# gtime2¶

Example of TGraphTime showing how the class could be used to visualize a set of particles with their time stamp in a MonteCarlo program.

Author: Rene Brun
This notebook tutorial was automatically generated with ROOTBOOK-izer from the macro found in the ROOT repository on Tuesday, November 29, 2022 at 11:17 AM.

Arguments are defined.

In [1]:
Int_t nsteps = 200;
Int_t np=5000;

In [2]:
if (np > 5000) np = 5000;
Int_t color[5000];
Double_t cosphi[5000], sinphi[5000], speed[5000];
TRandom3 r;
Double_t xmin = 0, xmax = 10, ymin = -10, ymax = 10;
TGraphTime *g = new TGraphTime(nsteps,xmin,ymin,xmax,ymax);
g->SetTitle("TGraphTime demo 2;X;Y");
Int_t i,s;
Double_t phi,fact = xmax/Double_t(nsteps);
for (i=0;i<np;i++) { //calculate some object parameters
speed[i]  = r.Uniform(0.5,1);
phi       = r.Gaus(0,TMath::Pi()/6.);
cosphi[i] = fact*speed[i]*TMath::Cos(phi);
sinphi[i] = fact*speed[i]*TMath::Sin(phi);
Double_t rc = r.Rndm();
color[i] = kRed;
if (rc > 0.3) color[i] = kBlue;
if (rc > 0.7) color[i] = kYellow;
}
for (s=0;s<nsteps;s++) { //fill the TGraphTime step by step
for (i=0;i<np;i++) {
Double_t xx = s*cosphi[i];
if (xx < xmin) continue;
Double_t yy = s*sinphi[i];
TMarker *m = new TMarker(xx,yy,25);
m->SetMarkerColor(color[i]);
m->SetMarkerSize(1.5 -s/(speed[i]*nsteps));

Info in <TCanvas::MakeDefCanvas>:  created default TCanvas with name c1

gROOT->GetListOfCanvases()->Draw()