int Macro2(){
    auto c=new TCanvas();c->SetGrid();
    TGraphErrors graph_expected("./chiffres.txt","%lg %lg %lg");
    graph_expected.SetTitle("Measurement XYZ and Expectation;" "lenght [cm];"
                            "Arb.Units");
    graph_expected.SetFillColor(kYellow);
    graph_expected.DrawClone("E3AL"); // E3 draws the band
    TGraphErrors graph("./chiffres.txt","%lg %lg %lg");
    graph.SetMarkerStyle(kCircle);
    graph.SetFillColor(0);
    graph.DrawClone("PESame");
    // Draw the Legend
    TLegend leg(.1,.7,.3,.9,"Lab. Lesson 2");
    leg.SetFillColor(0);
    leg.AddEntry(&graph_expected,"Expected Points");
    leg.AddEntry(&graph,"Measured Points");
    leg.DrawClone("Same");
    graph.Print();
    return 0;
}