void plot_histo () 
{
// ...to illustrate an apparent bug in root plotting of a histogram

    TCanvas *cr = new TCanvas("cr","cr",1,1,400,600); 
    cr->SetTopMargin(0.03);    cr->SetBottomMargin(.2);
    cr->SetRightMargin(0.03);    cr->SetLeftMargin(0.13);
    cr->SetTickx(1); cr->SetTicky(); 
    cr->Divide(1,2);
    
    TH1D *h = new TH1D("h", "h", 3, 0, 3.); // histo of interest
    h->SetBinContent(1, 0.8);
    h->SetBinContent(2, 1.4);
    h->SetBinContent(3, 0.6);
    h->SetLineColor(kRed); 
    h->SetLineWidth(3);
    h->SetLineStyle(1);
    h->SetMarkerSize(2.0);
    h->SetMarkerStyle(20);

    dum=new TH2D("dum","dum",10,0,3.0,10,0,2); // ...full hist range 
    dum2=new TH2D("dum2","dum1",10,0.0001,2.9999,10,0,2); // ... and reduced by epsilon

    cr->cd(1);
    dum->Draw();
    h->Draw("SAMEhist");    
    h->Draw("sameP");

    cr->cd(2);
    dum2->Draw();
    h->Draw("SAMEhist");    
    h->Draw("sameP");

}