//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
//
// root -l computeDrellYanPtllWeight.C+
// root -l -b -q computeDrellYanPtllWeight.C+
//
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
void computeDrellYanPtllWeight(TString fname = "h_pt2l_mm")
{
gInterpreter->ExecuteMacro("PaperStyle.C");
TFile* file = TFile::Open("figures/Control/01_DY/" + fname + ".root");
TH1D* ratio = (TH1D*)file->Get("ratio");
// Draw the ratio
//----------------------------------------------------------------------------
TCanvas* c1 = new TCanvas("c1", "c1");
ratio->SetMinimum(0.85);
ratio->SetMaximum(1.20);
ratio->Draw("ep");
TString ytitle = Form("data / MC ratio / %.0f GeV", ratio->GetBinWidth(0));
SetAxis(ratio, ratio->GetXaxis()->GetTitle(), ytitle, 1.7, 1.8);
// Draw the old function
//----------------------------------------------------------------------------
TF1* fOld = new TF1("fOld", "[3]*(0.95 - [0]*TMath::Erf((x-[1])/[2]))", 0, 90);
fOld->SetLineColor (kGreen+2);
fOld->SetMarkerColor(kGreen+2);
// https://github.com/latinos/PlotsConfigurations/blob/master/Configurations/ggH/nuisances_iteos.py#L969-L977
fOld->SetParameter(0, 0.1);
fOld->SetParameter(1, 14.0);
fOld->SetParameter(2, 8.8);
fOld->SetParameter(3, 1.08683);
fOld->Draw("same");
// Draw the old function error band
//------------------------------------------------------------------------------
if (errorband)
{
TF1* fOld_down = (TF1*)fOld->Clone("fOld_down");
TF1* fOld_up = (TF1*)fOld->Clone("fOld_up");
fOld_down->SetParameter(0, 13.6);
fOld_down->SetParameter(1, 8.6);
fOld_up->SetParameter(0, 14.4);
fOld_up->SetParameter(1, 9.0);
fOld_down->Draw("same");
fOld_up ->Draw("same");
}
// Update the fit parameters of the old function
//
// 1 p0 6.85257e-02 2.99341e-01 1.42129e-05 4.16760e-04
// 2 p1 1.24518e+01 4.76906e+01 3.55312e-03 6.41625e-07
// 3 p2 5.40627e+00 7.83907e+01 6.49546e-03 -1.96376e-06
// 4 p3 1.05396e+00 3.48880e-01 1.58779e-05 -3.97115e-05
//
//----------------------------------------------------------------------------
TF1* fNew = new TF1("fNew", "[3]*(0.95 - [0]*TMath::Erf((x-[1])/[2]))", 0, 90);
fNew->SetLineColor (kRed+1);
fNew->SetMarkerColor(kRed+1);
fNew->SetParameter(0, 0.1);
fNew->SetParameter(1, 10);
fNew->SetParameter(2, 1);
fNew->SetParameter(3, 1);
ratio->Fit(fNew, "mlr0");
fNew->Draw("same");
// Draw the updated error band
//------------------------------------------------------------------------------
if (errorband)
{
TF1* fNew_down = (TF1*)fNew->Clone("fNew_down");
TF1* fNew_up = (TF1*)fNew->Clone("fNew_up");
fNew_down->SetParameter(0, 0.97 * fNew->GetParameter(0));
fNew_down->SetParameter(1, 0.97 * fNew->GetParameter(1));
fNew_up->SetParameter(0, 1.03 * fNew->GetParameter(0));
fNew_up->SetParameter(1, 1.03 * fNew->GetParameter(1));
fNew_down->Draw("same");
fNew_up ->Draw("same");
}
// Fit Lorenzo's function
//
// 1 p0 1.17864e-01 7.44869e-01 1.03478e-05 1.79528e-03
// 2 p1 1.34231e+01 6.10789e+01 2.78074e-03 6.38697e-06
// 3 p2 9.76801e+00 1.03947e+02 5.51661e-03 -2.28998e-06
// 4 p3 1.01367e+00 6.56154e-01 1.29644e-05 -1.36428e-04
// 5 p4 2.50141e-03 2.62347e-02 1.53669e-07 -1.11290e-01
// 6 p5 1.10637e-05 1.42769e-04 1.32442e-09 1.17953e+01
//
//----------------------------------------------------------------------------
TF1* fLo = new TF1("fLo", "([3] + [4]*x - [5]*x*x) * (0.95 - [0]*TMath::Erf((x-[1])/[2]))", 0, 150);
fLo->SetLineColor (kBlue);
fLo->SetMarkerColor(kBlue);
fLo->SetParameter(0, 0.131835);
fLo->SetParameter(1, 14.1972);
fLo->SetParameter(2, 10.1525);
fLo->SetParameter(3, 0.876979);
fLo->SetParameter(4, 4.11598e-03);
fLo->SetParameter(5, 2.35520e-05);
ratio->Fit(fLo, "mlr0");
// Get the point where the first derivative is closest to zero
//
// fLo = 0.9608 and d(fLo)/d(ptll) = -0.000110 for ptll = 119 GeV
//
//----------------------------------------------------------------------------
float smallest_derivative_value = 999;
float smallest_derivative_x = 999;
for (int x=90; x<120; x++)
{
if (fLo->Derivative(x) < smallest_derivative_value)
{
smallest_derivative_value = fLo->Derivative(x);
smallest_derivative_x = x;
}
}
printf("\n fLo = %.4f and d(fLo)/d(ptll) = %f for ptll = %.0f GeV\n\n",
fLo->Eval(smallest_derivative_x),
fLo->Derivative(smallest_derivative_x),
smallest_derivative_x);
// Draw Lorenzo's function in two ranges
//----------------------------------------------------------------------------
fLo->SetRange(0, smallest_derivative_x);
fLo->Draw("same");
TF1* fHi = new TF1("fHi", "[0]", smallest_derivative_x, 150);
fHi->SetLineColor (kBlue);
fHi->SetMarkerColor(kBlue);
fHi->SetParameter(0, fLo->Eval(smallest_derivative_x));
fHi->Draw("same");
// Legend
//----------------------------------------------------------------------------
DrawLegend(0.69, 0.83, (TObject*)fOld, " old fit");
DrawLegend(0.69, 0.77, (TObject*)fNew, " new fit");
DrawLegend(0.69, 0.71, (TObject*)fLo, " Lorenzo's fit");
// Save
//----------------------------------------------------------------------------
ratio->Draw("ep,same");
c1->SaveAs(fname + "_ratio_fit.png");
}
