.root","RECREATE");
// create tree
TTree t1("t1","Tree with new LorentzVector");
XYZTVector *v1 = new XYZTVector();
t1.Branch("LV branch","ROOT::Math::XYZTVector",&v1);
R.SetSeed(1);
timer.Start();
for (int i = 0; i < n; ++i) {
double Px = R.Gaus(0,10);
double Py = R.Gaus(0,10);
double Pz = R.Gaus(0,10);
double E = R.Gaus(100,10);
//CylindricalEta4D<double> & c = v1->Coordinates();
//c.SetValues(Px,pY,pZ,E);
v1->SetCoordinates(Px,Py,Pz,E);
t1.Fill();
}
f1.Write();
timer.Stop();
std::cout << " Time for new Vector " << timer.RealTime() << " " << timer.CpuTime() << std::endl;
t1.Print();
// create tree with old LV
TFile f2("mathcoreVectorIO_2.root","RECREATE");
TTree t2("t2","Tree with TLorentzVector");
TLorentzVector * v2 = new TLorentzVector();
TLorentzVector::Class()->IgnoreTObjectStreamer();
TVector3::Class()->IgnoreTObjectStreamer();
t2.Branch("TLV branch","TLorentzVector",&v2,16000,2);
R.SetSeed(1);
timer.Start();
for (int i = 0; i < n; ++i) {
double Px = R.Gaus(0,10);
double Py = R.Gaus(0,10);
double Pz = R.Gaus(0,10);
double E = R.Gaus(100,10);
v2->SetPxPyPzE(Px,Py,Pz,E);
t2.Fill();
}
f2.Write();
timer.Stop();
std::cout << " Time for old Vector " << timer.RealTime() << " " << timer.CpuTime() << endl;
t2.Print();
}
void read() {
TRandom R;
TStopwatch timer;
TFile f1("mathcoreVectorIO_1.root");
// create tree
TTree *t1 = (TTree*)f1.Get("t1");
XYZTVector *v1 = 0;
t1->SetBranchAddress("LV branch",&v1);
timer.Start();
int n = (int) t1->GetEntries();
std::cout << " Tree Entries " << n << std::endl;
double etot=0;
for (int i = 0; i < n; ++i) {
t1->GetEntry(i);
etot += v1->Px();
etot += v1->Py();
etot += v1->Pz();
etot += v1->E();
}
timer.Stop();
std::cout << " Time for new Vector " << timer.RealTime() << " " << timer.CpuTime() << std::endl;
std::cout << " TOT average : n = " << n << "\t " << etot/double(n) << endl;
// create tree with old LV
TFile f2("mathcoreVectorIO_2.root");
TTree *t2 = (TTree*)f2.Get("t2");
TLorentzVector * v2 = 0;
t2->SetBranchAddress("TLV branch",&v2);
timer.Start();
n = (int) t2->GetEntries();
std::cout << " Tree Entries " << n << std::endl;
etot = 0;
for (int i = 0; i < n; ++i) {
t2->GetEntry(i);
etot += v2->Px();
etot += v2->Py();
etot += v2->Pz();
etot += v2->E();
}
timer.Stop();
std::cout << " Time for old Vector " << timer.RealTime() << " " << timer.CpuTime() << endl;
std::cout << " TOT average:\t" << etot/double(n) << endl;
}
void mathcoreVectorIO() {
#if defined(__CINT__) && !defined(__MAKECINT__)
gSystem->Load("libMathCore");
gSystem->Load("libPhysics");
// in CINT need to do that after having loading the library
using namespace ROOT::Math;
cout << "This tutorial can run only using ACliC, compiling it by doing: " << endl;
cout << "\t .x tutorials/math/mathcoreVectorCollection.C+" << endl;
//gROOT->ProcessLine(".x tutorials/math/mathcoreVectorCollection.C+");
return;
#endif
int nEvents = 100000;
write(nEvents);
read();
}
Last change: Wed Dec 17 10:56:15 2008
Last generated: 2008-12-17 10:56
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