{
    TRandom3 rnd;
    
    TH1F *h1 = new TH1F("h1","A Random Histogram",120,-1,11.);
    
    for(int i=0;i<100000;i++) {
        double r = rnd.Rndm();
        double x = -log(1.-r);
        
        h1->Fill(x);
    }
    
    h1->SetFillColor(50);
    h1->Draw();
}