void FitFunc()
{
    TGraphErrors *graph_no_target = new TGraphErrors("without_target.csv", "%lg, %lg, %*lg, %lg");
    graph_no_target->SetMarkerStyle(21);
    graph_no_target->SetMarkerColor(kBlue);
    graph_no_target->SetLineColor(kBlue);
    
    TCanvas *c1 = new TCanvas("c1", "Data without target", 800, 600);
        gPad->SetLogy();
    graph_no_target->Draw("APE");
    graph_no_target->GetXaxis()->SetLimits(-50, 50);
    graph_no_target->SetMinimum(1e-1);
    graph_no_target->SetMaximum(1000000);
    
    
    TF1 *fitFunc = new TF1("fitFunc",  "[0]*( (1-[1])*ROOT::Math::normal_pdf(x - [2], [3])  +  [1]*ROOT::Math::tdistribution_pdf( (x-[2])/[4], [5])  ) ", -50, 50);
    fitFunc->SetNpx(1000);
    fitFunc->SetParLimits(0,1e5,1e6);
    fitFunc->SetParLimits(1,0,1.);
    fitFunc->SetParLimits(2,-1.,1.);
    
    fitFunc->SetParameters(300000, 0.05, 0.1, 0.6, 3, 3);
    
    
    
    graph_no_target->Fit(fitFunc,"LME");
    
    TGraphErrors *graph_target = new TGraphErrors("with_target.csv", "%lg, %lg, %*lg, %lg");
        
    
    
    TF1Convolution *f_conv = new TF1Convolution("fitFunc", "ROOT::Math::tdistribution_pdf(x/[1],[0])", -50,50, true);
       f_conv->SetRange(-50,50.);
       f_conv->SetNofPointsFFT(1000);
       TF1 *f = new TF1("f_conv", *f_conv, -50., 50., f_conv->GetNpar());
    
    
    for(int i=1;i<=5;i++)
    f->FixParameter(i,fitFunc->GetParameter(i));
    
    
    
    
    
    f->SetParameter(0,5e6);
    f->SetParameter(6,10);
    f->SetParameter(7,10);
    f->SetNpx(1000);
    TCanvas *c2 = new TCanvas("c2", "Data with target", 800, 600);
    gPad->SetLogy();
    graph_target->Draw("APE");
    graph_target->GetXaxis()->SetLimits(-50, 50);
    graph_target->SetMinimum(1e-1);
    graph_target->SetMaximum(1000000);
    
    
    
    
    graph_target->Fit(f, "LME", "", -50, 50);
    f = graph_target->GetFunction("f_conv");
    f->GetNDF();
    f->GetChisquare();
    f->GetProb();

        std::cout << "Chi-squared: " << f->GetChisquare() << std::endl;
        std::cout << "NDF: " << f->GetNDF() << std::endl;
        std::cout << "Probability: " << f->GetProb() << std::endl;

    
}