//----------------------------------------------------
poissoninit(double xmu=3.,int nent=1000000,int nbin=20){
  cout << "This is the first call that sets up the histogram" << endl;
  cout << "Mean of the Poisson is " << xmu << endl;
  cout << "Number of entries " << nent << endl;
  cout << "Number of bins " << nbin << endl;
int nbinp=nbin+3;
double xmax=nbin+0.5;
TH1D *h1=new TH1D("h1","Poisson",nbinp,-2.5,xmax);
int i;
TRandom3*r=new TRandom3(0);
for (i=0; i<nent;i++){h1->Fill(r->Poisson(xmu));}
gStyle->SetOptStat(220002210);
h1->GetXaxis()->SetTitle("Events Per Experiment");
h1->GetYaxis()->SetTitle("Experiments Per 1 Event Bin");
h1->Draw();
}
//----------------------------------------------------