// Divide and add 1D Histograms

void format_h(TH1F* h, int linecolor){
    h->SetLineWidth(3);
    h->SetLineColor(linecolor);
    }

void macro6(){

    auto sig_h=new TH1F("sig_h","Signal Histo",50,0,10);
    auto gaus_h1=new TH1F("gaus_h1","Gauss Histo 1",30,0,10);
    auto gaus_h2=new TH1F("gaus_h2","Gauss Histo 2",30,0,10);
    auto bkg_h=new TH1F("exp_h","Exponential Histo",50,0,10);

    // simulate the measurements
    TRandom3 rndgen;
    for (int imeas=0;imeas<4000;imeas++){
        bkg_h->Fill(rndgen.Exp(4));
        if (imeas%4==0) gaus_h1->Fill(rndgen.Gaus(5,2));
        if (imeas%4==0) gaus_h2->Fill(rndgen.Gaus(5,2));
        if (imeas%10==0)sig_h->Fill(rndgen.Gaus(5,.5));}

    // Format Histograms
    int i=0;
    for (auto hist : {sig_h,bkg_h,gaus_h1,gaus_h2})
        format_h(hist,1+i++);

    // Sum
    auto sum_h= new TH1F(*bkg_h);
    sum_h->Add(sig_h,1.);
    sum_h->SetTitle("Exponential + Gaussian;X variable;Y variable");
    format_h(sum_h,kBlue);

    auto c_sum= new TCanvas();
    sum_h->Draw("hist");
    bkg_h->Draw("SameHist");
    sig_h->Draw("SameHist");

    // Divide
    auto dividend=new TH1F(*gaus_h1);
    dividend->Divide(gaus_h2);

    // Graphical Maquillage
    dividend->SetTitle(";X axis;Gaus Histo 1 / Gaus Histo 2");
    format_h(dividend,kOrange);
    gaus_h1->SetTitle(";;Gaus Histo 1 and Gaus Histo 2");
    gStyle->SetOptStat(0);

    TCanvas* c_divide= new TCanvas();
    c_divide->Divide(1,2,0,0);
    c_divide->cd(1);
    c_divide->GetPad(1)->SetRightMargin(.01);
    gaus_h1->DrawNormalized("Hist");
    gaus_h2->DrawNormalized("HistSame");

    c_divide->cd(2);
    dividend->GetYaxis()->SetRangeUser(0,2.49);
    c_divide->GetPad(2)->SetGridy();
    c_divide->GetPad(2)->SetRightMargin(.01);
    dividend->Draw();
}