Modify TPaveStat

[PPierre]

Hi !

I am trying to superpose two histogram that I extract from a TTree with a selection. I achieved to display the superposed histograms in the same Canvas, the problem is that the TPaveStats box display only one mean and one StdDev.
I would like to display the means both of the first histogram and the second (in the TPaveStats box). I tried to implement and run the ROOT website tutorial about TPaveStat modification but nothing change except the TPaveStats name…

TFile f("total.root");
    if (f.IsZombie()) {
        cout << "Error, no file total.root in /analyse" << endl;
        exit(-1);
    } else {
        TTree *T = (TTree*)f.Get("mytree");
TCanvas *c2 = new TCanvas("c2","Flux Analogue & Biaised vs energy");
            c2->cd();
            T->Draw("flux:energy","flag","prof CLP");
            T->GetHistogram()->SetTitle("Flux Biased");
            T->SetLineColor(kRed);
            T->GetHistogram()->GetYaxis()->SetTitle("#Phi");
            T->GetHistogram()->GetXaxis()->SetTitle("E(MeV)");
            gPad->Update();
            T->Draw("flux:energy","!flag && score==1","prof SAME CLP");
            T->GetHistogram()->SetTitle("Flux Analogue");
            T->SetLineColor(kBlue);
            T->GetHistogram()->GetYaxis()->SetTitle("#Phi");
            T->GetHistogram()->GetXaxis()->SetTitle("E(MeV)");
            gPad->BuildLegend(0.6,0.4,09,0.6,"","PL");
            
            // Retrieve the stat box
            TPaveStats *ps = (TPaveStats*)c2->GetPrimitive("stats");
            ps->SetName("mystats");
            TList *listOfLines = ps->GetListOfLines();
            
            // Add a new line in the stat box.
            TLatex *myt = new TLatex(0,0,"Test = 10");
            myt->SetTextFont(42);
            myt->SetTextSize(0.04);
            myt->SetTextColor(kRed);
            listOfLines->Add(myt);
            
            // the following line is needed to avoid that the automatic redrawing of stats
            T->GetHistogram()->SetStats(0);
            c2->Modified();
}

Could you tell me what I did wrong ?
Thanks greatly.

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[Wile_E_Coyote]

Post a small “standalone reproducer”, which one can run (i.e., including any ROOT files that are needed).