void macro()
{

    
    auto h1 = new TH1D("h1_gaus","Mass original (amu); Mass;Counts",202.0,39.5,140.5);
    auto h1_smeared = new TH1D("h1_gaus_smeared","Smeared Mass (amu);Mass; Counts",202.0,39.5,140.5);
    double amu=0;
    for(long int i=0;i<100000;i++)
    {
        amu=gRandom->Gaus(87.52,12.);
        h1->Fill( amu );
        h1_smeared->Fill( amu + gRandom->Gaus(0,3.5));
    }
    
    
    for(long int i=0;i<20000;i++)
    {
        amu=gRandom->Gaus(105.,20.);
        h1->Fill( amu );
        h1_smeared->Fill( amu + gRandom->Gaus(0,3.5));
    }
    
    
    TF1Convolution *f_conv = new TF1Convolution("gaus(0)+gaus(3)", "gaus", 30.,150., true);

    f_conv->SetRange(30.,150.);
    f_conv->SetNofPointsFFT(1000);
    TF1 *f = new TF1("f", *f_conv, 40., 140., f_conv->GetNpar());
    
    TF1 *f_gaus = new TF1("f_gaus_original","gaus(0)+gaus(3)", 40., 140.);
    
    
    f->SetParLimits(0,0.,1e6);
    f->SetParLimits(3,0.,1e6);
    
    f->SetParLimits(1,60.,120.);
    f->SetParLimits(4,60.,120.);
    
    f->SetParLimits(2,1.,100.);
    f->SetParLimits(5,1.,100.);
    
    f->SetParNames("A_{1}","#mu_{1}","#sigma_{1}","A_{2}","#mu_{2}","#sigma_{2}","Amplitude Convolution","#mu_conv","#sigma_res");
    f->SetParameters(1e4,90.,13., 100 ,90,30, 1000,0.,3.5);
    f->FixParameter(f_conv->GetNpar() -3 ,1.);
    f->FixParameter(f_conv->GetNpar() -2 ,0.);
    f->FixParameter(f_conv->GetNpar()-1, 3.5);
    
    TCanvas *c = new TCanvas("c","c",800,1000);
    c->Divide(1,2);
    
    c->cd(1);
    h1->Draw();
    
    c->cd(2);
    h1_smeared->Draw();
    
    h1_smeared->Fit(f,"ME");
    
    c->cd(1);
    f_gaus->SetParameters(f->GetParameters());
    double convoluted_gauss_area= 3.5*TMath::Sqrt(2*TMath::Pi());
    
    f_gaus->SetParameter(0,convoluted_gauss_area*f_gaus->GetParameter(0));
    f_gaus->SetParameter(3,convoluted_gauss_area*f_gaus->GetParameter(3));
    f_gaus->Draw("same");
       
}